Record Details

NUCLEAR TRANSFER IN RABBITS AND GOATS

KrishiKosh

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Field Value
 
Title NUCLEAR TRANSFER IN RABBITS AND GOATS
 
Creator SAMBASIVA RAO, B
 
Contributor SESHAGIRI RAO, A (Major)
SUBRAMANYAM NAIDU, K
RAO, V.H
CHANDRASEKHARA RAO, T.S
 
Subject NUCLEAR TRANSFER ; RABBITS; GOATS
 
Description THESES
A B S T R A C T
A study was undertaken to standardize methods for the production of cloned rabbit and goat embryos using both blastomeres and somatic cells as nuclear donors. Superovulated (rabbit) and in vitro matured (goat) oocytes were enucleated and used as recipient cytoplasts.
A total of 941 cloned rabbit embryos were produced using fresh (324) and frozen-thawed (647) blastomeres as nuclear donors. Ninety five per cent of frozen thawed and 94% of fresh blastomeres successfully fused to the enucleated oocytes. In both these groups of cloned embryos the rate of cleavage was 80%. Forty six and 44% of cloned and cleaved embryos developed to morula stage in the two groups respectively. Similarly 26 and 24%

of the cloned and cleaved embryos developed into blastocysts in vitro in the two groups respectively.
Two sources of blastomeres and four sources of oocytes were tested in different oocytes-blastomere combinations for their ability to support the in vitro development of cloned rabbit embryos. It was observed that when both the oocytes and the blastomeres originated from the same genetic strain, the rate of development of cloned embryos to blastocyst stage was significantly better.
Super ovulated oocytes were collected from the donor does at 14, 17 or 19h phCG and electro fused with blastomeres at >18, >20 or >22h phCG. Though the oocytes collected at 14h phCG and fused to blastomeres at >20h phCG with four DC pulses of 2.5kV/cm exhibited relatively poor fusion rate, this group exhibited the best development to blastocyst stage along with the oocytes collected at 19h phCG and fused to blastomeres at >22h by a single DC pulse of 3.5kV/cm. It was concluded that it was necessary to adjust the electrical fusion / activation protocols to suit the age of oocytes at collection and fusion.
Cloned rabbit embryos produced from fresh blastomeres only had developed to live offspring on transfer to recipient does. Further use of oocytes collected at 17h phCG along with fresh blastomeres only supported full term development of cloned rabbit embryos in recipient does. While, overall less than 1% of the cloned rabbit embryos developed to term, 1.7% of cloned rabbit embryos produced from oocytes collected at 17h phCG and fresh blastomeres developed to term. None of the cloned rabbit embryos produced from frozen-thawed blastomeres developed to live offspring in this study. DNA fingerprinting of the cloned rabbits was undertaken using three different primers. All the three primers indicated that the rabbit bunnies were genetically identical which confirmed their clonal nature.
A total of 694 somatic cell cloned rabbit embryos were produced of which 279 were from cultured fetal fibroblasts and 415 from contemporary cumulus cells. Except that cumulus cell generated cloned embryos showed a significantly higher fusion rate, there were no differences in other development parameters studied. Though somatic cell cloned embryos developed to blastocyst stage more frequently than blastomeres cloned embryos, none of the somatic cell cloned embryos whether produced from fetal fibroblasts or cumulus cells developed to term in the recipient does.
A total of 628 cloned goat embryos were produced of which, 402 were from blastomeres, 174 from fetal fibroblasts and 52 from contemporary cumulus cells. Blastomeres fused better than somatic cells to the in vitro matured and enucleated goat oocytes (76 vs 58%). While the cleavage rates were similar in all the three groups of cloned goat embryos, blastocyst development was significantly better in blastomere cloned (65%) than somatic cell cloned (32 and 41%) goat embryos.
On transfer of 145 blastomere, 40 fetal fibroblast and 38 contemporary cumulus generated cloned embryos to recipient does, none of the recipients became pregnant and no cloned kids were produced.
College of Veterinary Science , TIRUPATI – 517 502
 
Date 2016-12-21T15:46:21Z
2016-12-21T15:46:21Z
2003-10
 
Type Thesis
 
Identifier http://krishikosh.egranth.ac.in/handle/1/91931
 
Language en
 
Format application/pdf
 
Publisher Sri Venkateswara Veterinary University, TIRUPATI – 517 502,A.P