title: Cloned embryos from semen. Part 2: intergeneric nuclear transfer of semen-derived eland (Taurotragus oryx) epithelial cells into bovine oocytes.
abstract: The production of cloned offspring by nuclear transfer (NT) of semen-derived somatic cells holds considerable potential for the incorporation of novel genes into endangered species populations. Because oocytes from endangered species are scarce, domestic species oocytes are often used as cytoplasts for interspecies NT. In the present study, epithelial cells isolated from eland semen were used for intergeneric transfer (IgNT) into enucleated bovine oocytes and compared with bovine NT embryos. Cleavage rates of bovine NT and eland IgNT embryos were similar (80 vs. 83%, respectively; p > 0.05); however, development to the morula and blastocyst stage was higher for bovine NT embryos (38 and 21%, respectively; p < 0.0001), than for eland IgNT embryos (0.5 and 0%, respectively). DNA synthesis was not observed in either bovine NT or eland IgNT cybrids before activation, but in 75 and 70% of bovine NT and eland igNT embryos, respectively, cell-cycle resumption was observed at 16 h postactivation (hpa). For eland IgNT embryos, 13% had > or = 8 cells at 84 hpa, while 32% of the bovine NT embryos had > or = 8 cells at the same interval. However, 100 and 66% of bovine NT and eland IgNT embryos, respectively, that had > or = 8 cells synthesized DNA. From these results we concluded that (1) semen-derived epithelial cell nuclei can interact and be transcriptionally controlled by bovine cytoplast, (2) the first cell-cycle occurred in IgNT embryos, (3) a high frequency of developmental arrest occurs before the eight-cell stage in IgNT embryos, and (4) IgNT embryos that progress through the early cleavage stage arrest can (a) synthesize DNA, (b) progress through subsequent cell cycles, and (c) may have the potential to develop further.
authors.affiliation: Department of Animal Sciences, Louisiana State University Agricultural Center, Baton Rouge, Louisana 70803, USA.
authors.forename: Liesl
authors.initials: L
authors.lastname: Nel-Themaat
authors.forename: Martha C
authors.initials: MC
authors.lastname: Gómez
authors.forename: C Earle
authors.initials: CE
authors.lastname: Pope
authors.forename: Monica
authors.initials: M
authors.lastname: Lopez
authors.forename: Gemechu
authors.initials: G
authors.lastname: Wirtu
authors.forename: Jill A
authors.initials: JA
authors.lastname: Jenkins
authors.forename: Alex
authors.initials: A
authors.lastname: Cole
authors.forename: Betsy L
authors.initials: BL
authors.lastname: Dresser
authors.forename: Kenneth R
authors.initials: KR
authors.lastname: Bondioli
authors.forename: Robert A
authors.initials: RA
authors.lastname: Godke
mesh_terms: D000818:Animals; D000866:Antelopes / Q000502:physiology*; D001973:Bromodeoxyuridine / Q000494:pharmacology; D002417:Cattle; D002453:Cell Cycle / Q000502:physiology; D002478:Cells, Cultured; D019976:Cloning, Organism / Q000379:methods*; D004247:DNA / Q000096:biosynthesis; D004847:Epithelial Cells / Q000166:cytology / Q000502:physiology*; D005260:Female; D005434:Flow Cytometry; D008297:Male; D053652:Nuclear Transfer Techniques; D009865:Oocytes / Q000166:cytology / Q000502:physiology*; D012661:Semen / Q000502:physiology*
chemical_list: D004247:DNA; D001973:Bromodeoxyuridine