Studies in fish have reported the presence and function of fatty acid (FA)-sensing systems comparable in many aspects to those known in mammals. Such studies were carried out in juvenile and adult fish, but the presence of FA sensing systems and control of food intake has never been evaluated in early stages, despite the importance of establishing when appetite regulation becomes functional in larval fish. In this study we aimed to elucidate the possible effects of different specific FA on neural FA sensing systems and neuropeptides involved in the control of food intake in Senegalese sole post-larvae. To achieve this, we orally administered post-larvae with different solutions containing pure FA - oleate (OA), linoleate (LA), α-linolenate (ALA) or eicosapentaenoate (EPA) - and evaluated changes in mRNA abundance of neuropeptides involved in the control of food intake and of transcripts related to putative FA-sensing systems, 3 h and 6 h post-administration. Results of neuropeptide gene expression were relatively consistent with the activation of anorectic pathways (enhanced cart4 and pomcb) and decrease in orexigenic factors (npy) following intake of FA. Even if there were a few differences depending on the nature of the FA, the observed changes appear to suggest the existence of a putative anorectic response in fish post-larvae to the ingestion of all four tested FA. However, changes in neuropeptides cannot be explained by the integration of metabolic information of FA in circulation through FA sensing mechanisms in the brain. Only the reduction in mRNA levels of acc in OA- (6 h), ALA- (3 h) and EPA-treated (3 h and 6 h) post-larvae could be indicative of the presence of a FA sensing system, but most genes were either not significantly regulated (fat/cd36-lmp2, acly, kir6.x, srebp1c) or were affected (fat/cd36-pg4l, fas, cpt1.1, cpt1.2, cpt1.3, sur, pparα and lxrα) in a way inconsistent with FA sensing mechanisms.
Orally administrated fatty acids enhanced anorectic potential but did not activate central fatty acid sensing in Senegalese sole post-larvae
2023 JEB Outstanding Paper Prize shortlist and winner
The JEB Editors are delighted to announce the shortlisted authors for the 2023 JEB Outstanding Paper Prize. Read the winning paper - Tiny spies: mosquito antennae are sensitive sensors for eavesdropping on frog calls - by Hoover Pantoja-Sanchez and Brian Leavell from Ximena Bernal's lab at Purdue University, USA.
JEB Science Communication Workshop for ECRs
If you’re an early-career researcher interested in science communication and are attending the SEB Annual Conference in Prague this summer, come a day early and join the JEB Editors at a sci comm workshop to learn the key writing skills needed to promote your research to a broad audience beyond your peers (1 July at 14.30-17.30). Places are limited to 24 attendees, and applicants should apply through the SEB registration page by 30 April 2024.
Bridging the gap between controlled conditions and natural habitats in understanding behaviour
Novel technologies enable behavioural experiments with non-model species, in naturalistic habitats and with underexplored behaviours. In their Commentary, Scholz and colleagues discuss how to obtain a deeper understanding of the natural ecology and lifestyle of study animals.
Beluga metabolic measures could help save species
To help save animals from extinction, it’s important to understand what each species needs to survive. This led Jason John et al. to measure the metabolic rates of captive belugas to develop a ‘fish calculator’ showing that the whales need to eat ~23 salmon per day.
ECR Workshop on Positive Peer Review
Are you an ECR looking for tips on how to write concise, astute and useful manuscript reviews? If so, join the JEB Editors at a 2-hour JEB-sponsored Workshop on Positive Peer Review at the Canadian Society of Zoologists annual meeting in Moncton on 9 May 2024 at 13.00-15.00. There are 25 spaces for ECRs and selection is first come, first serve. To sign up, check the ECR Workshop box when you register for the CSZ meeting.
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