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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 adrenal glands are paired abdominal endocrine organs vital to the bird's health. The present research aimed to provide a comprehensive examination of the histological, ultrastructural, and immunohistochemical investigations of the adrenal gland in Japanese quail during the post hatching period. The current study was performed on 21 healthy Japanese quail chicks at different post hatching periods. Our results showed the adrenal gland is surrounded by a connective tissue capsule, which consists of dense collagen fibers containing large blood vessels, chromaffin cells, autonomic ganglia, fibroblasts, and migrating Schwann cells. The zonation of the adrenal gland is composed of a subcapsular layer, a peripheral zone, and a central zone, which gets more pronounced with age. At the ultrastructural level, the interrenal cells take the steroid-secreting cells characters; they have varying amounts of lipid droplets and abundant mitochondria. Adrenal medullary chromaffin cells showed positive immunoreactivity to the NSE. With increasing age, the chromaffin tissue's Sox10 immunoreactivity increased. β-catenin is expressed within the plasmalemma and the cytoplasm of the interrenal and chromaffin cells and its reactivity increased with age, especially in the chromaffin cells. Our results indicate the adrenal gland undergoes significant morphological changes during the postnatal life. Overall, the postnatal period is an important time for the development and maturation of the adrenal glands., (© 2023 Wiley Periodicals LLC.)

The avian embryo has been used as a model system for more than a century and has led to fundamental understanding of vertebrate development. One of the strengths of this model system is that the effect of, and interaction among, tissues can be directly assessed in chimeric embryos. We have previously shown that signals from the forebrain contribute to facial morphogenesis by regulating the shape of the expression domain of Sonic hedgehog (SHH) in the Frontonasal Ectodermal Zone (FEZ). In this article, the method of generating the forebrain chimeras and provide illustrations of the outcomes of these experiments is described.

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.

Zinc plays an important role in the regulation of insulin-like growth factor-I (IGF-I). IGF system, in turn, has a key role in the development and functions of the reproductive organs. This research was performed to investigate the effects of different sources of zinc on IGF-I gene expression and testicular development in pre-pubertal male Japanese quail. A total of 512 unsexed day-old Japanese quail chicks were randomly divided into 16 groups (4 dietary treatments × 4 replicates) and kept for 35 days. The control group diet was not supplemented with zinc whereas the diets of three groups were supplemented with 25 mg kg -1 zinc oxide (ZnO), zinc oxide nanoparticle (ZnON), and zinc-methionine (Zn-Met). On days 28 and 35, one birds from each subgroup were weighed, bled, and euthanized to evaluate gonado-somatic index (GSI), testicular histology, serum testosterone concentration, cloacal gland index (CGI), and the testicular IGF family gene expression. The results showed that GSI was higher in ZnON (2.307) than control (1.619) on day 35 (P < .05). Germinal epithelium thickness was higher in ZnON (78.88 μm) and Zn-Met (79.73 μm) than control (67.73 μm) on day 35 (P < .05). On day 35, the testosterone concentration was lowest in the control (5.830 ng/ml, P < .05). The CGI of 35-day-old birds was higher in Zn-Met (411.28) than the control (307.59, P < .05). IGF-IR mRNA expression was highest in Zn-Met group on day 28. Therefore, supplementation of diet with Zn-methionine is superior to other sources of zinc for diet supplementation in immature Japanese quail., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

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.)

In this study, 600 1-day-old Japanese quail chicks (Coturnix coturnix japonica) were used to investigate the effects of bacteriocin and organic acids on performance and intestinal histomorphology and microbiology. Chicks were allocated to 6 groups, i.e., control, Bac150 (150 mg/kg bacteriocin), Bac300 (300 mg/kg bacteriocin), OA (3 g/kg organic acid blend), Bac150+OA (150 mg/kg bacteriocin + 3 g/kg organic acid blend), and Bac300+OA (300 mg/kg bacteriocin + 3 g/kg organic acid blend) group. The trial lasted 35 days. At the end of the trial, a statistical increase was not observed in the performance parameters of chicks with feed additives. However, 300 mg/kg bacteriocin + 3 g/kg organic acid supplementation given together has been found to have more positive effects on intestinal microbiology and histomorphology (P < 0.05). Consequently, it is understood that the use of these feed additives together will achieve better results.

