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1. The E3 ubiquitin protein ligase 1 (WWP1) gene, the mutation of which causes muscular dystrophy in chickens, is expressed not only in the pectoral muscle, but also in a number of tissues such as the kidney. Therefore, this study examined some parameters related to kidney function in muscular dystrophic (MD) chickens. 2. Plasma osmolality, Na+ and K+ concentrations, aldosterone levels, and the expression of aquaporin (AQP) 2, AQP3, and α subunits of the amiloride-sensitive epithelial sodium channel (αENaC) were analysed in the kidneys of 5-week-old MD chickens and White Leghorn (WL) chickens under physiological conditions or after one day of water deprivation. 3. Plasma osmolality, Na+ concentrations, and plasma aldosterone levels were significantly higher in MD chickens than in WL chickens. αENaC mRNA expression levels were lower in MD chickens than in WL chickens. AQP2 and AQP3 mRNA expression levels were similar in the two strains of chickens. 4. Plasma osmolality correlated with aldosterone levels and AQP2 and αENaC mRNA levels in WL chickens. In MD chickens, plasma osmolality correlated with AQP2 mRNA levels, but not with plasma aldosterone or αENaC mRNA levels. 5. These results suggest that neither water reabsorption nor the expression of AQP2 and AQP3 is impaired in MD chickens and that a WWP1 gene mutation may or may not directly induce an abnormality in Na+-reabsorption in the kidneys of MD chickens, potentially through αENaC.

During early development in vertebrates, pluripotent cells are generated from the neural crest and migrate according to their presumptive fate. In birds and mammals, one of the progeny cells, melanoblasts, generally migrate through a dorsolateral route of the trunk region and differentiate to melanocytes. However, Silky is an exceptional chicken in which numerous melanoblasts travel via a ventral pathway and disperse into internal organs. Finally, these ectopic melanocytes induce heavy dermal and visceral melanization known as Fibromelanosis (Fm). To identify the genetic basis of this phenotype, we confirmed the mode of inheritance of Fm as autosomal dominant and then performed linkage analysis with microsatellite markers and sequence-tagged site markers. Using 85 backcross progeny from crossing Black Minorca chickens (BM-C) with F1 individuals between White Silky (WS) and BM-C Fm was located on 10.2–11.7 Mb of chicken chromosome 20. In addition, we noticed a DNA marker that all Silky chickens and the F1 individuals showed heterozygous genotyping patterns, suggesting gene duplication in the Fm region. By quantitative real-time PCR assay, Silky line-specific gene duplication was detected as an ∼130-kb interval. It contained five genes including endothelin 3 (EDN3), which encoded a potent mitogen for melanoblasts/melanocytes. EDN3 with another three of these duplicated genes in Silky chickens expressed almost twofold of those in BM-C. Present results strongly suggest that the increase of the expression levels resulting from the gene duplication in the Fm region is the trigger of hypermelanization in internal organs of Silky chickens.

Six polymorphic sites of the bovine prion protein gene (PRNP) were genotyped in 569 animals of Asian native cattle, Japanese breeds, purebred mythun (Bos frontalis), and mythun x cattle composite animals. At the 23-bp indel site, a deletion (23-) allele was a major allele in all populations except mythun. At the 12-bp indel site, an insertion (12+) allele was a major allele in all populations. The 14-bp indel site was polymorphic in all Asian native cattle. In the octapeptide repeat region, a six-repeat allele was a major allele in all populations, and 5/5 and 4/6 genotypes were detected in Japanese Black and Mongolian cattle and in mythun, respectively. Two nonsynonymous single nucleotide polymorphisms (SNPs) (K3T and S154N) were detected in Asian native cattle and mythun. Haplotype analysis using the genotypes of the six sites estimated 33 different haplotypes. The haplotype 23- 12- K 6 S 14+ was found in all populations.

The objective of the present study was to conduct the genetic characterization of nine experimental chicken lines based on multilocus microsatellite analysis. Commercial chicken lines were also analyzed in order to compare their levels of genetic uniformity with those of the experimental lines. In six experimental lines, more than 80% of genotyped loci showed fixed allele for all individuals in each line, whereas only 17.5% of genotyped loci were fixed in commercial lines, at the maximum. One of experimental lines (GSN/1) was categorized as a highly inbred line on the basis of all individuals having the same, single allele at every microsatellite locus. Genetic information obtained from the present study should be helpful for the utilization and management of experimental chicken resources.

Polymorphisms in the prion protein gene (PRNP) are known to be associated with transmissible spongiform encephalopathies in human, sheep and goats. There is tentative association between PRNP promoter polymorphism and bovine spongiform encephalopathy (BSE) susceptibility in cattle. In this study, we genotyped for six bovine PRNP polymorphic sites including a 23-bp indel in the promoter, a 12-bp indel in the intron 1, two nonsynonymous single nucleotide polymorphisms (SNPs), octapeptide repeats in the coding region and a 14-bp indel in the 3'-untranslated region in 178 animals representing Japanese Brown, Kuchinoshima feral, Mishima, Japanese Shorthorn and Holstein. In 64 Japanese Brown cattle, three indel sites were polymorphic. All of the six sites were monomorphic in Kuchinoshima. The 23-bp and 12-bp indel sites were polymorphic in Mishima cattle. The 23-bp and 14-bp indel sites were polymorphic in Japanese Shorthorn cattle. Both SNP sites were monomorphic in all cattle examined in this study. At the 23-bp indel site, the genotype frequencies of Japanese Brown and Holstein breeds were similar to that of BSE affected cattle. We estimated 12 different haplotypes from these genotypic data. A '23-12-K6S14+' haplotype was the major haplotype in all populations, whose frequencies ranged from 0.50 to 1.00.

The phylogenetic positions of the Bayanbulak sheep in China and the Sipsu sheep in Bhutan in the northern Asian sheep group were determined on the basis of allele frequency data for five informative and polymorphic loci of blood protein and nonproteins, such as transferrin (TF), arylesterase (ES), hemoglobin-beta (HB-beta), X-protein (XP), and potassium transport (KE), using different electrophoretic and ion-densitometric techniques. Based on Nei's genetic distance, clustering analysis by the UPGMA method showed that the Bayanbulak sheep is clustered in the northern Asian sheep group. Furthermore, the Bayanbulak sheep belongs to a subgroup containing the Khalkhas and Hu sheep of the Mongolian sheep group, which is distinguished from another subgroup of the small-tailed Han, Tan, Tong, and Wadi sheep. The Bayanbulak sheep was closest to the Hu sheep, despite a morphological difference in the fat deposits. In addition to these findings, the Sipsu sheep was verified to belong to the Baruwal sheep.

