A LINKAGE GROUP ON PIG CHROMOSOME-4 COMPRISING THE LOCI FOR BLOOD-GROUP-L, GBA, ATP1B1 AND 3 MICROSATELLITES

Restriction fragment length polymorphisms (RFLPs) were described for t he porcine loci for P-glucosidase (GBA) and the beta-polypeptide 1 of the Na+,K+-transporting ATPase (ATP1B1). Linkage analyses using a thre e-generation pedigree provided evidence for the assignment of ATP1B1, GBA and two microsatellite loci (S0001 and S0067) to a previously desc ribed linkage group comprising the loci for blood group L (EAL) and an anonymous microsatellite (S0097). The linear order of the six markers was determined with confidence by multipoint analyses and the length of the linkage group was estimated at 88 CM. This linkage group was as signed to pig chromosome 4 on the basis of a previous physical localiz ation of the ATP1B1 gene. In situ hybridization data for S0001 present ed in this study were consistent with a localization on chromosome 4 a nd suggested a regional localization to 4p12-p13. The present study re veals conflicting data concerning the genetic localization of the K88 loci controlling the expression of the receptors for the E. coli pilus antigens. One group has reported data suggesting a loose linkage betw een K88 and EAL, now mapped to chromosome 4, whereas two other groups have found linkage between K88 and the transferrin locus (TF), mapped to chromosome 13 by in situ hybridization.