Levis R, Hazelrigg T, Rubin G M
Science. 1985 Aug 9;229(4713):558-61. doi: 10.1126/science.2992080.
The white gene of Drosophila is expressed normally when introduced at many different sites in the genome by P-element-mediated DNA transformation, but is expressed abnormally when inserted at two particular genomic positions. It is now demonstrated that the mutant expression in these two cases is caused by the surrounding chromosomal region into which the white gene has been inserted. The white gene could be moved from these two positions, where it confers a mutant phenotype, to other positions in the genome where it confers a wild-type phenotype. However, flies in which white has been moved to one new location have an unusual mosaic phenotype.
通过P因子介导的DNA转化将果蝇的白眼基因导入基因组的许多不同位点时，它能正常表达，但插入到两个特定的基因组位置时则异常表达。现已证明，这两种情况下的突变表达是由白眼基因插入的周围染色体区域引起的。白眼基因可以从这两个赋予突变表型的位置转移到基因组中其他赋予野生型表型的位置。然而，白眼基因已转移到一个新位置的果蝇具有异常的镶嵌表型。