Histocompatibility was assessed in the RIR-Y8/NU, BL-E, YL, and WL-G chicken closed colonies by hemagglutination test using anti-red blood cell (RBC) antibodies (HT), skin transplantation test (STT), and formation of isohemagglutinins (FIHs) during STT. The YL individuals all showed the survival of skingrafts for more than 17 days with no FIHs in STT and no RBC antigenic variations in HT, indicating a histocompatible nature together with high homogeneity at serological loci. The BL-E as well as WL-G closed colonies were also found to be histocompatible in the STT with no FIHs, although the HT showed heterogeneities at serological locus/loci other than the B and C blood group loci which have significant effects on histocompatibility or FIHs in chicken. In the RIR-Y8/NU closed colonies, one individual in 6 reciprocal combinations of the STT showed early skingraft rejection with positive FIHs caused by different B locus alleles, and the HT suggested relatively high heterogeneities at the other serological loci too. The closed colonies of YL, BL-E, and WL-G will be useful avian materials for transplantation or related experiments, but RIR-Y8/NU needs further pedigree selection for serological homogeneity.

A genetic linkage map for Suncus murinus was previously constructed with 11 marker loci. In this study, we developed 172 new microsatellite and three RFLP markers, and re-constructed a new framework map by combining all markers. The new map comprises 42 markers that are distributed into 12 linkage groups, two of which are assigned to chromosomes, and spans 403.5 cM with an average inter-marker distance of 13.5 cM.

The musk shrew (Suncus murinus) is an insectivore species that inhabits tropical and subtropical Asia widely. To clarify the genetic relationship among wild musk shrew populations, we examined the electrophoretic variants of biparentally inherited genetic markers at 10 loci coding for eight blood proteins/enzymes in a total of 639 animals and compared the results obtained from the mitochondrial DNA data. The principal-component analysis performed using the allele frequency data revealed that the 17 populations could be divided into two major groups, a South Asian group and a Southeast Asian group that includes several island populations bound by Myanmar. The degrees of genetic divergence among populations were higher within the Southeast Asian group than within the South Asian group. This finding was incongruent with the mtDNA diversity. Analysis conducted at the individual level showed that a shrew from the central region in Myanmar that carries a South Asian type of mtDNA showed the electrophoretic variants specific to the Southeast Asian group, suggesting that this region is a contact zone between the two major groups.

Previous QTL studies have identified 24 QTLs for body weight and growth from 3 to 10 weeks after birth in an intersubspecific backcross mouse population between C57BL/6J and wild Mus musculus castaneus that has 60% of the body size of C57BL/6J. The castaneus allele at the most potent QTL (Pbwg1) on proximal chromosome 2 retards growth. In this study we have developed a congenic strain with a 44.1-Mb interval containing the castaneus allele at Pbwg1 by recurrent backcrossing to C57BL/6J. The congenic mouse developed was characterized by significantly higher body weight gain between 1 and 3 weeks of age and lower weight of white fat pads at 10 weeks of age than C57BL/6J. However, no clear difference in body weight at 1-10 weeks of age was observed between congenic and C57BL/6J strains. QTL analysis with 269 F(2) mice between the two strains did not identify any QTLs for body weight at 1, 3, 6, and 10 weeks of age, but it discovered eight closely linked QTLs affecting body weight gain from 1 to 3 weeks of age, lean body weight, weight of white fat pads, and body length within the Pbwg1 region. The castaneus alleles at all fat pad QTLs reduced the phenotypes, whereas at the remaining growth and body composition QTLs, they increased the trait values. These results illustrate that Pbwg1, which initially appeared to be a single locus, was resolved into several loci with opposite effects on the composition traits of overall body weight. This gives a reason for the loss of the Pbwg1 effect found in the original backcross population.

Objectives: This study aimed to develop a novel type 2 diabetes model designated the HND (Horio–Niki diabetic) mouse, by transferring diabetogenic genes from wild castaneus mice (Mus musculus castaneus) captured in the Philippines into laboratory mice (C57BL/6J:B6). Methods: Offspring from the cross between a wild male and a B6 female were backcrossed to the sire. One male backcross which exhibited fasting hyperglycemia was crossed with a B6 female to comprise the fundamental stock (F0). Thereafter, full-sib mating was performed, and mice with impaired glucose tolerance were selected and bred from the F2 generation. Characterization of the phenotype of HND mice and insulin release from their islets was evaluated with F12 generation males. Results: The male HND mice were lean, and spontaneously exhibited impaired glucose tolerance at a high incidence rate at 6 weeks of age. Their serum insulin levels in response to intraperitoneal glucose were markedly attenuated. However, glucose-induced insulin release from isolated HND islets was not affected. Notably, inhibition of glucose-induced insulin release by epinephrine was more pronounced in HND islets than in B6 islets. Moreover, in vivo treatment of HND mice with the α2-adrenergic receptor agonist clonidine resulted in marked hypoinsulinemic hyperglycemia. Conclusions: We suggest the HND mouse may be a distinctive and useful model for type 2 diabetes with impaired neural control of insulin secretion.

The FGS/Kist strain of mice, a new animal model for focal glomerulosclerosis (FGS) in humans, was previously established by recurrent selection for high proteinuria, which is a principal marker of FGS, from descendants of CBA/Nga and RFM/Nga strains. We performed a genome-wide scan for quantitative trait loci (QTLs) affecting proteinuria in a population of 356 backcross progeny derived from a cross between FGS/Kist and the standard normal strain, C57BL/6J. Five proteinuria QTLs (Ptnu1-5) were detected at the genome-wide 5% or less level. Ptnu1 and Ptnu2, located on Chromosomes (Chrs) 8 and 17, respectively, had main effects on proteinuria and also interacted epistatically with each other. However, Ptnu3 on Chr 9 and Ptnu4 and Ptnu5 both on Chr 15 had epistatic interaction effects only. Except for the epistatic interaction effect of Ptnu4 and Ptnu5, all alleles derived from FGS/Kist were responsible for the high proteinuria. These results indicated that the genetic control of proteinuria is complex and the identified QTLs may provide new insights into the pathogenesis of FGS in mice as well as in humans.

Avian circadian rhythms are regulated by a multiple oscillatory system consisting of the pineal, the suprachiasmatic nucleus (SCN) and the eye. In the present study, ontogeny of circadian clock in the pineal and the SCN of chick embryo was examined using Per2 expression as a marker. A daily rhythmicity of Per2 expression was first detectable at embryonic day (ED) 18 in the pineal and at ED 16 in the SCN under light-dark (LD) cycles. The amplitude of the rhythmicity increased during the development. In contrast, little expression was observed during the development in constant darkness. These results suggest that although circadian clock matures by the end of the embryonic life in chicken, LD cycles are required for the expression of the Per2.