Avian heads are characterized as having two extensive air-filled systems lined with epithelia; the paranasal and paratympanic sinuses. Many diverticula derived from the paratympanic sinus system are known to reticulate with each other to form a single merged pneumatic space within the adult braincase. However, the development of these complex branching and reticulating epithelia has not been examined in detail. In this study, we describe the comprehensive developmental pattern of the paratympanic sinus and its associated soft tissues in a model bird, Japanese quail (Coturnix japonica). The data are derived from three-dimensional reconstructions based on histological sections and soft tissue enhanced micro-CT data. Those data provide the foundation of the complex hierarchical developmental pattern of the paratympanic sinus system. Moreover, associations with other tissues help establish key morphologies that identify each pneumatic entity. This study clarifies the developmental relationships of the ventral portions of the paratympanic sinus system, the siphoneal diverticulum and marginal sinus, based on the ligaments associated with the Eustachian tube. In addition, detailed histological pneumatic morphologies reveal hitherto unknown epithelial diversity, which may be indicative of equally complex developmental processes. We use the pneumatization of the quadrate as an example to support a close relationship with vascular growth and pneumatic epithelia invasion into ossified bone. We confirm pneumatic diverticula never enter into cartilages, possibly due to the absence of vasculature in these tissues. Lastly, we use the concept of a morphogenetic tree as a tool to help present the complex developmental pattern of the paratympanic sinus system and apply it toward inferring pneumatic morphologies in a nonavian theropod braincase., (© 2019 Wiley Periodicals, Inc.)

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.)

The health of oviduct circulation is very important for normal egg production. The present work describes the histology and histochemistry of vessels of different types on the oviduct of quail. Arteria, venae and lymphatics of the oviduct were described clearly. In addition, special vascular elements were observed presenting circular, longitudinal and oblique smooth muscle fibres on the blood vessel wall. Glomus cells were observed at typical glomus vessels, atypical glomus vessels and on the wall of some of arteria and arteriolae. Also, spirally oriented blood vessels were observed. Dark brown pigment was detected in the wall of arteria, venae, lymphatics and the special types of blood vessels., (© 2019 Blackwell Verlag GmbH.)

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.

The intestinal physiology and mechanisms involved in nutrient transport are not well established in quails (Coturnix coturnix japonica). The present study assessed the growth performance, morphological development, duodenal density and the expression of Sglt1 and Glut2 of female Japanese quails from 1 to 49 days of age. The three small intestine segments were sampled weekly from 1 to 49 days of age to evaluate villus height, crypt depth and villus: crypt ratio, and goblet cell counts. Scanning electronic microscopy was used to determine duodenal villus density, and real-time polymerase chain reaction (qPCR) was used to study the sodium/glucose cotransporter-1 Sglt1 and glucose transporter Glut2 in the jejunum. Villus height and crypt depth in the duodenum, jejunum and ileum increased with age until 42 and 49 days of age (P < 0.001), and regression analysis evidenced a quadratic effect (P < 0.0001), indicating increasing values to a maximum and then a decrease afterwards. Goblet cell counts increased (P < 0.001) in duodenum, jejunum and ileum from 1 to 42 days, decreasing at 49 days, which was also corroborated by the regression analysis. Villus density in the duodenum was greater in the first week, decreased with age and increased again at 42 days, probably due to the proximity with egg production onset. The expression of Sglt1 and Glut2 mRNA in the jejunum varied with age. In conclusion, the intestinal mucosa of female Japanese quail developed morphologically until 42days and functionally until earlier ages, indicating an adaptation to the exogenous diet during the first weeks of life.

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 melanocortin 1 receptor (MC1R) gene was investigated as a candidate for plumage variations in Chinese painted quail, Coturnix chinensis. Four silent and two missense nucleotide polymorphisms were identified. The correspondent amino acid changes, p.Glu92Lys and p.Pro292Leu, were found in Blue Face and Red Breasted animals respectively. Blue Face is a melanic phenotype similar to the co-dominant Extended Brown of Japanese quail, and both share the p.Glu92Lys mutation. The association of p.Pro292Leu with the recessive Red Breasted was confirmed in 23 animals from an experimental F2 cross., (© 2018 Stichting International Foundation for Animal Genetics.)

