Perry D, Nilsen L J, Kuramitsu H K
Infect Immun. 1985 Oct;50(1):130-5. doi: 10.1128/iai.50.1.130-135.1985.
A cloned glucosyltransferase (gtfA) fragment, inserted adjacent to an erythromycin resistance (Eryr) marker in plasmid pVA891, was used in transformation experiments to determine the genetic location of gftA on the Streptococcus mutans chromosome. Eryr (gftA) cotransformed with a methionine (Met+) marker at a frequency of approximately 23%, whereas cotransfer with a number of other markers was not observed. The number of Met+ transformants was approximately 50-fold greater than the number of Eryr transformants. Furthermore, over 20% of the Eryr transformants were always Met+, whereas less than 1% of the Met+ transformants were Eryr, indicating the extreme asymmetrical cotransfer of these markers. The results indicate that S. mutans genes can be mapped by this procedure.
将一个克隆的葡糖基转移酶（gtfA）片段插入质粒pVA891中红霉素抗性（Eryr）标记附近，用于转化实验，以确定gftA在变形链球菌染色体上的基因位置。Eryr（gftA）与甲硫氨酸（Met+）标记共转化的频率约为23%，而未观察到与其他一些标记的共转移。Met+转化体的数量比Eryr转化体的数量大约多50倍。此外，超过20%的Eryr转化体始终是Met+，而Met+转化体中只有不到1%是Eryr，这表明这些标记的共转移极度不对称。结果表明，变形链球菌基因可通过此方法进行定位。
