Breed Differences in Serum Testosterone Levels of Male Pigs Are Highly Correlated with Differences in Testicular mRNA Levels of Enzymes and Proteins Involved in Testosterone Biosynthesis Process.

To clarify the causes of breed differences in serum testosterone levels of male pigs, which affect the mRNA expression of drug metabolizing enzymes and drug transporters in the liver and kidney, we focused on testicular enzymes and proteins involved in testosterone biosynthesis process and comparatively examined their mRNA levels by real time RT-PCR among low serum testosterone-type Landrace pigs and high serum testosterone-type Meishan and Landrace/Meishan-crossbreed (LM and ML) pigs. Testicular mRNA levels of the enzymes (3-hydroxy-3-methylglutaryl-CoA synthase 1 and 3-hydroxy-3-methylglutaryl-CoA reductase) and proteins (low density lipoprotein receptor and scavenger receptor class B member 1) affecting intracellular levels of cholesterol, a precursor of testosterone, were 2-5-fold higher in Meishan, LM and ML pigs than in Landrace pigs. Likewise, the mRNA levels of steroidogenic acute regulatory protein, which imports cholesterol to the inner mitochondrial membrane, and of testosterone biosynthesis enzymes (CYP11A1 and CYP17A1) were over 10-fold and approximately 3-fold higher, respectively, in Meishan, LM and ML pigs than in Landrace pigs.

Recessive mutation on mouse chromosome 13 associated with abnormal hair texture and cardiomyopathy.

An autosomal recessive mutation (aht) associated with abnormal hair texture and cardiomyopathy spontaneously arose in the Y-chromosome consomic mouse strain DH-Chr Y . The aht/aht mouse phenotypes closely resembled those of rul/rul mice, which were caused by a mutation in desmoplakin (Dsp) on chromosome 13. Quantitative trait locus (QTL) mapping using (DDD/Sgn × DH-Chr Y -aht heterozygotes) F mice demonstrated that aht is contiguous with Dsp on chromosome 13.

Identification of a novel mutant allele of LIM homeobox transcription factor 1 alpha (dreher) in mice.

A male mouse exhibiting bidirectional circling behavior was identified in a Y-chromosome consomic strain known as DH-Chr Y . The putative mutation responsible for the circling behavior was inherited in an autosomal recessive manner and was termed circ. To identify its causative gene, we performed exome sequencing; of the 34 candidates discovered, we found a novel nonsynonymous single nucleotide variation in LIM homeobox transcription factor 1 alpha (Lmx1a) (c.

Low pup survival rate is associated with maternal Naq3 genotype and hypothalamic Vps8 expression levels in mice.

Pups born from females of the inbred mouse strain RR/Sgn tend to have low survival rates during rearing. We have previously identified Naq3, a quantitative trait locus underlying this low pup survival rate. In the present study, we confirmed the effect of Naq3 in congenic mice and investigated whether Vps8 is a candidate gene for Naq3.

Genetic analysis of the mandible morphology in DDD.Cg-/Sgn and C57BL/6J inbred mice.

Quantitative trait loci (QTL) mapping analysis was performed for the mandible morphology in DDD.Cg-/Sgn and C57BL/6J inbred mice. The size and shape of the mandible was analysed by landmark-based geometric morphometrics as the centroid size and principal components (PCs), respectively.

Effects of quantitative trait loci determining testicular weight in DDD/Sgn inbred mice are strongly influenced by circulating testosterone levels.

Objective: Testicular growth and development are strongly influenced by androgen. Although both testis weight and plasma testosterone level are inherited traits, the interrelationship between them is not fully established. Males of DDD/Sgn (DDD) mice are known to have extremely heavy testes and very high plasma testosterone level among inbred mouse strains.

Quantitative trait loci that determine plasma insulin levels in F intercross populations produced from crosses between DDD/Sgn and C57BL/6J inbred mice.

When compared to C57BL/6J (B6) mice, DDD/Sgn (DDD) mice has substantially higher plasma insulin levels in both sexes. In this study, we performed quantitative trait loci (QTL) mapping of plasma insulin levels in F male mice produced by crosses between DDD and B6 mice. By single-QTL scans, we identified one significant QTL on chromosome 9.

