Knockdown of Methoprene-Tolerant Arrests Ovarian Development in the Sogatella furcifera (Hemiptera: Delphacidae)

Abstract

Juvenile hormone (JH) is responsible for repressing larval metamorphosis and inducing vitellogenesis and egg production in insects. Methoprene-tolerant (Met) is known to be an intracellular receptor and transducer of JH. We examined the role of Met in ovarian development in the rice pest Sogatella furcifera (Horváth). We first cloned and sequenced S. furcifera Met (SfMet). The SfMet protein belongs to the basic helix–loop–helix/Per-Arnt-Sim (bHLH-PAS) family with a bHLH domain and two PAS domains (PAS-A and PAS-B). SfMet was expressed in all developmental stages and tissues but was most highly expressed in the ovaries of adult females. Furthermore, RNA interference (RNAi) mediated silencing of SfMet substantially reduced the expression of SfVg, decreased yolk protein deposition and blocked oocyte maturation and ovarian development. These results demonstrate that SfMet plays a key role in female reproduction in S. furcifera and suggest that targeting this gene could be an effective way of controlling this pest.

CRISPR/Cas9‐mediated methoprene‐tolerant 1 knockout results in precocious metamorphosis of beet armyworm (Spodoptera exigua) only at the late larval stage

“…Similar results were obtained in many lepidopterans such as G. molesta , C. suppressalis and H. armigera (Ma et al, 2018; Miao et al, 2020; Zhang et al, 2019). Higher expression in adults also suggests its function in reproduction, as in S. furcifera and H. armigera (Hu et al, 2019; Ma et al, 2018).…”

Juvenile hormone regulates the reproductive diapause through Methoprene‐tolerant gene in Galeruca daurica

“…Kr‐h1 plays a crucial role in oocyte maturation and ovarian development (Kayukawa et al ., 2012). In Sogatella furcifera , Met knockdown repressed the Kr‐h1 expression, and regulated the vitellogenesis (Hu et al ., 2019). In contrast, scilencing Met by RNAi could block ovarian development and/or suppress Vg gene expression in T. castaneum (Parthasarathy et al ., 2010), Pyrrhocoris apterus (Smykal et al ., 2014) and Bactrocera dorsalis (Yue et al ., 2018).…”

“…Methoprene‐tolerant (Met), a member of the bHLH‐PAS (basic helix–loop–helix‐Per‐Arnt‐Sim) transcription factor family, is considered as the JH intranuclear receptor in insects such as Drosophila melanogaster (Jindra et al ., 2013). Some studies have revealed that as a universal JH receptor, Met regulates insect development and reproduction, and is involved in vitellogenesis and oogenesis (Guo et al ., 2014; Villallobos‐Sambucaro et al ., 2015; Hu et al ., 2019). Krüppel homologue 1 ( Kr‐h1 ), as an early JH‐response gene downstream of Met, plays a key role in maintaining larval or nymphal status and in promoting adult reproduction (Belles and Santos, 2014).…”

“…Besides, it is also important that regulating JH levels through biosynthesis and degradation in insect reproduction. The expression of juvenile hormone binding protein (JHBP) and juvenile hormone acid methyltransferase (JHAMT) genes in the juvenile hormone synthesis pathway is regulated by JH, and can be induced by exogenous Methoprene (Ritdachyeng et al ., 2012; Hu et al ., 2019). In addition, juvenile hormone esterase (JHE) and juvenile hormone epoxide hydrolase (JHEH) have been shown to play roles in the degradation pathway of JH, being critical for the reproductive diapause in insects (Zhu et al ., 2017; Hu et al ., 2019).…”

Regulation of Krüppel homolog 1 expression by photoperiod in the bean bug, Riptortus pedestris

“…Knockdown of either Met or Kr‐h1 resulted in reduced Vg expression and impeded ovarian development with lowered fecundity in B. dorsalis (Yue et al ., 2018). Similar findings have also been reported in Sogatella furcifera , Nilaparvata lugens and the red flour beetle, T. castaneum (Lin et al ., 2015; Jiang et al ., 2017; Hu et al ., 2019, 2020; Naruse et al ., 2020). Sheng et al .…”