| 释义 |
oocyte Biol.|ˈəʊəsaɪt|
[f. oo- + -cyte, as ad. G. ovocyte (now oozyte) (T. Boveri 1892, in Anat. Hefte Abt. II. I. 446): see ovo-.]
An egg mother-cell, which gives rise to a mature ovum by meiosis; the primary oocyte gives rise in meiosis I to the secondary oocyte and a small polar body; the secondary oocyte gives rise to the mature ovum and another polar body in meoisis II. Also (with some writers), a polar body so produced. Cf. ovocyte.
1895Jrnl. R. Microsc. Soc. 511 (heading) Peculiar mitosis in young oocytes of salamander. 1927[see ootid]. 1945W. J. Hamilton et al. Human Embryol. ii. 12 The formation of the first polar spindle..initiates the first maturation, or reduction, division, the oocyte dividing into a larger cell, the secondary oocyte, and a much smaller cell, the first polar body. 1946B. M. Patten Human Embryol. ii. 31 The primary oöcyte divides to form two secondary oöcytes. One of these receives little cytoplasm and is called the first polar body. 1968Passmore & Robson Compan. Med. Stud. I. xxxvii. 10/2 All the primary oocytes so formed begin their first meiotic division before birth, but the completion of prophase is arrested until after puberty... Meiosis restarts in individual oocytes when their follicles undergo maturation in subsequent ovarian cycles... The remainder of the first meiotic division is completed by the time of ovulation, at which time a secondary oocyte is released into the tube. The second meiotic division follows immediately and..is not normally completed until the oocyte is penetrated by a spermatozoon. 1970Ambrose & Easty Cell Biol. xii. 390 Only one ovum is formed from each oöcyte in contradistinction to the four sperm formed from each spermatocyte. |