Effects of the Y-chromosome and the dominant hemimelia mutation on the morphology of the mouse mandible.

The aims of this study were to test whether the Y-chromosome and the autosomal dominant hemimelia (Dh) mutation can affect mandible morphology in mice. I analyzed mandible size and shape using landmark-based geometric morphometrics in 16 DH-Chr Y -+/+ (@ represents one of the inbred strain names) strains and observed significant differences in mandible size. The largest mandible was identified in strain DH-Chr Y and the smallest in strain DH-Chr Y .

Identification of Quantitative Trait Loci That Determine Plasma Total-Cholesterol and Triglyceride Concentrations in DDD/Sgn and C57BL/6J Inbred Mice.

DDD/Sgn mice have significantly higher plasma lipid concentrations than C57BL/6J mice. In the present study, we performed quantitative trait loci (QTL) mapping for plasma total-cholesterol (CHO) and triglyceride (TG) concentrations in reciprocal F male intercross populations between the two strains. By single-QTL scans, we identified four significant QTL on chromosomes (Chrs) 1, 5, 17, and 19 for CHO and two significant QTL on Chrs 1 and 12 for TG.

Locus on chromosome 16 is significantly associated with increased tendency to lose pups in females of the RR/Sgn inbred mouse strain.

Females of the inbred mouse strain RR/Sgn have an apparent tendency to lose pups during rearing. To identify genes underlying this abnormal maternal phenotype, we performed quantitative trait loci (QTL) mapping in 349 (C57BL/6 J × RR/Sgn) F  × RR/Sgn backcross mice and identified one significant and one suggestive QTL on chromosomes 16 and 4, respectively. We assigned the gene symbol nurturing ability QTL 3 (Naq3) to the QTL on chromosome 16.

Quantitative trait loci that control body weight in DDD/Sgn and C57BL/6J inbred mice.

Inbred DDD/Sgn mice are heavier than inbred C57BL/6J mice. In the present study, we performed quantitative trait loci (QTL) mapping for body weight using R/qtl in reciprocal F male populations between the two strains. We identified four significant QTL on Chrs 1, 2, 5, and 17 (proximal region).

Genetic analysis of low survival rate of pups in RR/Sgn inbred mice.

Newborn offspring of the inbred mouse RR/Sgn strain have a low survival rate prior to weaning. We hypothesized that this is a consequence of an inferior nurturing ability of RR/Sgn mothers and that RR/Sgn mothers have a tendency to lose their pups. We performed quantitative trait locus (QTL) mapping for inferior nurturing ability and tendency to lose pups in RR/Sgn mothers.

Effect of the Y chromosome on testis weight in mice.

We investigated the effect of the Y chromosome on testis weight in (B6.Cg-A(y) × Y-consomic mouse strain) F1 male mice. We obtained the following results: (1) Mice with the Mus musculus domesticus-type Y chromosome had significantly heavier testis than those with the M.

Genetic analysis of litter size in mice.

We performed quantitative trait locus (QTL) mapping analysis for litter size (total number of pups born and/or number of pups born alive) in 255 backcross mice derived from C57BL/6J and RR/Sgn inbred mice. We identified one significant QTL on chromosome 7 and 4 suggestive QTLs on chromosomes 3, 5, 10 and 13. In addition, two suggestive QTLs were identified on chromosomes 1 and 4 for the number of stillbirth.

Further characterization of diabetes mellitus and body weight loss in males of the congenic mouse strain DDD.Cg-A(y.).

The A(y) allele at the agouti locus causes obesity and promotes linear growth in mice. However, body weight gain stops between 16 and 17 weeks after birth, and then, body weight decreases gradually in DDD.Cg-A(y) male mice.

Effect of the Y chromosome on plasma high-density lipoprotein-cholesterol levels in Y-chromosome-consomic mouse strains.

