Nucleotide diversity on the ovine Y chromosome.
To investigate the impact of male-mediated introgression during the evolution of sheep breeds, a sequencing approach was used to identify single nucleotide polymorphisms (SNPs) from the male-specific region of the ovine Y chromosome (MSY). A total of 4380 bp, which comprised nine fragments from five MSY genes was sequenced within a panel of 14 males from seven breeds. Sequence alignment identified a single segregating site, an A/G SNP located approximately 1685 bp upstream of the ovine SRY gene. The resulting estimation of nucleotide diversity (piY = 0.90 +/- 0.50 x 10(-4)) falls towards the lower end of estimates from other species. This was compared with the nucleotide diversity estimated from the autosomal component of the genome. Sequence analysis of 2933 bp amplified from eight autosomal genes revealed a nucleotide diversity (piA = 2.15 +/- 0.27 x 10(-3)) higher than previously reported for sheep. Following adjustment for the contrasting influence of effective population size and a male biased mutation rate, comparison revealed that approximately 10% of the expected nucleotide diversity is present on the ovine Y chromosome.
Meadows
J R S
JR
CSIRO Livestock Industries, Level 5 Queensland Bioscience Precinct, 306 Carmody Road, St Lucia 4067, Australia.
Hawken
R J
RJ
Kijas
J W
JW
D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D014644:Genetic Variation; D008297:Male; D008969:Molecular Sequence Data; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D012756:Sheep / Q000235:genetics*; D013045:Species Specificity; D014998:Y Chromosome / Q000235:genetics*
D017931:DNA Primers