Identification of C14-labelled male chromatin at fertilization in colchicine-treated mouse eggs
✍ Scribed by Edwards, R. G. ;Sirlin, J. L.
- Publisher
- John Wiley and Sons
- Year
- 1959
- Tongue
- English
- Weight
- 534 KB
- Volume
- 140
- Category
- Article
- ISSN
- 0022-104X
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✦ Synopsis
KnstitzLte of Animal Genetics, Edinburgh FOUR FIGURES
Colchicine prevents the normal segregation of chromosomes at anaphase, possibly by suppressing the initiation of fiber formation in the spindle proteins at the centromeres and mitotic centers (Mazia, '55). The treatment of mouse eggs with colchicine at fertilization induces heteroploidy in many embryos. The induction of heteroploidy was ascribed to the freeing of the maternal chromosomes from their attachment to the spindle of the second maturation division, which led to many eggs containing one or several pronuclei after fertilization (Edwards, '58). Identification of the male and female pronuclei in eggs treated with colchicine should confirm this assumption and provide evidence of the history of the chromosomes of the heteroploid embryos. I n the present work, spermatozoa labelled with adenine C14 were used to identify male chromatin and pronuclei by means of autoradiography.
Spermatozoa are labelled as follows. Thirty days after an intraperitoneal injection of adenine-8-CX4 into male mice a low percentage of spermatozoa in the ejaculate are labelled, i.e., show a positive autoradiograph. This percentage, and the intensity of labelling, increases rapidly until approximately 38-42 days after the injection when many of the spermatozoa