Showing papers by "Tad S. Sonstegard published in 1999"

Turkey Sperm Mobility Influences Paternity in the Context of Competitive Fertilization

Abstract: We have devised a novel means of investigating competitive fertilization in turkeys, using microsatellite genotyping to identify male parentage. Our results demonstrate that sperm mobility is a mechanism responsible in part for paternity efficiency in turkeys. Sperm mobility is composed of several parameters in which sperm motility is a component. Differences between ejaculates in the number of sperm penetrating into a dense, insert, nontoxic solution were measured and used to classify males into high, average, or low sperm mobility phenotypes. Microsatellite genotyping was used to determine parentage of poults after equal numbers of sperm from 10 males (either high or average phenotype, n = 5, mixed with low phenotype, n = 5) were inseminated simultaneously. In a separate study, the numbers of sperm hydrolyzing the perivitelline layer of eggs were compared between hens inseminated with sperm from high-, average-, or low-phenotype males. Overall, heterospermic inseminations resulted in consistently fewer offspring produced by low-mobility phenotype males. This correlated with physiological data in which semen from the low-mobility males had reduced numbers of sperm at the fertilization site as determined by sperm hole counts in the perivitelline layer of eggs. This is the first illustration of a measurable sperm trait predictive of paternity success in a competitive fertilization trial in turkeys, a species that is predominately reproduced by artificial insemination of multiple-sire pools.

Isolation of Complementary Deoxyribonucleic Acids Encoding Putative Secreted and Membrane-Bound Folate Binding Proteins from Endometrium of Swine

Abstract: Two distinct forms of endometrial folate binding protein (FBP) cDNAs were isolated using reverse transcription-polymerase chain reaction and 3' and 5' rapid amplification of cDNA ends (RACE) procedures. On the basis of the absence or presence of an intact glycophosphatidylinositol linkage site in the C terminus of the predicted amino acid sequences, the two forms appear to encode secreted and membrane-bound forms of FBP. The cDNAs for the putative secreted and membrane forms encoded 252- and 249-amino acid proteins, respectively, that were 73% identical with each other and were 66-82% identical with other known FBPs. However, the nucleotide sequences within the 5' untranslated region and from codons 224 and 223 of the secreted and membrane forms, respectively, to the 3' ends of each RNA, were divergent. The divergence in the 3' ends of the two cDNAs was exploited to determine changes in concentrations of each mRNA in the endometrium during the estrous cycle and early pregnancy. Northern blots of endometrial total RNA probed with a putative secreted FBP specific probe indicated that mRNA concentrations do not change during early pregnancy. In contrast, blots probed with a putative membrane FBP specific probe indicated that mRNA concentrations increase dramatically from Day 15 to Day 24 of pregnancy. Finally, N-terminal amino acid sequencing of FBP purified from Day 15 pregnant uterine flushings matched the secreted form of FBP mRNA. These data are consistent with a role for putative secreted and membrane-bound forms of FBPs in the transport of folate to the developing swine conceptus during early pregnancy.

Physical mapping of the bovine, caprine and ovine homologues of the paired box gene PAX8.

Abstract: The PAX8 gene, a member of the human paired box gene family, was mapped by FISH to chromosome 11 in cattle and goat and to the short arm of chromosome 3 in sheep. The cytogenetic position of PAX8 on BTA 11 and on its homologue OAR 3p lies in the region where the interleukin beta (IL1B) gene has been previously located, (BTA 11q22. 1-->q22.3 and OAR 3p25-->q26 respectively; Lopez-Corrales et al., 1998). The results indicated that PAX8 as well as interleukin beta and interleukin alpha (IL1B and IL1A) genes detected on the human chromosome segment HSA 2q13-->q21 maintain a similar order and location in these three related species. In addition, the breakpoint in conserved synteny can now be narrowed to a position between the protein C (PROC) and PAX8 genes, which lie in close proximity on HSA 2.