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Background: Quail is an efficient poultry species known for many years, and its productivity is highly affected by gastrointestinal function, health, digestion and commensal bacteria. Specific histological parameters and nutrient absorption-related genes could be used to study intestinal functionality and efficiency., Objectives: This study aimed to evaluate the mRNA abundance of nutrient absorption-related genes and intestinal histology changes in laying Japanese quail during productive lifespan., Methods: A total of 135 quails from a commercial flock at different egg production periods (early production [EP, 6 weeks of age], pick production [PP, 21 weeks of age] and post pick production [PPP, 40 weeks of age]) were randomly selected (n = 45/group) and kept for 6 weeks. Production performance was evaluated during last 2 weeks of the experimental period, and tissue samples were taken from the duodenum, jejunum and ileum for histological analysis and mRNA abundance purposes at the end of the experiment. The mRNA abundance of the CALB1, SGLT1, SGLT5, EAAT3 and NaPi-IIb genes were compared among groups., Results: Production period did not affect the eggshell thickness, goblet cell number and mRNA abundance of CALB1, EAAT3 and NaPi-IIb (p > 0.05). The PPP quails had the highest egg weight and FCR compared to EP and PP quails (p < 0.001). Egg production and egg mass of the EP and PP quails were higher than those of PPP quails (p < 0.001). Moreover, EP quails had the highest villus height (VH)/crypt depth (CD) ratio in the duodenum and jejunum and the lowest VH:CD in the ileum compared with the PPP quails (p < 0.01). The lowest SGLT1 mRNA abundance was noted in the PP quails, whereas EP quails had the highest SGLT5 mRNA abundance (p < 0.05)., Conclusions: In conclusion, although histology parameter changes were in-line with the lowest performance observed in the PPP quails, the current results failed to show a relationship between mRNA abundance changes and production performance attributes at different productive lifespans., (© 2024 The Author(s). Veterinary Medicine and Science published by John Wiley & Sons Ltd.)

Japanese quails (Coturnix japonica) have a high reproductive rate because they reach sexual maturity very early. This short rearing time results in increasing interest among breeders and consumers. The aim of the study was a comparative analysis of two genotypes and sexes of Japanese and Pharaoh quails and their impact on body weight, carcass composition, meat quality, digestive system morphometry and leg bone dimensions. The study involved 40 birds (10 females and 10 males), Japanese quail and Pharaoh quail, 42 days old. Quail genotype had an effect (P < 0.05) on body weight, carcass weight, and some percentage of carcass elements. In addition, there was a significant effect of quail genotype on intramuscular fat and water content of pectoral and leg muscles. The origin of the quails interacted (P < 0.05) with the lightness (L*), yellowness (b*), cutting work, hardness, springiness, chewiness, gumminess, fibre cross-sectional area, vertical fibre diameter, and perimysium thickness of pectoral muscle. In addition, genotype was found to influence some anatomical traits, such as the percentage of proventriculus, heart, and liver on body weight, lengths and diameters of duodenum, caeca, and colon, and most dimensions of leg bones (femur and tibia). The sex of the birds significantly (P < 0.05) affected body weight, carcass weight, percentage of skin with subcutaneous fat in the carcass, as well as water content, lightness (L*), and springiness, most microstructure characteristics of pectoralis muscle, and also water and protein contents, and yellowness (b*) of leg muscles. In addition, differences were found between males and females (P < 0.05) in terms of duodenum and caeca diameter, length of greatest and medial femur, and greatest length of tibia. It can be stated that in terms of body weight and carcass weight as well as some meat quality features (protein content, fat content, fiber cross-sectional area), the pharaoh quail was the better genotype, while in terms of the proportion of muscles in the carcass and selected meat quality features: hardness, gumminess, chewiness, Japanese quails turned out to be better., (© 2024. The Author(s).)

In avian species, male fertility significantly impacts reproductive success. This study investigates the relationship between proctodeal gland size in male Japanese quails and sperm function, as well as female fertility duration. Six hundred adult Japanese quails were selected and housed in individual cages. Males (n = 300) were divided into 6 groups (50/group) based on the size of their proctodeal glands. Females (n = 300) were randomly assigned to corresponding groups. After acclimatization, sperm kinematics and the frequency and weight of foam discharge were evaluated. Males were paired with females for 24 h, and eggs were collected for 20 d postcopulation. Eggs were incubated to assess fertility duration. Fresh eggs (n = 20/group/d) were used to assess sperm penetration into the perivitelline membrane on the 2nd, 9th, and 16th d postinsemination. Plasma testosterone levels and the testes' relative weight were determined. The results indicated a significant increase (p < 0.0001) in sperm concentration, total and progressive motility, and nearly all sperm kinematic parameters such as VSL, VCL, VAP, LIN, WOB, and STR values as the size of the proctodeal gland increased. Quails copulated with males having a small and average proctodeal gland area (<400 mm 2 ) laid fertile eggs for a shorter period and had significantly fewer sperm penetration holes than those mated with males having a larger proctodeal gland area (>400 mm 2 ). The proctodeal gland size was positively correlated with testicular weight, plasma testosterone concentrations, and sperm kinetic variables. The results indicate that the size of the proctodeal gland in males can be used to predict sperm function and the duration of fertility in Japanese quail., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

The purpose of the study was to compare young (6-wk-old) and spent (52-wk-old) Japanese quail in terms of body weight, carcass characteristics, and some meat quality traits. Whole carcasses were dissected, pectoral muscles and leg muscles were sampled for determination of basic chemical composition and L*a*b* color parameters, while m. pectoralis major was sampled for texture and microstructure traits. Age of quails had a significant effect on body weight, carcass weight, carcass yield, pectoral muscle, abdominal fat and skin with subcutaneous fat, and carcass remainders contents in eviscerated carcass. Spent quails had significantly higher intramuscular fat content in pectoral and leg muscles and protein content in breast muscle, and also lower content of water in breast and leg muscles than young quails. Slaughter age significantly affected lightness (L*) and redness (a*) of pectoral muscles, as well as texture traits (except for cohesiveness) and microstructure of m. pectoralis major, except for thickness of perimysium and endomysium. Regardless of age, quail sex had an effect on the carcass traits studied (except for leg muscle content), intramuscular fat content of pectoral and leg muscles, water content of leg muscles and yellowness of pectoral muscle. In addition, a significant effect of quail sex was found on cutting work, springiness, chewiness and marked microstructural characteristics, except for vertical fiber diameter. The interaction between age and sex was significant for most slaughter and microstructural characteristics and also WB-shear force of m. pectoralis major, and L*, b* pectoral muscles. Higher fatness of carcasses, higher intramuscular fat in meat, and poorer textural and microstructural characteristics of m. pectoralis major spent Japanese quail indicate poorer fulfillment of most consumers' requirements compared to carcasses and meat of young quails., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

