MSGID: 1:317/3 643633eb   
   PID: hpt/lnx 1.9.0-cur 2019-01-08   
   TID: hpt/lnx 1.9.0-cur 2019-01-08   
    Jellyfish and fruit flies shed light on the origin of hunger regulation   
      
      
     Date:   
         April 11, 2023   
     Source:   
         Tohoku University   
     Summary:   
         To survive, all organisms must regulate their appetite. Hormones   
         and small proteins called neuropeptides perform this process,   
         stimulating feelings of hunger and fullness. When researchers noted   
         the similarities between GAWamide, a neuropeptide that regulates   
         feeding in the Cladonema jellyfish, and myoinhibitory peptide,   
         a neuropeptide that regulates feeding in fruit flies, they decided   
         to test whether they could exchange the two. Their success in doing   
         so highlights the deep evolutionary origins of feeding regulation.   
      
      
         Facebook Twitter Pinterest LinkedIN Email   
   FULL STORY   
   ==========================================================================   
   Decades' worth of research has shown that the motivation to feed,   
   i.e., hunger and feelings of fullness, is controlled by hormones and   
   small proteins called neuropeptides. They are found in a wide array of   
   organisms like humans, mice and fruit flies. Such a widespread occurrence   
   suggests a common evolutionary origin. To explore this phenomenon,   
   a research group has turned to jellyfish and fruit flies, discovering   
   some surprising results.   
      
      
   ==========================================================================   
   Although jellyfish shared a common ancestor with mammals at least 600   
   million years ago, their bodies are simpler; they possess diffused   
   nervous systems called nerve nets, unlike mammals which have more   
   concrete structures such as a brain or ganglia. Still, jellyfish possess   
   a rich repertoire of behaviors, including elaborate foraging strategies,   
   mating rituals, sleep and even learning. Despite their important position   
   in the tree of life, these fascinating creatures remain understudied,   
   and almost nothing is known about how they control their food intake.   
      
   The group, which was led by Hiromu Tanimoto and Vladimiros Thoma   
   from Tohoku University's Graduate School of Life Sciences, focused on   
   Cladonema, a small jellyfish with branched tentacles that can be raised   
   in a laboratory. These jellyfish regulate how much they eat based on   
   how hungry they are.   
      
   "First, to understand mechanisms underlying feeding regulation, we   
   compared the gene expression profiles in hungry and fed jellyfish,"   
   said Tanimoto. "The feeding state changed the expression levels of   
   many genes, including some that encode neuropeptides. By synthesizing   
   and testing these neuropeptides, we found five that reduced feeding   
   in hungry jellyfish."  The researchers then honed in on how one such   
   neuropeptide -GLWamide - - controls feeding. A detailed behavioral   
   analysis revealed that GLWamide inhibited tentacle shortening, a crucial   
   step for transferring captured prey to the mouth. When the researchers   
   labelled GLWamide, they found it was present in motor neurons located in   
   the tentacle bases, and feeding increased GLWamide levels. This led to   
   the conclusion that, in Cladonema, GLWamide acts as a satiety signal --   
   a signal sent to the nervous system indicating that the body has had   
   enough food.   
      
   Yet the researchers' quest to explore the evolutionary significance   
   of this finding did not stop there. Instead, they looked to other   
   species. Fruit flies' feeding patterns are regulated by the neuropeptide   
   myoinhibitory peptide (MIP).   
      
   Fruit flies lacking MIP eat more food, eventually becoming obese.   
      
   Interestingly, MIP and GLWamide share similarities in their structures,   
   suggesting they are related through evolution.   
      
   "Since the functions of GLWamide and MIP have been conserved despite   
   600 million years of divergence, this led us to ponder whether it was   
   possible to exchange the two," said Thoma. "And we did exactly that,   
   first giving MIP to jellyfish and then expressing GLWamide in flies   
   that had no MIP."  Amazingly, MIP reduced Cladonema feeding, just   
   as GLWamide had. Furthermore, the GLWamide in flies eliminated their   
   abnormal over-eating, pointing to the functional conservation of the   
   GLWamide/MIP system in jellyfish and insects.   
      
   Tanimoto notes that their research highlights the deep evolutionary   
   origins of a conserved satiety signal and the importance of harnessing a   
   comparative approach. "We hope that our comparative approach will inspire   
   focused investigation of the role of molecules, neurons and circuits in   
   regulating behavior within a wider evolutionary context."   
       * RELATED_TOPICS   
             o Plants_&_Animals   
                   # Marine_Biology # Animals # Sea_Life # Food #   
                   Food_and_Agriculture # Evolutionary_Biology #   
                   Pests_and_Parasites # Agriculture_and_Food   
       * RELATED_TERMS   
             o Breastfeeding o Anterior_pituitary o Anchovy o Hummingbird   
             o Hematophagy o Appetite o Toucan o Protein   
      
   ==========================================================================   
   Story Source: Materials provided by Tohoku_University. Note: Content   
   may be edited for style and length.   
      
      
   ==========================================================================   
   Journal Reference:   
      1. Vladimiros Thoma, Shuhei Sakai, Koki Nagata, Yuu Ishii, Shinichiro   
         Maruyama, Ayako Abe, Shu Kondo, Masakado Kawata, Shun Hamada,   
         Ryusaku Deguchi, Hiromu Tanimoto. On the origin of appetite:   
         GLWamide in jellyfish represents an ancestral satiety   
         neuropeptide. Proceedings of the National Academy of Sciences,   
         2023; 120 (15) DOI: 10.1073/ pnas.2221493120   
   ==========================================================================   
      
   Link to news story:   
   https://www.sciencedaily.com/releases/2023/04/230411105906.htm   
      
   --- up 1 year, 6 weeks, 1 day, 10 hours, 50 minutes   
    * Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)   
   SEEN-BY: 15/0 106/201 114/705 123/120 153/7715 226/30 227/114 229/110   
   SEEN-BY: 229/111 112 113 307 317 400 426 428 470 664 700 292/854 298/25   
   SEEN-BY: 305/3 317/3 320/219 396/45   
   PATH: 317/3 229/426