Salz H K, Flickinger T W, Mittendorf E, Pellicena-Palle A, Petschek J P, Albrecht E B
Department of Genetics, Case Western Reserve University, Cleveland, Ohio 44106-4955.
Genetics. 1994 Mar;136(3):1075-86. doi: 10.1093/genetics/136.3.1075.
This study describes the identification, function and molecular characterization of deadhead, a Drosophila thioredoxin homolog. Although in vitro studies have shown that thioredoxin can post-translationally regulate the activity of many different proteins, we find that this homolog is not essential for viability. The phenotypic analysis of two different mutations which eliminate function suggests that dhd is essential for female meiosis. The majority of eggs laid by females homozygous for null mutations are fertilized but fail to complete meiosis. A small number of escaper embryos initiate development and display a range of phenotypes suggesting functions in both preblastoderm mitosis and head development. Our analysis of deadhead's RNA expression pattern is consistent with its maternal effect function: the RNA is predominately expressed in the nurse cells of the ovary, is maternally deposited into the egg, but does not appear to be zygotically expressed during embryogenesis. Thus both our genetic and molecular data are consistent with a function during meiosis and preblastoderm mitosis. Whether the head defect indicates an additional function or is an indirect consequence of earlier defects remains to be determined.
本研究描述了果蝇硫氧还蛋白同源物deadhead的鉴定、功能及分子特征。尽管体外研究表明硫氧还蛋白可在翻译后调节许多不同蛋白质的活性，但我们发现该同源物对果蝇的生存力并非必需。对消除其功能的两种不同突变进行的表型分析表明，dhd对雌性减数分裂至关重要。纯合无效突变雌性所产的大多数卵已受精，但无法完成减数分裂。少数逃逸胚胎开始发育，并表现出一系列表型，表明其在前胚盘有丝分裂和头部发育中均有作用。我们对deadhead RNA表达模式的分析与其母体效应功能一致：RNA主要在卵巢的滋养细胞中表达，通过母体沉积到卵中，但在胚胎发育过程中似乎没有合子表达。因此，我们的遗传和分子数据均与减数分裂和前胚盘有丝分裂期间的功能一致。头部缺陷是表明存在额外功能还是早期缺陷的间接后果，仍有待确定。