We examined the effect of the Persian Gulf algae derivates, phycocyanin (PC) and fucoidan (FUC), on production performance, egg quality, intestinal histomorphology, ileal microflora, and egg yolk biochemistry of laying Japanese quail. A total of 250 six-wk-old Japanese quails with an average body weight of 215 ± 10 g were allocated to 5 treatments, 5 replicates and 10 birds in each replicate in a completely randomized design. The treatment groups received PC (from Spirulina platensis) and FUC (from brown seaweed) in their drinking water while control groups did not. Treatment groups received PC and FUC at 20 or 40 mg/L levels (denoted as PC20, PC40, FUC20, and FUC40, respectively). All birds were fed the same diet. All treatments significantly improved the percentage of hen day egg production (HDEP) (P = 0.002), egg mass (P = 0.002), and feed conversion ratio (FCR) (P = 0.022) but no difference was noted in egg weight (EW) and feed intake (FI). Different levels of PC and FUC significantly increased the thickness of eggshells (P = 0.022); however, the weight of the digestive tract (liver, spleen, proventriculus, gizzard, and pancreas) and oviduct was not affected. Algal derivates improved the villus height (P = 0.007) and crypt depth (P = 0.007) of the duodenum, as well as, the villus height (P = 0.005) and crypt depth (P = 0.026) of the jejunum. Both algal derivates positively affected the intestinal microflora (populations of Lactobacillus (P = 0.017), Coliform (P = 0.005), and Clostridium (P = 0.000)) whereas aerobic bacteria were unaffected. Yolk cholesterol P = 0.012) and yolk malondialdehyde P = 0.050) content were significantly reduced in experimental treatments compared to the control group. In conclusion, our results showed that the treatment of laying Japanese quails with algal derivates positively affects quail performance, intestinal morphology, intestinal microflora, and yolk cholesterol and malondialdehyde. Additional studies exploring optimal dosages and mechanisms of action is warranted to fully understand the scope of the algae derivates in poultry production., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

The spleen is considered a key player in birds' immunity. The stroma and the parenchyma of the spleen of the adult quail were demonstrated histologically, histochemically, and ultrastructurally. A thin capsule and the absence of trabeculae were the most characteristics of spleen stroma. The demarcation between white pulp and red pulp was not observed in the quail. White pulp formed from the periarterial lymphatic sheath and the periellipsoidal lymphatic sheath, both of which were surrounded by arteriole and ellipsoid, respectively. Ellipsoids appeared more numerous and were characterized by cuboidal lining of the epithelium and supporting cells. Red pulp consisted of sinuses and cords. White pulp and red pulp of the quail spleen contained various cells, such as red blood cells, macrophages, heterophils with characteristic granules, lymphocytes of different sizes, dendritic cells, plasma cells, and telocytes. In addition, closed circulation and open circulation established the blood flow on the spleen.

The mechanical performance of limb bones is closely associated with an animal's locomotor capability and is thus important to our understanding of animal behaviour. This study combined a geometrical analysis and three-point bending tests to address the question of how the mechanical performance of the femurs of Japanese quail (Coturnix coturnix japonica) and pigeon (Columba livia domestica) respond to changing functional demands during ontogeny. Results showed that hatchling quails had stiff bone tissues, and the femoral ultimate loads scaled negatively with body mass, corresponding to high functional demands during early growth. The hatchling pigeon femora had weak material properties but they showed a dramatic increase in Young's modulus during growth. Consequently, although femoral cross-sectional geometry showed negative allometry, the ultimate loads scaled positively with body mass. Older pigeons had more circular bone cross-sections than younger pigeons, probably due to load stimulation changes occurred shortly after the onset of locomotion. Negative allometry and isometry of the cross-sectional geometry of hind limb bones were observed in flying birds and ground-dwelling birds, respectively. The correspondence between geometrical change and locomotor pattern suggests that ontogenetic changes in cross-sectional geometry may be an effective indicator of avian locomotor behaviour., (© 2019 Anatomical Society.)

The upper beak bone of birds is known to be overlain by the rhinotheca, which is composed of the horny sheath of keratinous layers. However, the details of the structure and growth pattern of the rhinotheca are yet to be understood. In this study, the microstructure of the rhinotheca from chicken specimens of different growth stages (ranging from 1 to ~ 80 days old) was analyzed using a combination of thin section and scanning electron microscopy observations, and small-angle X-ray scattering analysis. We found that the rhinotheca comprises three different layers - outer, intermediate, and inner layers - throughout its growth. The outer layer arises from the proximal portion of the beak bone and covers the dorsal surface of the rhinotheca, whereas the intermediate and inner layers originate in the distal portion of the beak bone and underlie the outer layer. This tri-layered structure of the rhinotheca was also observed in wild bird specimens (grey wagtail, king quail, and brown dipper). On the median plane, micro-layers making up the outer and inner layers are bedded nearly parallel to the rostral bone at the base. However, more distally positioned micro-layers of the outer layer are more anteverted distally. The micro-layers of the intermediate layer are bedded nearly perpendicular to those of the outer and inner layers on the median plane. The growth of micro-layers in the intermediate layer adds thickness to the rhinotheca, which causes the difference in profile between the beak bone and the rhinotheca in the distal portion of the beak. Moreover, the entire intermediate layer grows distally as new proximal micro-layers form. The outer layer is dragged distally by the intermediate layer as a result of its distal growth, for the three layers are closely packed to each other at their boundaries. Furthermore, the occurrence of the intermediate and inner layers in the distal portion of the rostral bone may be because the distal end of the beak is frequently used and worn, and the rhinotheca therefore needs to be replaced more frequently at the distal end. The rhinotheca structure described here will be an important and useful factor in the reconstruction of the beaks of birds in extinct taxa., (© 2019 Anatomical Society.)

New strategies must be developed to improve poultry performance and health. One of these strategies is the use of supplementations as sodium butyrate (SB) to improve the physiological status and then increasing the growth performance, but the best period of age in which the addition of SB is more effective on birds is not well understood. Therefore, the aim of this study was to investigate the effect of dietary inclusion of SB supplementation through the first, second or whole growth period on some physiological indices and growth performance of growing Japanese quail. In total, 240 unsexed 1-day-old quail chicks were divided into four groups (three replicates per group of 20 chicks in each). The first group was fed basal diet without SB from 1 to 42 days (control, T1), while SB at a rate of 1 g/kg basal diet was mixed with the feed of the 2nd, 3rd and 4th groups of chicks from 1 to 21 days (SB 1 to 21, T2), 1 to 42 days (SB 1 to 42, T3) and 22 to 42 days (SB 22 to 42, T4) of age, respectively. The results stated that addition of SB significantly improved live BW at 21 days, feed conversion ratio (FCR) and BW gain (BWG) during 1 to 21 days in T2 and T3 groups compared to T1 and T4 groups. During the whole period, group T3 had higher BWG and better FCR than the other groups (T1, T2 and T4). At 21 days, no significant differences among all treatments were detected on haematology and serum biochemistry except total protein and cholesterol. At 42 days, SB supplementation significantly improved most serum constituents, haematological parameters, villus height and width of intestine and morphometry of immune organs. The group fed SB throughout the experiment (T3) showed the best results. In conclusion, it is recommended feeding quail on diets containing SB through the whole growth period to show its affirmative impact on the growth and physiological indices.

Chickens and Japanese quail (Coturnix japonica) have traditionally been the primary avian models in developmental biology research. Recently, the blue-breasted quail (Coturnix chinesis), the smallest species in the order Galliformes, has been proposed as an excellent candidate model in avian developmental studies owing to its precocious and prolific properties. However, data on the embryonic development of blue-breasted quail are scarce. Here, we developed a normal developmental series for the blue-breasted quail based on developmental features. The blue-breasted quail embryos take 17 days to reach the hatching period at 37.7°C. We documented specific periods of incubation in which significant development occurred, and created a 39-stage developmental series. The developmental series for the blue-breasted quail was almost identical to that for chickens and Japanese quail in the earlier stages of development (stages 1-16). Our staging series is especially useful at later stages of development (stages 34-39) of blue-breasted quail embryos as a major criterion of staging in this phase of development was the weight of embryos and the length of third toes., (© 2018 The Authors. Animal Science Journal published by John Wiley & Sons Australia, Ltd on behalf of Japanese Society of Animal Science.)

