Toward the identification of female gonad-stimulating factors in crustaceans

Crustacean Genomics: Implications for Physiology and Systematic Studies.-- 29 pages, 6 figures, 1 table, supplementary material https://doi.org/10.1007/s10750-017-3497-4Over many decades there were numerous attempts to isolate gonad-stimulating factors (GSF) in crustaceans. Before omic technologies, the main neuroendocrine factors identified as ovarian development regulators in crustaceans were inhibitory in nature, belonging to the CHH family of neuropeptides produced in the eyestalk. Eyestalk ablation thus leads to ovarian development and this technique is still used in shrimp farms to induce maturation although some biological issues arise. In this manuscript, we review the current knowledge on potential GSF with emphasis on several key candidates and discuss how novel sequencing technologies might aid in better understanding the nature of the ovarian development in crustaceans. However, the gap between the rapid pace at which sequence databases are produced and mined and the experimental work that lags behind do not yet allow us to know the nature of the GSF in crustaceans. Three possible reasons are suggested: (1) crustaceans represent a very large and diverse group, then different species could have GSF of different compounds; (2) it is possible that crustaceans employ multiple hormonal factors to control vitellogenesis; (3) crustaceans might not need a GSF. Reproduction is only negatively regulated by CHH family peptidesThe current study was supported by a Marie Curie International Research Staff Exchange Scheme Fellowship within the 7th European Community Framework Programme (612296-DeNuGReC) and by the Australian Research Council Discovery Project (DP160103320)Peer Reviewe

Towards the identification of Female Gonad Stimulating Factor in crustaceans

The Crustacean Society (TCS) Mid-Year Meeting, 9-22 June 2017, BarcelonaOver many decades there were numerous attempts to isolate gonad stimulatory factors (GSFs) in crustaceans. Many factors including biogenic amines, lipid metabolites, short and long neuropeptides were shown to stimulate various aspects of ovarian development like maturation and cyclic yolk accumulation during vitellogenesis with inter-species variation in their effect. The main neuroendocrine factors identified as ovary development regulators though, are inhibitory in nature, belonging to the crustacean hyperglucemic hormone (CHH) family of neuropeptides which are primarily produced in the eyestalk. Eyestalk ablation thus leads to ovarian development. Unlike the vertebrate pathway which relies primarily on stimulatory factors, this suppressive mechanism that has evolved in crustaceans perhaps explains the elusive nature of the GSF. The suppressive upstream effect might have enabled development of many different stimulatory mechanisms to evolve rapidly, all leading to ovarian development when suppression is removed. In this manuscript, we review the current knowledge on potential GSFs with emphasis on several key candidates and discuss how novel sequencing technologies might aid in better understanding the nature of the ovary development in crustaceans. Critically, the gap between the rapid pace at which sequence databases are produced and mined and the experimental work that lags behind is highlightedPeer Reviewe