Novel Y Chromosomal Haplotypes Reveal Wild and Domestic Sheep Diversity

1. Meadows J R S et al. (2004) Anim Genet. 35(5):379-85. Meadows J R S et al. (2006). Anim Genet. Epub Jul 26.Ryder M L. (1984) Evolution of domestic animals (ed Mason IL), pp. 63-84. Longman, New York. Scherf B D. (2000) Food and Agriculture Organization of the United Nations, pp. 58, Rome. Tapio M et al. (2006) Mol Biol Evol. (9):1776-1783. Epub Jun 16. Novel Y Chromosomal Haplotypes Reveal Wild and Domestic Sheep Diversity JENNIFER R. S. MEADOWS1,2, OLIVIER HANOTTE3, CORD DRÖGEMÜLLER4, JORGE CALVO5, ROBERT GODFREY6, DAVID COLTMAN7, JILLIAN F. MADDOX8, NURBIY MARZANOV9, JUHA KANTANEN10 IBRAHIM CEMAL11, ELISHA GOOTWINE12, STEFAN HEINDLEDER13 AND JAMES W. KIJAS1 1CSIRO Livestock Industries, St. Lucia, Australia, 2University of New England, Armidale, Australia, 3International Livestock Research Institute, Nairobi, Kenya, 4University of Berne, Berne, Switzerland, 5Unidad de Tecnologia en Production Animal, Zaragoza, Spain, 6University of the Virgin Islands, Kingshill, US Virgin Islands, 7University of Alberta, Alberta, Canada, 8University of Melbourne, Melbourne, Australia, 9Russian Academy of Agricultural Sciences, Dubrovitsy, Russia, 10MTT Agrifood Research Finland, Jokioinen, Finland, 11Faculty of Agriculture, Adnan Menderes University, Aydin, Turkey, 12Institute of Animal Science, The Volcani Center, Bet Dagan, Israel,13University of Adelaide, Adelaide, Australia. e-mail: Jennifer.Meadows@csiro.au • INTRODUCTION • Mesolithic man began sheep domestication 8000 – 9000 years ago (Ryder 1984), on going process which has resulted in the establishment of more than 1400 breeds (Scherf 2000) • Mitochondrial study show 4 (A, B, C, D) maternal signatures of domestication (Tapio et al, 2006) • Modern sheep breeding male mediated - controlled matings, small number of males contribute disproportionately large number of progeny to subsequent generations • Male specific region of the Y chromosome (MSY) - haploid-state alleles in the absence of X - Y recombination allows haplotypes to be identified which define individual male lineages • Very low rates of nucleotide diversity have been reported within the MSY(Meadows et al, 2004) • Ovis species in overlapping ranges can mate and produce fertile offspring – need to examine wild sheep from domestic ranges to trace lineages Table 1. Geographic origin, breed code, number of individuals and haplotype distribution for 74 breeds of domestic sheep and 6 wild species Table 2. Comparison of haplotypes generated through the combination of a compound microsatellite and five SNP, all observed from the sex-determining region (SRY) of the ovine Y chromosome. 1SRYM18 is a compound microsatellite comprised of a pentanucleotide [TTTTG]m and dinucleotide [TG]n repeat separated by an insertion/ deletion (indel G/-). The total SRYM18 length is reported in base pairs (bp). B A Figure. 1 Median joining network diagrams show the approximate location of the seven major geographic regions from which sheep were sampled. (A) Inset, a median network diagram was constructed using haplotype data from 668 domestic and wild sheep. The diagram illustrates the relationship between haplotypes when SRY M18 architecture present. (B) Breeds were grouped into seven major geographic regions as described in Table 1. North America is represented by two networks, one for wild and one for domestic sheep. O. ammon and O. vignei are absent from the world map as their region of origin was unknown. The size of individual network diagrams are region specific and are therefore not directly proportional to each other. Networks weighted and constructed as per Meadows et al, 2006. • RESULTS and DISCUSSION • oY1 only SNP that is polymorphic within species (A /G in O. aries) • A-oY1 had the highest frequency (77.7%) within 598 domestic sheep drawn from at least 74 breeds sampled from North America, the Caribbean, Africa, Europe, the Middle East and Central Asia,Asia, Australia • Size holoplasy in SRYM18 e.g. 143bp allele in Bighorn, Thinhorn, European Mouflon, Argali and domestic sheep • SRYM18 - compound repeat array displaying fixed differences that identified Bighorn, Thinhorn sheep as distinct from the European Mouflon, Urial, Argali and domestic sheep • Y haplotypes show 2 distinct domestic lineages (defined by A-oY1 vs G-oY1) • Mouflon all carry H6, only “wild” animal to group with domestic sheep • H6 very common, widespread (identical by state or identical by descent?) • Haplotype localisation - H12 Turkey; H9 Ethiopia; H10 Nigeria • Haplotype spread reflects animal movement - H8 from centre of known maternal domestication region, Near East, (Tapio et al, 2006) to Europe, Africa • H4 from Near East, east to Asia and maybe following route of Zebu cattle south-west to Africa (Ryder 1984) • Caribbean (H5 in Europe), Australian (H5 Europe, H4 Africa) sheep reflect sheep history • Caribbean sheep anecdotally African origin, but no H4, H8 or H9 • High rate of Y chromosomal dispersal during development of domestic sheep – 4.8% of total observed variation partitioned between major geographic regions (Caribbean, Nth America, Australia removed from calculation)