The aim of the present study was to investigate the efficacy of early probiotics (single dose) administered in different ways, on quails' performance, small intestine morphology, blood biochemistry, and immune response. In total, 192 day-old chicks were used in one of the following experimental groups before being transferred to a raising room: 1) Control (no probiotic administered), 2) oral gavage, 3) spray, and 4) vent lip. Four replicates of 12 chicks per cage were considered for each treatment and birds were raised up to 35 d in the same conditions. Probiotic treated birds had higher d 1 to 35 feed intake than the control group (P < 0.05). In addition, oral-gavaged birds had a higher body weight gain as compared to the control (P < 0.05). The values of duodenum length and villus height of the oral group and ileum length and villus height of the vent lip group were greater than that of the control (P < 0.01). Regardless of the method of administration, probiotics resulted in deeper crypts and in a higher number of goblet cells in the duodenum and ileum as compared to the control (P < 0.01). The administration of probiotics resulted in increased plasma uric acid (P < 0.05), glucose, and total protein (P < 0.01). The concentration of hemoglobin was slightly higher in probiotic-supplemented groups. While a decreased concentration of triglyceride was observed in vent-lip probiotic-administered birds compared to control (P < 0.05), the concentration of cholesterol was not significantly affected by treatments (P > 0.01). None of the immune-related parameters were affected by the probiotic (P > 0.05). Single dose usage of probiotics exerts its beneficial effects on quails' body weight gain, feed intake and mortality in 1 to 35 d period, regardless of the route of administration. This work generally supports the efficacy of single-dose usage of probiotics and suggests the spray of probiotics as an early, single-dose administration method., (© 2017 Poultry Science Association Inc.)

An experiment was conducted to evaluate egg quality and ultrastuctural measurements of eggshell using a Scanning Electron Microscope (SEM) in 2 lines (selected and control) of Japanese quail. A selection program was applied over 22 consecutive generations for higher egg production and lower broken egg percentage. The results revealed that the females of the selected line produced significantly (P < 0.01) higher egg mass compared to that of the control line. Also, the selection procedure significantly improved feed conversion ratio. The eggshells of the selected line had a higher breaking strength compared to those of the control line, although there was no difference between them in shell thickness. Significantly higher wet (P < 0.01) and dry (P < 0.05) eggshell percentages were found in the selected line. In general, the eggshells of the selected line had a lower total score (good) of ultrastructural evaluation compared to the control line. According to scanning electron microscope data, the incidence of certain structural variants was more common in eggshells of the control line suggesting poor shell strength. The incidence of alignment was more prevalent in control eggshells compared to selected ones, suggesting lower resistance to breakage. Late fusion and large interstitial spaces of the palisade layer indicating decreased resistance to fracture were observed in control eggshells. It could be concluded that the improvement eggshell quality may be caused by the long-term selection for lower cracked and broken egg rates from generation to generation., (© 2016 Poultry Science Association Inc.)

The aim of the present study was to investigate the effect of gender on the histological and histochemical structures of different anatomical regions of the kidney in Japanese quail (Coturnix japonica). Tissue samples from cranial, middle and caudal divisions of each kidney were obtained from 20 male and 20 female adult, healthy Japanese quail. The sections stained with hematoxylin & eosin ( H & E: ), Masson's trichrome, Verhoeff's, Alcian blue (pH 2.5), Periodic acid-Schiff, and Gomori's method for reticulum. Unusual findings of the kidney in Japanese quail were the presence of three types of nephrons, all the connective tissue fibers in capsule and interlobular septa and AB-reactions of the proximal convoluted cells. No significant sex-based differences were found. The various histological structures of the kidney showed no significant differences among different divisions of the left and right kidneys. It is concluded that the general histological and histochemical properties of the kidney in Japanese quail were similar to those of chickens and some other species, but that there were also some differences. One of the major differences was brush border of interdigitating microvilli on luminal surface of collecting ducts in Japanese quail., (© 2016 Poultry Science Association Inc.)

Conditions experienced during prenatal development can have long-lasting organizational effects on offspring. Maternal carotenoids deposited in the eggs of birds and other oviparous species play an important role during fast embryonic growth and chick development through their antioxidant properties. However, the long-term consequences of variation in maternal carotenoid transfer for the offspring have seldom been considered. Since plasma carotenoid levels at adulthood are known to influence testis size and yolk carotenoid levels influence the ability to extract carotenoids later in life, we hypothesized that maternally transmitted carotenoids might influence gonad size at adulthood. Here, we showed that male Japanese quail (Coturnix japonica) originating from a carotenoid-enriched egg had smaller testes than control individuals at adulthood. This result shows that yolk carotenoids have long-term organizational effects. In addition, given that carotenoid intake at sexual maturity increases sperm quality and that a decreased testis size is associated with a lower sperm production, we propose that carotenoid exposure during embryo development might influence a trade-off between ejaculate size and sperm quality., (© 2016 The Author(s).)

The objectives of this study were to investigate the muscle fiber characteristics of the pectoralis major muscle, and its relation to growth performance in the random bred control (RBC) and heavy weight (HW) Japanese quail lines at 42 days of age. The HW line had greater body (232.0 v. 100.2 g, P < 0.001) and pectoralis major muscle (19.0 v. 6.2 g, P < 0.001) weights than the RBC line. Color differences were observed between the superficial and deep regions of the pectoralis major muscle, with the superficial region showing a higher value of lightness than the deep region of the RBC or HW lines (P < 0.001). The percentage of the superficial region in the pectoralis major muscle was higher in the HW line compared with the RBC line (46.2% v. 38.0%, P = 0.017). There were no significant differences in the total fiber number in the superficial and deep regions between the two quail lines (P = 0.718). The HW quail line showed a larger mean fiber cross-sectional area (CSA; 375.5 v. 176.6 μm², P < 0.001) and type IIA fiber CSA (243.7 v. 131.9 μm², P < 0.001) than the RBC quail line. The HW line also had greater CSA percentage (60.2% v. 34.2%, P < 0.001) and number percentage (41.6% v. 14.2%, P < 0.001) of type IIB fibers, although there were no significant differences in type IIB fiber CSA between the RBC and HW lines (P = 0.219). Therefore, greater body and muscle weights of the HW line are caused by differences in muscle fiber characteristics, especially the proportion of type IIB fiber and the CSA of type IIA fiber, compared with the RBC line. The results of this study suggest that muscle fiber hypertrophy has more impact on body and muscle weights of the different quail lines than muscle fiber hyperplasia.

Across taxa, the early rearing environment contributes to adult morphological and physiological variation. For example, in birds, environmental temperature plays a key role in shaping bill size and clinal trends across latitudinal/thermal gradients. Such patterns support the role of the bill as a thermal window and in thermal balance. It remains unknown whether bill size and thermal function are reversibly plastic. We raised Japanese quail in warm (30°C) or cold (15°C) environments and then at a common intermediate temperature. We predicted that birds raised in cold temperatures would develop smaller bills than warm-reared individuals, and that regulation of blood flow to the bill in response to changing temperatures would parallel the bill's role in thermal balance. Cold-reared birds developed shorter bills, although bill size exhibited 'catch-up' growth once adults were placed at a common temperature. Despite having lived in a common thermal environment as adults, individuals that were initially reared in the warmth had higher bill surface temperatures than cold-reared individuals, particularly under cold conditions. This suggests that blood vessel density and/or the control over blood flow in the bill retained a memory of early thermal ontogeny. We conclude that post-hatch temperature reversibly affects adult bill morphology but irreversibly influences the thermal physiological role of bills and may play an underappreciated role in avian energetics.

