Production of Cloned Calves Following Nuclear Transfer with Cultured Adult Mural Granulosa Cells1

Abstract

Adult somatic cell nuclear transfer was used to determine the totipotent potential of cultured mural granulosa cells, obtained from a Friesian dairy cow of high genetic merit. Nuclei were exposed to oocyte cytoplasm for prolonged periods by electrically fusing quiescent cultured cells to enucleated metaphase II cytoplasts 4-6 h before activation (fusion before activation [FBA] treatment). Additionally, some first-generation morulae were recloned by fusing blastomeres to S-phase cytoplasts. A significantly higher proportion of fused embryos developed in vitro to grade 1-2 blastocysts on Day 7 with FBA (27.5 +/- 2.5%) than with recloning (13.0 +/- 3.6%; p < 0. 05). After the transfer of 100 blastocysts from the FBA treatment, survival rates on Days 60, 100, 180, and term were 45%, 21%, 17%, and 10%, respectively. Ten heifer calves were delivered by elective cesarean section; all have survived. After the transfer of 16 recloned blastocysts, embryo survival on Day 60 was 38%; however, no fetuses survived to Day 100. DNA analyses confirmed that the calves are all genetically identical to the donor cow. It is suggested that the losses throughout gestation may in part be due to placental dysfunction at specific stages. The next advance in this technology will be to introduce specific genetic modifications of biomedical or agricultural interest.

Parthenogenetic activation of bovine oocytes using single and combined strontium, ionomycin and 6-dimethylaminopurine treatments

“…2 Departamento de Medicina Veterinária Preventiva e Reprodução Animal, FCAV -UNESP, Via de Acesso Prof. Paulo Donato Castellane, s/n, 14884-900, Jaboticabal, SP, Brazil. 3 Departamento de Ciências Básicas, FZEA -USP, Avenida Duque de Caxias Norte, 225, 13635-900, Pirassununga, SP, Brazil. somatic cell nuclear transfer (SCNT; Wells et al, 1999), intracytoplasmic sperm injection (ICSI; Suttner et al, 2000) and round-spermatid injection (ROSI; Loren & Lacham-Kaplan, 2006). Furthermore, activation is used for elucidation of events during early embryonic development (Soloy et al, 1997) and for studies on genomic imprinting (Solter, 1988).…”

Women with high telomerase activity in luteinised granulosa cells have a higher pregnancy rate during in vitro fertilisation treatment

“…Some researchers have found that a small proportion of ovarian GCs that are isolated from antral follicles can divide and form colonies, which demonstrates that some GCs exhibit the growth characteristics of stem cells [23][24][25][26][27]. Furthermore, prior studies have indicated that the success rate of cloning by nuclear transfer from GCs was 2.8% [28], compared with overall success rates of less than 0.4% from mammary epithelial cell lines [29] and 0.9% from cumulus cells [30], respectively. Do GCs possess TA because they originate from stem cells, and what is the level of TA exhibited in GCs during various stages of follicular development?…”

Production of HanWoo(Bos taurus coreanae) Fetuses Following Interbreed Somatic Cell Nuclear Transfer.

“…63(9): 945-948, 2001 Production of cloned animal by somatic cell nuclear transfer has recently been developed. The birth of live offspring derived from embryos reconstructed with somatic cells have been reported in several species; sheep [10], cattle [1,3,8], and mouse [7].Animal cloning technology can be used to preserve endangered mammalian species by interbreed or interspecies nuclear transfer. The success of interbreed nuclear transfer was reported in last surviving cow of the Enderby island cattle breed [9].…”

“…63(9): 945-948, 2001 Production of cloned animal by somatic cell nuclear transfer has recently been developed. The birth of live offspring derived from embryos reconstructed with somatic cells have been reported in several species; sheep [10], cattle [1,3,8], and mouse [7].…”