Project description:Dog breeding promotes within-group homogeneity through conformation to strict breed standards and also drives between-group heterogeneity in pursuit of distinct morphological forms and characteristic breed traits. In this study, the genotype-first approach was adapted to the dog genome to investigate coding variation from over 2000 dogs, leading to discoveries of new mutations related to craniofacial morphology and stature. Breed enriched variants were prioritized according to gene constraint, which was calculated using a mutation model derived from trinucleotide substitution probabilities in the dog. Most priority variants were not associated with genomic signatures for breed differentiation, as these regions were enriched for constrained genes intolerant to nonsynonymous variation, suggesting a model of breed phenotype diversification based on regulatory changes to essential genes. Identification of trait-associated variants in dogs informs new biological roles of genes. Improved collection of breed disease risk data, along with increased breed representation, will drive further discoveries.
Project description:To investigate the effect of mechanical ventilation and mechanical ventilationon with PEEP application on diaphragmatic dysfunction, we established a model of mechanical ventilation on New Zealand rabbit, in which rabbits in the experimental group were ventilated with/without PEEP application for 48 hours continuously
Project description:SNP genotyping was used to determine if the free living Highland Wild dogs of Papua, Indonesia are the ansestors of captive New Guinea Singing Dogs.
Project description:The effect of sex on the penetrance of autosomal dominant Mendelian conditions is an understudied area of research. Variants in CHD1 have previously been identified in females with Pilarowski-Bjornsson syndrome (PILBOS), a recently described cause of developmental delay. We now demonstrate that both sexes can show signs of PILBOS, although males are more likely to display PILBOS phenotypes when carrying more severe variants. A novel mouse model carrying a human-derived missense variant in the Chd1 gene (Chd1R616Q/+) shows female-restricted disease phenotypes including growth retardation, anxiety and hypotonia. Orchiectomy of male mice unmasks a growth retardation phenotype in Chd1R616Q/+ mutants compared to orchiectomized wild type (WT) littermates. Conversely, testosterone supplementation in female Chd1R616Q/+ mice and WT littermates rescues the growth phenotype, suggesting that androgens dictate PILBOS disease penetrance. On the human population level, we demonstrate a significant overrepresentation of healthy males carrying rare missense variants in CHD1 in the gnomAD database, further supporting a male protective effect against CHD1 variants. We further identify 212 other genes that show similar missense variant overrepresentation in males. Together our data suggests androgen-regulated sexual dimorphism in Pilarowski-Bjornsson syndrome and opens up novel avenues to understand the mechanistic basis of sexual dimorphism of autosomal Mendelian disorders.
Project description:Australian working Kelpie dogs are known to be affected with an autosomal recessive form of inherited cerebellar ataxia (cerebellar abiotrophy, CA) that is characterised by a degeneration of Purkinje and granule cells in the cerebellar cortex. The clinical signs of CA include cerebellar ataxia, head tremor, motor in-coordination, wide based stance and high stepping gait, with varied clinical onset age. The clinical and pathological features are similar to cerebellar ataxias in humans. The genome-wide association study on a group of working Kelpies affected with the later onset form of CA identified a region on chromosome 9 to be strongly associated with the disease phenotype. Homozygosity analysis and whole genome sequencing identified a missense single nucleotide polymorphism, that segregated with the CA phenotype.