The direct R-banding fluorescence in situ hybridization (FISH) method was used to map 18S-28S ribosomal RNA genes and 10 human cDNA clones on the chromosomes of the musk shrew (Suncus murinus). The chromosomal locations of 18S-28S ribosomal RNA genes were examined in the five laboratory lines and wild animals captured in the Philippines and Vietnam, and the genes were found on chromosomes 5, 6, 9, and 13 with geographic variation. The comparative mapping of 10 cDNA clones of human chromosome 1 demonstrated that human chromosome 1 consisted of at least three segments homologous to Suncus chromosomes (chromosomes 7, 10, and 14). This approach with the direct R-banding FISH method is useful for constructing comparative maps between human and insectivore species and for explicating the process of chromosomal rearrangements during the evolution of mammals.

In order to construct a chicken (Gallus gallus) cytogenetic map, we isolated 134 genomic DNA clones as new cytogenetic markers from a chicken cosmid DNA library, and mapped these clones to chicken chromosomes by fluorescence in situ hybridization. Forty-five and 89 out of 134 clones were localized to macrochromosomes and microchromosomes, respectively. The 45 clones, which localized to chicken macrochromosomes (Chromosomes 1–8 and the Z chromosome) were used for comparative mapping of Japanese quail (Coturnix japonica). The chromosome locations of the DNA clones and their gene orders in Japanese quail were quite similar to those of chicken, while Japanese quail differed from chicken in chromosomes 1, 2, 4 and 8. We specified the breakpoints of pericentric inversions in chromosomes 1 and 2 by adding mapping data of 13 functional genes using chicken cDNA clones. The presence of a pericentric inversion was also confirmed in chromosome 8. We speculate that more than two rearrangements are contained in the centromeric region of chromosome 4. All 30 clones that mapped to chicken microchromosomes also localized to Japanese quail microchromosomes, suggesting that chromosome homology is highly conserved between chicken and Japanese quail and that few chromosome rearrangements occurred in the evolution of the two species.

We performed a genome-wide quantitative trait locus (QTL) analysis of body weight at 10 weeks of age in a population of 321 intercross offspring from SM/J and A/J mice, progenitor strains of SMXA recombinant inbred strains. Interval mapping revealed two significant QTLs, Bwq3 (body weight QTL3) and Bwq4, on Chromosomes (Chrs) 8 and 18 respectively, and five suggestive QTLs on Chrs 2, 6, 7, 15 and 19. Bwq3 and Bwq4 explained 6% of the phenotypic variance. The SM/J alleles at both QTLs increased body weight, though the SM/J mouse was smaller than the A/J mouse. On the other hand, four of the five suggestive QTLs detected had male-specific effects on body weight and the remainder was female-specific. These suggestive QTLs explained 5-6% of the phenotypic variance and all the SM/J alleles decreased body weight.

A genome-wide scan for quantitative trait loci (QTLs) controlling body weight at 10 weeks after birth was carried out in a population of 387 intersubspecific backcross mice derived from a cross between C57BL/6J inbred mice (Mus musculus domesticus) and wild mice (M. m. castaneus) captured in the Philippines, in order to discover novel QTLs from the wild mice that have about 60% lower body weight than C57BL/6J. By interval mapping, we detected four QTLs: a highly significant QTL on Chromosome (Chr) 2, which was common in both sexes; two significant QTLs on Chr 13, one male-specific and the other female-specific; and a suggestive male-specific QTL on X Chr. By composite interval mapping, we confirmed the presence of the three QTLs on Chrs 2 and 13, but not of the male-specific X-linked QTL. The composite interval mapping analysis newly identified three QTLs: a significant male-specific QTL on Chr 11 and two highly significant female-specific QTLs on Chrs 9 and X. Individual QTLs explained 3.8-11.6% of the phenotypic variance, and all the QTL alleles derived from the wild mice decreased body weight. A two-way analysis of variance revealed a significant epistatic interaction between the Chr 2 QTL and the background marker locus D12Mit4 on Chr 12 only in males. The interaction effect unexpectedly increased body weight. The chromosomal region containing the Chr 2 QTL did not coincide with those of growth or fatness QTLs mapped in previous studies. These results suggest that a population of wild mice may play an important role as new sources of valuable QTLs.

Hereditary, persistent, right oviduct manifested in an inbred line (PNP/DO line) from the Fayoumi breed of chickens was investigated for form of expression and mode of inheritance. Females in the PNP/DO line have varying lengths of elongated right oviducts, besides the normal left ovary, and oviducts that generally possess, irrespective of their total length, regions similar to those normally observed in a left oviduct. Observations of embryos indicated that the existence of right oviduct in this line could be attributed to the slow regression of right Mullerian duct during the embryonic stage, and left-right asymmetry in female genital system is intrinsic in this line. Intracrosses of the PNP/DO line produced 93% of female embryos with persistent right Mullerian ducts at the next generation, and reciprocal crosses of the PNP/DO line and control strains produced 5 and 30% of female embryos with persistent right Mullerian ducts in the F1 and N2 generations, respectively. Mating results suggested that this mutant trait is controlled by two pairs of autosomal recessive genes with major effects and numerous loci that have minor effects. Thus, expression of this trait is due to the interaction of major loci and the background genotype.

The karyotype of the tamaraw (Bubalus mindorensis, 2n = 46) was investigated by RBG-banding technique and compared with those of the river and the swamp cytotypes of domestic water buffalo (B. bubalis). The tamaraw karyotype consisted of 6 submetacentric and 16 acrocentric autosome pairs (NAA = 56), and X and Y chromosomes. The RBG-banded karyotype of the three taxa had a high degree of homology, and the tamaraw karyotype could be explained by a Robertsonian translocation between chromosomes 7 and 15 and by a telomere-centromere tandem fusion between chromosomes 4p and 12 of the standardized river buffalo cytotype (2n = 50, NAA = 58). The buffalo satellite I and II DNAs were localized to the centromeric regions of all the tamaraw chromosomes. The biarmed chromosome 2 of the tamaraw resulting from the fusion between chromosomes 7 and 15 of the standard contained much larger amounts of the satellite I DNA than the other biarmed chromosomes, suggesting that this chromosome was formed by a relatively recent Robertsonian fusion. The (TTAGGG)n telomeric sequence was specifically localized to the telomeric region of all the buffalo chromosomes. The 18S + 28S rDNA was localized to the telomeric regions of the chromosomes 5p, 7, 19, 21, and 22 of the tamaraw and of their homologous chromosomes in the river and swamp buffalo cytotypes.

