## Abstract Suspensions of lysolecithinβtreated sperm were injected into blastomeres of twoβcell embryos which had been arrested with the extract of unfertilized eggs containing cytostatic factor (CSF). Whereas the CSFβarrested blastomeres remained unchanged if no sperm were injected, those injecte
Cell division and determination of the dorsal lip inRana pipiens embryos
β Scribed by Grant, Philip ;Youngdahl, Pamela
- Publisher
- John Wiley and Sons
- Year
- 1974
- Tongue
- English
- Weight
- 579 KB
- Volume
- 190
- Category
- Article
- ISSN
- 0022-104X
No coin nor oath required. For personal study only.
β¦ Synopsis
Abstract
UV irradiation of vegetal halves of fertilized eggs of Rana pipiens delays the onset of gastrulation and inhibits neural induction. To test a hypothesis that delay in dorsal lip formation results from inhibition of mitotic activity in vegetal halves we examined the incorporation of thymidine H^3^ into DNA of whole and half irradiated embryos. Tritium labeled thymidine was injected into control and irradiated eggs and at six hour intervals samples were taken until controls had reached mid gastrula stages. Whole embryos as well as animal and vegetal halves were compared for levels of incorporation into DNA. No significant differences were seen between control and irradiated whole or animal half embryos but irradiated vegetal halves displayed a 15β20% reduction in incorporation into DNA at 18 and 24 hours. This result is consistent with (but by no means proves) the hypothesis that UV inducedgastrulation delay results from inhibition of cell division of vegetal half cells.
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