Dosage requirements of Ultrabithorax and bithoraxoid in the determination of segment identity in Drosophila melanogaster.
Dosage requirements of Ultrabithorax and bithoraxoid in the determination of segment identity in Drosophila melanogaster.
复制标题
确定果蝇节段同一性时 Ultrabithorax 和 bithoraxoid 的剂量要求。
DOI：
10.1093/genetics/124.2.357
复制
发表时间：
1990
期刊：
影响因子：
3.3
通讯作者：
Smolik-Utlaut,SM
中科院分区：
文献类型：
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作者：
Smolik-Utlaut,SM
野生型超双胸(Ubx)和双胸(BxD)功能主要负责确定果蝇胚胎中副节段6(PS6)的身份，从而确定成体第三胸段(PT3)后室和第一腹段前室(Aa1)的身份。所描述的实验旨在测试增加Ubx+和BxD+的剂量影响PS5向PS6转化的能力。结果与以下观点一致：(1)Ubx+和BxD+的多个拷贝导致PS5内的一些细胞具有PS6细胞的特征，但不会导致PS5向PS6的整体段旁转化；(2)细胞同一性不仅取决于Ubx+的活性，还取决于其浓度；(3)Ubx+与野生型触角蛋白(ANTP)基因之间的相互作用建立了pt2中的片段同一性。在携带8个Ubx+和BxD+拷贝的1龄幼虫中，T3Setal带的细毛向A1 Setal带的钩状结构转变。该区段内的其他结构不受影响。在成虫身上，笼头的尺寸变小了。在携带8剂野生型Ubx和BxD的成年人中，通过减少双胸复合体(BX-C)调节剂Polycomb(Pc)的数量，可以看到pt2细胞(翼)向PT3细胞(Haltere)的转化。然而，在这些动物的幼虫中，T3Setal带的转化并不增强。只有当动物携带一份Pc时，触角复合体(ant-C)基因与pt2中Ubx+和BxD+功能之间的相互作用才具有剂量敏感性。在这些动物中，翅膀向龟头的转变显著增强。
The wild-type Ultrabithorax (Ubx) and bithoraxoid (bxd) functions are primarily responsible for establishing the identity of parasegment 6 (PS6) in the Drosophila embryo and thus the identity of the posterior compartment of the third thoracic segment (pT3) and the anterior compartment of the first abdominal segment (aA1) in the adult. The experiments described were designed to test the ability of an increased dosage of Ubx+ and bxd+ to affect the transformation of PS5 toward PS6. The results are consistent with the ideas that (1) multiple copies of Ubx+ and bxd+ cause some cells within PS5 to take on the characteristics of PS6 cells but do not cause an overall parasegmental transformation of PS5 toward PS6, (2) cellular identity depends not only on the activity of Ubx+ but on its concentration as well, and (3) that an interaction between Ubx+ and the wild-type Antennapedia (Antp) gene establishes segmental identity in pT2. In the first instar larvae carrying eight copies of Ubx+ and bxd+ the fine hairs of the T3 setal belt are transformed toward the hook-like structures of the A1 setal belt. Other structures within this segment are unaffected. In the adult, the haltere is reduced in size. The transformation of pT2 cells (wing) toward pT3 cells (haltere) is seen in adults carrying eight doses of wild type Ubx and bxd by decreasing the amount of the bithorax complex (BX-C) regulator Polycomb (Pc). However, the transformation of the T3 setal belt is not enhanced in the larvae of these animals. The interaction between the genes of the Antennapedia complex (ANT-C) and the Ubx+ and bxd+ functions in pT2 is dosage sensitive only when the animals carry one copy of Pc. In these animals, the transformation of wing toward haltere is significantly enhanced.