Background: Plasma high-density lipoprotein (HDL)-cholesterol level is a clinically important quantitative phenotype that widely varies among inbred mouse strains. Several genes or loci associated with plasma HDL-cholesterol levels have been identified on autosomes and the X chromosome. In contrast, genes or loci on the Y chromosome have not attracted significant attention hitherto.

Genetic background (DDD/Sgn versus C57BL/6J) strongly influences postnatal growth of male mice carrying the A(y) allele at the agouti locus: identification of quantitative trait loci associated with diabetes and body weight loss.

Background: Mice carrying the A(y) allele at the agouti locus become obese and are heavier than their non-A(y) littermates. However, this does not hold true for the genetic background of the DDD mouse strain. At 22 weeks of age, DDD.

QTL mapping of genes controlling plasma insulin and leptin concentrations: metabolic effect of obesity QTLs identified in an F2 intercross between C57BL/6J and DDD.Cg-A(y) inbred mice.

DDD.Cg-A(y) female mice developed massive obesity as compared with B6.Cg-A(y) female mice.

Y chromosome of the inbred mouse KK/Ta strain is associated with reduced body size in Y-consomic strains.

Background: We have established 17 Y chromosome consomic (Y-consomic) mouse strains in an inbred DH/Sgn strain. In this study, based on investigations in four different genetic backgrounds, we proved that the Y chromosome of the inbred mouse KK/Ta strain is associated with reduced body size.

Findings: In the DH-Chr Y-+/+ background, Y chromosome substitution significantly decreased the body weight in DH-Chr Y(KK)-+/+ and DH-Chr Y(SJL)-+/+ strains, and the DH-Chr Y(KK)-+/+ strain was the lightest among the 17 Y-consomic strains.

Quantitative trait locus mapping of genes associated with vacuolation in the adrenal X-zone of the DDD/Sgn inbred mouse.

Background: Adrenal gland of mice contains a transient zone between the adrenal cortex and the adrenal medulla: the X-zone. There are clear strain differences in terms of X-zone morphology. Nulliparous females of the inbred mouse DDD strain develop adrenal X-zones containing exclusively vacuolated cells, whereas females of the inbred mouse B6 strain develop X-zones containing only non-vacuolated cells.

Quantitative trait locus mapping of genes that control body length and plasma insulin-like growth factor 1 level in mice.

Background: The Ay allele at the agouti locus causes obesity and promotes linear growth in mice. The effect of the Ay allele on obesity has been extensively investigated, whereas its effect on body length is only poorly analyzed. To gain insight into the genetic control of body length, quantitative trait locus (QTL) analysis was performed in F2 female mice produced by crossing C57BL/6 J females and DDD.

Development of an efficient method for genotyping at the gd locus in NC/Sgn mice based on PCR-RFLP analysis.

Growth deficit (gd) is a recessive mutation that occurs spontaneously in the inbred NC/Sgn mouse strain. Because homozygotes (gd/gd) of both sexes are sterile, they must be produced by mating putative heterozygous carriers (+/gd) whose phenotypes are essentially the same as those of wild-type +/+ mice. The objectives of this study were to develop an efficient method that distinguished a gd allele from a wild-type allele and, if possible, to identify nucleotide substitutions responsible for the gd mutation.

Quantitative trait loci that control plasma lipid levels in an F2 intercross between C57BL/6J and DDD.Cg-A(y) inbred mouse strains.

The objectives of this study were to characterize plasma lipid phenotypes and dissect the genetic basis of plasma lipid levels in an obese DDD.Cg-A(y) mouse strain. Plasma triglyceride (TG) levels were significantly higher in the DDD.

Genetic dissection of testis weight in mice: quantitative trait locus analysis using F(2) intercrosses between strains with extreme testis weight, and association study using Y-consomic strains.

In the present study, dissection of genetic bases of testis weight in mice was performed. Autosomes and the X chromosome were searched using traditional quantitative trait locus (QTL) scans, and the Y chromosome was searched by association studies of Y-consomic strains. QTL analysis was performed in ♀DDD × ♂CBA F(2) mice; the inbred mouse DDD has the heaviest testes, whereas the inbred mouse CBA has the lightest testes.