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

Abstract

Clathrin heavy chain (Chc) is a constituent of clathrin-coated vesicles and serves important functions in endocytosis and intracellular membrane trafficking but appears 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. However, 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 developmental 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 fifthinstar 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.

Clathrin‐dependent endocytosis plays a critical role in larval and pupal development, and female oocyte production in the red flour beetle (Tribolium castaneum)

“…Overall, this study provides strong evidences that clathrin‐dependent endocytosis plays an important role in larval and pupal development, and female oocyte production in addition to cellular uptake of dsRNA, as we previously reported in T. castaneum 13 . The inhibition of the oocyte production in T. castaneum females when the expression of TcChc or TcVhaSFD was suppressed by RNAi is likely caused by blocking the yolk uptake of oocytes, which relies on clathrin‐dependent endocytosis 8,42,44 . However, because clathrin‐dependent endocytosis is responsible for internalizing diverse substances including nutrients, pathogens, antigen, growth factors, and proteins, the impacts of RNAi against these clathrin‐dependent endocytic pathway genes are expected to be very broad.…”

“…The Chc gene is essential in many organisms 41 . The loss‐ Chc‐ phenotype or RNAi‐mediated knockdown of the gene are lethal in many insects and other organisms 8,13,42,43 . One important function of Chc is its involvement in yolk uptake in oocytes through clathrin‐dependent endocytosis.…”

“…41 The loss-Chcphenotype or RNAi-mediated knockdown of the gene are lethal in many insects and other organisms. 8,13,42,43 One important function of Chc is its involvement in yolk uptake in oocytes through clathrin-dependent endocytosis. In C. elegans, for example, depletion of the Chc transcript by RNAi led to decreased yolk uptake in oocytes and resulted in dead progeny.…”

“…7 Indeed, it has been shown that the suppression of the gene encoding the clathrin heavy chain (Chc) by RNA interference (RNAi) causes high mortality in the migratory locust (Locusta migratoria). 8 AP complexes are key components of this pathway as they bind to clathrin and endocytic regulatory proteins to stimulate the formation of the clathrin coat. Four distinct types of AP complexes (AP-1, AP-2, AP-3 and AP-4) have been revealed and characterized in mammalian cells.…”

“…The function of clathrin is essential in the development and survival of an organism, and the loss of clathrin phenotype is always lethal 7 . Indeed, it has been shown that the suppression of the gene encoding the clathrin heavy chain ( Chc ) by RNA interference (RNAi) causes high mortality in the migratory locust ( Locusta migratoria ) 8 …”