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Influence of nocodazole on the development of donor blastomeres from 16-cell stage bovine embryos in nuclear transfer.
1995
Tanaka H. | Takahashi Y. | Hishinuma M. | Kanagawa H. | Kariya T.
The aim of the present study was to establish a reliable procedure with nocodazole treatment for the synchronous cleavage of blastomeres of bovine embryos used as nuclear donors for nuclear transfer. Sixteen-cell stage embryos derived from in vitro-maturation, fertilization and culture were used. In three initial experiments, embryos were incubated in mTCM-199 + FCS with various concentrations (0-20 mu-M) of nocodazole under 5% CO2 in air. The concentrations required to arrest the blastomeres in the mitotic phase were examined. The effects of 10 mu-M nocodazole were also examined by observation of the division rate of blastomeres after the removal of nocodazole. Ninety percent (90%) of the blastomeres were arrested in the mitotic phase when embryos were exposed to 10 and 20 mu-M nocodazole. Exposure to 10 mu-M nocodazole had the highest blastomere-cleavage rate (47%). When the exposure period to 10 mu-M nocodazole was prolonged to 36 hr, the division rate of the blastomeres decreased. Furthermore, the effects of 2 culture conditions (mTCM-199 under 5% CO2 in air vs modified synthetic oviduct fluid medium under 5% CO2, 5% O2 and 90% N2) were compared on the division rate of blastomeres of embryos exposed to 10 mu-M nocodazole for 12 hr. When the embryos were exposed to nocodazole in mSOF, the division rate of blastomeres was improved to about 60%. The blastomeres produced by this treatment condition were used as nuclear donors and the developmental potential of the reconstituted embryos was investigated. The developmental rate to the blastocyst stage was 30.1% (58/193). Five embryos were transferred to 5 recipient cows and 2 of the 5 recipients (40%) became pregnant. Subsequently, one normal calf was born.
Afficher plus [+] Moins [-]Influence of time after the removal of nocodazole from nuclear donors on the development of reconstituted embryos in bovine nuclear transplantation.
1995
Tanaka H. | Takahashi Y. | Hishinuma M. | Kanagawa H.
The present study examined the influence of post-cleavage time of nuclear donors on the development of reconstituted embryos in bovine nuclear transfer. Blastomeres of 16-cell stage embryos derived from in vitro-maturation, fertilization and culture were used as nuclear donor source. They were treated with 10 mu-M nocodazole for 12 hr. Blastomeres that cleaved within 3 hr after the removal of nocodazole were used-for the study. Metaphase II (M-II) oocytes were used as recipient cytoplasm. IN experiment 1, donor blastomeres at 6, 11 and 15 hr after the removal of nocodazole and donor blastomeres no treated with nocodazole were transferred into ethanol-exposed and enucleated oocytes. The reconstituted embryos produced by donor blastomeres oat 6 hr after the removal of nocodazole had a significantly higher developmental rate to the blastocyst stage than those at 15 hr and the untreated groups (P<0.01). In experiment 2, blastomeres at 6 hr after the removal of nocodazole used as nuclear donors were transferred into ethanol-exposed and enucleated M-II oocytes. The reconstituted embryos with ethanol-exposed and enucleated oocytes as recipient cytoplasm had a significantly higher rate of initial-cleavage (P<0.05) and development to the blastocyst stage (P<0.01) than non ethanol-exposed and enucleated M-II oocytes. These results demonstrate that the development of reconstituted embryos was improved when cleaved donor blastomeres after the removal of nocodazole were immediately transferred (at 3-6 hr post-cleavage) into activated enucleated oocytes by exposure to ethanol.
Afficher plus [+] Moins [-]UTILISATION PATTERN OF ICT (INFORMATION COMMUNICATION TECHNOLOGY) AMONG UNDERGRADUATE VETERINARY STUDENTS IN SOUTHERN STATES OF INDIA
2022
C. Manivannan | K.M. Sakthivel | N. Narmatha | V. Uma | S. Karthikeyan
A study was undertaken with the objective of assessing the utilisation pattern of ICT (Information Communication Technology) among undergraduate veterinary students in southern states of India. Data were collected from 248 final year undergraduate students of 12 veterinary colleges in five southern states of India viz. Tamil Nadu, Kerala, Karnataka Andhra Pradesh and Telangana through pretested questionnaire. The findings of the study revealed that majority of the students studied had 3-4 years of experience in using internet and accessed internet through mobile phone (61.29%). One-third (33.06%) of the students used internet 2-3 days in a week for academic activity while, 30.65% used internet every day for personal activity. The study revealed that students used internet mainly for the preparation of assignments (97.58%). The major problems faced by the students in using ICT tools were slow speed of internet (77.82%) and inadequate number of computers (75.81%) in the institutions. It could be concluded that veterinary students had accessed substantial information technology resources and had knowledge towards computer and internet. Provision of structured information technology training for veterinary students would help them to acquire necessary skills to maximise the utilisation of online veterinary resources. nbsp;
Afficher plus [+] Moins [-]Yolk sac utilization in ostrich (Struthio camelus) chicks
2004
Mushi, E.Z. (Botswana Agriculture College, Gaborone (Botswana)) | Binta, M.G. | Chabo, R.G.