SEQUENCE-TAGGED MICROSATELLITE SITES AS MARKERS IN CHICKEN REFERENCE AND RESOURCE POPULATIONS

Two chicken genomic libraries were screened for the presence of poly(T G/AC) microsatellite tracts. The number of positive clones was low, co nfirming the low frequency of such microsatellites in the chicken geno me relative to mammalian genomes. Polymorphism of 29 microsatellite tr acts, comprising 11 from the library screening and 18 obtained from Ge nBank, was examined in the East Lansing and Compton reference families , in a resource population formed by a cross between a single White Ro ck broiler and inbred Leghorn females, and in a panel of birds from fi ve layer stocks. Twenty microsatellites, primarily of the poly(TG/AC) type, were polymorphic in at least one of the populations. Thirteen of the microsatellites were polymorphic in the East Lansing reference fa mily and 13 were also polymorphic in the resource population, confirmi ng that the genetic distance between White Rock and White Leghorn is a bout as great as between Jungle fowl and White Leghorn. Only six micro satellites were polymorphic in the Compton reference family, formed by a cross between two White Leghorn strains. Twelve of the microsatelli tes were mapped in the East Lansing and/or Compton reference families. These were well dispersed among the various linkage groups and did no t show any indications of terminal clustering.