We discovered two mouse strains (SMXA-5 and SMXA-9) with hyperinsulinemia among the substrains and progenitor strains (SM/J and A/J) of the SMXA recombinant inbred (RI) strains, and characterized the two strains at 20 weeks of age. SMXA-5 (mean +/- S.E.M: 9.6 +/- 1.7 ng/ml) and SMXA-9 (7.7 +/- 1.3 ng/ml) males had higher serum immunoreactive insulin levels than SM/J (1.4 +/- 0.3 ng/ml) and A/J (1.1 +/- 0.1 ng/ml) males in the nonfasting condition. The hypoglycemic response to insulin at 30 min after injection was significantly less in SMXA-5 males than in SM/J mice. Glucose tolerance test revealed that the incidence of impaired glucose tolerant males was 58% (11/19) in SMXA-5 and 42% (10/24) in SMXA-9 strains, but none in SM/J and A/J strains. SMXA-5 (209 +/- 29 mg/dl) and SMXA-9 (235 +/- 31 mg/dl) had higher serum triglyceride levels than SM/J (126 +/- 14 mg/dl) and A/J (89 +/- 5 mg/dl) males in the nonfasting condition. Histologic examination revealed enlarged islets in the pancreas of hyperinsulinemic SMXA-5 male mice. Moreover, SMXA-5 and SMXA-9 mice exhibited mild obesity. SMXA-5 and SMXA-9 males were therefore characterized by hyperinsulinemia, impaired glucose tolerance, hypertriglyceridemia and mild obesity which resembled some of the phenotypes of human Syndrome X, although both progenitor strains were normal so far as we examined. Since the RI strains are a powerful tool to facilitate polygenic-trait analysis, SMXA-5 and SMXA-9 mice will be useful materials to investigate the genetic basis of complex diseases, and are possible new metabolic models in relation to hyperinsulinemia.

In the SMXA recombinant inbred (RI) strains, we measured body weight, blood insulin and lipid (triglyceride, total cholesterol and phospholipid) levels in each strain. In the five traits, mean values of substrains varied remarkably and showed a continuous spectrum of distribution, suggesting control by multiple genes at distinct loci for each trait. We also screened for quantitative trait loci (QTLs) involved in the five traits. Suggestive QTLs for body weight (Chromosomes 1 and 6), insulin (Chromosomes 1, 3, 10 and 17), triglyceride (Chromosomes 4 and 11) and phospholipid (Chromosome 18) levels were detected. The SMXA RI strains are unique tools for analyzing genetic factors that influence body weight, blood insulin and lipids levels.

The complete mitochondrial DNA (mtDNA) control region was cloned and sequenced in the musk shrew, Suncus murinus, Insectivora. The general aspect was similar to that found in other mammals. We have found in two locations of this region the presence of arrays of tandem repeats like those in other shrew species. One array was located in the left domain containing the termination-associated sequences (TAS) and the length of a copy was 77 bp. The other repeats were situated upstream from the recognition site for the end of H-strand replication in the right domain and were 20 bp long. The left halves of the control region containing the former repeats were sequenced and compared in several laboratory lines and wild animals from different localities, variations in copy number of repeated sequences were found both among individuals and within an individual. A comparative study of repeated sequences provides useful indication for the origin and evolution of tandem repeated sequences. Strand slippage and mispairing during replication of mtDNA with concerted manner is currently regarded as a dominant theory to account molecular mechanism for tandemly repeated sequences, and the pattern of sequence and length variation in our study supports this theory. Our results, however, suggest that the evolution of the repeated sequences containing the TAS in the musk shrew might go through the process of two steps; at the first step one complete repeated and several incomplete repeated sequences had reproduced in common ancestor of the shrew, and the second stage step-up of complete repeated sequences occurred with concerted evolution after differentiation into continental and insular groups.

We investigated an odontometrical difference in the mandibular molars (M1, M2, and M3) of two laboratory strains of the musk shrew (Suncus murinus) originating in Bangladesh (BAN strain) and Tokunoshima Island of Japan (TKU strain). We used skulls from two strains of shrews that were maintained under identical laboratory conditions. Mesiodistal and buccolingual crown diameters in the trigonid and talonid of the mandibular molars were measured with a measuring microscope, calibrated to 0.001 mm. The crown proportion was expressed by the crown indices calculated from the measurements. Size reduction was analyzed quantitatively according to the reduction index. All crown dimensions were significantly larger in BAN shrews than in TKU shrews (P < 0.01). Sexual differences were noted in the talonid dimensions, while interstrain differences were clearly evident in the trigonid dimensions. The crown indices in M1 showed the least interstrain difference of the three molars. The crown indices showed that TKU shrews had relatively larger buccolingual diameters and talonid diameters than BAN shrews, and the reduction indices showed that TKU shrews had relatively larger M2 and M3 than BAN shrews. To extract the variance components of tooth shape, a principal component analysis was performed after the variables were standardized. After Varimax rotation, each factor was interpreted. The first three factors accounted for 79.9% of all variances. The first component represented the mesiodistal crown proportion of the trigonid-to-talonid crown component. The second and third components represented the relative size of buccolingual diameters in the distal molars for M1. The principal component scores showed that TKU shrews had relatively larger talonids and distal molars than BAN shrews.

The EDS (early-onset diabetes in suncus) colony has been developed as a new closed breeding colony of the musk shrew (Suncus murinus, Insectivora) exhibiting a high incidence of spontaneous diabetes mellitus. We investigated the characteristic features of diabetic shrews in this colony. All diabetic shrews are characterized by glycosuria (Tes-tape value > or = 3+), hyperglycemia (23.3 +/- 0.8 mmol/l) and polyuria, and they were affected by the age of 3 months. Cumulative incidence (64.1% in males and 27.8% in females) was kept intact after the age of 3 months. The growth pattern of diabetic shrews was similar to that of non-diabetic shrews, and obesity was not consistent in diabetic shrews. The intraperioneal glucose tolerance test revealed both impaired glucose tolerance and impaired insulin secretion in diabetic shrews. Insulin sensitivity of diabetic shrews decreased in the intraperioneal insulin tolerance test. Neither severe hypertrophy nor lymphocytic infiltration was observed in pancreatic islets of diabetic shrews. These facts suggested that diabetic shrews in the EDS colony should be classified as early-onset non-insulin dependent diabetes mellitus (NIDDM) without obesity. Early-onset of severe hyperglycemia with impaired glucose tolerance is a distinctive character compared with other non-obese NIDDM models in rodents. We concluded that the diabetic shrews in the EDS colony are a new animal model of human NIDDM without obesity.

