Caratterizzazione genetica della razza Bracco Francese ed analisi comparative con le principali razze canine

Il sequenziamento del genoma canino ha contribuito a migliorare l’accuratezza delle stime di diversità genetica ed ha anche generato diversi studi sulle relazioni tra le diverse razze allevate (Vaysse et al., 2011; Parker et al., 2017). Tuttavia, alcune razze rimangono ancora poco caratterizzate. È il caso del Bracco Francese tipo Pyrénées. Lo scopo di questo lavoro è stato quello di caratterizzare a livello genomico la razza e studiarne le relazioni con altre razze allevate nel mondo. Sono stati raccolti i campioni di sangue da 48 individui. La genotipizzazione è stata condotta mediante l’Illumina CanineHD BeadChip (173.662 marcatori). Diversi parametri di diversità genetica sono stati cal…

Paramentri genetici e bio-economici per caratteri di interesse zootecnico nella razza ovina Valle del Belice

Genome-wide scan for Runs of Homozygosity in Valle del Belice sheep

The current availability of very large numbers of single nucleotide polymorphisms (SNPs) throughout the genome makes these markers particularly suitable for the detection of genomic regions where a reduction in heterozygosity occurred and offers new opportunities to improve the accuracy of inbreeding (F) estimates. Runs of homozygosity (ROH) are contiguous lengths of homozygous segments of the genome where the two haplotypes inherited from the parents are identical. Here, we investigated the occurrence and the distribution of ROH in medium-density SNP genotypes (~ 50 000) in order to characterize autozygosity in 512 individuals of Valle del Belice sheep and identify the regions of the genom…

Suitability of simplified milk recording methods for genetic evaluations using test-day models in dairy sheep

Nowadays in dairy sheep, test-day records are collected monthly under an alternate morning/evening system. This alternate system was implemented because of the steady increase in recording cost per sheep observed in the last few decades. Furthermore, additional modifications to the testing schemes have been proposed to reduce the costs of milk recording. In dairy sheep, the cost for milk recording is indeed too high compared both with individual outputs and with other dairy species. Therefore, the purposes of the present study were: i) to compare estimated breeding values (EBVs) for milk yield using different simplified testing schemes with a test-day sire model; ii) to evaluate the effect …

A genome-wide perspective on the population structure of Italian cattle breeds

Despite the growing diffusion of cosmopolite specialized breeds, several autochthonous cattle breeds and populations are still bred in Italy. The aim of this study was to provide a high-resolution picture of the genome-wide diversity and population structure of Italian local cattle breeds using medium-density genome-wide SNP markers. After data editing, the dataset included 800 samples from 32 breeds that were genotyped for 31 013 SNPs. For several breeds we observed a low level of polymorphism and genetic diversity, that together with the small effective population sizes confirmed threat of extinction. According to the runs of homozygosity analysis, evidence of recent inbreeding was strong…