Abstract
Meiotic recombination, an important process during gamete formation, ensures proper chromosome segregation and contributes to genetic variation. It is clear from previous studies that at least one crossover (CO) per chromosome arm is necessary to avoid mis-segregation, and placement of CO is not random, showing preferences called “hotspots.” The total number of CO per spermatocyte differs between strains of mice, however this has not been evaluated in sheep. This study used a cytogenetic approach to quantify the number of CO per spermatocyte for three breeds of sheep: Suffolk, Icelandic, and Targhee. Further, the number and location of the CO were characterized for each chromosome pair within the spermatocytes. Significant differences in the number of CO per spermatocyte was identified between individuals within and across breeds (P<0.01). Additionally, a correlation was identified between the number of CO and length of the homologous chromosome pair, as well as distinct CO location patterns.