Final report submitted to International Development Research Centre / Buffaloes - Guelph / Malaysia, phase I

Includes 9 annexe

Seminar on Buffalo Genotypes for Small Farms in Asia

Meeting: Seminar on Buffalo Genotypes for Small Farms in Asia, 15-19 May 1989, Serdang, MYMissing several page

Introduction: Dangerous Dynamism in Asia's Nuclear Future

The article of record as published may be found at https://www.jstor.org/stable/10.2307/2490529

Expression of sex chromosome-linked genes during bovine preattachment development in vitro

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Sex-chromosome linked gene expression in in-vitro produced bovine embryos

v2002o

In vitro production of cattle-water buffalo (Bos taurus--Bubalus bubalis) hybrid embryos

Interspecific hybrid embryos are useful models for the study of maternal-fetal interactions, transmission pattern of species-specific markers and parental contributions to growth and developmental potential of pre-attachment embryos. In an attempt to investigate the possibility of producing hybrid embryos of domestic cattle (Bos taurus) and water buffalo (Bubalus bubalis), cattle oocytes were exposed to buffalo sperm and buffalo oocytes were exposed to cattle sperm and the cleavage rate and the post-fertilisation features of hybrid embryos up to the blastocyst stage were compared with those of buffalo and cattle embryos. The cleavage rate in buffalo oocytes exposed to cattle sperm was low (40.8%), with only 8.8% of these hybrid embryos reaching the blastocyst stage. Cattle oocytes exposed to buffalo sperm showed 86.3% cleavage, while 25.9% of these attained the blastocyst stage. The speed of development of both types of hybrids was intermediate between that of cattle and buffalo embryos, with hatching occurring on day 7.5 in hybrid embryos, day 8-9 in cattle and day 7 in buffalo. The proportions of cells contributing to the trophectoderm and the inner cell mass were closer to those of the maternal species in both types of hybrid embryos. Our results indicate that cattle-water buffalo hybrid embryos produced using inter species gametes are capable of developing to advanced blastocyst stages and that their in vitro fate, and developmental potential, are influenced by the origin of the oocyte