1. Particle size reductions of fibre-rich materials alter structure, functional and digestive properties. To determine the effects of using fibre as an additive in Japanese quail rations on performance and gut physiology, a trial using micronised wheat fibre (MWF) at levels of 0.0, 5, 10 and 15 g/kg in feed was conducted. 2. Growth rate and feed efficiency were significantly improved when diets contained MWF while feed intake was not affected by levels of the fibre. As MWF content increased, the relative weight of gizzard and gastrointestinal tract (GIT) significantly increased whereas liver relative weight significantly decreased. 3. MWF inclusion significantly increased relative length of gut segments, villi height, villus thickness, the villi height to crypt depth proportion in jejunum and ileum and the number of goblet cells in different parts of intestine. 4. Tibia weight, length and ash content were increased linearly with rising MWF inclusion. Litter moisture was affected by MWF inclusions in a quadratic manner. The colony forming unit (CFU/g) of Streptococci spp. in ileal digesta was decreased with increasing MWF inclusion levels in the diet. 5. In conclusion, MWF can be used as a feed additive in quail diets and its inclusion in feed resulted in better performance, beneficial changes in intestinal microbial counts and improvements in small intestine morphology.

The role of thecal glands in the ovary of birds remains controversial. Using transmission electron microscopy and immunohistochemistry, immunohistochemical localisation of cyclooxygenase I and II (COX-1 and COX-2), oestrogen receptor α and β (ER-α and ER-β), androgen receptor (AR) and progesterone receptor (PR), a detailed analysis of the thecal glands was performed. Our ultrastructural studies revealed that the thecal glands of the quail ovary consist of 2 cell types, steroid-producing cells (SPCs) and enclosing cells (ENCs). The SPCs are large, light cells containing a varying number of lipid droplets. Their cytoplasm is characterised by a large amount of smooth endoplasmic reticulum. The ENCs are always located at the periphery of the gland. Some ENCs contain an abundant number of microfilaments, but lipid droplets and dense bodies were rare. Within 1 gland, SPCs with distinct COX-2 immunostaining were interspersed between usually larger numbers of moderately COX-2-positive cells. A completely different staining pattern was observed for COX-1, where the cytoplasm of the ENCs was distinctly immunopositive. The SPCs stained only weakly with antibodies to COX-1. The thecal glands showed distinct reactions for ER-β but only a weak to negative one for ER-α, PR, and AR. Our immunohistochemical and ultrastructural data support our hypothesis that the thecal glands of the quail are involved in steroid hormone and prostaglandin synthesis. The prostaglandins secreted by the thecal glands probably contribute to the ovulation of the follicle first in the hierarchy., (© 2018 S. Karger AG, Basel.)

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.)

In order to study the effect of specific phase relation of neural oscillations on reproductive regulation and the response of AVT (the avian homologue of mammalian AVP) the expression of AVT in the shell gland was monitored in sexually immature quail. In this study 3-week-old female Japanese quail were administered with serotonin precursor, 5-hydroxytryptophan followed by the dopamine precursor, l-dihydroxyphenylalanine at interval of 8h and 12h daily over a period of 13days. At thirty two days post treatment, a significant decrease in gonadal activity was seen in 8h quail although 12h quail exhibited an increase as compared to controls. A significant decrease in plasma estradiol level was noted in 8h quail while 12h exhibited no significant difference compared to controls. To address the relative roles of estrogen mediated action we also investigated estrogen receptor alpha (ER-α) expression and localization in the shell gland by visualizing it through confocal immuno-fluorescence microscopy. Results indicate increased expression of immunoreactive (ir)-AVT (myometrium), ir-ER-α (epithelial cells of endometrial region), along with significant increase in hypothalamic, plasma and shell gland AVT and a rapid increase in egg laying thus maintaining full breeding condition in 12h while low expression of ir-AVT and ir-ER-α was observed in 8h quail along with a significant decrease in hypothalamic, plasma and shell gland AVT with the suppression of gonads thereby stopping the egg-laying behaviour was noted. These findings not only suggest the modulation of gonadal development by changing the specific phase relation of neural oscillations but also demonstrate a parallel relation of AVT and gonadal activity in both conditions. It is concluded that the egg laying performance in response to AVT is regulated by the temporal phase relationship of neurotransmitters, and in part, this effect appears to be estrogen dependent., (Copyright © 2016 Elsevier Inc. All rights reserved.)

