New Hormone Discovered That Affects Ovarian Development in Peppermint Shrimp

Greg Howard
2nd August, 2024

New Hormone Discovered That Affects Ovarian Development in Peppermint Shrimp

Peppermint Shrimp (Lysmata vittata)

Photo adapted from: inbetweenbays / CC BY (Source)

Key Findings

  • Researchers at Jimei University identified a new hormone, Lvit-GIH2, in the hermaphrodite shrimp Lysmata vittata
  • Lvit-GIH2 is widely expressed in multiple tissues and increases from the male to the hermaphrodite phase, indicating a role in ovarian development
  • Experiments showed that Lvit-GIH2 inhibits ovarian development by suppressing vitellogenin and its receptor, essential for egg development
Recent research from Jimei University has provided new insights into the role of type II crustacean hyperglycemic hormone (CHH) neuropeptides in the hermaphrodite shrimp Lysmata vittata. The study identified two transcripts of type II CHHs, named MIH/GIH1 (later termed Lvit-GIH1) and MIH/GIH2 (tentatively named Lvit-GIH2), and explored their roles in ovarian development[1]. Crustacean hyperglycemic hormones (CHHs) are known to play diverse roles in crustaceans, including the regulation of molting, metabolism, reproduction, and osmoregulation[2]. These hormones are part of a larger family of neuropeptides that have been studied extensively over the years[3]. In crustaceans, CHHs are primarily produced in the eyestalks and have a significant impact on various physiological processes[4]. In the study, the researchers first identified the open reading frame (ORF) of Lvit-GIH2, which was found to be 333 base pairs in length. This ORF encodes a precursor protein consisting of a 32-amino acid signal peptide and a 78-amino acid mature peptide, sharing high sequence similarity with other type II subfamily peptides in crustaceans. This discovery is consistent with earlier findings that have identified similar peptides across various crustacean species[2][3]. The study revealed that Lvit-GIH2 is widely expressed in multiple tissues of Lysmata vittata. Quantitative real-time PCR (qRT-PCR) analysis indicated that the expression of Lvit-GIH2 increased from the male phase to the euhermaphrodite phase, suggesting a role in the regulation of ovarian development. This finding aligns with previous research that has shown the involvement of CHH-family peptides in reproductive processes[3]. To further investigate the function of Lvit-GIH2, the researchers conducted RNA interference (RNAi) and recombinant protein (rGIH2) addition experiments. These experiments demonstrated that Lvit-GIH2 suppresses the expression of vitellogenin (Lvit-Vg) in the hepatopancreas and vitellogenin receptor (Lvit-VgR) in the ovary. Vitellogenin is a precursor to yolk protein, essential for egg development, and its receptor is crucial for its uptake into oocytes. This suppression indicates that Lvit-GIH2 plays an inhibitory role in ovarian development, similar to the previously identified Lvit-GIH1. The study also employed RNA sequencing (RNA-seq) to analyze changes in the ovary after the addition of rGIH2. The results showed that several pathways and genes related to ovarian development were negatively regulated by rGIH2. These included pathways involved in cysteine and methionine metabolism and apoptosis, as well as genes such as 17bHSD8, IGFR, and CHH. This comprehensive analysis provides a deeper understanding of how Lvit-GIH2 influences ovarian development at the molecular level. The findings from this study contribute to the broader understanding of the multifunctional roles of CHH-family peptides in crustaceans. Previous studies have highlighted the importance of these peptides in regulating various physiological processes, including metabolism, molting, and reproduction[2][3][4]. The identification of Lvit-GIH2 and its inhibitory role in ovarian development adds to this body of knowledge and opens up new avenues for research into the regulation of reproduction in crustaceans. In summary, the study from Jimei University has identified and characterized a new type II CHH neuropeptide, Lvit-GIH2, in the hermaphrodite shrimp Lysmata vittata. This peptide is widely expressed in multiple tissues and plays an inhibitory role in ovarian development by suppressing the expression of vitellogenin and its receptor. These findings enhance our understanding of the complex regulatory mechanisms governing reproduction in crustaceans and underscore the diverse roles of CHH-family peptides in these organisms.

GeneticsAnimal ScienceMarine Biology

References

Main Study

1) A new type II CHH neuropeptide involves ovarian development in the peppermint shrimp, Lysmata vittata.

Published 1st August, 2024

https://doi.org/10.1371/journal.pone.0305127

Related Studies

2) Crustacean neuropeptides: structures, functions and comparative aspects.

Journal: Experientia, Issue: Vol 48, Issue 5, May 1992

3) The Crustacean Hyperglycemic Hormone Superfamily: Progress Made in the Past Decade.

https://doi.org/10.3389/fendo.2020.578958

4) The CHH-superfamily of multifunctional peptide hormones controlling crustacean metabolism, osmoregulation, moulting, and reproduction.

https://doi.org/10.1016/j.ygcen.2011.11.035


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