Submitted to: Animal Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 6, 2002
Publication Date: December 1, 2002
Citation: KIM, J.G., NONNEMAN, D.J., VALLET, J.L., CHRISTENSON, R.K. MAPPING OF THE PORCINE ALPHA-FETOPROTEIN (AFP) GENE TO SWINE CHROMOSOME 8. ANIMAL GENETICS. 2002. v. 33(6). p. 471-472. Interpretive Summary: Uterine capacity is a component trait contributing to litter size in the pig. Previous gene mapping analyses identified a region on chromosome 8 that is important for uterine capacity. Alpha-fetoprotein (AFP) is the predominant protein in fetal plasma during early gestation in the pig. Comparison of porcine and human genetic maps suggests that the AFP gene may be located in this region. We have obtained the full coding regions of the porcine AFP (GenBank accession no. AF517770). Using a single nucleotide polymorphism marker for AFP, the AFP gene was mapped at position 60.4 cM on chromosome 8 in the Meat Animal Research Center (MARC) swine linkage map. The location of the porcine AFP gene is on porcine chromosome 8 and in the region that is known to be important for uterine capacity. The data support AFP as a candidate gene for uterine capacity. These findings will aid in the study of the role of AFP in uterine capacity and litter size in the pig.
Technical Abstract: Alpha-fetoprotein is the predominant protein in fetal plasma during early gestation (Days 15-30) in the pig. Comparison of porcine and human genetic maps suggests that the AFP gene may be located near the uterine capacity quantitative trait locus (QTL) on porcine chromosome 8. A cDNA clone containing the full coding region of the porcine alpha-fetoprotein (AFP) has been isolated (GenBank accession no. AF517770) from the "Meat Animal Research Center (MARC) 2 PIG" expressed sequence tag (EST) library by iterative screening. After alignment of the sequence with the human AFP gene sequence, primers to amplify across putative intron 10 were designed based on the porcine cDNA sequence. The PCR product containing putative intron 10 was confirmed by sequencing (GenBank accession no. AY120900). The amplified genomic DNA of eight parents (seven F1 sows and one White composite boar) from the MARC Swine Reference Population were bidirectionally sequenced and evaluated for polymorphisms. A C/T single nucleotide polymorphism was detected in intron 10, position 476 from the exon/intron boundary. This polymorphism was heterozygous in six of the seven F1 sows. An assay was designed to genotype this polymorphism on a MALDI-TOF mass spectrometer. This marker generated 68 informative meioses in the MARC Swine Reference Population. The AFP gene was mapped to chromosome 8 position 60.4 cM, which is the same position as marker S0017 on the current MARC swine chromosome 8 linkage map (http://www.marc.usda.gov/) using CRI-MAP. The most significant two-point linkage detected was with S0017 (LOD=18.36) at 0 recombination. The location of the porcine AFP gene is within the 95% confidence interval of uterine capacity QTL on chromosome 8 (Rohrer et al., J Anim Sci 77, 1385-1391, 1999).