摘要
HmgD基因编码果蝇高流动性蛋白(Highmobilitygroupproteins,HMG)的同源物,它可以参与染色质的组装。目前关于HMGD蛋白在果蝇胚胎发育过程中的作用尚无定论。我们采用UAS-Gal4系统,通过功能获得性突变的方法研究了HmgD基因过量表达对果蝇发育的影响。结果表明:HmgD过量表达对果蝇胚胎期发育的影响较弱,而对后期幼虫的发育具有很大的影响;HmgD过量表达的果蝇胚胎死亡率增高,但这种影响不是很大,因为一部分胚胎仍然能够发育至成体;但是当HmgD在广泛表达的Gal4驱动子(ActGal4)的控制下过量表达时导致子代大量死亡,特别是用4个拷贝的转基因果蝇进行杂交时,后代中的突变型在三龄幼虫末期全部死亡;部分突变型幼虫体内长有黑色素瘤,其血淋巴中的血细胞数量极显著地高于野生型。RT-PCR分析表明,突变幼虫中与血细胞增殖有关的Ras-MAPK途径和Toll途径被异常激活。这些结果显示:HmgD过量表达可能引起染色质结构疏松,激活了特定的转录因子,从而引发了三龄幼虫期异常的转录调控,并导致幼虫死亡[动物学报52(2):335-341,2006]。
The high mobility group proteins gene （HmgD） encodes the Drosophila homologue of high mobility group proteins, which are thought to have an architectural function in chromatin. At present, the facts and ideas about the function of HMGD protein during embryogenesis of Drosophila are controversial. To further analyse the function of HMGD on the development of Drosophila, we have generated UASPHmgD transgenic flies and overexpressed this gene under the maternal control and under the control of a ubiquitous Gal4 protein, respectively. The present study showed that some effects on the viability of the embryos appeared to link with the overexpression of HmgD. Yet, these effects were weak since some of the embryos survived until adulthood. However, overexpression of HmgD under the control of a ubiquitous Gal4 protein （ActGal4） caused serious lethality. Especially, four copies of transgenic flies in this expression system caused 100% lethality of the progeny at the late larval stage. Some of these larvae were with the melanotic tumours, and the hemoeyte number was increased dramatically in hemolymph isolated from these larvae with respect to wild type larvae. RT-PCR analysis showed that both Ras-MAPK pathway and Toll pathway involved in the hemoeytes proliferation were abnormally activated in the mutant larvae. These results suggest that overexpression of HmgD, which could induce a loose chromatin structure, may activate specific transcription factors out of schedule so as to cause aberrant transcriptional control in larval stage. The detailed pathways that the overexpression of HmgD results in the increasing of larval hemocytes and the lethality of the third instar larvae with the defect of pupation are underway .
出处
《动物学报》
SCIE
CAS
CSCD
北大核心
2006年第2期335-341,共7页
ACTA ZOOLOGICA SINICA
基金
国家自然科学基金(No.30300035)
教育部留学回国人员科研启动基金[教外司留(2004)527号]资助项目~~
关键词
果蝇
HmgD
过量表达
发育
Drosophila, HmgD, Overexpression, Development