The colocalization of immunoreactivity to nitric oxide synthase (NOS), vasoactive intestinal polypeptide (VIP) and tyrosine hydroxylase (TH) in the superior cervical ganglion (SCG) was investigated in the quail. In this bird, a substantial amount of NOS-immunoreactive (IR) cells were consistently found in the SCG without colchicine treatment or nerve ligation. The finding worthy of pointing out was that three-fourths of these NOS-IR cells were positive for TH. VIP-IR cells appeared with markedly low frequency than NOS-IR cells. They were generally small in size and often located in the ganglion peripheral. There were no VIP-IR cells positive for TH or negative for NOS: VIP immunoreactivity always appears in NOS-IR cells negative for TH. Thus, the results of the present study clearly showed the existence of two distinct subpopulations of postganglionic NOS-IR neurons (one is catecholaminergic and negative for VIP, and the other is non-catecholaminergic and positive for VIP). This suggests that nitric oxide (NO) and possibly VIP act as postganglionic neurotransmitters or neuromodulators in the quail SCG. The predominant appearance of the former category of NOS-IR cells must be considered in relation to some specific NO-induced controlling mechanisms of SCG neurons.

The prenatal environment is a source of phenotypic variability influencing the animal's characteristics. Prenatal stress affects not only the development of offspring, but also that of the following generation. Such effects have been best documented in mammals but can also be observed in birds, suggesting common processes across phylogenetic orders. We found previously that Japanese quail females stressed during laying produced offspring with higher fearfulness, probably related to modulation of testosterone levels in their eggs. Here, we evaluated long-term effects of prenatal stress by analysing reproductive traits of these F(1) offspring and, then, the development of their subsequent (F(2)) offspring. The sexual behaviour of F(1) prenatally stressed (F1PS) males was impaired. F1PS females' eggs contained less yolk and more albumen, and higher yolk testosterone and progesterone levels than did F(1) prenatal control females. The fearfulness of F(2) prenatally stressed quail was greater than that of F(2) prenatal control quail. These F(2) behavioural differences paralleled those evidenced by their parents, suggesting trans-generational transmission of prenatal stress effects, probably mediated by egg compositions of F1PS females.

Analyses of how intralimb coordination during locomotion varies within and across different taxa are necessary for understanding the morphological and neurological basis for locomotion in general. Previous findings suggest that intralimb proportions are the major source of kinematic variation that governs intralimb coordination across taxa. Also, independence of kinematics from habitat preference and phylogenetic position has been suggested for mammals. This leads to the hypothesis that among equally sized bird species exhibiting equal limb proportions, similar kinematics can be observed. To test this hypothesis, the bipedal locomotion of two distantly related ground-dwelling bird species (Eudromia elegans and Coturnix coturnix) and of a less terrestrial species (Corvus monedula) was investigated by means of a biplanar high-speed X-ray videographic analysis. Birds exhibited similar intralimb proportions and were filmed over a broad range of speed while moving on a treadmill. Joint and limb element angles, as well as pelvic rotations, were quantified. Regarding fore-aft motions of the limb joints and elements, a congruent pattern of intralimb coordination was observed among all experimental species. The sample of species suggests that this is largely independent of their habitat preference and systematic position and seems to be related to demands for coping with an irregular terrain with a minimum of necessary control. Hence, the initial hypothesis was confirmed. However, this congruence is not found when looking at medio-lateral limb motions and pelvic rotations, showing distinct differences between ground-dwellers (e.g. largely restricted to a parasagittal plane) and C. monedula (e.g. increased mobility of the hip joint).

Current research was conducted to estimate heritability and genetic correlations for carcass composition and fat deposition in Japanese quail at 42 and 91 d of age. Studied traits were BW at 42 and 91 d of age (BW42, BW91), carcass weight and percentage, breast meat weight and percentage, thigh weight and percentage, abdominal fat weight and abdominal fat percentage (AFP), skin weight and skin percentage (SP) as a measure of subcutaneous fat, and the percentage of breast intramuscular fat (IFP). Genetic parameters were estimated by restricted maximum likelihood using ASREML software. The heritability estimates of BW and the weight of carcass traits were higher (from 0.45 for BW42 to 0.63 for breast meat weight) than the percentage of carcass traits (from 0.11 for thigh percentage to 0.19 for breast meat percentage). The heritability estimates for SP, AFP, and IFP as fat deposition tissues were 0.17, 0.26, and 0.20, respectively. There were high genetic correlations between BW42 with the weight and percentage of carcass components (from 0.65 to 0.98). Body weight at 42 d of age also showed positive genetic correlations with skin weight and SP (0.80 and 0.23, respectively), abdominal fat weight and AFP (0.44 and 0.21, respectively), and IFP (0.28). A positive genetic correlation between SP and AFP (0.51) was observed. Present results indicated that the percentage of breast intramuscular fat is a heritable trait and selection for increasing BW and decreasing abdominal and subcutaneous fats will improve carcass composition and breast meat quality in Japanese quail. In addition, selection against abdominal and subcutaneous fat does not change intramuscular fat and the quality of breast meat.

Contrary to humans, most ovarian tumors in other species do not arise from the ovarian surface epithelium but are of follicular-, stromal- or germ-cell origin. One of the few species where ovarian cancer arises from the ovarian surface epithelium (OSE) is chicken (Gallus domesticus). Little is known about the morphology of the OSE in other avian species. In our study we analyzed the OSE morphology of Japanese quail (Coturnix japonica) using ultrastructural and histochemical techniques. Carbohydrate residues have been studied by using a panel of fluorescein isothiocyanate labeled lectins. Japanese quails are commonly used animal models in biomedical research as their housing is comparatively inexpensive and they show a short generation interval. Our ultrastructural and histochemical results demonstrate that the quail ovarian surface epithelium shows characteristic features which resemble the epithelia of both chicken and human. Additionally, the ovarian surface epithelium of the Japanese quail contains cytokeratin as well as vimentin intermediate filaments in their cytoplasm. Therewith and among other parts the quail OSE shows many characteristic features also seen in those of humans, which may qualify quail's ovary as a potential animal model for human ovarian carcinomas., (© 2011 The Authors. Journal compilation © 2011 Japanese Society of Animal Science.)

The effect of fat accumulation on the prediction of in vivo body composition by a total body electrical conductivity (TOBEC) technique was evaluated using Japanese quail at 2 life periods (0 to 21 d and 28 to 70 d of age) that differ significantly in the fatness of birds. In total, 119 quail of 14 age categories were weighed and scanned by the TOBEC analyzer, and their carcasses were subjected to chemical analysis. The prediction equations for chemical composition (percentage of water, lipids, and lean tissue) and body masses (weight of body, water, lipids, and lean tissue) were obtained by linear regression analysis. The equations involved the E-value as the independent variable. In both growth phases, a high accuracy of estimation was found for the total body, lean, and water masses (0.85 ≤ R(2) ≤ 0.98), whereas a low accuracy of estimation was observed for percentages of lipids, lean tissue, and water (0.27 ≤ R(2) ≤ 0.64). Most of the variables showed a worse estimation in the late than in the early growth phase; the maximum difference was observed for the lipid mass (R(2) = 0.35 vs. 0.90, respectively). The correlations between analyzed variables and the residual error distributions of regression models demonstrated that the lower power of the models in the late versus early growth phase may be attributed to an enhanced fat accumulation in sexually mature birds. Their high fat reserves considerably decrease body hydration, which negatively influences the estimation of body composition based upon the TOBEC procedure.

