Submitted to: Midwestern Section of the American Society of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: 11/26/2004
Publication Date: 9/1/2005
Citation: Vallet, J.L., Freking, B.A., Leymaster, K.A., Christenson, R.K. 2005. A 12 bp insertion/deletion (in/del) polymorphism in the secreted folate binding protein (sFBP) gene is associated with uterine capacity and ovulation rate in swine [abstract]. Journal of Animal Science. 83 (Supplement 2):87.
Technical Abstract: Secreted FBP is present in the uterus during early pregnancy. This protein increases two orders of magnitude during early gestation and plays a role in transport of folate to the conceptus. A comparison of the nucleotide sequence of the cDNA and gene for sFBP indicated a 12 bp difference in exon 1 of the gene. The 12 bp in/del polymorphism is within a set of 12 bp degenerate tandem repeats, creating either 2 or 3 repeats, which alters a possible RNA hairpin structure in this region. Our objective was to determine whether the in/del was associated with reproductive traits in swine. Gilts (n = 407) from the control, ovulation rate and uterine capacity selected lines at MARC were unilaterally hysterectomized-ovariectomized (UHO), mated, and killed at 105 days of gestation. Corpora lutea and live fetuses were counted for each gilt, a blood sample was collected from each fetus, and each fetus and placenta was weighed. A second group of intact gilts (n = 131) from the OR line was mated and farrowed. Numbers of fully formed piglets and piglets born alive were recorded. DNA was isolated from each gilt to determine genotype. Secreted FBP gene specific primers were developed and used to amplify the region surrounding the in/del, resulting in products of 169 (del) and 181 (in) bp, which were resolved on a 10% acrylamide gel. The in/del had no effects on fetal weight, placental weight or fetal hematocrit. Uterine capacity was greater (P < 0.01) for del/del (8.0 +/ 0.5) than for in/in UHO gilts (6.8 +/ 0.1), and in/del gilts were intermediate (7.2 +/ 0.2). There were fewer (P < 0.05) CL for del/del (13.7 +/ 0.6) than for in/in or in/del UHO gilts (15.2 +/ 0.2 for both). No effects of genotype on litter size of intact gilts from the OR line were detected. These results indicate that the del allele of the sFBP gene is associated with increased uterine capacity and decreased ovulation rate, resulting in no net effect on litter size.