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United States Department of Agriculture

Agricultural Research Service

Title: (Brief Note) Linkage Mapping of the Porcine Chromogranin B (Chgb) Gene to Chromosome 17

Authors
item Kim, Jong
item Nonneman, Danny
item Vallet, Jeffrey
item Rohrer, Gary
item Christenson, Ronald

Submitted to: Animal Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 5, 2005
Publication Date: April 1, 2005
Citation: Kim, J.G., Nonneman, D., Vallet, J.L., Rohrer, G.A., Christenson, R.K. 2005. (Brief Note) Linkage mapping of the porcine chromogranin B (CHGB) gene to chromosome 17. Animal Genetics. 36(2):168.

Interpretive Summary: Chromogranins are a group of proteins that mediate sorting and aggregation of hormones and neuropeptides into cellular secretory granules. One of the these proteins, Chromogranin B (CHGB; also called secretogranin I), is found in secretory granules throughout cells of the endocrine and nervous system. Because of its role in hormone secretion, CHGB is critically involved in reproductive function. Two cDNA clones, one containing the full coding region (pCHGB1; GenBank accession no. AY613916) and another containing a partial coding region (pCHGB2; GenBank accession no. AY623647) of the porcine CHGB were isolated from the Meat Animal Research Center (MARC) 2PIG cDNA library and sequenced. A single nucleotide polymorphism (SNP) in the coding region (nucleotide 1568, AY613916, and nucleotide 876, AY623647) was identified in the 2 clones. This SNP was evaluated in the eight parents (seven F1 sows and one White composite boar) of the MARC Swine Reference Population. The SNP was confirmed and its inheritance could be observed in the piglets from 5 of the 7 F1 sows and 1 boar in the MARC Swine Reference Population. Using these inheritance patterns, the CHGB gene was determined to be on swine chromosome 17. This is consistent with previous observations indicating that the human CHGB gene is located in an area of human chromosome 20 that is similar to the area of swine chromosome 17 containing the CHGB gene.

Technical Abstract: Chromogranins mediate sorting and aggregation of hormones and neuropeptides into cellular secretory granules. Because of its role in hormone secretion, CHGB is critically involved in reproductive function. Two cDNA clones, one containing the full coding region (pCHGB1; GenBank accession no. AY613916) and another containing a partial coding region (pCHGB2; GenBank accession no. AY623647) of the porcine CHGB, were isolated from the Meat Animal Research Center (MARC) 2PIG expressed sequence tag (EST) library. A silent single nucleotide polymorphism (SNP) in the coding region (nucleotide 1568, AY613916, and nucleotide 876, AY623647) was identified in the 2 clones. Primers were designed to amplify a 941 bp product in the coding region of the gene. The forward and reverse primers correspond to bases 1056-1075 and 1996-1975 of the porcine CHGB cDNA (GenBank accession no. AY613916). This SNP was evaluated in the eight parents (seven F1 sows and one White composite boar) of the MARC Swine Reference Population by sequencing PCR products amplified from genomic DNA. The A/G polymorphism at nucleotide 1568 of GenBank (accession no. AY613916) was heterozygous in 5 of the 7 F1 sows and 1 boar of the MARC Swine Reference Population. An assay was designed to genotype this polymorphism by primer extension with analyte detection on a MALDI-TOF mass spectrometer using a pair of internal primers. The internal forward and tailed reverse primers correspond to bases 1459-1480 and 1660-1639 of the porcine CHGB cDNA (GenBank accession no. AY613916). This marker generated 64 informative meioses in the MARC swine reference population. The CHGB gene was mapped using CRI-MAP to chromosome 17, relative position 30.2 cM, which is the same position as microsatellite marker SWR1133 on the current MARC swine chromosome 17 linkage map (http://www.marc.usda.gov/). The most significant two-point linkage of CHGB detected was with SWR1133 (LOD = 18.06) at 0.0 recombination.

Last Modified: 8/22/2014
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