ISSN:
1573-6865
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary Glucose-6-phosphate dehydrogenase activity was analysed cytophotometrically in oocytes and pre-implantation embryos of mice. A bimodal distribution pattern was not found. Therefore, female and male embryos could not be discriminated on the basis of linkage of the enzyme with the X-chromosome during the pre-implantation period. The dehydrogenase activity in ovulated eggs and pre-implantation embryos up to the 8-cell stage was 65% of that present in follicular oocytes. In morulae and blastulae, the activity was further decreased to a level that was only 10–20% of the activity present in oocytes. The dramatic decrease in dehydrogenase activity could not be explained by modulation of the enzyme molecules, because K M values did not vary strongly. It is unlikely that the abundant activity of glucose-6-phosphate dehydrogenase in oocytes is due to high activity of the pentose phosphate pathway because of the low activity of 6-phosphogluconate dehydrogenase, the next step in this pathway. It is concluded that high activity of glucose-6-phosphate dehydrogenase in oocytes is needed for keeping oocytes viable, and for generation of NADPH which is important for the fertilization process.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00159121
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