Submitted to: Molecular Reproduction and Development
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 11, 2003
Publication Date: August 1, 2003
Citation: KIM, J.G., VALLET, J.L., CHRISTENSON, R.K. CHARACTERIZATION OF PORCINE UTERINE AMPHIREGULIN. Molecular Reproduction and Development. 2003. v. 65(4). p. 366-372. Interpretive Summary: Uterine capacity is a component trait contributing to litter size in swine. Previous genome mapping revealed a region on porcine chromosome 8 associated with uterine capacity. Comparison of porcine and human genetic maps suggests that the porcine amphiregulin gene may be located in this region. The objectives of this study were to 1) obtain full-length amphiregulin cDNA, 2) examine amphiregulin mRNA expression from porcine endometrium, and 3) map the amphiregulin gene. Using reverse transcription- polymerase chain reaction and by screening of an expressed sequence tag library, we obtained full-length amphiregulin cDNA. Amphiregulin mRNA was expressed in endometrium of both Meishan and White composite pigs on day 30 of pregnancy. Amphiregulin may support early development in the pig. The amphiregulin gene was mapped to 65 cM on chromosome 8 near the region that was known to be associated with uterine capacity. These novel findings may provide insight into the function of amphiregulin during pregnancy in pigs and support our hypothesis that the amphiregulin gene may affect uterine capacity.
Technical Abstract: Uterine capacity contributes to litter size in swine. Previous genome mapping revealed a quantitative trait locus (QTL) for uterine capacity on chromosome 8. Comparison of porcine and human genetic maps suggests that the porcine amphiregulin gene may be in this region. Objectives of this study were to 1) clone the full length cDNA for amphiregulin, 2) examine whether amphiregulin mRNA is expressed, and 3) map the amphiregulin gene. Using reverse transcription-polymerase chain reaction and iterative screening of an expressed sequence tag library, we obtained 1109 and 1221 bp amphiregulin cDNAs. The deleted 112 bp correspond to exon 5 of the human amphiregulin gene. Exon 5 codes for the cytoplasmic domain of amphiregulin. The loss of exon 5 caused a frame shift, inserting a stop codon after the transmembrane domain corresponding to human exon 4. Both forms of amphiregulin mRNAs were present in the endometrium of day 30 pregnant White ecomposite and Meishan gilts. The short form appears to be predominant. Sequences of clones from a porcine bacterial artificial chromosome genomic library containing exon 5 of the amphiregulin gene indicated that the deletion was likely caused by differential splicing. Amphiregulin gene was mapped to 65 cM on chromosome 8 near the uterine capacity QTL using three microsatellite markers. These novel findings may provide insight into the function of amphiregulin during pregnancy in pigs.