DEVELOPING MICROSATELLITE MARKERS FROM CDNA - A TOOL FOR ADDING EXPRESSED SEQUENCE TAGS TO THE GENETIC-LINKAGE MAP OF THE CHICKEN

A chicken embryonic cDNA library was screened with a (TG)(13) probe in order to develop polymorphic microsatellite markers. The redundancy o f the embryonic cDNA library with a chicken brain cDNA library, which was used for microsatellite development in a previous study, was extre mely high. Of the 300 (TG)(13) positive clones, only 80 were unique fo r the embryonic cDNA library. Still, nine expressed sequences derived from the embryonic cDNA library were mapped in the Wageningen (WAU) re source population. In addition seven microsatellite markers from the c hicken brain cDNA library, which were monomorphic or unlinked in the t wo international reference families in the previous study, were also m apped in the WAU population. Three of the 16 mapped chicken expressed sequence tags (ESTs) showed relatively high percentages of sequence si milarity to sequences found in other species. As two of these genes, R AB6 and ZFX/ZFY, have been mapped in humans, they contribute to the co mparative map of the chicken.