Lethal giant larvae gene is required for normal nymphal development and midgut morphogenesis in Locusta migratoria

Disruption of morphogenesis,an essential process in organismal development,can lead to disruption of biological processes,reduction in fitness,or even death of an organism.The roles of lethal giant larvae(Lgl)protein in maintaining tissue organization have been studied extensively in mammals,but little is known about this gene's roles in promoting correct tissue morphogenesis in insects.In this study,we identified an Lgl ortholog in Locusta migratoria.RT-qPCR results revealed that LmLgl was constitutively expressed during third,fourth,and fifth instar nymphs.Furthermore,LmLgl showed highest expression in the ovary followed by wing pads,midgut,hindgut,Malpighian tubules,and foregut of the third-instar nymphs.To examine the role of LmLgl in L.migratoria development,RNA interference was performed during nymphal stages.Silencing of LmLgl increased body size but decreased bodyweight by 9.0%.Histological sections of the midgut revealed abnormal large masses of disordered epithelial cells in dsLmLgl-injected nymphs.In addition,downregulation of LmLgl transcript levels significantly altered the morphological structure in midgut,resulting in the formation of tumor-like structures.Our results indicated that LmLgl may act as a tumor-suppressor gene,which plays an essential role in maintaining a normal morphological structure in the midgut of L.migratoria.Our results also suggest that LmLgl may be explored as a potential target for developing dsRNA-based biological pesticides for managing insect pests.

Clathrin heavy chain is essential for the development and reproduction of Locusta migratoria

Clathrin heavy chain(Chc)is a constituent of clathrin-coated vesicles and serves important functions in endocytosis and intracellular membrane trafficking but ap-pears to have physiological roles also at the organismal level.Most of what we know about Chc functions originates from studies performed in fungal or vertebrate cells.How-ever,the physiological functions of Chc in insects remain poorly understood.Here,we identified a Chc ortholog from a Locusta migratoria transcriptome database.RT-qPCR revealed that LmChc was constitutively expressed in fifth-instar nymphs.In this develop-mental stage,LmChc showed the highest expression in the ovary followed by hemolymph,testis,hindgut,midgut,and foregut.In isolated hemocytes,we detected the Chc protein in patches at the plasma membrane.To examine the role of LmChc in L.migratoria during development,RNA interference was performed by injecting dsRNA into the early fifth-instar nymphs.Silencing of LmChc caused a lethal phenotype with molting defect from nymph to adult.In addition,silencing of LmChc resulted in abnormal development of the ovaries,the size of which was significantly smaller than that in controls.Taken together,our results suggest that LmChc is a vital gene in L.migratoria that plays an important role in growth,development,and reproduction.LmChc may be used as an efficient RNAi target gene for developing dsRNA-based biological insecticides to manage insect pests.