催青温度对家蚕二化性品种滞育激素受体基因表达的影响及基因的结构特征  

Influence of Incubation Temperature on Expression of Diapause Hormone Receptor Genes in Bivoltine Bombyx mori Variety and Structural Features of the Gene

作　　者：王力刚[1] 宋海韬[1] 黄勇[1,2] 汪生鹏[1,2] 唐顺明[1,2] 赵巧玲[1,2] 沈兴家[1,2] 

机构地区：[1]江苏科技大学,江苏镇江212003 [2]中国农业科学院蚕业研究所,农业部蚕桑遗传改良重点开放实验室,江苏镇江212018

出　　处：《蚕业科学》2011年第2期215-223,共9页ACTA SERICOLOGICA SINICA

基　　金：国家自然科学基金项目(No.31072083)

摘　　要：家蚕二化性品种的卵滞育与否受上代环境影响,25℃高温明催青将产滞育卵,而15℃低温暗催青将产非滞育卵。为探究催青温度调控二化性家蚕滞育的分子机制,对从家蚕卵巢细胞中克隆的家蚕滞育激素受体基因(Bmdhr)的5种cDNA进行生物信息学分析,结果表明Bmdhr基因的5种cDNA由相同的mRNA转录本通过不同的剪接方式而来,其中Bmdhr mR-NA-1与Bmdhr mRNA-2编码的氨基酸序列相同,Bmdhr mRNA-4编码的氨基酸序列与家蚕滞育激素BmDHR-1的序列相似度达99.2%。将家蚕二化性品种秋丰的蚕卵用蛾区半分法分成2组,分别以15℃暗催青和25℃明催青,利用实时荧光定量PCR分析催青温度对家蚕不同发育时期及蚕体组织中Bmdhr基因mRNA转录的影响。结果显示:Bmdhr mRNA-1主要在蛹期卵巢中表达,在对滞育激素最敏感的化蛹后4 d时,其转录水平急速上升至峰值,并且高温催青的转录水平高于低温催青;Bm-dhr mRNA-4主要在各发育时期的蚕体血液中表达,特别是在高温明催青条件下,其在蛹期血液中的转录水平是低温暗催青的7.7倍,说明BmDHR-4可能是决定家蚕二化性品种卵滞育与否的关键因子之一;Bmdhr mRNA-5在化蛹后2～3 d的卵巢中转录水平高,且低温催青的转录水平高于高温催青,化蛹后3 d其转录水平开始下降,至化蛹后4～5 d 2种催青处理间的转录水平无显著差异。研究结果为阐明家蚕滞育的分子机制积累了实验数据。Diapause of bivoltine silkworm（Bombyx mori） eggs is influenced by the living environment of their parental generation.When bivoltine silkworm eggs（parental generation） are incubated at 25 ℃ in lightness,the moths will lay diapause eggs.In contrast,when the eggs are incubated at 15 ℃ in darkness,the moths will lay non-diapause eggs.For probing into the molecular mechanism of how incubation temperature regulates diapause in bivoltine silkworm,bioinformatic analysis was carried out on the 5 cDNAs of diapause hormone receptor gene,namely Bmdhr cDNA-1 to Bmdhr cDNA-5,which were cloned from the ovary of B.mori.The results showed that these 5 cDNAs of Bmdhr gene were from the same mRNA transcript through different splicing patterns.Among them,Bmdhr cDNA-1 and Bmdhr cDNA-2 encoded the same amino acid sequence.Amino acid sequence encoded by Bmdhr cDNA-4 had 99.2% identity with that of BmDHR-1.Eggs of bivoltine silkworm strain Qiufeng were divided into two groups with the half-egg-batch method.One group was incubated at 15 ℃ in darkness and the other at 25 ℃ in lightness,respectively.By using real-time fluorescent quantitative PCR,the influences of incubation temperature on the transcription of Bmdhr mRNA were analyzed in different developmental stages and in various tissues.The results showed that：Bmdhr mRNA-1 was expressed mainly in ovaries of pupae and its mRNA level quickly reached the peak level at day 4 after pupation during which the pupae were most sensitive to diapause hormone,and the peak mRNA level of the group incubated at 25 ℃ was significantly higher than that incubated at 15 ℃.Bmdhr mRNA-4 was expressed mainly in hemolymph of silkworm at various developmental stages.Especially,its expression level from incubation at 25 ℃ in lightness was 7.7 times to that at 15 ℃ in darkness,implying that BmDHR-4 might be a key factor determining whether the next generation eggs fall into diapause.Expression level of Bmdhr mRNA-5 was high in ovaries of pupae at 2~3 d after pupation,and its mRNA leve

关 键 词：家蚕 滞育激素受体 序列同源性 催青温度 基因表达 实时荧光定量PCR 

分 类 号：S882.34[农业科学—特种经济动物饲养]