title: Bovine somatic cell nuclear transfer using recipient oocytes recovered by ovum pick-up: effect of maternal lineage of oocyte donors.
abstract: The efficiency of bovine nuclear transfer using recipient oocytes recovered by ultrasound-guided follicle aspiration (ovum pick-up [OPU]) was investigated. Oocyte donors were selected from 2 distinct maternal lineages (A and B) differing in 11 nucleotide positions of the mitochondrial DNA control region. A total of 1342 cumulus-oocyte complexes (COCs) were recovered. The numbers of total COCs and class I/II COCs recovered from donors of lineage A were higher (P < 0.001) than those obtained from lineage B. Follicle aspiration once per week yielded a higher (P < 0.001) total number of COCs per session than aspiration twice per week, whereas the reproduction status of donors (heifer vs. cow) had no effect on OPU results. Of the 1342 oocytes recovered, 733 (55%) were successfully matured in vitro and used for nuclear transfer. Fusion was achieved in 550 (75%) karyoplast-cytoplast complexes (KCCs), resulting in 277 (50%) cleaved embryos on Day 3. On Day 7 of culture, 84 transferable embryos (15% based on fused KCCs) were obtained. After 38 transfers (10 single, 22 double, and 6 triple transfers), 9 recipients (8 double and 1 triple transfer) were diagnosed as pregnant on Day 28, corresponding to a pregnancy rate of 24%. The proportion of transferable embryos on Day 7 was significantly (P < 0.05) influenced by maternal lineage of oocyte donors and by the frequency of follicle aspiration. Our study demonstrates the feasibility of generating nuclear transfer embryos with defined cytoplasmic background. These will be valuable tools to experimentally dissect the effects of nuclear and cytoplasmic components on embryonic, fetal, and postnatal development.
authors.affiliation: Department of Molecular Animal Breeding and Biotechnology, Ludwig-Maximilian University, D-85764 Oberschleissheim, Germany.
authors.forename: Katja
authors.initials: K
authors.lastname: Brüggerhoff
authors.forename: Valeri
authors.initials: V
authors.lastname: Zakhartchenko
authors.forename: Hendrik
authors.initials: H
authors.lastname: Wenigerkind
authors.forename: Horst-Dieter
authors.initials: HD
authors.lastname: Reichenbach
authors.forename: Katja
authors.initials: K
authors.lastname: Prelle
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Schernthaner
authors.forename: Ramiro
authors.initials: R
authors.lastname: Alberio
authors.forename: Helmut
authors.initials: H
authors.lastname: Küchenhoff
authors.forename: Miodrag
authors.initials: M
authors.lastname: Stojkovic
authors.forename: Gottfried
authors.initials: G
authors.lastname: Brem
authors.forename: Stefan
authors.initials: S
authors.lastname: Hiendleder
authors.forename: Eckhard
authors.initials: E
authors.lastname: Wolf
mesh_terms: D000818:Animals; D001483:Base Sequence; D002417:Cattle; D019070:Cell Lineage / Q000235:genetics*; D002467:Cell Nucleus / Q000235:genetics* / Q000378:metabolism; D002478:Cells, Cultured; D003001:Cloning, Molecular; D004272:DNA, Mitochondrial / Q000737:chemistry; D005314:Embryonic and Fetal Development; D005260:Female; D005838:Genotype; D006107:Granulosa Cells / Q000648:ultrastructure; D008460:Meat; D008892:Milk; D008969:Molecular Sequence Data; D009865:Oocytes / Q000254:growth & development / Q000502:physiology*; D010063:Ovum / Q000166:cytology / Q000502:physiology*; D010375:Pedigree; D011247:Pregnancy; D012098:Reproduction / Q000502:physiology; D014465:Ultrasonics
chemical_list: D004272:DNA, Mitochondrial