It has been known for many decades that nonmammalian vertebrates detect light by deep brain photoreceptors that lie outside the retina and pineal organ to regulate seasonal cycle of reproduction. However, the identity of these photoreceptors has so far remained unclear. Here we report that Opsin 5 is a deep brain photoreceptive molecule in the quail brain. Expression analysis of members of the opsin superfamily identified as Opsin 5 (OPN5; also known as Gpr136, Neuropsin, PGR12, and TMEM13) mRNA in the paraventricular organ (PVO), an area long believed to be capable of phototransduction. Immunohistochemistry identified Opsin 5 in neurons that contact the cerebrospinal fluid in the PVO, as well as fibers extending to the external zone of the median eminence adjacent to the pars tuberalis of the pituitary gland, which translates photoperiodic information into neuroendocrine responses. Heterologous expression of Opsin 5 in Xenopus oocytes resulted in light-dependent activation of membrane currents, the action spectrum of which showed peak sensitivity (lambda(max)) at approximately 420 nm. We also found that short-wavelength light, i.e., between UV-B and blue light, induced photoperiodic responses in eye-patched, pinealectomized quail. Thus, Opsin 5 appears to be one of the deep brain photoreceptive molecules that regulates seasonal reproduction in birds.

Developmental biology research has used various avian species as model organisms for studying morphogenesis, with the chick embryo being used by the majority of groups. The focus on the chick embryo led Hamburger and Hamilton to develop their definitive staging series nearly 60 years ago and this series is still the mainstay of all laboratories working with avian embryos. The focus on the chick embryo has somewhat overshadowed the importance of another avian embryo that has proved to be equally powerful, the Japanese quail. Since the late 1960s, chimeras have been produced using chick and quail embryos and this technique has revolutionized the approach taken to the investigation of the cellular and molecular interactions that occur during development. Reviews of the literature demonstrate that many research groups are using the quail embryo in a number of established and new ways, and this species has become a primary animal model in developmental biology. Some staging of quail has been performed but this has been incomplete and variations in descriptions, stages and incubation timings mean that comparisons with the chick are not always easily made. There appears to be general agreement that, at the early stages of embryogenesis, there is little developmental difference between chick and quail embryos, although the basis for this has not been established experimentally. The accelerated ontogeny of quail embryos at mid to late stages of development means that registration with the chick is lost. We have therefore developed a definitive developmental stage series for Japanese quail so that differences are fully characterized, misconceptions or assumptions are avoided, and the results of comparative studies are not distorted.

Development of cerebral perivascular nerves immunoreactive for vasoactive intestinal polypeptide (VIP) was investigated in the Japanese quails, using immunohistochemistry and quantitative analysis. VIP-immunoreactive (VIP-IR) nerves supplying the anterior circulation appeared on the cerebral carotid artery (CCA) at embryonic day 10 and on the cerebroethmoidal artery (CEA) after hatching. Nerves from the CCA increased greatly in number and spread progressively during successive embryonic stages, while those from the CEA were sparse all through the post-hatching stages, mostly remained limited to this vessel wall. The distribution of VIP-IR nerves to the respective major arteries of the anterior circulation from the two vascular routes was basically similar among post-hatching day (P) 15, P20, P30 and P50. Likewise, no clear statistical difference was observed with regard to the nerve density of the corresponding arteries in the four age groups. These findings suggest that VIP-IR innervation of the quail anterior circulation usually attains its mature pattern at the third week after hatching.

The immunocompetence handicap hypothesis (ICHH) suggests that the male sex hormone testosterone has a dual effect; it controls the development and expression of male sexually selected signals, and it suppresses the immune system. Therefore only high quality males are able to fully express secondary sexual traits because only they can tolerate the immunosuppressive qualities of testosterone. A modified version of the ICHH suggests that testosterone causes immunosuppression indirectly by increasing the stress hormone corticosterone (CORT). Lines of Japanese quail (Coturnix japonica) selected for divergent responses in levels of plasma CORT were used to test these hypotheses. Within each CORT response line (as well as in a control stock) we manipulated levels of testosterone in castrated quail by treatment with zero (sham), low or high testosterone implants, before testing the birds' humoral immunity and phytohaemagglutinin (PHA)-induced immune response, as well as body condition. The PHA-induced response was not significantly affected by CORT selected line, testosterone treatment or their interaction. There was, however, a significant effect of CORT line on humoral immunity in that the control birds exhibited the greatest antibody production, but there was no significant effect of testosterone manipulation on humoral immunity. The males in the sham implant treatment group had significantly greater mass than the males in the high testosterone group, suggesting a negative effect of high testosterone on general body condition. We discuss these results in the context of current hypotheses in the field of sexual selection.

Here we show the temporal-spatial orchestration of early heart morphogenesis at cellular level resolution, in vivo, and reconcile conflicting positional fate mapping data regarding the primary heart-forming field(s). We determined the positional fates of precardiac cells using a precision electroporation approach in combination with wide-field time-lapse microscopy in the quail embryo, a warm-blooded vertebrate (HH Stages 4 through 10). Contrary to previous studies, the results demonstrate the existence of a "continuous" circle-shaped heart field that spans the midline, appearing at HH Stage 4, which then expands to form a wide arc of progenitors at HH Stages 5-7. Our time-resolved image data show that a subset of these cardiac progenitor cells do not overlap with the expression of common cardiogenic factors, Nkx-2.5 and Bmp-2, until HH Stage 10, when a tubular heart has formed, calling into question when cardiac fate is specified and by which key factors. Sub-groups and anatomical bands (cohorts) of heart precursor cells dramatically change their relative positions in a process largely driven by endodermal folding and other large-scale tissue deformations. Thus, our novel dynamic positional fate maps resolve the origin of cardiac progenitor cells in amniotes. The data also establish the concept that tissue motion contributes significantly to cellular position fate - i.e., much of the cellular displacement that occurs during assembly of a midline heart tube (HH Stage 9) is NOT due to "migration" (autonomous motility), a commonly held belief. Computational analysis of our time-resolved data lays the foundation for more precise analyses of how cardiac gene regulatory networks correlate with early heart tissue morphogenesis in birds and mammals.

Differences in developmental instability were assessed in female offspring of Japanese quail hens selected for reduced (low stress, LS) or exaggerated (high stress, HS) plasma corticosterone (B) response to stress and treated with a placebo or B during egg formation. Hens of each line were implanted (s.c.) with either a silastic tube containing no B (controls) or one filled with B. Female chicks hatched from each of the 4 line x implant treatment combinations were retained for examination of 3 bilateral traits at 130 d of age: length of the tibiotarsus, middle toe length, and distance between the auditory canal and the nares (face length, FL). Greater bilateral trait size variances were associated with measurement of tibiotarsus length (P < 0.04) and middle toe length (P < 0.06) in the HS line, supporting our previous findings in the opposite sex that developmental instability (i.e., fluctuating asymmetry, FA) of certain morphological traits is more pronounced in HS than LS adult quail. The HS quail are also known to exhibit greater adrenocortical responsiveness to a wide range of stressors, and they are more easily frightened than LS birds. Therefore, the line differences in FA (HS > LS) found previously in males and herein in females may simply reflect the differential responsiveness of the birds to chronic social and physical environmental stressors. In addition, the present study detected more (albeit marginally so, P < 0.06) bilateral variability (i.e., heightened FA) in FL of quail hatched from mothers treated with B, a finding entirely due to the very high FL variance observed in the female offspring of B-treated HS hens. Because others have found in ovo B treatment to be associated with heightened FA in chick tarsus bone length and because we have also demonstrated that greater yolk B deposition occurs in eggs from both unstressed and stressed HS quail hens than their LS counterparts, the present maternal B treatment may be acting independently, or in combination with HS genomic effects, to adversely affect developmental stability.