This study aims to enhance the anatomical knowledge of the ear of the adult quail (Coturnix coturnix) through the creation of a scaled 3D model utilizing data from micro-CT images. In addition, 17 annotated histological sections of the quail's ear are aligned to their 3D position in the model. The resulting anatomical atlas provides an intuitive insight into the 3D anatomy and can be used for medical education. The model also allows measuring anatomical structures and can thus serve as reference for the quail's auricular anatomy and as a basis to evaluate clinical diagnostic imaging results., (© 2015 Blackwell Verlag GmbH.)

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.)

Aim: To compare the histological, morphological and the biophysical measurements between hen and quail corneas, in order to determine which of them were better suited for use as an animal model for research into corneal refractive surgery., Material and Methods: A study was performed using the biophysical measurements of the cornea (curvature, thickness, refraction, and axial length) of 20 animals (10 hens and 10 quails). The corneas were then prepared for histological analysis under microscopy light., Results: The analysis showed that both groups have the same number of corneal layers as the human cornea and with an evident Bowman's layer. The thickness of the hen cornea and axial length of the eye, 225.3±18.4μm and 12.8±0.25mm, respectively, were larger than that of the quail (P<.01 and P<.001, respectively). The radius of curvature for the hen central cornea, 3.65±0.08mm, was greater than that for the quail (P<.001), but the refractive power of each cornea was similar. The proportion of total corneal thickness of the hen stroma, 82.6%, was more similar to that of the human than was the quail stroma, 72.5%. Within the hen stroma, the density of keratocytes, 8.57±1.49 per 5,000μm(2), was about half that in the quail stroma (P<.005)., Conclusions: Because of the large size of the hen cornea, the stromal thickness and proportional similarity of the corneal layers with human cornea, the hen maybe better than the quail as an alternative species suitable for use in studies of corneal refractive surgery., (Copyright © 2016 Sociedad Española de Oftalmología. Published by Elsevier España, S.L.U. All rights reserved.)

Artificial lights are essential for controlling the reproductive tract development of birds during puberty and therefore influence reproductive quality. The aim of this study was to evaluate the effect of different light sources on reproductive anatomic and physiological characteristics of female Japanese quail (Coturnix coturnix japonica). A total of 270 birds from one day of age were housed in a masonry shed divided into six rooms with light isolation. Each room was equipped with a different type of light bulb and contained seven cages with five birds in each. The light bulbs tested were: incandescent; compact fluorescent; and light-emitting diode (LED) in the colors white, blue, red and green. The experimental design was completely randomized with six treatments and seven replications of individual birds each. The anatomic and physiological condition of the birds was evaluated at four, eight and 12 weeks of age. The white LED bulb advanced (P<0.05) the sexual maturity by one week, resulted (P<0.05) in higher live weights and greater weight and relative percentage of ovarian stroma, oviduct and ovarian tissue at eight weeks of age. Higher plasma concentrations of estradiol and lipids were also observed (P<0.05) at eight weeks under the white LED bulb. At 12 weeks of age, the magnum and isthmus folding characteristics were better (P<0.05) with the red LED bulb. In conclusion, the photostimulation with the white LED bulb was more efficient at activating the reproductive cycle, hastening the onset of sexual maturity and increasing the development of reproductive organs after puberty., (Copyright © 2016 Elsevier B.V. All rights reserved.)

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).)

In birds, spectrum of egg white proteins deposited into the egg during its formation are thought to be essential maternal effects. Particularly, egg white lysozyme (LSM), exhibiting great between and within species variability, is considered to be essential for developing avian embryos due to its physiological, antimicrobial, and innate immune defense functions. However, there have been few studies investigating effects of LSM on early post-hatching phenotype, despite its broad physiological and protective role during embryogenesis. Here, we test how experimentally increased concentrations of egg white LSM affect hatchability in Japanese quail (Coturnix japonica) and chick phenotype immediately after hatching (particularly body weight, tarsus length, plasma LSM concentration, and plasma complement activity). Chicks from eggs with increased LSM concentration displayed reduced tarsus length compared to chicks from control eggs while hatchability, body weight and plasma LSM concentration were unaffected. It is worth noting that no effect of increased in ovo lysozyme on eggs hatchability could be related to pathogen-free environment during artificial incubation of experimental eggs causing minimal pressure on embryo viability. While tangible in vivo mechanisms during avian embryogenesis remain to be tested, our study is the first to document experimentally that egg white LSM appears to have growth-regulation role during embryo development, with possible underlying phenotypic consequences in the early post-hatching period in precocial birds., (© 2015 Wiley Periodicals, Inc.)

