Botella L M, Edström J E
Department of Molecular Genetics, University of Lund, Sweden.
Biol Cell. 1991;71(1-2):11-6. doi: 10.1016/0248-4900(91)90046-p.
Balbiani ring (BR) genes in polytene chromosomes of Chironomus salivary glands code for secretory proteins of the sp-I family, 10(6) D. They are used by the aquatic larva to spin a housing and feeding tube. The expression of the BR gene family undergoes correlated changes depending on the environment. In the presence of certain sugars, ethanol or glycerol the normally most active BR2 regresses and its products disappear. There is a parallel induction of a new BR, BR6, and a new sp-I protein. The change seems to represent an adaptative response to phosphate depletion in the larval haemolymph produced by the inducing agents. The BR2 (and BR1) products are heavily phosphorylated and the BR6 product non-phosphorylated. One of the BR2-coded sp-I proteins is cleaved off close to the C-terminus and material with properties expected of the resulting polypeptide can be recovered in the nuclei, accumulating in the BR. This might represent a feed-back signal from translation to transcription.
摇蚊唾液腺多线染色体中的巴尔比亚尼环（BR）基因编码sp-I家族的分泌蛋白，分子量为10(6) D。水生幼虫利用这些蛋白来构建一个栖息和进食的管子。BR基因家族的表达会根据环境发生相关变化。在存在某些糖类、乙醇或甘油的情况下，通常最活跃的BR2会退化，其产物消失。同时会平行诱导产生一个新的BR，即BR6，以及一种新的sp-I蛋白。这种变化似乎代表了对诱导剂导致的幼虫血淋巴中磷酸盐耗竭的一种适应性反应。BR2（和BR1）的产物高度磷酸化，而BR6的产物未磷酸化。BR2编码的一种sp-I蛋白在靠近C端处被切割，具有预期所得多肽特性的物质可在细胞核中回收，并在BR中积累。这可能代表了从翻译到转录的一种反馈信号。
