| 释义 |
prophase Cytology.|ˈprəʊfeɪz|
[ad. G. prophase (E. Strasburger 1884, in Arch. f. mikrosk. Anat. XXIII. 250): see pro-2 and phase.]
The first stage in a mitotic or meiotic nuclear division, preceding prometaphase, during which the chromosomes become visible and shorten and the nuclear envelope disappears. Also attrib. or as adj.
Prophase of the first meiotic division is divided into leptotene, zygotene, pachytene, diplotene, and diakinesis, in that order.
1884Jrnl. R. Microsc. Soc. IV. ii. 714 In both [plants and animals] we find that in the ‘prophases’ of nuclear division cytoplasm is collected at the future poles of the cell-nucleus. 1887tr. Strasburger's Bot. xxxii. 363 With this the preparatory phases of cell-division, the prophases, are completed.—Now begin the phases of separation and rearrangement of the daughter-segments, the metaphases of division. 1898Ibid. i. i. 62 The changes occurring in a mother nucleus preparatory to division are termed the prophases of the karyokinesis. 1903Bot. Gaz. XXXV. 250 The first division in Salamandra is characterized by a long period of growth of the cell and nucleus during the prophase..; the first longitudinal fission taking place during the prophase and the second during the metaphase or anaphase. 1911Q. Jrnl. Microsc. Sci. LVII. 27 The most important difference between the pre-meiotic and meiotic prophases is the entire absence in the former of any appearance of fusion of chromatin threads, such as takes place in zygonema. 1931E. B. Ford Mendelism & Evolution i. i. 18 Blocks of genes cross over together, as would be expected if, in fact, this phenomenon is due to the twisting of the chromosome threads round each other during the prophase of the reduction division. 1948R. A. R. Gresson Essent. Gen. Cytol. v. 33 (caption) Prophase chromosome to show arrangement of chromosomes. 1957C. P. Swanson Cytol. & Cytogenetics iii. 49 Prophase is said to be initiated at the moment when the chromosomes become visibly distinct. 1970Ambrose & Easty Cell Biol. ix. 296 In late prophase..the spindle develops and the asters move apart.
Hence proˈphasic a.
1913La Cellule XXIX. 311 The first indication that the prophasic changes have begun is seen in the breaking down of the anastomoses along the lines between the heavier portions of the reticulum. 1929Bot. Gaz. LXXXVIII. 376 In the latter case the visible division of the chromonema would always be prophasic. 1951H. C. Bold in G. M. Smith Man. Phycol. xi. 225 The Florideae furnish a conspicuous exception in that the spermatium nucleus is usually described as in a prophasic condition at the moment of union. |