| 释义 |
diplotene Biol.|ˈdɪpləʊtiːn|
[ad. Fr. diplotène (H. von Winiwarter 1900, in Archives de Biol. XVII. i. 70), f. diplo- + -tene.]
The fourth stage of the prophase of meiosis (following pachytene), in which the four chromatids of each tetrad begin to separate into two pairs, each pair containing one chromatid from each of the two orginal paired chromosomes. Also attrib. or as adj.
1925E. B. Wilson Cell (ed. 3) vi. 545 Probably, therefore, the diffuse stage should be regarded as a highly modified diplotene in which the duality of the early diplotene..in some manner persists throughout. 1929Jrnl. Genetics XXI. 5 Diplotene looping. As soon as the double threads begin to open to form the loops characteristic of diplotene..it appears as though..real association has been taking place only between two chromosomes..for the third chromosome is seen to be lying free. 1931Nature 9 May 711/1 At meiosis, it does not happen until pachytene (possibly at the moment at which the diplotene loops appear). Ibid., This condition is fulfilled by the pairing of chromosome threads when they are still single, and their separation at diplotene when they have at last come to divide. 1951G. H. Bourne Cytol. & Cell Physiol. (ed. 2) x. 435 After 3 days the oocytes entered the contraction phase, from which most of them had emerged by the 6th day, to pass into the pachytene phase; this was quickly followed by the diplotene. 1965Bell & Coombe tr. Strasburger's Textbk. Bot. (new ed.) i. i. 34 In diplotene the pairing of the still extended chromosomes, completed in pachytene, is again lost. |