BmPLA2 containing conserved domain WD40 affects the metabolic functions of fat body tissue in silkworm, Bombyx mori

Abstract

PLA2 enzyme hydrolyzes arachidonic acid, and other polyunsaturated fatty acids, from the sn-2 position to release free arachidonic acid and a lysophospholipid. Previous studies reported that the PLA2 in invertebrate organisms participates in lipid signaling molecules like arachidonic acid release in immune-associated tissues like hemocytes and fat bodies. In the present study, we cloned the BmPLA2 gene from fat body tissue of silkworm Bombyx mori, which has a total sequence of 1.031 kb with a 31.90 kDa protein. In silico results of BmPLA2 indicated that the protein has a putative WD40 conserved domain and its phylogeny tree clustered with Danaus plexippus species. We investigated the transcriptional expression in development stages and tissues. The highest expression of BmPLA2 was screened in fat body among the studied tissues of third day fifth instar larva, with a high expression on third day fifth instar larva followed by a depression of expression in the wandering stage of the fifth instar larva. The expression of BmPLA2 in female pupa was higher than that of male pupa. Our RNAi-mediated gene silencing results showed highest reduction of BmPLA2 expression in post-24 h followed by post-48 and post-72 h. The BmPLA2-RNAi larvae and pupa could be characterized by pharate adult lethality and underdevelopment. The phenotypic characters of fat body cells in RNAi-induced larva implied that BmPLA2 affects the metabolic functions of fat body tissue in silkworm Bombyx mori.

A Review of Diatom Lipid Droplets

“…P. tricornutum has a homologue of DOAP1, named PtLDP1, which contains a WD40/YVTN repeat domain and a proline-rich hydrophobic C-terminal domain [191]. Although WD40 repeats are a common motif, they are found in proteins which regulate and localize to LDs in animals [194][195][196]. PtLDP1 was identified by MS of isolated LDs and its in vivo localization on LDs was confirmed with an EYFP-fusion construct [191].…”

Prostaglandins and Other Eicosanoids in Insects: Biosynthesis and Biological Actions

“…The insect iPLA 2 s are separated into ankyrin and non-ankyrin types (Figure 3). An iPLA 2 gene was also identified from another lepidopteran insect, Bombyx mori (Orville Singh et al, 2016) and it is rich in glycine-histidine repeats. This iPLA 2 is highly expressed in fat body and RNAi treatments led to severe abnormal development and mortality.…”

Localization and functional analysis of the insect‐specific RabX4 in the brain of Bombyx mori

“…Lately, there have been some reports on the knockdown of important genes, such as transcription factors, phospholipase, and Rab3, using dsRNAi Orville Singh et al, 2016;Singh et al 2015;Yang et al, 2014;Zhang, Teng, Chen, & Li, 2014). In this study, RNAi-knockdown of RabX4 resulted in decreased expression of bombyxin in the brain, indicating that RabX4 may function in the transport of bombyxin in the brain of B. mori.…”

“…Lately, there have been some reports on the knockdown of important genes, such as transcription factors, phospholipase, and Rab3, using dsRNAi (Liang et al., ; Orville Singh et al., ; Singh et al. ; Yang et al., ; Zhang, Teng, Chen, & Li, ).…”