Project description:Through thousands of years of breeding and strong human selection, the dog (Canis lupus familiaris) exists today within hundreds of closed populations throughout the world, each with defined phenotypes. A singular geographic region with broad diversity in dog breeds presents an interesting opportunity to observe potential mechanisms of breed formation. Italy claims 14 internationally recognized dog breeds, with numerous additional local varieties. To determine the relationship among Italian dog populations, we integrated genetic data from 263 dogs representing 23 closed dog populations from Italy, seven Apennine gray wolves. Using 142,840 genome-wide SNPs, this dataset was used in the identification of breed development routes for the Italian breeds that included divergence from common populations for a specific purpose, admixture of regional stock with that from other regions, and isolated selection of local stock with specific attributes.
Project description:Peripheral blood mononuclear cell (PBMC) gene expression profiling is a low-invasive tool used in human diet intervention studies. In dogs this technique has been used to investigate disease states but not to examine the effect of diet. We tested the hypothesis that diet alters dog systemic immune cell gene expression profiles by comparing PBMC gene expression in dogs fed either a premium kibbled diet or a raw red meat diet for 9 weeks. Our results showed that diet shifted the dogs’ PBMC gene expression profile and these alterations corresponded with changes in plasma IgA levels. This illustrates that PBMC microarrays are a useful tool that may be applied to study the long-term effects of diet on health outcomes for the dog.
Project description:We compared the gene expression of ventral part of telenchephalon, hypothalamus and pituitary in grass puffer (Takifugu alboplumbeus) between the spring and neap tides during the breeding season using RNA-seq.
Project description:We study the changes occurring in the testes of Talpa occidentalis during the breeding cycle. The transcriptomic analysis of active, inactivating and regressed testis show that several molecular pathways that operate in Sertoli cells, involved in the control of spermatogenesis and BTB dynamics, are deregulated in the inactive gonad, and that the immuno privilege of the testes is lost during the non-breeding season.
Project description:We also study the changes occurring in the testes of Mediterranean pine mice living in the wastelands during the breeding cycle. The transcriptomic analysis of active and regressed testis show that several molecular pathways that operate in Sertoli cells, involved in the control of spermatogenesis and BTB dynamics, are deregulated in the inactive gonad, and that the immuno privilege of the testes is lost during the non-breeding season.
Project description:Free-breeding dogs have occupied the Galápagos islands at least since the 1830s, however, it was not until the 1900s that dog populations grew substantially, endangering wildlife and spreading disease. In 1981, authorities sanctioned the culling of free-roaming dogs. Yet there are currently large free-roaming dog populations of unknown ancestry on the islands of Isabela and Santa Cruz, whose ancestry has never been assessed on a genome-wide scale. Thus, we performed a complete genomic analysis of the current Galápagos dog population as well as historical Galápagos dogs sampled between 1969 and 2003, testing for population structure, admixture, and shared ancestry. Our dataset included samples from 187 modern and six historical Galápagos dogs, together with whole genome sequence from over 2,000 modern purebred and village dogs. Our results indicate that modern Galápagos dogs are recently admixed with purebred dogs but show no evidence of a population bottleneck related to the culling. Additionally, IBD analyses reveal evidence of shared shepherd-dog ancestry in the historical Galápagos dogs. Overall, our results demonstrate that the 1980s culling of dogs was ineffective in controlling population size and did little to reduce genetic diversity, instead producing a stable and expanding population with genomic signatures of historical dogs remaining today. The insights from this study can be used to improve population control strategies for the Galápagos Islands and other endangered endemic communities worldwide.
Project description:Mouse lemurs are basal primates that rely on chemo- and acoustic signalling for social interactions in their dispersed social systems. We examined the urinary protein content of two mouse lemurs species, within and outside the breeding season, to assess candidates used in species discrimination, reproductive or competitive communication. Urine from Microcebus murinus and Microcebus lehilahytsara contain a predominant 10kDa protein, expressed in both species by some, but not all, males during the breeding season, but at very low levels by females. Mass spectrometry of the intact proteins confirmed the protein mass and revealed a 30 Da mass difference between proteins from the two species. Tandem mass spectrometry after digestion with three proteases and sequencing de novo defined the complete protein sequence and located an Ala/Thr difference between the two species that explained the 30 Da mass difference. The protein (mature form: 87 amino acids) is an atypical member of the whey acidic protein family (WFDC12). Seasonal excretion of this protein, species difference and male-specific expression during the breeding season suggest that it may have a function in intra- and/or intersexual chemical signalling in the context of reproduction, and could be a cue for sexual selection and species recognition.
Project description:The inherent diversity of canines is closely intertwined with the unique color patterns of each dog population. These variations in color patterns are believed to have originated through mutations and selective breeding practices that occurred during and after the domestication of dogs from wolves. To address the significant gaps that persist in comprehending the evolutionary processes that underlie the development of these patterns, we generated and analyzed deep-sequenced genomes of 113 Korean indigenous Jindo dogs that represent five distinct color patterns to identify the associated mutations in CBD103, ASIP, and MC1R. The degree of linkage disequilibrium and estimated allelic ages consistently indicate that the black-and-tan dogs descend from the first major founding population on Jindo island, compatible with the documented literature. We additionally demonstrate that black-and-tan dogs, in contrast to other color variations within the breed, exhibit a closer genetic affinity to ancient wolves from western Eurasia than those from eastern Eurasia. Lastly, population-specific genetic variants with moderate effects were identified, particularly in loci associated with traits underlying body size and behavioral variations, potentially explaining the observed phenotypic diversity based on coat colors. Overall, comparisons of whole genome sequences of each coat color population diverged from the same breed provided an unprecedented glimpse into the properties of evolutionary processes maintaining variation in Korean Jindo dog populations that were previously inaccessible.
Project description:Well-defined, closed breeding populations coupled with excessive disease predispositions among purebred domestic dog breeds offer unique advantages to genetic studies of disease susceptibility. Advantages offered by canine population substructure, combined with similarity to human disease in terms of clinical presentation and response to treatment, make the dog a particularly attractive system for finding genes associated with cancer. Cancers that have been difficult to study in human families or populations are of particular interest, especially those associated with one or a small number of breeds and a high level of occurrence. Histiocytic sarcoma (HS) is a rare and poorly understood neoplasm in humans, however it occurs in 15-25% of Bernese Mountain Dogs (BMD). By combining genome-wide association studies from two geographic populations of BMD followed by fine mapping and sequencing, we have identified a cancer-associated haplotype within the MTAP/CDKN2A locus that is present in 95% of all affected BMD. The haplotype is within the region homologous to human chromosome 9p21, which has been implicated in numerous complex genetic diseases including several cancers. These results demonstrate the power of studying distinctive malignancies in highly predisposed dog breeds. Here, we establish a naturally occurring model of cancer susceptibility due to CDKN2 dysregulation, thus providing insight regarding this cancer-associated, complex, and yet poorly understood genomic region.