Molecular diversity of cattle, sheep and goats: historic migrations, modern breeding and future conservation.
Concerns about the reduction of genetic diversity in domestic animals have motivated several studies of molecular diversity within and among breeds. However, this has not yet led to any consensus on how to use these data for decisions on conservation priorities. Supported by two EU projects, we have compared the microsatellite and
Y-chromosomal diversity of European and Middle-Eastern breeds of cattle, sheep and goat. For all three species, regional clusters and genetic clines with a decrease in the number of alleles from South-East to North-West may reflect the Neolithic migration of livestock into Europe along different routes. Microsatellites as well as
Y-chromosomal haplotypes from cattle and goat show a clear geographical partitioning, indicating a restriction of gene flow by distance. The diversity pattern of cattle is proposed to be shaped also by (1) introgression of wild aurochs bulls in all northwestern dairy and in several Spanish breeds, and (2) expansion of a few popular breeds. However, gradients of cattle genetic diversity still coincide with historic boundaries that divided the northern and southern parts of France and Germany, respectively.
For the central and northwestern sheep a poor correlation between geography, genetic distances and Y-chromosomal haplotypes indicate a relatively frequent outcrossing with rams from distant regions. Despite a low number of alleles in the cattle, sheep and goat breeds from central and northwestern Europe, these breeds have a higher level of distinctness than southeastern and Asian breeds. We propose that molecular diversity and breed distinctness are to separate, but potentially conflicting criteria for conservation.
Hans Lenstra, Faculty of Veterinary Medicine Utrecht the Netherlands
After the seminar refreshments will be served, near lecture room
For further information contact:
Dr. Edwin Cuppen (088 75 519 69)
Dr. Guido van den Ackerveken (088 75 530 13)
Prof. dr. Cisca Wijmenga (088 75 584 27) or Dr. Bobby Koeleman (088 75 579 25)
or visit the Human Genetics homepage: www.genen.umcutrecht.nl
11 May 2006 04:00 PM, Roze collegezaal, UMC Utrecht