Abortive conjugation induced by UV-B irradiation at meiotic prophase inTetrahymena thermophila
✍ Scribed by Kobayashi, Takashi ;Endoh, Hiroshi
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 125 KB
- Volume
- 23
- Category
- Article
- ISSN
- 0192-253X
No coin nor oath required. For personal study only.
✦ Synopsis
Conjugating Tetrahymena were irradiated by ultraviolet-B (UV-B) at various stages of conjugation. When the conjugants were exposed to the UV-B at late meiotic prophase (the stage from pachytene to diplotene), abortive conjugation was induced at high frequencies. After completing meiosis, a significant number of the conjugants showed marked anomalies, i.e., failure of nuclear selection after meiosis, and abortion of the subsequent conjugation process such as a postmeiotic division to form gametic nuclei, nuclear exchange, synkaryon formation, and postzygotic development. The conjugating pairs retained the parental macronucleus and separated earlier as compared with a control. The resultant exconjugants degenerated meiotic products and became amicronucleates. These observations strongly suggest the presence of a UV-sensitive molecule that is expressed specifically at the meiotic prophase and that directs the subsequent development after meiosis. Dev.