MOLECULAR CHARACTERIZATION OF THE TRITHORAX GENE, A POSITIVE REGULATOR OF HOMEOTIC GENE-EXPRESSION IN DROSOPHILA
MOLECULAR CHARACTERIZATION OF THE TRITHORAX GENE, A POSITIVE REGULATOR OF HOMEOTIC GENE-EXPRESSION IN DROSOPHILA
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DOI：
10.1016/0925-4773(91)90062-b
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发表时间：
1991-09-01
影响因子：
2.6
通讯作者：
HARTE, PJ
中科院分区：
文献类型：
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作者：
BREEN, TR;HARTE, PJ
果蝇基因trithorax（trx）是双胸复合体（BX-C）和双足复合体（ANT-C）中许多同源异型基因正常表达所必需的。Trx突变纯合子的果蝇表现出与同源异型基因性梳减少（Scr）、超双胸（Ubx）、腹部-A（abd-A）和腹部-B（Abd-B）中功能丧失突变所引起的片段身份转换相似的片段身份转换。我们提出了一个分子特征的trx基因座，并表明，这是必要的正常水平的napedia（Antp），UBX，和abd-A蛋白的积累。有趣的是，trx功能的丧失对这些蛋白质的表达产生差异性影响; Ubx蛋白质水平大大降低，abd-A蛋白质水平降低至较小程度，而Antp蛋白质水平仅略微降低。使用含有25 kb trx转录单位的34 kb基因组DNA的P元件介导的转化鉴定了正常trx功能所必需的所有序列，并将可用于调节能力的5 ′和3 ′侧翼序列限制在相对小的区域。初级转录单位被差异剪接以产生具有不同发育概况的12和15 kb的两个大转录物。
The Drosophila gene trithorax (trx) is required for the normal expression of a number of the homeotic genes in the bithorax complex (BX-C) and the Antennapedia complex (ANT-C). Flies homozygous for trx mutations exhibit segmental identity transformations similar to those caused by loss-of-function mutations in the homeotic genes Sex combs reduced (Scr), Ultrabithorax (Ubx), abdominal-A (abd-A), and Abdominal-B (Abd-B). We present a molecular characterization of the trx locus and show that it is necessary for normal levels of Antennapedia (Antp), Ubx, and abd-A protein accumulation. Interestingly, the loss of trx function differentially affects the expression these proteins; Ubx protein levels are greatly reduced, abd-A protein levels are reduced to a lesser extent, and Antp protein levels are only slightly reduced. P-element mediated transformation using 34 kb of genomic DNA containing the 25 kb trx transcription unit identifies all sequences necessary for normal trx function and limits the 5' and 3' flanking sequences that could be used in a regulatory capacity to relatively small regions. The primary transcription unit is differentially spliced to produce two large transcripts of 12 and 15 kb that have different developmental profiles.