CDNA cloning, gene structure, and expression of Broad-Complex (BR-C) genes in the silkworm, Bombyx mori
CDNA cloning, gene structure, and expression of Broad-Complex (BR-C) genes in the silkworm, Bombyx mori
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DOI：
10.1016/j.ibmb.2004.06.005
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发表时间：
2004-09-01
影响因子：
3.8
通讯作者：
Fujrwara, Y
中科院分区：
文献类型：
--
作者：
Ijiro, T;Urakawa, H;Fujrwara, Y
为了阐明变态的分子机制，我们分析了家蚕 Bombyx mori 的广泛复合体 (BR-C) 基因。我们克隆了 BR-C Z1、Z2 和 Z4 同工型的完整编码区的 cDNA。 Z3 锌指序列发现于 Z2 同工型的 3'UTR 中。预测的氨基酸序列与果蝇和曼杜卡BR-C蛋白具有高度同源性。从 Bombyx BAC 文库中筛选出五个细菌人工染色体 (BAC) 克隆。构建了 170 kb 区域的限制性酶切图谱，并对总共 25.8 kb 的区域进行了测序。 BAC分析显示，BR-C基因的5'UTR由前两个外显子组成，而编码区包含一个核心区结构域，具有五个外显子和四个锌指外显子，顺序为Z1、Z4、Z2和Z3。表达分析显示 9.5、6.5 和 5.5 kb BR-C 转录本。这些在第五龄第 6 天的旋转蜕皮激素高峰期间增加，此时家蚕表皮发生蛹定型。此外，在该峰值之前，在表皮中检测到少量的BR-C mRNA。从第四龄第1天到第五龄第7天，BR-C mRNA也在脂肪体中表达。 (C) 2004 Elsevier Ltd. 保留所有权利。
To clarify the molecular mechanisms of metamorphosis, we analyzed the Broad-Complex (BR-C) gene in the silkworm, Bombyx mori. We cloned cDNAs for the full coding regions of the Z1, Z2, and Z4 isoforms of BR-C. The Z3 zinc finger sequence was found in the 3'UTR of the Z2 isoform. The predicted amino acid sequence showed high homology with Drosophila and Manduca BR-C proteins. Five bacterial artificial chromosome (BAC) clones were screened from a Bombyx BAC library. Restriction enzyme cleavage maps of 170 kb regions were constructed, and a total of 25.8 kb were sequenced. The BAC analysis showed that the 5'UTR of the BR-C gene consists of the first two exons, while the coding region contains a core region domain with five exons and four zinc finger exons in the order Z1, Z4, Z2, and Z3. Expression analysis revealed 9.5, 6.5, and 5.5 kb BR-C transcripts. These increased during the spinning ecdysone peak on day 6 of the fifth instar when pupal commitment occurs in the Bombyx epidermis. In addition, a small amount of BR-C mRNA was detected in the epidermis before this peak. BR-C mRNA was also expressed in the fat body from day I in the fourth instar to day 7 in the fifth instar. (C) 2004 Elsevier Ltd. All rights reserved.