Krüppel-homolog 1 mediates juvenile hormone action to promote vitellogenesis and oocyte maturation in the migratory locust

Since it was first postulated by Wigglesworth in 1934, juvenile hormone (JH) is considered a status quo hormone in insects because it prevents metamorphosis that is initiated by the molting hormone 20-hydroxyecdysone (20E). During the last decade, significant advances have been made regarding JH signaling. First, the bHLH-PAS transcription factor Met/Gce was identified as the JH intracellular receptor. In the presence of JH, with the assistance of Hsp83, and through physical association with a bHLH-PAS transcriptional co-activator, Met/Gce enters the nucleus and binds to E-box-like motifs in promoter regions of JH primary-response genes for inducing gene expression. Second, the zinc finger transcription factor Kr-h1 was identified as the anti-metamorphic factor which transduces JH signaling. Via Kr-h1 binding sites, Kr-h1 represses expression of 20E primary-response genes (i.e. Br, E93 and E75) to prevent 20E-induced metamorphosis. Third, through the intracellular signaling, JH promotes different aspects of female reproduction. Nevertheless, this action varies greatly from species to species. Last, a hypothetical JH membrane receptor has been predicted to be either a GPCR or a tyrosine kinase receptor. In future, it will be a great challenge to understand how the JH intracellular receptor Met/Gce and the yet unidentified JH membrane receptor coordinate to regulate metamorphosis and reproduction in insects.

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“…germanica (Lozano & Belles, ), P . apterus (Konopova et al ., ) and the locust, Locusta migratoria (Song et al ., ) (Fig. ).…”

Section: Jh Intracellular Receptor and Jh Response Elementmentioning

confidence: 93%

“…In L . migratoria , JH signaling promotes endoreplication of adult fat body cells to prepare the female for vitellogenesis (Guo et al ., ; Song et al ., ; Wu et al ., ) and is indispensable for basal oocyte development (Marchal et al ., ). In P .…”

Section: Regulation Of Reproduction By Jhmentioning

confidence: 99%

Juvenile hormone signaling – a mini review

Jia

2018

Insect Science

113

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“…Cumulative studies have demonstrated that JH exerts the genomic actions through its receptor, methoprenetolerant (Met) (6). JH induces the heterodimerization of Met with steroid receptor co-activator (SRC) (also known as Taiman in Drosophila or FISC in the mosquito, Aedes aegypti) to form a transcriptionally active complex to regulate the transcription of target genes in several insect systems, including the beetle Tribolium castaneum, silkworm Bombyx mori, migratory locust Locusta migratoria, and mosquito A. aegypti (1,(7)(8)(9)(10)(11).…”

mentioning

confidence: 99%

“…In many other insect species including the linden bug Pyrrhocoris apterus and the German cockroach Blattella germanica as well as Locusta migratoria, JH acts independently of 20E to stimulate vitellogenesis and oocyte maturation (3, 5, 19 -21). Knockdown of Met results in dramatic reduction of Vg expression and blocks oocyte maturation in T. castaneum, P. apterus, and L. migratoria (11,17,21). Despite this understanding of JH regulation, the molecular mechanisms of JH action in insect vitellogenesis and oocyte maturation remain poorly understood.…”

mentioning

confidence: 99%

Juvenile Hormone Activates the Transcription of Cell-division-cycle 6 (Cdc6) for Polyploidy-dependent Insect Vitellogenesis and Oogenesis

Guo

Xie

et al. 2016

Journal of Biological Chemistry

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Although juvenile hormone (JH) is known to prevent insect larval metamorphosis and stimulate adult reproduction, the molecular mechanisms of JH action in insect reproduction remain largely unknown. Earlier, we reported that the JH-receptor complex, composed of methoprene-tolerant and steroid receptor co-activator, acts on mini-chromosome maintenance (Mcm) genes Mcm4 and Mcm7 to promote DNA replication and polyploidy for the massive vitellogenin (Vg) synthesis required for egg production in the migratory locust (Guo, W., Wu, Z., Song, J., Jiang, F., Wang, Z., Deng, S., Walker, V. K., and Zhou, S. (2014) PLoS Genet. 10, e1004702). In this study we have investigated the involvement of cell-division-cycle 6 (Cdc6) in JH-dependent vitellogenesis and oogenesis, as Cdc6 is essential for the formation of prereplication complex. We demonstrate here that Cdc6 is expressed in response to JH and methoprene-tolerant, and Cdc6 transcription is directly regulated by the JH-receptor complex. Knockdown of Cdc6 inhibits polyploidization of fat body and follicle cells, resulting in the substantial reduction of Vg expression in the fat body as well as severely impaired oocyte maturation and ovarian growth. Our data indicate the involvement of Cdc6 in JH pathway and a pivotal role of Cdc6 in JHmediated polyploidization, vitellogenesis, and oogenesis.

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“…This conjecture is supported by the low expression of Krüppel homologue 1 ( Kr‐h1 ) in DD females (Fig. C); Kr‐h1 is directly induced by JH at the transcriptional level in insects and is therefore commonly used as a marker for JH signalling (Kayukawa et al ., ; Song et al ., ).…”

Section: Resultsmentioning

confidence: 99%

Absence of juvenile hormone signalling regulates the dynamic expression profiles of nutritional metabolism genes during diapause preparation in the cabbage beetle Colaphellus bowringi

Liu

Tan

Zhu

et al. 2017

Insect Molecular Biology

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Temperate insects have evolved diapause, a period of programmed developmental arrest during specific life stages, to survive unfavourable conditions. During the diapause preparation phase (DPP), diapause-destined individuals generally store large amounts of fat by regulating nutrition distribution for the energy requirement during diapause maintenance and postdiapause development. Although nutritional patterns during the DPP have been investigated at physiological and biochemical levels in many insects, it remains largely unknown how nutritional metabolism is regulated during the DPP at molecular levels. We used RNA sequencing to compare gene expression profiles of adult female cabbage beetles Colaphellus bowringi during the preoviposition phase (POP) and the DPP. Most differentially expressed genes were involved in specific metabolic pathways during the DPP. Genes related to lipid and carbohydrate metabolic pathways were clearly highly expressed during the DPP, whereas genes related to protein metabolic pathways were highly expressed during the POP. Hormone challenge and RNA interference experiments revealed that juvenile hormone via its nuclear receptor methoprene-tolerant mediated the expression of genes associated with nutritional metabolism during the DPP. This work not only sheds light on the mechanisms of diapause preparation, but also provides new insights into the molecular basis of environmental plasticity in insects.

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Krüppel-homolog 1 mediates juvenile hormone action to promote vitellogenesis and oocyte maturation in the migratory locust

Cited by 128 publications

References 44 publications

Juvenile hormone signaling – a mini review

Juvenile hormone signaling – a mini review

Juvenile Hormone Activates the Transcription of Cell-division-cycle 6 (Cdc6) for Polyploidy-dependent Insect Vitellogenesis and Oogenesis

Absence of juvenile hormone signalling regulates the dynamic expression profiles of nutritional metabolism genes during diapause preparation in the cabbage beetle Colaphellus bowringi

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