| Abstract |
Italian turkey populations, like other domesticated species, have undergone both natural and artificial selection, shaping their genetic makeup over time. This doctoral thesis focuses on describing and discussing the obtained findings aimed at genetic characterization and assisting in genetic improvement and conserving strategies of Italian turkey populations. Through high-throughput sequencing technologies, including SNP arrays and whole-genome sequencing, we investigated genomic variants, population genetic structure, runs of homozygosity, genomic inbreeding selection signatures and structure variations in Italian turkeys. Chapter 1 presents a comprehensive review of the background and knowledge about turkey breeding, genomic diversity, genomic inbreeding, signatures of selection and structure variations provides a general introduction. In Chapter 2, comprehensive genome-wide comparative analyses were performed based on genetic diversity indices, population genetic structure, runs of homozygosity, and genomic inbreeding coefficients between Basilicata and Apulian turkey populations and other Italian local turkey populations. We also detected selection signatures using his approach across all Italian turkey populations. The results showed that the Basilicata and Apulian turkey populations are separated from other Italian local turkey populations. These findings enhance the understanding of the genomic architecture of Italian local turkey populations. Chapter 3 focuses on the results of genetic diversity, runs of homozygosity (ROH), genomic inbreeding and selection signatures using the integrated haplotype score (iHS) and ROH methods in Basilicata and Apulian turkeys. Inbreeding coefficients based on2 ROH showed low to moderate values. Most of the genes within genomic regions identified using ROH and iHS methods are associated with production and reproduction, immunity, and adaptation traits. These discovered genes may aid in future breeding and preservation strategies in Basilicata and Apulian turkeys. Chapter 4 is focused on structure variations using whole genome sequencing (12x coverage). A total of 73 samples from Basilicata and Apulian turkey populations to apply a mapping approach that identified structural variants (SVs). A comprehensive structure variations catalogue was produced involving 6,712 deletions (DELs), 2,671 duplications (DUPs), 1,430 inversions (INVs) and 920 translocations (TRAs). This structural variation (SV) catalog not only expands our understanding of genetic diversity in turkeys but also provides valuable insights into the impact of SVs on economic traits. Chapter 5 provides a general discussion of the key findings from the entire research work. |