1. A study was conducted to evaluate the carcass composition of 1083 live birds using ultrasonic and morphological measurements and to estimate the genetic relationship between predicted and dissected carcass composition in Japanese quail. 2. Birds were reared for 35 d, and morphological measurements consisting of the length and width of breast muscle were recorded for all birds using a digital caliper. After slaughtering, the weight and percentage of carcass traits were measured on chilled carcasses. The dimensions of breast muscle were measured in 638 birds with an ultrasound scanner before slaughter at 35 d of age. 3. Genetic parameters from univariate and bivariate analyses were obtained by restricted maximum likelihood using ASREML software. 4. Genetic correlations between body weight at 35 d (BW35) and the percentage of carcass traits were low. Therefore, selection for BW35 may not effectively improve the yield of carcass components in Japanese quail. 5. High genetic correlations between carcass traits and ultrasonic measurements compared to morphological measurements suggest that the ultrasonic technique is a better method to improve breast weight and yield in Japanese quail.

We examined the effect of an abrupt change in diet fibre content on the feed intake, gastrointestinal morphology and utilisation of gastroliths by a small (ca. 40 g body mass) herbivorous bird, the King Quail (Coturnix chinensis). King Quail were acclimated for 14 days on a low-fibre (LF) pullet starter diet. Following acclimation, half the quail population was immediately switched to a 23% wood-shaving diluted high-fibre (HF) diet for a further 14 days. Contrary to expectations, we found no differences in feed intake, gut morphology or gastrolith mass between the LF- and HF-fed quail. However, when switched from the LF to HF diet, the quail commenced feed-sorting behaviours that permitted HF-fed animals to maintain body condition (mass, abdominal fat mass) without adjustments to intestinal organ sizes or gastrolith mass. Feed sorting was initiated only after exposure to the HF diet, which corresponded with an immediate reduction in food intake, suggesting that the sorting behaviour was cued by a physiological challenge associated with the HF diet. This challenge apparently induced preferential sorting behaviour and was possibly due to abrupt changes in the rate of food passage, impacting satiation or other internal cues.

The purpose of this study was to identify genomic regions, quantitative trait loci (QTL), affecting carcass traits on chromosome 1 in an F2 population of Japanese quail. For this purpose, two white and wild strains of Japanese quail (16 birds) were crossed reciprocally and F1 generation (34 birds) was created. The F2 generation was produced by intercrossing of the F1 birds. Phenotypic data including carcass weight, internal organs and carcass parts were collected on F2 animals (422 birds). The total mapping population (472 birds) was genotyped for 8 microsatellite markers on chromosome 1. QTL analysis was performed with interval mapping method applying the line-cross model. Significant QTL were identified for breast weight at 0 (P < 0.01), 172 (P < 0.05) and 206 (P < 0.01), carcass weight at 91 (P < 0.05), carcass fatness at 0 (P < 0.01), pre-stomach weight at 206 (P < 0.01) and uropygial weight gland at 197 (P < 0.01) cM on chromosome 1. There was also evidence for imprinted QTL affecting breast weight (P < 0.01) on chromosome 1. The proportion of the F2 phenotypic variation explained by the significant additive, dominance and imprinted QTL effects ranged from 1.0 to 7.3%, 1.2 to 3.3% and 1.4 to 2.2%, respectively.

This study describes the distribution of vimentin, desmin, smooth muscle actin (SMA) and laminin in the oviduct of the immature and mature Japanese quail. The cytoskeletal proteins vimentin, desmin and SMA have been shown to be involved in cellular support, differentiation, migration and contractility. Laminin is a major component of basement membranes. Luminal epithelia in the infundibular and magnal regions of immature and mature birds exhibited strong vimentin immunoreactivity. Luminal epithelial cells exhibiting strong vimentin immunoreactivity were present in the isthmus and shell gland regions of only mature quails. Infundibular glandular grooves displayed strong vimentin immunostaining. In contrast, the glandular epithelia of the magnum, isthmus and shell gland were vimentin immunonegative. Fibroblasts and vascular endothelial cells in the lamina propria of the oviductal regions studied exhibited strong vimentin immunostaining. Smooth muscle cells forming the tunica muscularis and vascular tunica media displayed strong desmin and SMA immunostaining. Strong laminin immunostaining was demonstrated in the basement membranes associated with smooth muscle cells, as well as in the basement membranes underlying the luminal and glandular epithelia. In conclusion, this study has shown that the immunolocalization of desmin, SMA and laminin in the oviduct of the Japanese quail is similar to that in the domestic fowl. However, differences in the immunoexpression of vimentin in the LE of the two avian species were shown to exist. In addition, the study has shown that the immunolocalization of vimentin in the Japanese quail varies depending on the oviductal region, as well as the developmental stage of the oviduct., (© 2013 Blackwell Verlag GmbH.)