The mutation designated "open eyelids at birth" arose spontaneously in the BAN strain of the musk shrew (Suncus murinus). This is the first report on this kind of mutation in the shrew. Mating experiments suggested that the mutant character is controlled by an autosomal recessive gene with about 43% penetrance. The symbol oeb(open eyelids at birth) was proposed for the mutant gene. Affected shrews were fully viable and fertile. Phenotypically, the affected shrews were characterized by one or both eyelids open at birth. By 9 days of age, the exposed and dried eyeballs usually dropped off and became missing or sometimes looked microphthalmic. Except for the eye abnormality, the affected shrews showed no obvious external abnormalities. Light-microscopically, the affected shrews with missing eyes or microphthalmia-like eyes did not have complete eye structures, and only remnants of some eye tissue were observed. In the phenotypically normal oeb/oeb shrews with closed eyelids at birth, no histological eye abnormalities were noted. Thus, the mutant character observed may simply be caused by a failure of the eyelids to close.

Immunodetection of methicillin-resistant Staphylococcus aureus (MRSA) by conventional methods employing mammalian immunoglobulins has unknown detection limits, and often yields false-positive results because of the presence of S. aureus protein A, which binds the Fc region of mammalian IgG. In this study, a new PBP2a-specific chicken IgY antibody was developed in inbred and conventional chickens, and used for the detection of MRSA using whole cell lysate samples. Our results showed that this chicken IgY antibody minimized the side effects of protein A. Moreover, enzyme-linked immunosorbent assay and immunochromatography systems were used with a monoclonal and polyclonal anti-PBP2a IgY antibody, clearly differentiating MRSA from methicillin-sensitive S. aureus and other methicillin-sensitive Staphylococcus spp. The detection limit of the immunochromatography was 10(8) colony-forming units; therefore, 1 colony on an agar plate was adequate to distinguish MRSA from non-MRSA. The specificity and sensitivity of this assay were almost similar to that of a commercially available latex agglutination test; however, the procedure used in this study was less complicated. The entire detection procedure, including sample preparation, takes only 20 min and does not require special equipment. Therefore, the use of this IgY antibody as a new tool for the detection of MRSA is highly recommended.

Supraependymal fibers of the house musk shrew (Suncus murinus) were examined by conventional scanning electron microscopy (SEM), backscattered electron (BSE) imaging of enzyme immunohistochemistry and by immunotransmission electron microscopy in the dorsal part of the third ventricular wall. In this region, ependymal cells were not so heavily ciliated and conventional SEM studies showed two main categories of supraependymal fibers. The first type consisted of long fibers fasciculated which were distributed over the ventricular surface between the anterior commissure and the subfornical organ. The second category was a thin fiber which was observed on the ependymal luminal surface. Some of these fibers had varicoses or terminal-like swellings. This type of supraependymal fiber seemed to originate in the first type of fiber bundles. To confirm the nature and the distribution of serotonin-immunoreactive supraependymal fibers, BSE imaging using immunohistochemical reactions was used. Serotonin-immunoreactive structures were shown as highlighted structures by means of a backscattered electron mode. These investigations revealed that the majority of both types of supraependymal fibers observed by conventional SEM contained serotonin. A moderate number of serotonergic supraependymal fibers was observed on the ventricular surface of the subfornical organ. Immunohistochemical studies using Vibratome sections of identical ventricular regions revealed the presence of serotonin-immunoreactive processes, with the use of light- and electron-microscopy. They were distributed in in the third ventricle just adjacent to the ependymal luminal surfaces. These fibers contained immunoreactive large cored vesicles and immunonegative small clear vesicles.

Staphylococcal enterotoxins (SEs), produced by Staphylococcus aureus, are a major cause of staphylococcal food poisoning. Traditionally, sandwich enzyme-linked immunosorbent assay (ELISA) and reverse passive latex agglutination with rabbit antibody IgG have been used to detect SEs. However, most of these kits require a long processing time and there is a risk of false-positive results since IgG reacts nonspecifically with protein A produced by S. aureus. In this study, we prepared antienterotoxin chicken IgY antibodies specific for each SE (SEA to SEE) without reaction to protein A, which enabled a drastic reduction in nonspecific reactions. ELISAs, lateral flow device (LFDs), and IgY-based immunopillar chips were developed for SE detection. All the ELISAs developed were as sensitive as commercially available kits. The SEs in milk were successfully detected by the ELISAs, LFDs, and immunopillar chips without any sample pretreatment. The LFD could detect SEA even at the low concentration of 0.2 ng/ml within 15 min in milk. The detection limit of the immunopillar chips for the SEs ranged from 0.01 to 0.1 ng/ml in milk; the SEs were detected within 12 min and specialized skills were not required. The ELISA and LFD detected SEA in dairy products artificially contaminated with S. aureus, including ice cream, yogurt, and cafe au lait, in a dose-dependent manner. In conclusion, IgY allows highly specific detection of SEs, and ELISAs, LFDs, and immunopillar chips should be useful tools for screening SEs in milk and dairy products.

The mithun (Bos frontalis), synonymous with mithan and gayal, is considered to be a domesticated form of gaur (B. gaurus). However, there has been a controversy concerning its origin. In an effort to address this issue, the mitochondrial cytochrome b (cytb) genes of 20 mithun from Myanmar and 13 from Bhutan were sequenced to trace its maternal origin. Seven cytb haplotypes were found in the 33 mithun, and the phylogenetic tree for these haplotypes clearly showed three embranchments involving five gaur types, a B. indicus type, and a B. taurus type. Sixteen Myanmar and 12 Bhutan mithun had gaur haplotypes, while a B. indicus haplotype was found in three Myanmar and one Bhutan mithun. The B. taurus haplotype was detected in a single Myanmar animal. These results demonstrated that the principal maternal origin of mithun was gaur and suggested that it was directly domesticated from gaur. However, some introgression of domestic cattle existed in current mithun populations. The presence of cattle mtDNA raised the question of how many cattle nuclear genes might have been integrated into the gene pool of mithun.

