Shotkoski F A, Fallon A M
Department of Entomology, University of Minnesota, St. Paul 55108.
Arch Insect Biochem Physiol. 1990;15(2):79-92. doi: 10.1002/arch.940150203.
A stepwise selection procedure was used to obtain from Mtx-5011 Aedes albopictus cells, variants with increased resistance to methotrexate (mtx). On the basis of growth, the Mtx-5011 derivatives were 270- to 3,000-fold more resistant to mtx than wild-type mosquito cells. Properties associated with mtx resistance in these cells were consistent with amplification of the dihydrofolate reductase (DHFR) gene. The cells overproduced DHFR protein, were enriched with DHFR mRNA, and DNA from resistant cells was enriched for a band that likely contained the DHFR coding sequence. Karyotype analysis indicated that high levels of resistance were accompanied by a conversion to tetraploidy, chromosome rearrangements, and an apparent duplication of one of the mosquito chromosomes.
采用逐步筛选程序从白纹伊蚊Mtx - 5011细胞中获得对甲氨蝶呤（mtx）抗性增强的变体。基于生长情况，Mtx - 5011衍生物对mtx的抗性比野生型蚊子细胞高270至3000倍。这些细胞中与mtx抗性相关的特性与二氢叶酸还原酶（DHFR）基因的扩增一致。这些细胞过量产生DHFR蛋白，富含DHFR mRNA，并且抗性细胞的DNA富含一条可能包含DHFR编码序列的条带。核型分析表明，高水平的抗性伴随着向四倍体的转变、染色体重排以及一条蚊子染色体的明显重复。