Molecular mechanisms regulating animal seasonal breeding in response to changing photoperiod are not well understood. Rapid induction of gene expression of thyroid-hormone-activating enzyme (type 2 deiodinase, DIO2) in the mediobasal hypothalamus (MBH) of the Japanese quail (Coturnix japonica) is the earliest event yet recorded in the photoperiodic signal transduction pathway. Here we show cascades of gene expression in the quail MBH associated with the initiation of photoinduced secretion of luteinizing hormone. We identified two waves of gene expression. The first was initiated about 14 h after dawn of the first long day and included increased thyrotrophin (TSH) beta-subunit expression in the pars tuberalis; the second occurred approximately 4 h later and included increased expression of DIO2. Intracerebroventricular (ICV) administration of TSH to short-day quail stimulated gonadal growth and expression of DIO2 which was shown to be mediated through a TSH receptor-cyclic AMP (cAMP) signalling pathway. Increased TSH in the pars tuberalis therefore seems to trigger long-day photoinduced seasonal breeding.

The innervation pattern of vasoactive intestinal polypeptide-immunoreactive (VIP-IR) nerves in the quail internal carotid artery (ICA) and cerebral arterial tree was investigated and compared with that of acetylcholinesterase-positive (AChE-P) nerves. The supply of VIP-IR nerves to the two arterial systems was distinctly richer than that of AChE-P nerves. It was focused mainly on the walls from the distal ICA to the caudal half of the anterior ramus (AR) through the cerebral carotid artery (CCA). Indeed, double staining clearly showed that numerous VIP+/AChE-axons were distributed over these arterial regions where VIP+/AChE+ or AChE+/VIP- axons were sporadic or often lacking. The finding that nerve bundles accompanying the ICA within the carotid canal contained abundant VIP+/AChE- nerve cells suggests that cerebrovascular VIP-IR nerves in the quail have their major source at these neurons and enter the cranial cavity through the CCA. Another significant finding was that a small number of nerve cells, which were mostly stained for AChE alone and occasionally for VIP alone or both, occurred in the major arteries located more rostral than the middle AR. Thus, the quail cerebral arterial tree, at least the rostral segment of the anterior circulation, is multiply innervated by these three distinct categories of the extracranial and intracranial VIP-IR and AChE-P neurons.

This study was conducted to reveal the morphological characteristics of the lung and air sacs in Coturnix coturnix japonica (Japanese quails). Ten quails were allocated into two groups. Tracheas of 5 quails with neoprene latex and 5 quails with methylmetacrylate were injected to fill the trachea and air sacs. Latex embalmed animals were stored in 10% formaldehyde solution for two months. Animals given methylmetacrylate were maserated in 30% potassium hydroxide at 40 degrees C for two days. Lungs were located in the dorsal part of the thorax and very close to the thoracic vertebrae and ribs. Shorter than the dorsal border, the ventral border lied between the 3rd and 6th ribs. Cervical, clavicular, cranial thoracic, caudal thoracic and abdominal sacs were identified. These sacs had connection with the 3rd, 4th and 5th lateroventral and 4th mediolateral bronchi. Saccus cervicalis was located on the left and right portions of the vertebrae cervicales et thoraricae with a pronounced communication ventromedially. However, the cervical sac aeration of only all cervical vertebrae was present in this study. Humerus was a non-aerated bone. Pneumatic foramen was absent and did not aerate the sternum. Cranial thoracic sac connected to the 1st, 2nd and 4th medioventral bronchi and gave no diverticulum for aeration. Cranial thoracic sac received air through the 4th medioventral and the 1st and 2nd lateroventral bronchi. Left and right abdominal air sacs paramedially produced diverticulum femorale, but this diverticulum did not enter the femur.

Poultry farmers in Pakistan use ethanol for treatment of respiratory diseases and as a growth promotant, but the effects on health and production of broilers are unknown. The effects of ethanol were investigated in quail at different doses through drinking water. One hundred and twenty Japanese quail of 39 days of age were purchased from a local market. They were divided randomly into five groups of 24 (groups 1, 2, 3, 4 and 5) and offered ethanol at dose rates 2%, 4%, 8% and 16%, respectively, while group 5 served as control. Quail offered 8% and 16% ethanol showed dullness, depression and staggering gait, while those given 2% and 4% ethanol showed decreased responsiveness for 2 to 3 h. The live weight, brain volume along with serum sodium and potassium decreased significantly (P<0.05) in all treated groups, while there was significant (P<0.05) increase in relative weight of the pancreas. The decrease in live weight varied from 3% to 35% in a dose-related manner. The brain weight decreased by 4% to 10% and the decrease was dose dependent. Brain volume showed a 25% to 51% decrease. The haematological parameters erythrocyte count, packed cell volume and haemoglobin concentration increased significantly (P<0.05), while the leukocyte count increases were not significant. Both serum sodium and potassium decreased in ethanol-treated groups (36% to 44% and 44% to 49%, respectively), almost in a dose-dependent manner. The results suggest that ethanol at these dose levels has significant deleterious effects on haematology, brain volume and serum electrolytes.

This study evaluated the effects of maternal dietary lipids on chemical components and mechanical and histological properties of tibia in progeny of Japanese quail fed different dietary lipids. Laying hens were fed a basal diet containing either soybean oil (SBO), hydrogenated soybean oil (HSBO), chicken fat (CF), or menhaden fish oil (FO) at 50 g/kg of the diet. The various maternal dietary lipid treatments did not affect growth of progeny at any developmental stage. There were no differences in tibial length, diameter, or collagen content. Tibial percentage ash was significantly higher in newly hatched progeny from hens fed the FO and HSBO diets. The levels of tibial deoxypyridinoline and total pyridinium crosslinks were higher in the FO and HSBO groups at hatch. At 7 d of age, the tibial deoxypyridinoline links remained higher in the FO group compared to the CF and SBO groups. Likewise, progeny from hens consuming the FO or HSBO diet had higher tibial shear force and stiffness at 7 and 14 d of age. There were no pronounced differences in tibial fracture energy and deflection among treatments. Maternal FO or HSBO enlarged the cartilaginous proliferative and hypertrophic zones of the tibial proximal end in newly hatched quail, which was accompanied by a thicker cortical bone in the diaphysis. However, the width of the hypertrophic zones tended to be smaller in these two groups coupled with improvement in trabecular density and cortical thickness in the proximal end and cortical density in the diaphysis at 3 wk of age. These results suggest that maternal dietary lipids altered bone development by influencing organic matrix quality and mineralization in embryos.

Cellular and molecular mechanisms underlying differences in beak morphology likely involve interactions among multiple embryonic populations. We exchanged neural crest cells destined to participate in beak morphogenesis between two anatomically distinct species. Quail neural crest cells produced quail beaks in duck hosts and duck neural crest produced duck bills in quail hosts. These transformations involved morphological changes to non-neural crest host beak tissues. To achieve these changes, donor neural crest cells executed autonomous molecular programs and regulated gene expression in adjacent host tissues. Thus, neural crest cells are a source of molecular information that generates interspecific variation in beak morphology.

High force coefficients, similar to those observed for revolving model hawkmoth wings in the accompanying paper (for which steady leading-edge vortices are directly observed), are apparent for revolving model (mayfly, bumblebee and quail) and real (quail) animal wings ranging in Reynolds number (Re) from 1100 to 26000. Results for bumblebee and hawkmoth wings agree with those published previously for Drosophila (Re approximately 200). The effect of aspect ratio is also tested with planforms based on hawkmoth wings adjusted to aspect ratios ranging from 4.53 to 15.84 and is shown to be relatively minor, especially at angles of incidence below 50 degrees. The normal force relationship introduced in the accompanying paper is supported for wings over a large range of aspect ratios in both 'early' and 'steady' conditions; local induced velocities appear not to affect the relationship.

