Gonadotropin‐releasing hormone‐like immunoreactivity in the planarian Bdelloura candida (Platyhelminthes, Tricladida)

Abstract

Abstract. Although peptides similar to gonadotropin‐releasing hormone (GnRH) peptides have been reported in various taxa of invertebrates, no such evidence has yet been identified for platyhelminths. Antibodies raised against mammalian GnRH were used to investigate the distribution of GnRH immunoreactivity in specimens of the triclad turbellarian Bdelloura candida (Maricola, Bdellouridae). While no GnRH immunoreactivity was detected in the brain and nerve cords, both the putative subepidermal and submuscular nerve plexuses appeared to be immunoreactive. GnRH immunoreactivity was also present in epidermal mucous cells, in parenchymal cells, including cells surrounding the branches of the intestine, in putative neuroendocrine cells associated with the testes, and in the vitellogenic gland cells associated with the oviduct. These observations suggest that the GnRH‐like material found in specimens of B. candida may be involved in a variety of functions, including a possible pheromone‐like role for mucous cells and the control of specific reproductive activities.

The identification and distribution of gonadotropin-releasing hormone-like peptides in the central nervous system and ovary of the giant freshwater prawn, Macrobrachium rosenbergii

“…In mollusks, the existence of immunoreactivity (ir)-GnRH was reported in gastropods, Halisoma trivolvis, Lymnaea stagnalis, and Aplysia californica (Goldberg et al 1993;Pazos and Mathieu 1999;Young et al 1999;Zhang et al 2000Zhang et al , 2007Tsai et al 2003), and a cephalopod, Octopus vulgaris (Di Cosmo and Di Cristo 1998;Di Cristo et al 2002;Iwakoshi et al 2002;Iwakoshi-Ukena et al 2004). Ir-GnRH was also observed in a cnidarian (Anctil 2000), a platyhelminthes (Anctil and Tekaya 2005) and a coral (Twan et al 2006). As in vertebrates, it was demonstrated that GnRH serves multiple functions in reproduction or reproductive related activities, such as induction of spawning in a tunicate, Ciona intestinalis (Terakado 2001;Adams et al 2003); a coral, Euphyllia ancora (Twan et al 2006), and a chiton, Mopalia sp.…”

Immunohistochemical detection of GnRH-like peptides in the neural ganglia and testis of Haliotis asinina

“…Several studies have reported the presence of GnRH-ir in neural and gonad tissues of invertebrates which include tunicates (Di Fiore et al, 2000;Tsutsui et al, 1998), mollusks (Goldberg et al, 1993;Iwakoshi et al, 2004;Nuurai et al, 2010;Pazos and Mathieu, 1999;Treen et al, 2012;Tsai et al, 2003;Young et al, 1999;Zhang et al, 2000Zhang et al, , 2008Amano et al, 2008Amano et al, , 2010, cnidarians (Ancil, 2000), planarians (Ancil and Tekaya, 2005), corals (Twan et al, 2006), prawn (Ngernsoungnern et al, 2008a), and shrimp (Ngernsoungnern et al, 2008b, c;Tinikul et al, 2011). The role that GnRH plays in invertebrate reproductive behavior has been particularly well studied.…”

Molecular cloning, expression pattern, and immunocytochemical localization of a gonadotropin-releasing hormone-like molecule in the gastropod mollusk, Aplysia californica

“…Its presence was once thought to be restricted to members of Phylum Chordata, but increasing evidence suggests otherwise. A large number of studies reported the presence of GnRH-immunoreactivity (ir) and bioactivity in the gastropods (Goldberg et al, 1993;Young et al, 1999;Zhang et al, 2000;Tsai et al, 2003), bivalves (Pazos and Mathieu, 1999;Nakamura et al, 2007), polyplacophorans , cephalopods (Di Cosmo and Di Cristo, 1998;Di Cristo et al, 2002), cnidarians (Anctil, 2000;Twan et al, 2006), and platyhelminthes (Anctil and Tekaya., 2005). Importantly, a dodecapeptide containing the structural core of chordate GnRH was isolated from the central nervous system (CNS) of the common octopus (Iwokoshi et al, 2002).…”