Identification of bovine and novel interferon-tau alleles in the American plains bison (Bison bison) by analysis of hybrid cattle x bison blastocysts.
The objective of this study was to generate bison x cattle hybrid embryos by in vitro fertilization, to assess their developmental potential, to determine the pattern of secretion of the embryonic signaling molecule interferon-tau (IFN-tau), and to identify novel IFN-tau mRNA polymorphism in the American plains bison. A total of 600 bovine oocytes were inseminated with frozen-thawed bison semen. Of these, 40.7% cleaved and 14.8% proceeded to the blastocyst stage. Individual blastocysts were cultured on a basement membrane (Matrigel) and their ability to attach and form outgrowths was monitored. A total of 36 blastocysts were cultured of which 22 formed outgrowths. During individual culture, medium samples were collected and their IFN-tau concentration was measured. On day 6 after onset of individual culture, attached outgrowths produced significantly more IFN-tau than unattached viable or degenerate blastocysts. At this time, female conceptuses also produced significantly more IFN-tau than their male cohorts. However, by day 12 this difference had disappeared. Total mRNA was extracted from three individual outgrowths and analyzed by RT-PCR. Subsequent sequencing of 28 clones showed several known bovine IFN-tau sequences as well as two novel sequences termed bisIFN-tau1 and 2. To determine the origin of these, DNA was extracted from bison semen and analyzed by PCR. One bovine IFN-tau sequence (bovIFN-tau1d) as well as bisIFN-tau2 and a third novel sequence bisIFN-tau3 were detected. This study demonstrates the feasibility of using hybrid embryos for the analysis of developmentally regulated gene expression in species where embryos may not be available.
Rasmussen
Terri A
TA
Division of Comparative Pathology, Tulane National Primate Research Center, 18703 Three Rivers Road, Covington, LA 70433, USA.
Ealy
Alan D
AD
Kubisch
H Michael
HM
D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D016164:Bison / Q000196:embryology* / Q000235:genetics*; D001755:Blastocyst / Q000502:physiology*; D002417:Cattle; D002478:Cells, Cultured; D002678:Chimera / Q000235:genetics; D047108:Embryonic Development / Q000235:genetics / Q000502:physiology; D005260:Female; D005307:Fertilization in Vitro; D006824:Hybridization, Genetic / Q000235:genetics*; D007370:Interferon Type I / Q000235:genetics*; D008297:Male; D008969:Molecular Sequence Data; D011110:Polymorphism, Genetic; D011257:Pregnancy Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D014158:Transcription, Genetic
D007370:Interferon Type I; D011257:Pregnancy Proteins; D012333:RNA, Messenger; C020947:interferon tau