FISH MAPPING OF 7 CDNA SEQUENCES IN THE PIG

Fluorescence in situ hybridization (FISH) technique was applied to loc alize seven clones derived from a porcine (SSC) intestinal directional ly cloned cDNA library. The size of the clones ranged from 1.1 to 1.3 kb. Three of the clones corresponded to histidyl-tRNA synthetase (HARS ), immunoglobulin alpha (IGA) and lysozyme (LYZ) and mapped to SSC2q28 -q29, 7q2.6 and 5p11 respectively. The available human-pig comparative painting data and sequence homology comparisons assisted in a tentati ve identification of the other three clones as glutathione-S-transfera se (GST), glutathione-S-transferase mu (GSTM1) and immunoglobulin lamb da gene cluster (IGL@). These clones mapped to SSC14q21, 5q2.4 and 14q 22-q23 respectively. The remaining clone representing an EST mapped to 1p24-p25. These localizations contribute to the transcript map in pig and are significant as comparative markers. Difficulties associated w ith the mapping of small sequences using FISH are discussed.