| 释义 |
hemizygous, a. Biol.|hɛmɪˈzaɪgəs|
[f. hemi- + homozygous a.]
Having a single unpaired allele at a particular genetic locus, as at all the loci in an XO pair of sex-chromosomes and some of the loci in an XY pair, rather than having two paired alleles, one on each homologous chromosome, as normally occurs in a diploid. So hemiˈzygote, a hemizygous organism; hemizyˈgotic a., hemizygous; hemiˈzygously adv., in a manner characteristic of a hemizygote.
1921W. A. Lippincott in Amer. Naturalist LV. 570, I should like to suggest the noun hemizeuxis (a half yoking) and the corresponding adjective hemizygous (half yoked). Should such a suggestion prove acceptable there would be the three adjective series: homozygous, heterozygous, and hemizygous, referring to the three possible conditions with respect to any single gene, namely, ‘like mates’, ‘differing mates’, and ‘no mate’. 1935H. J. Muller in Jrnl. Genetics XXX. 407 The terms ‘hemizygous’ and ‘hemizygote’ (Serebrovsky) refer to the condition of being haploid for a given gene when the genome as a whole is diploid; its usual usage is in connection with sex-linked genes in the sex in which they are haploid. Ibid., The normal gene, although apparently quite dominant to white and to the other mutants, must in reality be incompletely so, and the heterozygotes, being like uncompensated hemizygotes, must have a definitely lower average survival rate. 1939C. H. Waddington Introd. Mod. Genetics ii. 62 Muller has suggested that it would be better to speak of factors in haploid organisms such as male bees as hemizygous; and this word can also be used for factors (e.g. in an unpaired X chromosome) for which there is no allelomorph in a normal diploid. 1961Lancet 16 Sept. 626/2 In a hemizygous XO female, a recessive gene could express itself as in a heterozygous XY male. 1965J. A. Serra Mod. Genetics I. iv. 103 The genes for haemophilia and for colour-blindness have no allele in the Y chromosome, that is the males are hemizygotic for these factors. Ibid. 109 The yellow-black pair of alleles in cats producing either yellow or black hemizygous males but giving patched black and yellow or ‘tortoise-shell’ females when these are heterozygous. Ibid. 111 Such a character is transmitted from father to son and because there is no corresponding allele in the X chromosome, it manifests itself hemizygously. |