Blue-breasted quail (Coturnix chinensis) were filmed during take-off flights. By tracking the position of the centre of mass of the bird in three dimensions, we were able to calculate the power required to increase the potential and kinetic energy. In addition, high-speed video recordings of the position of the wings over the course of the wing stroke, and morphological measurements, allowed us to calculate the aerodynamic and inertial power requirements. The total power output required from the pectoralis muscle was, on average, 390 W kg(-1), which was similar to the highest measurements made on bundles of muscle fibres in vitro (433 W kg(-1)), although for one individual a power output of 530 W kg(-1) was calculated. The majority of the power was required to increase the potential energy of the body. The power output of these muscles is the highest yet found for any muscle in repetitive contractions. We also calculated the power requirements during take-off flights in four other species in the family Phasianidae. Power output was found to be independent of body mass in this family. However, the precise scaling of burst power output within this group must await a better assessment of whether similar levels of performance were measured across the group. We extended our analysis to one species of hawk, several species of hummingbird and two species of bee. Remarkably, we concluded that, over a broad range of body size (0.0002-5 kg) and contractile frequency (5-186 Hz), the myofibrillar power output of flight muscles during short maximal bursts is very high (360-460 W kg(-1)) and shows very little scaling with body mass. The approximate constancy of power output means that the work output varies inversely with wingbeat frequency and reaches values of approximately 30-60 J kg(-1) in the largest species.

The pattern of cerebrovascular substance P (SP)- and calcitonin gene-related peptide (CGRP)-immunoreactive (IR) innervation was investigated in the quail. SP- and CGRP-IR nerves were relatively a few in the rostral part of the anterior circulation, and very scanty or lacking in its caudal part and the whole of the posterior circulation. A significant finding was that the anterior circulation in the majority of individuals is furnished with a varying proportion of SP-IR nerves with or without CGRP immunoreactivity. There was a good correlation in the expression of CGRP immunoreactivity between SP-IR cells in the ophthalmic division of the trigeminal ganglion and SP-IR nerves supplying the major cerebral arteries. In the quail, SP- and CGRP-IR fiber bundles are usually present in the internal ethmoidal artery (IEA). From these and other findings, it is most probable that cerebral perivascular SP- and CGRP-IR nerves are mainly derived from the same categories of neurons in the primary sensory ganglion via the IEA. The close association of varicose SP-IR axons to the nerve cells in the pial arteries suggests that these intrinsic neurons may play some vasocontrolling roles through the modulatory effect of their pericellular SP-IR axons.

Plasma concentrations of 17beta-estradiol (E2) and left ovarian histology were investigated by light and electron microscopy in female Japanese quail from Day 10 of embryonic development through Day 7, posthatch. Plasma E2 levels remained relatively constant (102 to 140 pg/mL) in the embryo followed by a sharp decrease posthatch (47 to 70 pg/mL). Beginning on Day 10 of incubation, cells in the medullary portion (medullary cell; MC) of the left ovaries exhibited ultrastructural evidence of steroidogenic capability. The MC had numerous lipid droplets in close proximity to the smooth endoplasmic reticulum (SER). Mitochondria were also observed in the vicinity of the lipid droplets and SER. On Days 10 and 12, the cristae of the inner mitochondrial membranes were of a lamellar configuration; the cristae of some mitochondria in MC had a tubular appearance by Day 14. These data document relative ontogenic changes in ovarian morphology and plasma E2 levels during the early developmental period in female Japanese quail. These data further support the role of this steroid in sexual differentiation.

A monoclonal antibody (mAb) to epitopes on mitochondria from turkey spermatozoa cross-reacted with Japanese quail spermatozoal mitochondria. However, the pattern of binding was different from that observed for turkey sperm. The ultrastructure of quail spermatozoa was examined to determine the reason for this difference in antibody binding pattern. Light microscopy, as well as scanning (SEM) and transmission (TEM) electron microscopy, were used to study the morphology of spermatozoa from Japanese quail. Japanese quail had a sauropsid type of sperm cell, which is typical of nonpasserine birds. The spermatozoa were vermiform in shape, with a maximum width of 0.6 microm and an overall length between 230 and 250 microm. An acrosome (3.7 to 4.5 microm), nucleus (20.8 to 23.8 microm), midpiece (160 to 170 microm), and tail (40 to 60 microm) were observed. The TEM showed an acrosomal cap surrounding a perforatorium that inserted into the nucleus at the posterior end. Only a distal centriole was observed, which gave rise to a central axoneme with a 9+2 microtubular structure. The axoneme was encased by a spiraled mitochondrial sheath in the midpiece region (64 to 74% of the overall length of the sperm), and mitochondria numbers were estimated to be greater than 1,400 per sperm. In contrast, turkey sperm contain short midpieces with only 20 to 30 mitochondria per sperm. Differences in binding patterns of the mAb to turkey mitochondria between quail and turkey sperm were due to the presence of mitochondria on the exceptionally long midpieces of quail sperm.

A monoclonal antibody (mAb) to epitopes on mitochondria from turkey spermatozoa cross-reacted with Japanese quail spermatozoal mitochondria. However, the pattern of binding was different from that observed for turkey sperm. The ultrastructure of quail spermatozoa was examined to determine the reason for this difference in antibody binding pattern. Light microscopy, as well as scanning (SEM) and transmission (TEM) electron microscopy, were used to study the morphology of spermatozoa from Japanese quail. Japanese quail had a sauropsid type of sperm cell, which is typical of nonpasserine birds. The spermatozoa were vermiform in shape, with a maximum width of 0.6 microm and an overall length between 230 and 250 microm. An acrosome (3.7 to 4.5 microm), nucleus (20.8 to 23.8 microm), midpiece (160 to 170 micro/m), and tail (40 to 60 microm) were observed. The TEM showed an acrosomal cap surrounding a perforatorium that inserted into the nucleus at the posterior end. Only a distal centriole was observed, which gave rise to a central axoneme with a 9+2 microtubular structure. The axoneme was encased by a spiraled mitochondrial sheath in the midpiece region (64 to 74% of the overall length of the sperm), and mitochondria numbers were estimated to be greater than 1,400 per sperm. In contrast, turkey sperm contain short midpieces with only 20 to 30 mitochondria per sperm. Differences in binding patterns of the mAb to turkey mitochondria between quail and turkey sperm were due to the presence of mitochondria on the exceptionally long midpieces of quail sperm.

Short break (SBK) is a new semilethal mutation of Japanese quail (Coturnix japonica). The SBK individuals are characterized externally by short breaks, shanks, and digits. The shank is also thicker than the wild type. The shape of the mutant beak does not show a parrotlike appearance, contrasting with that of other poultry chondrodystrophic mutants reported in the literature. Bones in the fore and hind limbs of the SBK mutant are also shorter than the wild types. The humerus and ulna in the wing are significantly thicker than the wild types. Other bones in the wing and leg show approximately the same thickness as the wild types. The majority of the SBK mutants die at the late embryonic stage. Some chicks can hatch with no assistance, but almost all die around 3 days of age. However, a part of the SBK individuals (5.3%, 8/151) reach sexual maturity and can reproduce. Genetic analyses revealed that the SBK mutation is controlled by an autosomal recessive gene. The proposed gene symbol is sbk. The sbk gene is allelic to the previously reported stumpy-limb (sl) gene that expresses a somewhat similar phenotype to the SBK.

Hereditary multiple malformation (HMM), a new mutation of Japanese quail (Coturnix japonica), is controlled by an autosomal recessive gene. The proposed gene symbol for the mutant gene is hmm. The majority of the homozygotes die at the sixth day of incubation, and the remainder die at various stages by 15 days of incubation. The homozygotes surviving to the late embryonic stage have greatly shortened lower and upper beaks that are set apart and show an early embryo-like body shape, with feather buds but no plumules. Furthermore, they show syndactylous polydactyly in both fore and hind limbs. In the abdomen of the homozygote, a part of the ventriculus, liver, and small intestine protrudes out of the umbilicus region. In the skeleton of the late HMM embryos, ossification is generally delayed and morphogenetic abnormalities are observed all over the body. This mutant seems to become a powerful animal model in the research fields for morphogenesis.

