Identification of bovine and novel interferon-τ alleles in the American plains bison (bison bison) by analysis of hybrid cattle x bison blastocysts

• Published in: Molecular reproduction and development Vol. 70; no. 2; pp. 228 - 234
• Main Authors: Rasmussen, Terri A., Ealy, Alan D., Kubisch, H. Michael
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01-02-2005; Wiley-Liss
• Subjects: Alleles; Amino Acid Sequence; Animals; Biological and medical sciences; Bison - embryology; Bison - genetics; Bison bison bison; Blastocyst - physiology; Cattle; Cells, Cultured; Chimera - genetics; embryo; Embryology: invertebrates and vertebrates. Teratology; Embryonic Development - genetics; Embryonic Development - physiology; Female; Fertilization in Vitro; Fundamental and applied biological sciences. Psychology; Hybridization, Genetic - genetics; in vitro fertilization; Interferon Type I - genetics; Male; maternal recognition; Molecular embryology; Molecular Sequence Data; Polymorphism, Genetic; Pregnancy Proteins - genetics; RNA, Messenger - analysis; RNA, Messenger - genetics; Transcription, Genetic; Bison bison; embryo; Gene expression; In vitro fertilization embryo transfer; Signal transduction; Vertebrata; Mammalia; maternal recognition; Embryo culture; in vitro fertilization; Artiodactyla; Interferon tau; Ungulata; Polymorphism
• ISSN: 1040-452X; 1098-2795
• DOI: 10.1002/mrd.20198

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‐τ (IFN‐τ), and to identify novel IFN‐τ 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‐τ concentration was measured. On day 6 after onset of individual culture, attached outgrowths produced significantly more IFN‐τ than unattached viable or degenerate blastocysts. At this time, female conceptuses also produced significantly more IFN‐τ 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‐τ sequences as well as two novel sequences termed bisIFN‐τ1 and 2. To determine the origin of these, DNA was extracted from bison semen and analyzed by PCR. One bovine IFN‐τ sequence (bovIFN‐τ1d) as well as bisIFN‐τ2 and a third novel sequence bisIFN‐τ3 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. Mol. Reprod. Dev. 70: 228–234, 2005. © 2005 Wiley‐Liss, Inc.