ISSN:
1040-452X
Schlagwort(e):
Nuclear transfer
;
Bovine
;
Activation
;
Oocyte
;
Embryo
;
Life and Medical Sciences
;
Cell & Developmental Biology
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Biologie
Notizen:
Successful bovine nuclear transfer (NT) embyro production requires proper oocyte activation and transfer of a nucleus into this oocyte. However, the temporal relationship between these two events is unclear. The current study examined whether activation of the oocyte prior to fusion would induce nuclear swelling while also affecting development to morula and blastocyst stage and finally development to offspring. Aged oocytes can be activated by a number of techniques including exposure to room temperature. In this study oocyte activation was induced through three different means: reduced temperature culture alone, reduced temperature culture and calcium ionophore, and naturally, through the fertilization process. Electrofusion was carried out after the activation stimulus. When used in the NT procedure, activation of oocytes prior to fusion resulted in NT embryos that under went nuclear swelling and had a high developmental rate to morula and blastocyst stages. Also, these NT embryos developed to normal offspring when transferred to recipient animals. The addition of a calcium ionophore treatment to the reduced temperature culture was not beneficial and resulted in less nuclear swelling. The use of enucleated fertilized oocytes as recipient cytoplasm for the new nucleus resulted in NT embryos developing to morula and blastocyst stages at the same rate as room temperature activated NT embryos. Therefore, improved embryo development can be obtained from NT embryos if the aged recipient oocyte is activated prior to the time of fusion. Also, offspring were obtained from these pre-activated NT embryos. © 1994 Wiley-Liss, Inc.
Zusätzliches Material:
1 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/mrd.1080380111
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