GENOMIC MAPPING OF CHEMOKINE AND TRANSFORMING GROWTH-FACTOR GENES IN SWINE

Five chemokine genes, transforming growth factors alpha, beta 2 and 3 (TGFBA, TGFB-2, and TGFB-3), interleukin 8 (IL-8), and monocyte chemoa ttractant protein 2 (MCP-2), were mapped to porcine linkage groups on Chromosomes 3q, 10p, 7q, 8, and 12q, respectively. Restriction fragmen t length polymorphisms (RFLPs) for these genes were developed by South ern blot hybridization after digestion of porcine genomic DNA with Bam HI and MspI (TGFBA), BamHI and PvuII (TGFB-2), HindIII (TGFB-3), BglII (IL-8), and PstI (MCP-2) and used to genotype the USDA-MARC Swine Ref erence Population pigs. Sufficient informative meioses, 61 (TGFBA), 58 (TGFB-2), 28 (TGFB-3), 38 (IL-8), and 156 (MCP-2), were available to pursue two-point pairwise linkage analysis with over 1,000 existing lo ci in the USDA-MARC genome database to establish initial linkage (LOD > 3). Multi-point analysis with CRIMAP determined the most likely orde r for each new marker. The assignment of the five chemokine genes in s wine concurs with previous porcine/human chromosomal homologies based on results from ZOO-FISH and chromosomal painting experiments. These f indings add five new informative Type I markers within a single gene f amily to the swine genome and may help us understand the genetic basis for disease resistance in livestock.