Conserved synteny and gene order difference between human chromosome 12 and pig chromosome 5

A comparative map of human chromosome 12 (HSA 12) and pig chromosome 5(SSC 5) was constructed using ten pig expressed sequence tags (ESTs). These ESTs were isolated from primary granulosa cell cultures by differential display (EST b10b), or from a granulosa cDNA library (VIIIE1, DRIM, N*9, RIIID2 an d RVIC1) or from a small intestine cDNA library (ATPSB, ITGB7, MYH9, and ST AT2). Also used were two Traced Orthologous Amplified Sequence Tags (TOASTs ) (LALBA, TRA1), one microsatellite-associated gene (IGF1) and finally five human YACs selected for their cytogenetic position, with a view to increas ing the number of informative markers for the comparison. Large-insert clon es were obtained by screening a pig bacterial artificial chromosome (BAC) l ibrary with specific primers for each EST and TOAST and for IGF1. These BAC s were used as probes for fluorescent in situ hybridisation (FISH) both on porcine and human metaphases. In addition, the human YACs were FISH mapped on pig chromosomes. This allowed us to refine and, in some cases, to correc t the previous mapping obtained with a somatic cell hybrid panel. While the se data confirm chromosome painting results showing that the distal part of SSC 5p arm is conserved on HSA 22, while the rest of the chromosome corres ponds to HSA 12, they also demonstrate gene-order differences between human and pig. In addition, it was also possible to determine the position of th e synteny breakpoint. Copyright (C) 2001 S. Karger AG, Basel.