| 释义 |
mixoploid, a. (and n.) Biol.|ˈmɪksəʊplɔɪd|
[f. mixo- + -ploid.]
Containing cells which are of differing ploidy or, more widely, have differing numbers of chromosomes. Also as n., a mixoploid individual.
1931B. Němec in Rep. Proc. 5th Internat. Bot. Congr. 1930 233 Many plants contain under normal conditions both diploid and polyploid cells. It is easy to get experimentally plants containing a varying number of polyploid cells. The author designates such plants mixoploid. Ibid., Mixoploid organs tend to eliminate the polyploid cells when they form a minority, especially when they are highly polyploid. 1939Hereditas XXV. 111 As a result of the agar treatment entire plants occasionally become mixoploids. 1944Jrnl. Heredity XXXV. 359/2 Mixoploid tissue resulted from colchicine treatment. Ibid. 361/1 Individual anthers were mixoploid. 1951Nature 2 June 891/1 In many species the diploid tissue grows at the expense of the tetraploid, and such a mixoploid reverts rapidly to the diploid condition. 1967Current Sci. XXXVI. 307 (heading) Preferential elimination of diploid cells in a colchicine-induced mixoploid tissue. 1971J. Hamerton Human Cytogenetics I. vii. 224 Autosomal mosaics are less common, and about 1% of Down's syndrome patients are estimated to be mixoploids.
So ˈmixoploidy, the property or state of being mixoploid.
1931B. Němec in Rep. Proc. 5th Internat. Bot. Congr. 1930 233 (heading) Mixoploidy and the cellular theory. 1958C. P. Swanson Cytol. & Cytogenetics ix. 300 This gradual change, if caught before the completion of the entire process of doubling, will give both tissues of mixed ploidy and cells with an uneven degree of polyteny in the individual chromosomes. Mickey (1946, 1947) has also shown this type of mixoploidy to be true for the spermatogonia in the testes of the grasshopper, Romalea. 1963Levan & Müntzing in Portugaliae Acta Biol. A. VII. 10 The present writers would suggest that the term mixoploidy should include all cases in which cell populations contain more than one chromosome number irrespective of whether the numbers are euploid or aneuploid. Mixoploidy, thus, covers all cases of mosaicism and chimeric constitution in which the heterogeneity between different elements involves differences in chromosome number. Mixoploidy may originate by all kinds of mitotic irregularities, by cellular and nuclear fusions, or even by amitotic processes, provided they give rise to viable products. 1971J. Hamerton Human Cytogenetics I. vii. 225 In vitro studies on mixoploidy should include the use of single cell clones from a mixoploid culture so that the only genetic difference is confined to a single chromosome. |