| 释义 |
polymitosis Biol.|pɒlɪmaɪˈtəʊsɪs|
[f. poly- + mitosis.]
The occurrence of multiple mitotic cell divisions, esp. following meiosis in microsporogenesis; one of these divisions. So polymiˈtotic a., pertaining to, affected by, or being such cell divisions.
1931G. W. Beadle Mem. Cornell Agric. Exper. Station No. 135. 3 This genetic factor..has been given the name polymitotic for which the genetic symbol po is used. Ibid., On first thought, the term polymitotic may seem to be inappropriate on the grounds that normal maize plants have many mitoses. It may be pointed out that the polymitotic character is expressed only in the gametophytic generation in which there are normally but two mitotic divisions in maize. 1932C. D. Darlington Recent Adv. Cytol. xiii. 367 This property of having ‘polymitosis’ is inherited as a mendelian recessive character. 1937Ibid. (ed. 2) ix. 399 The spermatids are originally tetraploid through double non-reduction and by three polymitotic divisions become 32x. 1948Nature 5 June 874/1 Plants heterozygous for this gene must produce two genetically different kinds of pollen, one of which will be like the lethal polymitotic pollen borne on the homozygous plant. But none of this pollen shows polymitotic behaviour. Thus polymitosis is like incompatibility in heterostyled plants. 1973Cytologia XXXVIII. 515 A gene responsible for supernumerary cell division following meiosis which Beadle..termed the polymitotic division gene (po). Ibid. 518 Postmeiotic polymitoses were observed in reciprocal interspecific hybrids between two diploid Clarkia species... The genetic system responsible for these polymitoses is most likely not a simple recessive gene as is the case in maize but rather genic disharmony between the two parental sets of chromosomes. |