The electrophoretic variation in bovine hemoglobin-beta (HBB) is one of the most investigated genetic markers. The presence of a unique HBB variant, HBB(X), in Southeast Asian cattle has been reputed as a sign of gene-flow from wild bovine species. In this study, we analyzed the DNA sequences of HBB genes in domestic and wild bovine species to verify this belief. Isoelectric focusing of HBB chain revealed that the HBB(X) in domestic cattle had dimorphism and was separated into HBB(X1) and HBB(X2). The HBB(X1) had the same DNA sequence of the common HBB variant in gayal (Bos gaurus frontalis), while some of the HBB(X2) were identical with that of Cambodian banteng (Bos javanicus birmanicus). As a result, we confirmed that the bovine HBB variants can be a good indicator of introgression between wild and domestic cattle. The HBB(X1) was always predominant to HBB(X2) in the continental populations, suggesting that the gaur had contributed to the gene pool of domestic cattle in this region much more than the banteng. On the other hand, the mitochondrial DNA analysis could not detect gene-flow from wild species. Autosomal markers that can trace the phylogeny between alleles are suitable for the assessment of bovine interspecific introgression.

In the current study, milk protein variation was examined in cattle (Bos indicus), mithun (Bos frontalis), yak (Bos grunniens) and their hybrid populations in Bhutan to estimate genetic variability, conduct genetic characterization and assess the possibility of gene flow between mithun and cattle. Isoelectric focusing of 372 milk samples from 11 populations detected four molecular types of β-lactoglobulin (A, B, E and M), five molecular types of α(S1) -casein (A, B, C, E and X) and three molecular types of k-casein (A, B and X). Mithun and yak shared alleles but were found to exhibit different allele frequencies for the proteins studied. The degree of genetic variability within populations was measured by average heterozygosity and ranged from 24-40% in cattle, 26% for yak and 33% for mithun. We also resolved the traditional mithun and cattle hybridization system via principal component analysis. Our results suggested secondary introgression of mithun genes to the village Thrabum population, and a close genetic relationship between Bhutanese indigenous cattle and Indian cattle.

Photoperiodism is an adaptation mechanism that enables animals to predict seasonal changes in the environment. Japanese quail is the best model organism for studying photoperiodism. Although the recent availability of chicken genome sequences has permitted the expansion from single gene to genome-wide transcriptional analysis in this organism, the photoperiodic response of the domestic chicken is less robust than that of the quail. Therefore, in the present study, we examined the photoperiodic response of the red jungle fowl (Gallus gallus), a predecessor of the domestic chicken, to test whether this animal could be developed as an ideal model for studying the molecular mechanisms of seasonal reproduction. When red jungle fowls were transferred from short-day- to long-day conditions, gonadal development and an increase in plasma LH concentration were observed. Furthermore, rapid induction of thyrotropin beta subunit, a master regulator of photoperiodism, was observed at 16 h after dawn on the first long day. In addition, the long-day condition induced the expression of type 2 deiodinase, the key output gene of photoperiodism. These results were consistent with the results obtained in quail and suggest that the red jungle fowl could be an ideal model animal for the genome-wide transcriptional analysis of photoperiodism.

A behavioral mutant was found in the laboratory-bred musk shrew (Suncus murinus). The affected shrews were characterized by the behaviors of tight circling in both directions and frequent head shaking in horizontal. They could definitely be identified by at least day 10 after birth. These abnormal behaviors were steady and permanent through life. Mating experiments demonstrated that the mutant character is expressed by a single autosomal recessive gene in homozygote with complete penetrance. The pedigree analysis indicated that the gene was derived from one heterozygous male captured in Ginowan city, Okinawa. The name, waltzing, was proposed for this mutant character with the gene symbol wz. An abnormality of the balance organ was predicted for a cause of the abnormal behaviors, since, besides the circling and head shaking behaviors, the affected shrews could not keep the body stretching but twisted it frequently when they were held up by the tail and further they could not keep the head on the water surface at all. Nevertheless, the affected shrews were almost normal in gestation period, litter size, weaning ratio and body weight in comparison with the phenotypically normal ones. The mutant shrews have been maintained as a closed colony, the WZ line involved more than 30 individuals at every one generation.

To elucidate strain differences in the sex reversal of genetic females to phenotypic males, GSP and PNP/DO females were left ovariectomized (ovx) between one to three days after hatching, and the degree of masculinization based on sex-related characters, histological analysis of the right gonad and hormone assay were assessed at one year of age. The GSP and PNP/DO inbred lines were both derived from the Fayoumi breed and are only differentiated based on the red blood cell antigen type carried by each inbred line. Combs and wattles were found to be significantly bigger (P0.05) in the GSP ovx compared with the PNP/DO ovx chickens, although male plumage patterns were more pronounced in the PNP/DO ovx. Spurs were observed both in the GSP and PNP/DO ovx chickens with no significant difference (P0.05) in length compared with the respective male controls, and body weight was not significantly different (P0.05) compared with the female controls. The weight of the right gonad was significantly heavier (P0.05) in the GSP ovx than in the PNP/DO ovx. Positive correlations were found in the sex-related characters as well as the plasma testosterone level and right gonad weight in both the GSP and PNP/DO ovx chickens, but not in the spur length, which showed a negative correlation in the PNP/DO ovx chickens. Histological analysis revealed that the right gonads of the PNP/DO ovx chickens were morphologically developed compared with the GSP ovx chickens, which showed more advance stages of spermatogenesis. It could be inferred that PNP/DO females that exhibit a hereditary persistent right oviduct are more responsive to the masculinizing effect of ovariectomy compared with GSP females, suggesting that genetic background may have a possible contribution to the degree of masculinization and subsequent development of sex related characters.

Allele and genotype frequency distributions of prion protein (PrP) polymorphisms at three codons, 136, 154, and 171, in East Asian sheep were determined by PCR-RFLP analysis using 553 animals from nine local breeds of the northern group and four local breeds of the southern group. Based on the genotype distribution, the risk score for scrapie was estimated. Among the local breeds, ARQ appeared predominantly (0.7701-1), followed by ARH and ARR. From such a biased allele distribution, it was difficult to ascertain the prevalent genetic relationships. A marked difference in allele frequencies between the northern and southern groups was seen (P < 0.0001). The East Asian sheep had ARQ at the highest frequency (0.8834); in European sheep it was 0.5317. According to an assessment of scrapie risk in the PrP genotype classes, the predominant ARQ/ARQ in East Asian sheep corresponded to the risk score of R4. This finding suggests that East Asian sheep have a high level of genetic susceptibility to scrapie.

