Differential selection patterns between sexes could be revealed by ROH analysis in dairy goats

DEMYDA PEYRÁS S; PIROSANTO Y; RAMON M; ZIEGLER T; SANCHEZ M; FERNANDEZ ME; MUÑOZ ME; SOLÉ M; MOLINA A

Barcelona

Congreso; 37th International Society for Animal Genetics Conference; 2019

International Society for Animal Genetics

Runs of homozygosity (ROH) are becoming a valuable tool to analyze the evolution and genomic characteristics in animal populations. Here, we determined ROH patterns of 624 goats of the Spanish Florida breed to explore sex-related differences. Average ROH length, count and FROH (as a measure of the proportionof the genome covered by ROH) were obtained per individual, chromosome and sex group using DETECTRUNS package of R software, and differences were examined using general linear models (GLM) and LS preplanned comparison tests. Our results showed that males have longer ROH than females (2.559 vs 2.472 Mp respectively, P < 0.05), but with differences being only significant at CHI6 and CHI17 (P < 0.01). At the individual level, the number of ROH was highly variable and no significant differences were found between sex groups and chromosomes. Only for the CHI5, the number of ROH observed differed between males and females (1.54 and 1.85 respectively; P < 0.01). In a further analysis, the ROH counts were also determined in ROH > 8Mb, normally associated with recent inbreeding events. It was noteworthy that only 36% of females showed at least 1 ROH > 8Mb in comparison with 43% of the males, but with females showing an increased number of ROH in CHI4 (1.60 times higher, P < 0.05). The analysis of FROH showedstatistical differences only in CHI23, where the mean value of males was 1.63 times higher than females. In the case of recent FROH (derived from ROH > 8Mb), differences were observed in CHI8, where males showed a 3- times increased coverage. Finally, we also performed the analysis of the ROH incidence in an SNP basis which determined the existence of specific genomic regions were males showed increased ROH percentages of incidence than females and vice-versa. Those regions were more confined in females (covering part of 14 chromosomes) than in males (which included 17 chromosomes) in the general analysis. The analysis of ROH > 8Mb showed the opposite, with ROH distributed over 8 chromosomes for females and only in 3 chromosomes for males, but with an important ROH concentration in CHI11 for the latter. The higher number of ROH > 8Mb in males and the fact that they are confined to certain regions could be a consequence of recent selection (6 generations), with a greater selection intensity in the males, and in regions possible linked to productive traits. Our study suggests that ROH could be used to reveal genomic differences between sexes in goats.