Evidence for individual and between-family variability of the recombination rate in cattle

Abstract

We have conducted a study based on single sperm typing in a family design to assess patterns of variability of the male recombination rate in cattle. 2214 sperm of 37 bulls were typed for 11 loci on bovine Chromosomes (Chrs) 6, 23, and the sex chromosomes. Statistically significant individual variability of the recombination rate was observed for one interval in the pseudoautosomal region (PAR) of the bovine sex chromosomes; one marker interval on bovine Chr 23 exhibited individual variability that was close to significance. Thirty-five of the bulls were members of six paternal halfsib groups, and highly significant variability between families was found for one interval in the PAR. This variability may be due to DNA sequence differences in the PAR or to a genetic control of the recombination activity in this region. It is demonstrated that differences in the recombination rate of the magnitude observed in the present study may have a considerable impact on the power of QTL mapping experiments as well as on the sustainability of marker-assisted selection strategies.

Fine-Mapping of a Region of Variation in Recombination Rate on BTA23 to the D23S22–D23S23 Interval Using Sperm Typing and Meiotic Breakpoint Analysis

“…Recombination rate varied twofold between extremes for the DYA-DRB3 interval and fivefold between extremes for the DRB3-PRL interval. Recently, Simianer et al (1997) reported variation in for the CYP21-D23S21 interval, which is bounded by DRB3-PRL, consistent with the findings reported herein. For the DYA-PRL interval, differences in were attributable to bull 17, for which both DYA-DRB3 and DRB3-PRL were lower (Table 2).…”

“…In addition, the large number of meiotic products in a single semen sample permits accurate comparison of among different males (Park et al, 1995;Yu et al, 1996;Simianer et al, 1997) and fine-mapping of regions where variation in occurs (Hubert et al, 1994). Variation in within and between sexes may have important consequences for human and animal genetics, including accuracy of markerassisted selection and genetic diagnosis, identification of infertility and nondisjunction, and the understanding of linkage disequilibrium and haplotype evolution (Robinson, 1996).…”

An Enhanced Linkage Map of the Sheep Genome Comprising More Than 1000 Loci

“…Some of these differences are likely to be due to variation in recombination rates between individuals. This phenomenon has been demonstrated for male cattle, humans, and sheep (Yu et al 1996;Simianer et al 1997;Lien et al 1999), and it is likely that recombination rates will also vary amongst females. In addition, as shown by a recent study of human chromosome 19, sex differences in recombination rates also occur along individual chromosomes (Mohrenweiser et al 1998).…”

The Eutherian Pseudoautosomal Region

“…For example, while the genome-wide recombination rates in pigs are overall higher in females, its frequency in the PAR during male meiosis is almost 3-fold higher compared to female meiosis [Guo et al, 2009]. Similarly, genetic distances between the same PAR markers in cattle are 6 times longer in male meiosis than in female meiosis [Simianer et al, 1997], suggesting a higher recombination rate in this region in males.…”