The aspect of the oogonia during their premitotic DNA synthesis and of the premeiocytes during their premeiotic DNA synthesis was studied in turtles by autoradiography, after injection of 3H-thymidine. As in the adult laying quail, the intrafollicular oocytes of the adult turtle go through three successive stages: prelampbrush, lampbrush and postlampbrush. During the prelampbrush and lampbrush stage two kinds of nucleoli exist: peripheral and central. In contrast to avian yolk, during its final rapid growth, no polyhedric protein yolk units were found in turtle yolk. As in the yellow yolk of quail, highly osmiophilic alcohol insoluble satellite yolk (egg oil) accumulates between the protein globular yolk of Pseudemys. Turtle yolk globules increase in volume by fusion. The penetration of peripherally assembled yolk in the turtle germinal disc is analogous to what we have described in the quail. Also in postlampbrush germinal discs subcortical ooplasmic organelles are present. Below the turtle germinal disc no structure comparable to the avian nucleus of Pander could be observed. No pyriform cells (as in squamate reptiles) and no pyriform-like cells (as in birds: Callebaut, 1991 b) were found in the chelonian ovarian granulosa layer. We could not demonstrate functional lacunoperitoneal communications via openings in the hilus ovarii of the turtle as is the case in birds.

Cytoarchitectural study indicated that the dorsal motor nucleus of the vagal nerve (nX) was formed by two subnuclei in a coronal section. One of them had large and round neurons, and occupied the dorsal part of the nX (Xd). The second one had small and oval neurons, and occupied the ventral part of the nX (Xv). The double labeling fluorescent method was performed to determine the organization of preganglionic neurons in the nX innervating different muscles of the quail stomach. Injections of nuclear yellow (NY) into the proventriculus, and of fast blue (FB) into the gizzard showed that there were no double-labeled neurons in the nX. NY- and FB-labeled neurons were found throughout the nX. After separate injections of NY and FB into both the cranioventral and caudodorsal thick muscles, and the craniodorsal and caudodorsal thin muscles, many NY- and FB-labeled neurons were distributed and intermingled in the middle two thirds of the nX. Considerable numbers of double-labeled neurons were also found at the middle level of the nX. There was no side-predominancy of the population of the preganglionic neurons innervating the quail stomach. These results show that, many neurons of both sides of the nX are separately innervating both the proventriculus and gizzard, and considerable numbers of single neurons of the nX also innervate a pair of thin or thick muscles with collateral axons.

The cytoarchitecture and distribution patterns of the vagal preganglionic neurons within the dorsal motor nucleus of the vagus nerve (DMNX) innervating the proventriculus and the gizzard of the Japanese quail were examined by Nissl staining and the horseradish peroxidase (HRP) method. A 30% solution of HRP was injected into nine different gastric regions: the ventral and dorsal parts of the proventriculus, the caudodorsal and cranioventral thick muscles, the craniodorsal and caudoventral thin muscles, and the pylorus, and the ventral and dorsal tendons of the gizzard. Nissl preparations showed that the DMNX is composed of two cell groups, the dorsal magnocellular and mediocellular subnucleus (Xd) and the ventral parvicellular subnucleus (Xv). After injection of HRP into the ventral and dorsal parts of the proventriculus, HRP-labeled cells were predominantly observed in the left and right DMNX, respectively. The rostrocaudal distribution patterns of HRP-labeled cells in the Xd and Xv were symmetric on the left and right sides. The distribution patterns of labeled cells following the injection of HRP into each region of the gizzard showed that there was very little difference in the number of neurons between the left and right DMNX, and no topographic localization was found in the Xd and Xv. The vagal preganglionic neurons projecting to the gizzard lay more caudal than the ones for the proventriculus. This study suggested topographic localization in the distribution patterns of the vagal preganglionic neurons innervating the proventriculus and the gizzard.

Cytochrome oxidase cytochemistry was used to unequivocally identify the spread of mitochondria during oogenesis in the adult Japanese quail. This enabled us to compare their distribution with the distribution in the Xenopus laevis oocyte (Tourte et al, 1984). In the quail the paranuclear mitochondrial cloud initially disperses homogeneously but afterwards segregates into 2 populations: (i) a population localized in the basophilic cortical layer (surrounding the vegetal pole); and (ii) clusters of mitochondria distributed geometrically around the germinal vesicle in the animal pole. The mitochondria in these clusters have a high cytochrome oxidase activity, which reflects their functionality. This perinuclear crown of mitochondrial clusters actively replicates mtDNA in both animal species and builds up most of the stock of the mitochondria in the full-grown oocyte. Our study suggests that the perinuclear group of mitochondria will segregate in the somatic cells of the future embryo, whilst the original subcortical group will become localized in the primordial germ cells.

The purpose of this investigation was to study the incidence and size of smooth muscle tumors in several Japanese quail lines and to report recent correlated changes in mature BW and egg production. Laying females from lines selected solely (HW) or partly (HW-HP; HW-LP) for increased 4-wk BW or for decreased 4-wk BW (LW) and from the corresponding randombred control (R1) were used. Lines HW-HP and HW-LP were sublines of Line HW in which males were selected for increased 4-wk BW and females were selected for high or low level of total plasma phosphorus, respectively. Laying hens were examined for the presence of smooth muscle tumors after about 170 d of egg production (240 d of age). During Generations 19 through 26, mature BW was increasing in the HW line and decreasing in the LW line. Selection for either increased or decreased 4-wk BW resulted in decreased egg production, but the only significant change with generations was a decrease of 2.7 eggs per hen for a 120-d laying period in the LW line. Frequency and weight of the smooth muscle tumors were greater for females from the large-bodied lines than females from Line R1. No tumors were detected in LW females. Based on the linear regression of response on generations, tumor frequency was increasing in Line HW-LP but tumor weight was decreasing in this line. Tumor weight was increasing in the HW line. No other changes in tumor frequency or size were noted across generations. Weight of the tumors was not correlated with egg production. The presence of tumors did not seem to affect mortality during the laying period. The Japanese quail lines may serve as a useful animal model for the study of smooth muscle tumors in humans, chickens, and turkeys.

The axial mesoderm of the anterior head region was investigated in young chick and quail embryos by light and electron microscopy. Semithin sections showed that the axial head mesoderm consists of the head process and prechordal mesoderm. At the anterior end of the prechordal mesoderm, a group of columnar epithelial cells formed a pit-like structure. The bases of these columnar cells extended to the neural plate, thus limiting the prechordal mesoderm anteriorly. The cells lining the pit-like structure at its anterior end joined a cell accumulation made up of cells of mesenchymal character. Electron microscopy revealed that the columnar cells forming the pit-like structure were covered by a basal lamina which was discontinuous on its anterior aspect. No basal lamina was recognisable between the columnar epithelial cells and mesenchymal cells joining them anteriorly. The columnar epithelial cells bordering the prechordal mesoderm anteriorly were therefore assumed to be part of the endodermal germ layer. In agreement with the findings of other authors, it is proposed to term these axially located columnar cells of the endoderm the prechordal plate and to distinguish them from the prechordal mesoderm arising during gastrulation. For the mesenchymal cell accumulation anterior to the prechordal plate, participation in the formation of the prosencephalic mesenchyme is assumed. This implies that the definitive endodermal germ layer, like the ectodermal one represented by the neural crest, may also be able to contribute to mesenchyme formation in the head.