1. The objectives of the present study were to estimate heritability and genetic correlations for feed efficiency and body weight (BW) in Japanese quail. 2. Recorded traits during different weeks of the growing period were BW from hatch to 35 d, feed intake (FI), feed conversion ratio (FCR) and residual feed intake (RFI) from hatch to 28 d of age. 3. Genetic parameters were estimated by restricted maximum likelihood method using ASREML software. The results showed that heritability estimates for BW ranged from 0.11 to 0.22, and maternal permanent environmental effect was the highest at hatch (0.45). FCR, RFI and FI showed moderate heritabilities ranging from 0.13 to 0.40. 4.Genetic correlations of BW28 with FI0-28 (0.88) and RFI0-28 (0.1) and genetic correlation of FI0-28 with FCR0-28 (0.13) and RFI0-28 (0.52) were positive. A negative genetic correlation was found between BW28 and FCR0-28 (-0.49). There was a high positive genetic correlation (0.67) between RFI0-28 and FCR0-28. 5. In conclusion, selection for increased BW and reduced FI in a selection index could be recommended to improve feed efficiency traits including FCR and RFI in Japanese quail.

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.

Brain structures related to reproduction are thought to depend on the action of gonadal steroids acting either during early life (organizing irreversible effects) or adulthood (activating transient effects). More recently puberty has become a focus of attention and it was demonstrated that action of sex steroid hormones at this time plays a critical role in the final organization of brain and behavior. We studied by BrdU immunohistochemistry the ontogeny from hatching to sexual maturity of a previously identified cell population in the preoptic area labeled by a BrdU injection at the end of embryonic period (E12) of sexual differentiation in male and female Japanese quail. After an initial increase between E12 and hatching, the density of BrdU-immunoreactive cells decreased until the beginning of puberty but then increased again during sexual maturation in the caudal preoptic area specifically. Divisions of these cells took place in the brain parenchyma as indicated by the large numbers of pairs of labeled cells. No sex difference affecting these processes could be detected at any stage of development. Large numbers of new cells thus arise around puberty in the caudal preoptic area and presumably contribute to the reorganization of this structure that precedes the emergence of adult reproductive behaviors., (Copyright © 2013 Elsevier B.V. All rights reserved.)

The sexually dimorphic medial preoptic nucleus (POM) in Japanese quail has for many years been the focus of intensive investigations into its role in reproductive behavior. The present study delineates a sequence of descending pathways that finally reach sacral levels of the spinal cord housing motor neurons innervating cloacal muscles involved in reproductive behavior. We first retrogradely labeled the motor neurons innervating the large cloacal sphincter muscle (mSC) that forms part of the foam gland complex (Seiwert and Adkins-Regan [1998] Brain Behav Evol 52:61-80) and then putative premotor nuclei in the brainstem, one of which was nucleus retroambigualis (RAm) in the caudal medulla. Anterograde tracing from RAm defined a bulbospinal pathway, terminations of which overlapped the distribution of mSC motor neurons and their extensive dorsally directed dendrites. Descending input to RAm arose from an extensive dorsomedial nucleus of the intercollicular complex (DM-ICo), electrical stimulation of which drove vocalizations. POM neurons were retrogradely labeled by injections of tracer into DM-ICo, but POM projections largely surrounded DM, rather than penetrated it. Thus, although a POM projection to ICo was shown, a POM projection to DM must be inferred. Nevertheless, the sequence of projections in the male quail from POM to cloacal motor neurons strongly resembles that in rats, cats, and monkeys for the control of reproductive behavior, as largely defined by Holstege et al. ([1997], Neuroscience 80:587-598)., (Copyright © 2012 Wiley Periodicals, Inc.)

