From cytogenetics to cytogenomics: a new era in the diagnosis of chromosomal abnormalities in domestic animals

Identification of chromosomal abnormalities is an important issue in animal breeding and veterinary medicine. Routine cytogenetic diagnosis of domestic animals began in the 1960s with the aim of identifying carriers of centric fusion between
chromosome 1 and 29 in cattle. In the 1970s, chromosome banding techniques were introduced, and in the 1980s, the first cytogenomic techniques, based on the development of locus- and chromosome-specific probes, were used. Since the beginning of the twenty-first century, molecular techniques (such as polymorphism of microsatellite markers, droplet digital PCR, SNP microarrays, and whole genome sequencing) have begun to be widely used in animal breeding. This review is focused on the cytogenomic diagnosis of chromosome abnormalities in cattle, horses, pigs, dogs, and cats. We show that these approaches are very useful in large-population screening studies of the prevalence of aneuploidies (mainly of sex chromosomes) and structural rearrangements (centric fusions and reciprocal translocations).