PHOTOPERIODIC DIAPAUSE IN DROSOPHILA-MELANOGASTER INVOLVES A BLOCK TO THE JUVENILE-HORMONE REGULATION OF OVARIAN MATURATION
PHOTOPERIODIC DIAPAUSE IN DROSOPHILA-MELANOGASTER INVOLVES A BLOCK TO THE JUVENILE-HORMONE REGULATION OF OVARIAN MATURATION
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DOI：
10.1016/0016-6480(90)90102-r
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发表时间：
1990-08-01
影响因子：
2.7
通讯作者：
GILBERT, LI
中科院分区：
文献类型：
--
作者：
SAUNDERS, DS;RICHARD, DS;GILBERT, LI
将雌性黑腹果蝇（Drosophila melanogaster）置于短日照和中等低温（12 ℃）下。进入卵巢滞育状态，其中卵母细胞中的卵黄沉积被暂停（D. S.桑德斯，弗吉尼亚州。Henrich和L. I.吉尔伯特，美国国家科学院院刊Acad. Sci. USA 86，3748-3752，1989）。采用多克隆抗体进行酶联免疫吸附试验（ELISA）。黑腹果蝇卵黄多肽（YPs）的研究表明，滞育果蝇在血淋巴中合成和积累YPs，而在卵巢中合成和积累的YPs很少。非滞育女性在相同的温度，但在长的日子，和短日苍蝇，其中滞育被打破的温度上升或局部应用保幼激素（JH），表现出增强的YPs的滴度在卵巢中，这表明刺激吸收。测定保幼激素bisepoxide（JHB 3）和JH III的合成在体外由单个切除的侧咽体表明，腺体从nondiapausing苍蝇或侧咽体苍蝇，其中滞育已被打破合成JH的速率约4倍高于腺体滞育苍蝇。在培养基中添加法呢酸孵育的咽侧体的JH合成率增加，但增加的幅度相对较大，与非滞育苍蝇咽侧体。滞育果蝇的腺体呈现新出现或“不成熟”的腺体外观。卵巢滞育在12 ℃时终止。LD 10：14，滞育终止表现为卵黄发生速率的增加和每个卵黄发生雌虫完全发育的卵数量的增加。因此，短日照诱导的滞育是一种重要的滞育现象。黑腹果蝇的死亡是由于对JH刺激的从血淋巴中摄取卵黄蛋白的“阻断”所致，这是由咽侧体合成JH的速率降低引起的。光周期调节的咽侧体可能是通过大脑介导的。
Females of Drosophila melanogaster held under short-day photoperiods at a moderately low temperature (12.degree.) enter a state of ovarian diapause in which yolk deposition in the oocytes is suspended (D. S. Saunders, V. C. Henrich, and L. I. Gilbert, Proc. Natl. Acad. Sci. USA 86, 3748-3752, 1989). An enzyme-linked immunosorbent assay (ELISA) using polyclonal antibodies raised against D. melanogaster yolk polypeptides (YPs) showed that diapausing flies synthesize and accumulate YPs in the hemolymph, but very little in the ovary. Nondiapausing females at the same temperature but at long days, and short-day flies in which diapause was broken by an upshift in temperature or topical application of juvenile hormone (JH), showed enhanced titers of YPs in the ovaries, suggesting stimulated uptake. Determinations of juvenile hormone bisepoxide (JHB3) and JH III synthesis in vitro by single excised corpora allata showed that glands from nondiapausing flies or corpora allata from flies in which diapause had been broken synthesized JH at a rate about four times higher than glands from diapausing flies. Corpora allata incubated in medium supplemented with farnesoic acid showed an increase in the rate of JH synthesis, but the increase was relatively greater with corpora allata from nondiapausing flies. Glands from diapausing flies presented the appearance of newly emerged or "immature" glands. Ovarian diapause is terminated at 12.degree. LD 10:14 in 7 days following topical application of either JH III or JHB3 at a concentration of about 0.5 .mu.g per fly, diapause termination being expressed by an increased rate of vitellogenesis and by an increase in the number of fully developed eggs per vitellogenic female. It is concluded that the short-day-elicited diapause in D. melanogaster results from a "block" to the JH-stimulated uptake of yolk proteins from the hemolymph, caused by a reduced rate of JH synthesis by the corpus allataum. Photoperiodic regulation of the corpus allatum may be mediated via the brain.