MAPPING FOUR GENES FROM HUMAN CHROMOSOME 4 TO PORCINE CHROMOSOME 8 FURTHER DEVELOPS THE COMPARATIVE MAP FOR AN ECONOMICALLY IMPORTANT CHROMOSOME OF THE SWINE GENOME

Authors: Rohrer, Gary

Submitted to: Animal Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/7/1998
Publication Date: N/A
Citation: N/A

Interpretive Summary: Porcine chromosome 8 has been identified as possessing genes which influence components of litter size in swine. In order to identify the actual genes affecting litter size, we need to understand where the genes located on porcine chromosome 8 reside in the human genome. The homologous/analogous chromosome to porcine chromosome 8 is human chromosome 4.To facilitate the alignment of segments of porcine chromosome 8 with human chromosome 4, we mapped four genes located throughout human chromosome 4 to porcine chromosome 8. These assignments helped confirm that the genes located on the short arm of porcine chromosome 8 are aligned similarly on human chromosome 4. However, the genes located on the long arm of porcine chromosome 8 are in an opposite orientation relative to human chromosome 4, indicating that an inversion has occurred in this segment of the genome during evolution.

Technical Abstract: The comparative map between pig and man is at a very low resolution since few genes have been assigned in the porcine genome. Much of the information currently available only permits evaluation of the extent to which synteny has been conserved. A thorough evaluation of the conservation of gene order is often not possible. Since porcine chromosome (SSC) 8 has become the focal point of many efforts aimed at identifying quantitative trait loci affecting ovulation rate, genes distributed across human chromosome (HSA) 4 were physically mapped in the pig. A more refined comparative map of this region for these two species was produced. Four genes were selected based on their location in the human genome, the availability of nucleotide sequence and their genomic organization. The genes selected were fibroblast growth factor basic (FGF2; HSA 4q25-27), gonadotropin releasing hormone receptor (GNRHR; HSA 4q13), phosphodiesterase 6 B (PDE6B; HSA 4p16.3) and aminopeptidase S (PEPS; HSA 4p11-q12). Genomic libraries were screened via PCR and clones were physically assigned using fluorescence in situ hybridization. We physically mapped the four genes from HSA 4 to SSC 8p2.3 (PDE6B), 8p1.1 (PEPS), 8q1.1-1.2 (GNRHR) and 8q2.2-2.4 (FGF2). These assignments provide additional benchmarks for the comparative map and help define the level of gene order conserved between HSA 4 and SSC 8.