A new circadian variant was isolated by screening the intercross offspring of wild-caught mice (Mus musculus castaneus). This variant was characterized by an initial maintenance of damped oscillations and subsequent loss of rhythmicity after being transferred from light-dark (LD) cycles to constant darkness (DD). To map the genes responsible for the persistence of rhythmicity (circadian ratio) and the length of free-running period (tau), quantitative trait locus (QTL) analysis was performed using F(2) mice obtained from an F(1) cross between the circadian variant and C57BL/6J mice. As a result, a significant QTL with a main effect for circadian ratio (Arrhythmicity; Arrh-1) was mapped on Chromosome (Chr) 8. For tau, four significant QTLs, Short free-running period (Sfp-1) (Chr 1), Sfp-2 (Chr 6), Sfp-3 (Chr 8), Sfp-4 (Chr 11) were determined. An epistatic interaction was detected between Chr 3 (Arrh-2) and Chr 5 (Arrh-3). An in situ hybridization study of clock genes and mouse Period1::luciferase (mPer1::luc) real-time monitoring analysis in the suprachiasmatic nucleus (SCN) suggested that arrhythmicity in this variant might not be attributed to core circadian mechanisms in the SCN neurons. Our strategy using wild-derived variant mice may provide a novel opportunity to evaluate circadian and its related disorders in human that arise from the interaction between multiple variant genes.

A wide diversity of domesticated chicken breeds exist due to artificial selection on the basis of human interests. Miniature variants (bantams) are eminently illustrative of the large changes from ancestral junglefowls. In this report, the genetic characterization of seven Japanese miniature chicken breeds and varieties, together with institute-kept Red Junglefowl, was conducted by means of typing 40 microsatellites located on 21 autosomes. We drew focus to genetic differentiation between the miniature chicken breeds and Red Junglefowl in particular. A total of 305 alleles were identified: 27 of these alleles (8.9%) were unique to the Red Junglefowl with high frequencies (>20%). Significantly high genetic differences (F(ST)) were obtained between Red Junglefowl and all other breeds with a range of 0.3901-0.5128. Individual clustering (constructed from combinations of the proportion of shared alleles and the neighbour-joining method) indicated high genetic divergence among breeds including Red Junglefowl. There were also individual assignments on the basis of the Bayesian and distance-based approaches. The microsatellite differences in the miniature chicken breeds compared to the presumed wild ancestor reflected the phenotypic diversity among them, indicating that each of these miniature chicken breeds is a unique gene pool.

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.

This paper reviews studies on sex reversal experiments in chickens, production of sperm bearing a female-specific chromosome, its application for poultry resources and finally a mechanism of sex differentiation of gonads in the chicken.

The musk shrew (Suncus murinus) is a small mammalian species belonging to Insectivora. It is widely distributed in Asia. To identify the genetic relationship among wild musk shrew populations and examine its migration route, we investigated the populations of Cambodia and Bhutan by using mitochondrial DNA restriction fragment length polymorphism analysis and compared them with other Asian populations previously described. Four haplotypes were detected in Cambodia and eight in Bhutan. A total of 53 haplotypes were detected in Asia and were classified largely into two groups, the Continental and Island types, based on a minimum spanning network. From the distribution of mtDNA types in wild musk shrews, three major population groups are identified in Asia: South Asia, Southeast Asia, and Malay. It is suggested that the Malay population group was a mix of South and Southeast Asian population groups and that this was a contact area of the two groups. In addition, other contact areas between the South and Southeast Asian groups exist in Myanmar, but unlike the Malay, the Myanmar area was the border of these groups.

In 183 male progeny derived from a backcross between the FGS/Kist strain, a new mouse model for focal glomerulosclerosis (FGS) in humans, and the standard normal strain, C57BL/6J, we performed a genome-wide scan for quantitative trait loci (QTLs) affecting the glomerulosclerosis index (GSI) based on histological observation as well as kidney and body weights. Two QTLs for GSI (Gsi1-2) located on chromosomes (Chrs) 8 and 10, a kidney weight QTL (Kdw1) on Chr 19, and a body weight QTL (Bdw1) on Chr 13 were detected at the genome-wide 5% or less level. The allele derived from FGS/Kist increased GSI at Gsi1, but decreased it at Gsi2. The mice homozygous for the FGS/Kist allele decreased body and kidney weights. The identified QTLs accounted for 5-8% of the phenotypic variance.

To serve as an initial step in developing an ideal genetic marker map for the house musk shrew, Suncus murinus, 318 comparative anchor tagged sequence (CATS) primer pairs were assessed for polymorphism ascertainment and linkage mapping. Of the 112 (35.2%) CATS primer pairs that were successfully amplified by PCR in the shrew, 18 (16.1%) showed polymorphism between two mutant strains, BAN-kc, oeb and WZ. Linkage analysis of the polymorphic CATS markers and three visible mutant genes, kc, oeb and wz, genotyped in a 77 F2 mapping panel from a cross of the two mutant strains, assigned wz and five CATS markers into three linkage groups. Sequence analysis revealed that two (ADA and TXN) out of nine CATS amplified sequences had a total of six deletions of varying sizes and 17 single nucleotide polymorphisms (SNPs). BLAST search identified three CATS (ADA, CYP1A2, and TXN) products matching the genes from which they were originally designed, while the remaining six markers could not be identified. Together with the use of the detected SNPs as genetic markers, the five CATS markers linkage mapped in this species will serve as anchors in establishing the first framework map for locating loci affecting all heritable qualitative and quantitative traits in the musk shrew.

We performed a quantitative trait locus (QTL) analysis of eight body weights recorded weekly from 3 weeks to 10 weeks after birth and two weight gains recorded between 3 weeks and 6 weeks, and between 6 weeks and 10 weeks in an intersubspecific backcross population of wild Mus musculus castaneus mice captured in the Philippines and the common inbred strain C57BL/6J (M. musculus domesticus), to elucidate the complex genetic architecture of body weight and growth. Interval mapping identified 17 significant QTLs with main effects on 11 chromosomes. In particular, the main effect of the most potent QTL on proximal chromosome 2 increased linearly with age, whereas other QTLs exerted effects on either the early or late growth period. Surprisingly, although wild mice displayed 60% of the body size of their C57BL/6J counterparts, the wild-derived allele enhanced growth at two QTLs. Interestingly, five of the 17 main-effect QTLs identified had significant epistatic interaction effects. Five new epistatic QTLs with no main effects were identified on different chromosomes or regions. For one pair of epistatic QTLs, mice that were heterozygous for the wild-derived allele at one QTL and homozygous for that allele at another QTL exhibited the most rapid growth in all four possible genotypic combinations. Out of the identified QTLs, several showed significant sex-specific effects.

