Functional analysis of a NPC1 gene from the whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae)

Abstract

Niemann‐Pick C (NPC) disease is a neurodegenerative disorder related to cellular sterol trafficking and mutation of NPC1 gene is the main cause for this disease. The function of NPC1 have been reported in a few insects but rarely studied in hemipterans. In the present study, we investigate the function of NPC1 in a hemipteran pest, the whitefly Bemisia tabaci. It was found that B. tabaci had only one NPC1 homolog (BtNPC1), in contrast to two homologs in many other insects. BtNPC1 was ubiquitously expressed at all developmental stages and body parts of whiteflies, with the highest level in adult abdomen, and the expression of BtNPC1 was induced by cholesterol feeding. To further investigate the function of BtNPC1, leaf‐mediated RNA interference experiments were carried out. Results showed that knockdown of BtNPC1 led to reduced survival of whiteflies, as well as reduced fecundity. Moreover, knockdown of BtNPC1 affected the development and metamorphosis of whitefly nymphs. Taken these together, we conclude that BtNPC1 played a crucial role in sterol‐related biological processes of B. tabaci and might be used as an insecticide target for development of novel pest management approaches.

NPC Intracellular Cholesterol Transporter 1 Regulates Ovarian Maturation and Molting in Female Macrobrachium nipponense

“…Two homologous NPC1s ( NPC1a and NPC1b ) have been reported in H. sapiens , Mus musculus and D. melanogaster , and were found to be responsible for dietary cholesterol absorption and intracellular cholesterol transport, respectively [ 31 ]. However, other insects, such as B. tabacis , have been reported to only have NPC1, which may be involved in both of the above-mentioned physiological processes [ 24 ]. In this study, only one NPC1 homolog was found in M. nipponense , which exhibited three typical conserved domains of the NPC family (NPC1_N, SSD, and PTC).…”

“…In Drosophila spp., NPC1a had a wide tissue distribution, while NPC1b was only expressed in the midgut epithelial cells [ 31 ]. The highest expression of NPC1 in B. mori was found in the testes, while, in B. tabaci , it was in the abdomen [ 24 ]. These results suggest that NPC1 may play different crucial physiological roles in different species.…”

“…Mn-NPC1 tissue expression indicated that crustacean NPC1 may be mainly involved in the transport of sterols in the hepatopancreas, ovaries, and heart. In the insects B. mori and B. tabaci , expression of NPC1 was found in all of the larval stages and was highest in the early larval stages and in adults, suggesting that it not only plays a key role in development but is also an essential participant in adult-specific physiological activities [ 23 , 24 ]. In the crustacean M. nipponense , Mn-NPC1 was almost absent during embryonic development and the early larval developmental stages and was up-regulated until the 15th day after metamorphosis, suggesting that it was not involved in the developmental stages, but only played a key role in adults.…”

“…In B. mori , the knockdown of NPC1 led to cholesterol accumulation in cells and also affected larval molting [ 23 ]. In B. tabaci , RNAi knockdown of NPC1 resulted in a decrease in female fecundity and an increase in larval mortality [ 24 ]. Insect ecdysone, which regulates insect molting behavior, is crucial for growth in insects.…”

“…BtNPC1 knockdown led to reduced survival and fecundity. Knockdown of BtNPC1 also affected the development and metamorphosis of B. tabaci nymphs [ 24 ]. However, NPC1 has not yet been studied in crustaceans.…”