| 释义 |
extrachromosomal, a. Biol.
Brit. |ˌɛkstrəˌkrəʊməˈsəʊml|, U.S. |ˈˌɛkstrəˌkroʊməˈsoʊm(ə)l|
[‹ extra- prefix + chromosomal adj. at chromosome n. Derivatives]
Not associated with a chromosome; existing or occurring independently of chromosomes.
1906T. H. Montgomery Anal. Racial Descent in Animals iii. 89 Sexuality finds its expression and origin in extra-chromosomal differences. 1945H. Burrows Biol. Action Sex Hormones xviii. 352 A familial tendency to the development of mammary cancer in mice is largely dependent on an extrachromosomal factor. 1984L. W. Browder Developmental Biol. (ed. 2) vii. 295 During late pachynema and in diplonema, miniature nucleoli form in association with these rings of extrachromosomal DNA. 2003Internat. Jrnl. Toxicol. 22 135 These genes are frequently associated with large transferable extrachromosomal DNA elements called plasmids.
Derivatives. extrachromosomally adv. outside or independently of a chromosome.
1966Lancet 10 Dec. 1302/1 The determinants..are believed to be situated *extrachromosomally and are transferable to other sensitive bacteria by cell-to-cell contact. 1990Nucleic Acids Res. 18 331/1 The E. coli ada gene protein coding region has been ligated into an extrachromosomally replicating yeast expression vector. |