CHARACTERIZATION OF A POLYMORPHIC HEAT-SHOCK PROTEIN-70 GENE IN SWINEOUTSIDE THE SLA MAJOR HISTOCOMPATIBILITY COMPLEX

To characterize a hitherto unidentified swine Hsp70 gene, a cDNA libra ry was prepared from total RNA isolated from swine lymphocytes and hea t-shocked at 42-degrees-C for 2 h. One positive clone with a 2.6 kb in sert was found. Its sequencing revealed a maximum homology with the hu man inducible Hsp70B' gene. The genomic polymorphism of this insert wa s investigated by restriction fragment length polymorphism (RFLP) in a n informative family for the major histocompatibility complex SLA. Dig estion with PvuII generated 8 bands which were common to both parents, and for the male two extra bands at 0.69 and 0.64 kb. After digestion with PstI, there was also an extra band at 1.6 kb for the male in add ition to the seven bands common to both parents. The eleven offsprings ' RFLP patterns exibited all the common parental bands, but four pigle ts displayed the male's specific bands in addition. All the polymorphi c bands belonged to the same locus and segregated independently of SLA . Restriction mapping of the Hsp70 gene indicated the absence of intro ns, and showed that the polymorphic PstI site was located upstream of the gene's 5' coding region, and the PuuII site inside its coding regi on.