| 释义 |
parasexual, a. Genetics.|pærəˈsɛksjuːəl|
[f. para-1 + sexual a.]
Involving, exhibiting, or being a process by which recombination of genes from different individuals occurs without meiosis.
1954G. Pontecorvo in Proc. 9th Internat. Congr. Genetics 192 In the last ten years, processes other than standard sexual reproduction, and yet resulting in recombination of hereditary properties, have come to light in microorganisms of widely different groups... The purpose of the present paper is to give a summary of the work which has led, in our Laboratory, to the discovery in the filamentous fungi of another of these mechanisms, which could be called ‘para-sexual’. This mechanism, based on mitotic segregation and recombination, occurs side by side with a standard sexual cycle in one of the three species investigated. 1962Ann. Rev. Microbiol. XVI. 39 Using parasexual processes, 40 markers have been assigned to eight linkage groups in A[spergillus] nidulans. 1962G. Dalldorf Fungi & Fungous Dis. x. 135 Even in asexual fungi, recombinant types may arise through a parasexual process. 1970J. Webster Introd. Fungi 161 The occurrence of parasexual recombination explains how variation can occur in Fungi Imperfecti. 1974Nature 27 Sept. 321/2 Genetic analysis of their development [sc. that of cellular slime moulds] has been hampered by the apparent absence of a true sexual cycle, although progress has been made in parasexual genetic analysis. 1977P. B. & J. S. Medawar Life Sci. iii. 39 In some bacteria..the sexual process is restricted to something that amounts to hardly more than the infection of one bacterium by nucleic acid from another—the ‘parasexual’ process that lies at the root of the enormously important phenomenon of bacterial transformation.
Hence ˌparasexuˈality, the parasexual process.
1959Mycologia LI. 109 Somatic recombination or para⁓sexuality..reassorts genetic characters of heterokaryotic components in a vegetative system to yield products that are comparable to the meiotic products of the sexual process. 1974Nature 18 Jan. 142/1 Using an improved version of the methods employing parasexuality.., we have selected axenic resegregants carrying various markers from non-axenic strains. |