Identification of a critical interval for type 2 diabetes QTL on chromosome 4 in DDD-A mice.

Type 2 diabetes mellitus (T2D) in male KK-A and B6-A mice is typically associated with hyperinsulinemia, whereas male DDD-A mice exhibit a marked decrease in circulating insulin levels due to the loss of pancreatic islet β-cells. T2D in male DDD-A mice is linked to Nidd/DDD, a significant quantitative trait locus (QTL) mapped with a 95% confidence interval (CI) between 112.44 and 151.

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.

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.

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.

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.

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.

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.

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.