Deficiency of Acetyl-CoA Carboxylase Impairs Digestion, Lipid Synthesis, and Reproduction in the Kissing Bug Rhodnius prolixus

Abstract

Rhodnius prolixus is a hematophagous insect, vector of Chagas disease. After feeding, as blood is slowly digested, amino acids are used as substrates to fuel lipid synthesis, and adult females accumulate lipids in the fat body and produce eggs. In order to evaluate the importance of de novo fatty acid synthesis for this insect metabolism, we generated acetyl-CoA carboxylase (ACC) deficient insects. The knockdown (AccKD) females had delayed blood digestion and a shorter lifespan. Their fat bodies showed reduced de novo lipogenesis activity, did not accumulate triacylglycerol during the days after blood meal, and had smaller lipid droplets. At 10 days after feeding, there was a general decrease in the amounts of neutral lipids and phospholipids in the fat body. In the hemolymph, no difference was observed in lipid composition at 5 days after blood meal, but at day ten, there was an increase in hydrocarbon content and a decrease in phospholipids. Total protein concentration and amino acid composition were not affected. The AccKD females laid 60% fewer eggs than the control ones, and only 7% hatched (89% for control), although their total protein and triacylglycerol contents were not different. Scanning electron microscopy of the egg surface showed that chorion (eggshell) from the eggs laid by the AccKD insects had an altered ultrastructural pattern when compared to control ones. These results show that ACC has a central role in R. prolixus nutrient homeostasis, and its appropriate activity is important to digestion, lipid synthesis and storage, and reproductive success.

Feeding Asian honeybee queens with European honeybee royal jelly alters body color and expression of related coding and non-coding RNAs

“…We subsequently compared gene expression in NQs compared to CQs through whole transcriptome sequencing. Interestingly, seven DEGs were enriched into the above four key pathways ( Figure 3 ), which have been shown to participate in the regulation of insect body colors ( Eisner et al, 1997 ; Cole et al, 2005 ; Liu et al, 2020 ; Moraes et al, 2022 ). The KMO gene in silkworms acts as a transgenic marker, which turns the integument of the first instar larvae brown ( Kobayashi et al, 2007 ).…”

eIF3 subunit M regulates blood meal digestion in Rhodnius prolixus affecting ecdysis, reproduction, and survival

“…Their fat bodies show reduced de novo lipogenesis activity, do not accumulate triacylglycerol during the days after a blood meal, and have smaller lipid droplets. The females laid 60% fewer eggs and only 7% hatched (Moraes et al, 2022). Besides, blood digestion relies on the massive synthesis of proteins, such as digestive enzymes and perimicrovillar membrane proteins.…”

“…The females laid 60% fewer eggs and only 7% hatched (Moraes et al. , 2022). Besides, blood digestion relies on the massive synthesis of proteins, such as digestive enzymes and perimicrovillar membrane proteins.…”

Silencing of the 20S proteasomal subunit-α6 triggers full oogenesis arrest and increased mRNA levels of the selective autophagy adaptor protein p62/SQSTM1 in the ovary of the vector Rhodnius prolixus

“…The morphologically dynamic character of the LDs in the fat body of R . prolixus over the gonotrophic cycle and under different conditions of molecular perturbations has been documented in a number of investigations [ 89 – 91 ]. Thus, it is plausible that the shift to larger LDs in the fat body of Prosα6-silenced insects is related to metabolic changes imposed by the in situ reduced proteasomal activity and/or to the altered integrated endocrine signals arising from the ovary under an oogenesis arrest, the later matter will be further discussed in the next session.…”