E93 expression and links to the juvenile hormone in hemipteran mealybugs with insights on female neoteny
E93 expression and links to the juvenile hormone in hemipteran mealybugs with insights on female neoteny
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E93 表达及其与半翅目粉蚧保幼激素的联系以及对雌性幼态持续的见解
DOI：
10.1016/j.ibmb.2018.11.008
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发表时间：
2019
影响因子：
3.8
通讯作者：
Minakuchi Chieka
中科院分区：
文献类型：
--
作者：
Vea Isabelle Mifom;Tanaka Sayumi;Tsuji Tomohiro;Shiotsuki Takahiro;Jouraku Akiya;Minakuchi Chieka
昆虫变态产生有生殖能力的成虫，通常伴随着翅膀的直接或间接发育。在一些有翅昆虫中，成虫会因生活史的变化而改变。例如，在介壳虫和粉蚧中，有生殖能力的雌虫保留幼年特征并且没有翅膀。转录因子E93触发变态并与保幼激素途径协同作用，保证从幼年成功过渡到成年。我们之前提供了日本粉蚧雌性发育过程中保幼激素途径非典型下调的证据。在这里，我们通过鉴定其亚型、评估其表达模式并评估外源保幼激素模拟处理对E93的影响，进一步研究E93如何参与幼态无翅雌性的产生。这项研究根据日本粉蚧 cDNA 鉴定了 5' 端的三个 E93 亚型，并表明雌性发育发生在几乎没有 E93 转录本的情况下，这与雄性变态相反。此外，虽然雄性发育通常受到外源保幼激素模拟治疗的影响，但雌性似乎对治疗不敏感，并且没有观察到保幼激素信号传导的上调。此外，对雌性若虫进行保幼激素模拟处理对E93转录没有明显影响，而对雄性预蛹进行处理则导致E93转录耗尽。在这项研究中，我们强调将非典型变态案例作为补充系统进行检查的重要性，以更好地了解昆虫变态的分子机制。例如，调节E93表达的因素尚不清楚。研究E93转录的调控机制可以为识别诱导或抑制E93转录的因素提供线索，进而触发男性成年发育或女性幼态持续。
Insect metamorphosis produces reproductive adults and is commonly accompanied with the direct or indirect development of wings. In some winged insects, the imago is altered by life history changes. For instance, in scale insects and mealybugs, reproductive females retain juvenile features and are wingless. The transcription factorE93triggers metamorphosis and plays in concert with the juvenile hormone pathway to guarantee the successful transition from juvenile to adult. We previously provided evidence of an atypical down-regulation of the juvenile hormone pathway during female development in the Japanese mealybug. Here, we further investigate howE93is involved in the production of neotenic wingless females, by identifying its isoforms, assessing their expression patterns and evaluating the effect of exogenous juvenile hormone mimic treatment onE93. This study identifies threeE93isoforms on the 5’ end, based on Japanese mealybug cDNA and shows that female development occurs with the near absence ofE93transcripts, as opposed to male metamorphosis. Additionally, while male development is typically affected by exogenous juvenile hormone mimic treatments, females seem to remain insensitive to the treatment, and up-regulation of the juvenile hormone signaling is not observed. Furthermore, juvenile hormone mimic treatment on female nymphs did not have an obvious effect onE93transcription, while treatment on male prepupae resulted in depletedE93transcripts. In this study, we emphasize the importance in examining atypical cases of metamorphosis as complementary systems to provide a better understanding on the molecular mechanisms underlying insect metamorphosis. For instance, the factors regulating the expression ofE93are largely unclear. Investigating the regulatory mechanism ofE93transcription could provide clues towards identifying the factors that induce or suppressE93transcription, in turn triggering male adult development or female neoteny.