Powell J R, Lichtenfels J M
Genetics. 1979 Jun;92(2):603-12. doi: 10.1093/genetics/92.2.603.
Drosophila pseudoobscura is polymorphic for tissue-specific expression of alpha-amylase in adult midguts. This enzyme is encoded by a single locus, Amy, on the third chromosome. In this paper we show: (1) Up to about 12 days post-eclosion, the midgut activity patterns remain stable; after 12 days areas not showing activity previously begin to show activity. Thus, the genes controlling the expression of Amy are temporally acting. (2) Diet affects the quantitative, but not the qualitative, expression of Amy. (3) The expression of Amy in adult midguts is under genetic control. Selection for different frequencies of patterns is possible; realized heritabilities are 0.20 to 0.50. Partial linkage with third chromosome inversions has been demonstrated; the genes or elements controlling Amy expression are not, however, confined to the third chromosome. (4) The genetic elements controlling tissue-specific expression of amylase do not coordinately control the expression of five other "digestive-type" enzymes that were studied.--This polymorphism appears to be analogous to that studied by Abraham and Doane (1978) in D. melanogaster, wherein they have mapped regulatory genes.
在成年果蝇的中肠中，拟暗果蝇（Drosophila pseudoobscura）的α-淀粉酶存在组织特异性表达的多态性。这种酶由位于第三条染色体上的一个基因座Amy编码。在本文中我们表明：（1）羽化后约12天内，中肠的活性模式保持稳定；12天后，之前未显示活性的区域开始显示活性。因此，控制Amy表达的基因具有时间作用。（2）饮食影响Amy的定量表达，但不影响其定性表达。（3）成年果蝇中肠中Amy的表达受遗传控制。可以针对不同频率的模式进行选择；实现的遗传力为0.20至0.50。已证明与第三条染色体倒位存在部分连锁；然而，控制Amy表达的基因或元件并不局限于第三条染色体。（4）控制淀粉酶组织特异性表达的遗传元件并不协同控制所研究的其他五种“消化型”酶的表达。——这种多态性似乎类似于亚伯拉罕和多恩（1978年）在黑腹果蝇（D. melanogaster）中所研究的多态性，他们在其中绘制了调控基因。
