Bovine somatic cell cloning-from cultured cell to cloned calf /
To develop an efficient bovine fetal fibroblast cell cloning protocol a multivariate model was used to analyze the effect of seven factors on nuclear transfer (NT) embryo development from 1266 nuclear transfers. Enucleation time and donor cell serum starvation significantly affected in vitro develop...
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
1999.
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| Subjects: | |
| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=730319141&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | To develop an efficient bovine fetal fibroblast cell cloning protocol a multivariate model was used to analyze the effect of seven factors on nuclear transfer (NT) embryo development from 1266 nuclear transfers. Enucleation time and donor cell serum starvation significantly affected in vitro development of nuclear transfer embryos to blastocyst (p < 0.05). More NT blastocysts developed from serum-starved compared with serum-fed bovine fetal fibroblasts (34.5% vs 18.8%,. p = 0.008). NT embryos activated with Butyrolactone-I (BL-I) developed to blastocyst at similar rates to those activated with 6-dimethylaminopurine (DMAP; 22.4% vs 20.2%,. p = 0.18). The majority of these blastocysts were of diploid chromosome content (65% of BL-I and 63% of DMAP). Ten BL-I activated blastocysts were transferred into four recipient cows, with two normal fetuses surgically recovered at 45 days of gestation. The totipotency of cells from a 21 year old bull was demonstrated with the production of six Day 30 fetuses. One of these fetuses was surgically removed to generate a cell line. The NT blastocyst development rate was similar for these regenerated, cloned fetal cells (39/140,. 28%) and the original adult cells (53/190,. 28%). The Day 30 pregnancy rates were not significantly different for blastocysts derived from the adult (6/26; 23%) or fetal (5/29,. 13%) cells. One NT tutus derived from the adult cells is due to be born in August, 1999. Improved NT blastocyst development was observed from passage 18 cells compared with passage 2 cells (44.6% vs 35.4%*, p = 0.07), while the Day 30 pregnancy rates (11% vs 15%) were not significantly different. In a clinical trial, 13 third trimester cloned transgenic fetuses were observed, five of which died in utero, two calves died after birth, and only six remain alive. Four of the seven dead animals possessed similar severe cardiopulmonary and placental abnormalities. These results illustrate the inefficiency of the NT process, which entails high rates of early embryonic loss, followed by late gestation and neonatal abnormalities. |
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| Item Description: | Vita. "Major Subject: Veterinary Physiology". |
| Physical Description: | xiii, 101 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilm Inc. |
| Bibliography: | Includes bibliographical references (leaves 89-100). |