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.

1. The genetic architecture of the avian uncoupling protein (avUCP) was investigated and the relationship between avUCP gene expression and the amount of abdominal fat of Japanese quail was determined by quantitative real-time PCR. 2. The Japanese quail avUCP gene consists of six exons and five introns. Sequences of nucleotides and amino acids were 94·6% and 86·0% identical to those of the chicken avUCP gene, and phylogenetic analysis showed that the Japanese quail avUCP gene consists of the same clusters as the chicken and turkey avUCP. 3. Expression of the avUCP gene was significantly higher in the Pectoralis major (1·28 ± 0·24) than in the Biceps femoris (0·63 ± 0·14). 4. A positive correlation coefficient between the avUCP gene expression in the Pectoralis major and Biceps femoris was observed (r = 0·79, P = 0·02), whereas a negative correlation coefficient was observed between the abdominal fat percentage (AFP) and gene expression in both the Pectoralis major (r = -0·82, P = 0·01) and Biceps femoris (r = -0·61, P = 0·11). 5. The avUCP gene was associated with the accumulation of abdominal fat in Japanese quail and it was concluded that modulation of avUCP gene expression could be utilised to control abdominal fat accumulation in poultry.

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).

In a recent study (Comp. Biochem. Physiol. B. (2010)155: 301-308) we reported that the fatty acids (FA) of the avian (7 species) total lung phospholipids (PL) (i.e. lung parenchyma and surfactant together) provide allometric properties. To test whether this allometric scaling also occurs in either of the above components, in six gallinaceous species, in a body weight range from 150 g (Japanese quail, Coturnix coturnix japonica) to 19 kg (turkey, Meleagris gallopavo) the PL FA composition (mol%) was determined in the pulmonary surfactant, in native and in thoroughly lavaged lungs (referred to as lung parenchyma). In all three components docosahexaenoic acid (DHA) showed significant and negative allometric scaling (B = -0.056, -0.17 and -0.1, respectively). Surfactant PLs provided further negative allometry for palmitic acid and the opposite was found for palmitoleate and arachidonate. In the lung parenchymal PLs increasing body weight was matched with shorter chain FAs (average FA chain length) and competing n6 and n3 end-product fatty acids (positive allometry for arachidonic acid and negative for DHA). Negative allometric scaling was found for the tissue malondialdehyde concentration in the native and lavaged lungs (B = -0.1582 and -0.1594, respectively). In these tissues strong correlation was found between the MDA concentration and DHA proportion (r = 0.439 and 0.679, respectively), denoting the role of DHA in shaping the allometric properties and influencing the extent of in vivo lipid peroxidation of membrane lipids in fowl lungs.

The adult male Japanese quail has a well developed cloacal gland that produces meringue-like white foam. The physiological significance of the cloacal gland and its foam is still unclear. Therefore, we conducted two experiments to establish the functional role of the cloacal gland and its foam in natural mating and oviducal sperm transport. In the first experiment, artificial insemination of equal numbers of spermatozoa diluted in foam extract and normal saline once in a week were used to determine the role of foam in sperm transport in the female oviduct. After artificial insemination, eggs were collected to measure fertility, the duration of the fertile period, sperm holes and attached spermatozoa in the perivitelline membrane. Higher (P<0.05) fertility and greater duration of the fertile period were observed when semen was inseminated along with foam extract compared with normal saline. Further, the sperm holes and trapped spermatozoa in the perivitelline membrane were also higher (P<0.05) in the presence of foam extract. In the second experiment, two males with bigger and smaller cloacal gland areas were allowed to mate with a female. The mating attempts of males with larger cloacal gland were more successful (P<0.05) than males with smaller cloacal glands. Our results indicated that cloacal foam improves sperm transport in the female oviduct and that males with larger cloacal gland areas are preferred during mating.