The FGS/Nga mouse strain, established from an outcross between CBA/N and RFM/Nga mice strains, has previously been reported as a spontaneous mouse model for focal glomerular sclerosis (FGS) and is considered to have two pairs of autosomal recessive genes associated with FGS. In this study, we examined the changes of seven renal lesion-related parameters, blood urea nitrogen (BUN), creatinine, albumin and total protein in plasma, urinary protein, systolic blood pressure, and a glomerulosclerosis index on histological observation, in 20-week-old FGS/Nga mice and their age-matched two parental strains, CBA/N and RFM/Nga. The levels of plasma BUN and creatinine, urinary protein and systolic blood pressure were significantly increased in FGS/Nga, compared with those of the parental strains. RFM/Nga mice showed slightly elevated levels of all biochemical makers. In histological analysis, a higher glomerulosclerosis index was observed in FGS/Nga than the two parental strains. RFM/Nga mice appeared to have slight sclerotic lesions of glomeruli, but no renal failure was observed in CBA/N mice. These results suggest that at least one mutant gene that causes the progression of renal lesion in FGS/Nga mice is derived from RFM/Nga.

A number of quantitative trait loci (QTLs) for postnatal growth have previously been reported in mice. As effects of the QTLs are usually small and similar to one another in magnitude, it is generally difficult to know which loci are major contributors to postnatal growth. We applied principal component analysis to a genome-wide search for QTLs affecting postnatal growth in body weight weekly recorded from 3 to 10 weeks of age in an intersubspecific backcross population of C57BL/6J inbred mice (Mus musculus domesticus) and wild mice (M. m. castaneus) captured in the Philippines, in order to discover new QTLs from a gene pool of the wild mice and uncover major loci underlying variation in postnatal growth. Principal component analysis classified phenotypic variation in body weights at different ages into two independent principal components: the first principal component (PC1) extracted information on the entire growth process and the second principal component (PC2) contrasted middle (3-6 weeks of age) with late (6-10 weeks) growth phases. Simple interval mapping and composite interval mapping revealed 10 significant QTLs with main effects on PC1 or PC2 on eight chromosomes. Of these, the six main-effect QTLs interacted epistatically with one another or three new additional QTLs on different chromosomal regions without main effects. Several of the identified QTLs with main effects and/or epistatic interaction effects appeared to be sex specific. These results suggest that the identified 13 QTLs, most of which affected the entire growth process, are very important contributors to complex genetic networks of postnatal growth.

Quantitative trait locus (QTL) analysis of serum insulin, triglyceride, total cholesterol and phospholipid levels at 10 weeks of age was performed in 321 F2 offspring from SM/J and A/J mice. Interval mapping revealed a total of 22 suggestive QTLs affecting the four traits: two insulin QTLs on Chromosomes (Chrs) 6 and 8; six triglyceride QTLs on Chrs 4, 8, 9, 11, 12 and 19; six total-cholesterol QTLs on Chrs 1, 3, 4, 14, 17 and 19; and eight phospholipid QTLs on Chrs 2, 3, 4, 6, 8, 10 and 19. Gender influenced the expression of eight of the suggestive QTLs. The total-cholesterol QTLs on Chrs 4, 14 and 17, the triglyceride QTL on Chr 9 and the phospholipid QTL on Chr 4 were specific to females. The phospholipid QTLs on Chrs 2 and 6 and the insulin QTL on Chr 8 were specific to males. In addition, common QTLs involved in the regulation of some of the traits were identified. The female-specific QTL on Chr 4 appeared to be involved in the regulation of total cholesterol and phospholipid levels. The QTL on Chr 8 affected insulin and phospholipid levels, whereas the Chr 19 QTL was common to the three lipid parameters.

It is known that retinally degenerate C57BL/6J ( rd/rd) mice have unattenuated circadian photosensitivity. However, the authors have previously found that CBA/J ( rd/rd) mice that carry the same rd mutation have attenuated circadian photosensitivity compared to normal CBA/N (+/+) mice. In the present study, a quantitative trait locus (QTL) analysis using C57BL/6J ( rd/rd) and CBA/J ( rd/rd) mice was conducted in order to identify the genes affecting circadian photosensitivity of the rd mice. As a result, several putative QTLs on three separate chromosomes (8, 12, 17) were detected, which indicates that circadian photosensitivity in rd mice is altered by multiple genes. Identification of these genes may provide new insights into the understanding of regulation of circadian photoentrainment and sleep-wake disorders.

In birds, females are heterogametic (ZW), while males are homogametic (ZZ). It has been proposed that there is no dosage compensation for the expression of Z-linked genes in birds. In order to examine if the genes are inactivated on one of the two Z chromosomes, we analyzed the allelic expression of the B4GALT1 and CHD-Z genes on Z chromosomes in male chickens. One base substitution was detected among 15 chicken breeds and lines examined for each gene, and cross mating was made between the breeds or lines with polymorphism. cDNAs were synthesized from cultured cell colonies each derived from a single cell of an F1 male embryo. The allelic expression of the B4GALT1 gene was examined by restriction fragment length polymorphism analysis of the PCR products digested with RsaI, and that of the CHD-Z gene by the single nucleotide primer extension (SNuPE) method. Both of the genes displayed biallelic expression, suggesting that these Z-linked genes were not subject to inactivation in male chickens. Comparison between expression levels in males and females by real-time quantitative PCR suggested that expression was compensated for the CHD-Z gene but not for the B4GALT1 gene.

The EDS (early-onset diabetes in suncus) colony was developed as a new laboratory colony of the musk shrew and is characterized by a high incidence of early-onset spontaneous non-insulin dependent diabetes mellitus (NIDDM). We examined blood lipid (triglyceride [TG], total cholesterol [TC], phospholipid [PL], free fatty acid [FFA]) and liver lipid (TG, TC, PL) concentrations to investigate the features of lipid metabolism in these animals. All lipid concentrations examined both in blood and liver of the diabetic shrews had a tendency toward higher values than those in non-diabetic shrews. The PL concentration was the only parameter that barely showed a significant difference. Values for all blood lipid concentrations in diabetic shrews at 7-9 months tended to be higher than those of 2-month-old diabetic shrews, although the difference was not significant. These findings indicate that diabetic EDS shrews exhibit a much milder defect of lipid metabolism induced by NIDDM than other rodent models.

The EDS colony, developed as a new laboratory colony of the musk shrew, is characterized by a high incidence of early-onset spontaneous non-insulin dependent diabates mellitus (NIDDM). In this colony, a few diabetic shrews exhibited a cataract at 1 month after the onset of diabetes, and all diabetic shrews had bilateral cataracts at 5 months after the onset of diabetes. In contrast, cataractous animals were never observed among non-diabetic shrews. These results suggest that the cataract in the EDS colony is a diabetic complication.