Fatty acid synthase 2 contributes to diapause preparation in a beetle by regulating lipid accumulation and stress tolerance genes expression

Abstract

Diapause, also known as dormancy, is a state of arrested development that allows insects to survive unfavorable environmental conditions. Diapause-destined insects store large amounts of fat when preparing for diapause. However, the extent to which these accumulated fat reserves influence diapause remains unclear. To address this question, we investigated the function of fatty acid synthase (FAS), which plays a central role in lipid synthesis, in stress tolerance, the duration of diapause preparation, and whether insects enter diapause or not. In diapause-destined adult female cabbage beetles, Colaphellus bowringi, FAS2 was more highly expressed than FAS1 at the peak stage of diapause preparation. FAS2 knockdown suppressed lipid accumulation and subsequently affected stress tolerance genes expression and water content. However, silencing FAS2 had no significant effects on the duration of diapause preparation or the incidence of diapause. FAS2 transcription was suppressed by juvenile hormone (JH) and the JH receptor methoprene-tolerant (Met). These results suggest that the absence of JH-Met induces FAS2 expression, thereby promoting lipid storage in diapause-destined female beetles. These results demonstrate that fat reserves regulate stress tolerance genes expression and water content, but have no significant effect on the duration of diapause preparation or the incidence of diapause.

Multiple functions of CREB-binding protein during postembryonic development: identification of target genes

“…The present study also revealed that fatty acid synthase (FAS) expression was also regulated by TcCBP. The FAS is another important player during diapause preparation in insects and lipid synthesis [ 83 ]. The transcription of FAS is suppressed by JH and the JH receptor Met.…”

A fatty acid synthase gene (FASN3) from the integument tissue of Rhodnius prolixus contributes to cuticle water loss regulation

“…To date, the function of insect FASN genes has been thoroughly studied only in some Drosophila species (Parvy et al, 2012;Chung et al, 2014;Wicker-Thomas et al, 2015). More recently, Tan et al (2017) showed that FASN silencing suppresses lipid accumulation, affecting stress tolerance and water content in female Colaphellus bowringi beetles undergoing diapause. In Drosophila serrata, RNAi-mediated knockdown of FASN3 using an oenocyte-specific driver was lethal, whilst knockdown of FASN2 led to a significant reduction in cuticle methyl-branched HCs, associated with a decrease in desiccation resistance (Chung et al, 2014).…”

De novo characterization of Phenacoccus solenopsis transcriptome and analysis of gene expression profiling during development and hormone biosynthesis

“…According to the KEGG pathway analysis, fifteen, six, and eleven pathways were observed as significantly enriched for DEGs of EggI vs. second instar, second vs. third instar, and third instar vs. adult females, respectively. The pathway enriched for different developmental stages were glycerolipid metabolism 69 , FoxO-signaling pathway 20 , 70 – 73 , Hippo signaling pathway 74 – 76 , fatty acid biosynthesis 77 – 79 , biosynthesis of amino acids 41 , 80 – 85 and steroid biosynthesis 86 – 88 suggesting that genes in these pathways seem to be involved in early developmental process. Likewise, we have identified all the genes coding for enzymes involved in juvenile and ecdysteroid hormone biosynthetic pathways and found many of them as potential RNAi targets for silencing (Fig.…”