Biology subjects

Wulff, J. P.

Publications and source records attributed to Wulff, J. P..

3 recordsLinked to original sources

bioRxiv2025

Neuropeptide F regulates adult female response to diet, larval locomotion and several larval physiological processes in Lucilia cuprina cuprina

The blowfly Lucilia cuprina dorsalis is a highly detrimental ectoparasite of sheep responsible for causing flystrike, a condition that can result in severe morbidity and potentially lead to death if left untreated. In contrast, Lucilia cuprina cuprina is necrophagous and not a pest. We have been interested in identifying the genes that may play a role in the evolution of a parasitic lifestyle in blowflies. The objective of the present work was to explore the physiological role of the L. cuprina long neuropeptide F gene (LcNPF) in L. c. cuprina. We used CRISPR/Ca9 to generate a strain carrying a loss-of-function knock-in mutation for LcNPF. An RNA-Seq analysis was performed, and physiological and behavioral assays were conducted to evaluate the role of LcNPF in larvae and adult flies. Our findings indicate that functional disruption of the LcNPF gene significantly impairs egg hatching, larval survival, weight gain, crawling speed and larval time to pupariation. These phenotypic changes were corroborated by RNA-Seq analysis, which revealed downregulation of transcripts in LcNPF null mutated larvae associated with the respective physiological processes. In contrast, the foraging behavior of the larvae under the tested conditions was not affected. Interestingly, NPF appears to be essential for the oviposition preference of females for rotten meat but not for male mating behavior or fertility. Our results suggest that NPF signaling plays a central regulatory role in multiple physiological processes across both the larval and adult stages. Highlights{square} A loss-of-function knock-in mutation of the LcNPF gene was obtained using CRISPR/Cas9. {square}LcNPF-homozygous mutant larvae showed decreased weight gain, locomotion and survival on rotten meat. {square}Disruption of the LcNPF gene eliminated the female preference for oviposition in rotten meat. {square}LcNPF does not appear to be essential for normal fertility or male mating behavior as homozygotes were comparable to wild type

molecular biology↗

bioRxiv2024

Genetic analyses suggest that larval and adult stages of Lucilia cuprina employ different sensory systems

BackgroundThe blowfly Lucilia cuprina is a destructive parasite of sheep that causes flystrike or myiasis. Larvae consume the animals living flesh, producing large wounds that can lead to death. Growing resistance to conventional control methods has prompted the analysis of alternative strategies. MethodsAn RNA-Seq analysis was used to identify sensory receptors and other genes relevant to the physiology of L. cuprina larvae. Adult females and larvae of the same species carrying a loss-of-function mutation for the L. cuprina odorant coreceptor gene (LcupOrco) were obtained by gene editing. Their response to fresh and rotten meat at different temperatures was evaluated. ResultsThe RNA-Seq analysis of whole larvae at different stages and third instar head and gut tissues, suggested that odorant (OR), gustatory, ionotropic and pickpocket receptors may not play a central role in the L. cuprina larval sensory signaling and digestive systems. Rather, ATP-binding cassettes (ABCs) were highly enriched in head and gut RNA, and odorant-binding proteins (OBPs) only in the head. To confirm that ORs are not essential for larval detection of rotten beef, diet-choice assays were performed including larvae and adults homozygous for a null mutation in LcupOrco. While the attraction of adult females to rotten beef was fully disrupted, LcupOrco mutant larvae showed no change in diet preference. ConclusionsThe expression pattern of the ABC and OBP gene families suggests a central role in the sensory system of the L. cuprina larva for these receptors. Behavioral assays showed that ORs are essential for the adult female response to rotten beef, but not for larval behavior. These findings are consistent with high levels of expression of LcupOrco in the adult female antenna but very low expression in larvae.

genetics↗

bioRxiv2022

The role of neuropeptides in regulating ecdysis and reproduction in the hemimetabolous insect Rhodnius prolixus

In ecdysozoan animals, moulting entails the production of a new exoskeleton and the shedding of the old one during ecdysis. It is induced by a pulse of ecdysone that regulates the expression of different hormonal receptors and activates a peptide-mediated signalling cascade. In Holometabola, the peptidergic cascade regulating ecdysis has been well described. However, very little functional information regarding the neuroendocrine regulation of ecdysis is available for Hemimetabola, which displays an incomplete metamorphosis. Here, we studied neuropeptides related to ecdysis regulation in the hemi-metabolous insect Rhodnius prolixus. The RNA interference-mediated reduction of ETH expression in fourth instar nymphs resulted in lethality at the expected time of ecdysis, thereby showing its crucial role in this process. Furthermore, the results revealed the involvement of ETH in the regulation of reproductive fitness. Different from holometabolous, the knockdown of ETH in adult females led to failures in egg hatching without affecting the oviposition. Most of the first instar nymphs hatched from the eggs laid by females injected with dsEH, dsCCAP and dsOKA died at the expected time of ecdysis, indicating the crucial involvement of these genes for post-embryonic development. No phenotypes were observed upon CZ knockdown in nymphs or adult females. The conservation of the role of these neuropeptides in regulating ecdysis and reproduction throughout the class Insecta is discussed. Summary statementThe information provided here is of interest for evolutive studies on the neuroendocrine regulation of ecdysis and reproduction in insects, and the research for new targets to control pest insects.

developmental biology↗