The avian inner perivitelline layer (IPVL), a homologous structure to the mammalian zona pellucida, is deposited between the granulosa cells and the oocyte cell membrane during folliculogenesis. In this glycohistochemical study, a panel of fluorescein isothiocyanate (FITC)-labelled lectins was used to characterise and localise the oligosaccharide sequences of the IPVL glycoproteins at different stages of follicular development in the quail ovary. Deacetylation and sialidase digestion were also performed prior to lectin cytochemistry. Contrary to mammals, where the topographical distribution of these carbohydrates is not uniformly distributed throughout the zona pellucida, indicating the regionalisation of oligosaccharide chains, our results demonstrated a homogenous lectin staining of the comparatively thin IPVL. We also found variations in the presence and distribution of the carbohydrate residues in the IPVL during different stages of follicular growth. The IPVL of pre-vitelline follicles distinctly stains with WGA, sWGA and SBA, demonstrating the presence of D-GlcNAc, Neu5Ac and α-D-GalNac in the glycoproteins of the forming IPVL. No staining was found with ConA (specific for α-D-Man, α-D-Glc), LCA (α-D-Man, α-D-Glc), PNA (β-D-Gal-(1-3)-D-GalNAc, VAA (Gal), DBA (α-D-GalNAc(1-3)-GalNAc and UEA-I (α-L-Fuc). With continuing follicular growth of the oocyte and the follicle, this staining pattern changed. LCA and PNA-staining in the IPVL became distinctly positive. As the IPVL of immature oocytes distinctly stains with WGA/sWGA-FITC, but spermatozoa do not bind to immature zona, it appears questionable that carbohydrate residues detected by WGA/sWGA play a major role in sperm-IPVL binding, as suggested in previous investigations., (© 2011 Blackwell Verlag GmbH.)

Traditionally, our understanding of developmental biology has been based on the fixation and study of embryonic samples. Detailed microscopic scrutiny of static specimens at varying ages allowed for anatomical assessment of tissue development. The advent of confocal and two-photon excitation (2PE) microscopy enables researchers to acquire volumetric images in three dimensions (x, y, and z) plus time (t). Here, we present techniques for acquisition and analysis of three-dimensional (3D) time-lapse data. Both confocal microscopy and 2PE microscopy techniques are used. Data processing for tiled image stitching and time-lapse analysis is also discussed. The development of a transgenic Japanese quail system, as discussed here, has provided an embryonic model that is more easily accessible than mammalian models and more efficient to breed than the classic avian model, the chicken.

Traditionally, our understanding of developmental biology has been based on the fixation and study of embryonic samples. Detailed microscopic scrutiny of static specimens at varying ages allowed for anatomical assessment of tissue development. The advent of confocal and two-photon excitation (2PE) microscopy enables researchers to acquire volumetric images in three dimensions (x, y, and z) plus time (t). The development of transgenic Japanese quail has provided an embryonic model system that is more easily accessible than mammalian models and more efficient to breed than the classic avian model, the chicken. This protocol describes the methods necessary to prepare transgenic quail embryos for imaging in vitro, and for acquiring, processing, and analyzing three-dimensional (3D) time-lapse images.

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.

Adult male quail show high levels of aromatase activity in the preoptic area-hypothalamus (POA-HYP), which parallels the high number of aromatase-immunoreactive cells and elevated mRNA concentrations detected in this brain region by in situ hybridisation. Interestingly, females display considerably lower aromatase activity than males but have almost equal numbers of aromatase-immunoreactive cells and express similar levels of aromatase mRNA. Aromatase activity in the male POA-HYP can be rapidly regulated by calcium-dependent phosphorylations, in the absence of changes in enzyme concentration. In the present study, we investigated whether aromatase activity is differentially regulated by phosphorylations in males and females. A linear increase in accumulation of aromatisation products was observed in both sexes as a function of time but the rate of conversion was slower in females. Saturation analysis confirmed the lower maximum velocities (V(max) ) in females but indicated a similar affinity (K(m) ) in both sexes. Aromatase activity in females reacted differentially to manipulations of intracellular calcium. In particular, chelating calcium with ethylene glycol tetraacetic acid (EGTA) resulted in a larger increase of enzymatic activity in males than in females, especially in the presence of ATP. A differential reaction to kinase inhibitors was also observed between males and females (i.e. a larger increase in aromatase activity in females than in males after exposure to specific inhibitors). These findings suggest that the nature of aromatase is conserved between the sexes, although the control of its activity by calcium appears to be different. Additional characterizations of intracellular calcium in both sexes would therefore be appropriate to better understand aromatase regulation., (© 2011 The Authors. Journal of Neuroendocrinology © 2011 Blackwell Publishing Ltd.)