Submitted to: Mammalian Genome
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/2/1999
Publication Date: N/A
Citation: N/A Interpretive Summary: Orexin-A and orexin-B are closely-related peptide hormones that are made from the same gene. Injection of orexins has resulted in increased food consumption in rodents, sheep, and young pigs. Locating (mapping) the orexin gene within the pig's chromosomes will permit the application of new biotechnology designed to rapidly select for genetic improvements in appetite and growth. The present study established the location of the pi orexin gene to be on pig chromosome 12. Genetic selection based on naturally occurring differences in the orexin gene can now be performed. This new information is being used by scientists to determine the importance of this gene on swine production parameters. Improved appetite, growth, and production efficiency will improve profitability for the producer and will maintain an affordable and plentiful supply of pork for the consumer.
Technical Abstract: The prepro-orexin gene was mapped to SSC12 p13-p11 with complete concordance using the somatic cell hybrid panel. The NlaIII polymorphic site was genotyped in the PiGMaP reference families. Linkage mapping with the PiGMaP families confirmed the physical mapping location of prepro-orexin. The results of two-point analysis showed that prepro-orexin ngene significantly linked to three markers on porcine chromosome 12 (SSC12). The linked markers (LOD score and cM distances in parentheses) were PRKARIA (4.7, 34), Chl-l (8.1, 37), and BRCAl (5.85, 95). To date, prepro-orexin has not been mapped in the human. Based on information from this mapping study and chromosomal painting, we can predict that the human prepro-orexin gene is located on chromosome 17 (q21-q22). The effect of prepro-orexin on regulating feed intake and the localization of this gene in the pig genome suggests that it may be a candidate gene for appetite. To date, no quantitative trait loci have been found on chromosome 12 for feed intake and growth. Further study on the effect of this gene on feed intake and growth is underway.