| 释义 |
leptotene Cytology.|ˈlɛptəʊtiːn|
[ad. F. leptotène (H. von Winiwarter 1900, in Arch. de Biol. XVII. 55): see lepto- and -tene.]
The first stage of the prophase of the first meiotic division, in which the chromosomes are apparent as fine slender threads. Also attrib. or as adj.
[1900Jrnl. R. Microsc. Soc. 654 The reticulum gives rise to a chromatic thread.., which at first fills the nuclear cavity (leptotænic stage).] 1912Jrnl. Exper. Zool. XIII. 360 The pre-synaptic leptotene. Ibid. 362 Are the leptotene-threads of this period chromosomes? Ibid. 368 Figs. 73 a and 73 b show two early leptotene-nuclei of this species. 1925E. B. Wilson Cell (ed. 3) vi. 541 In the case of animals..the leptotene-spireme is not continuous but consists of separate segments. 1964G. H. Haggis et al. Introd. Molecular Biol. vii. 197 The chromosomes at leptotene must each consist of two chromatids so closely apposed as to give the appearance of a single structure. 1970Ambrose & Easty Cell Biol. x. 325 The cell nuclei at this stage contain chromosomes in the form of very fine single threads, hence the name leptotene, meaning ‘slender ribbon’. |