Brain Control Reproduction by the Endocrine System of Female Blue Gourami (Trichogaster trichopterus)

Abstract

Blue gourami belongs to the Labyrinithici fish and the Anabantiform order. It is characterized by a specific organ located above its gills for the respiration of atmospheric oxygen. This specific adaptation to low oxygen levels affects reproduction that is controlled by the brain, which integrates different effects on reproduction mainly through two axes—the gonadotropic brain pituitary gonad axis (BPG) and the hypothalamic-pituitary-somatotropic axis (HPS axis), including the interactions between them. This brain control reproduction of the Anabantoidei suborder summarizes information that has been published on the hormones involved in controlling the reproduction system of a model female blue gourami fish (Trichogaster trichopterus), including unpublished data. In the whole-brain transcriptome of blue gourami, 17 transcription genes change during vitellogenesis in the brain. The hormones involved in reproduction in blue gourami described in the present paper include: Kisspeptin 2 (Kiss 2) and its receptors 1 and 2 (KissR 1 and 2); gonadotropin-releasing hormone 1, 2 and 3 (GnRH1, 2 and 3); GnRH receptor; pituitary adenylate cyclase-activating polypeptide (PACAP) and its related peptide (PRP); somatolactin (SL); follicle-stimulating hormone (FSH); luteinizing hormone (LH); growth hormone (GH); prolactin (PRL), 17β-estradiol (E2); testosterone (T); vitellogenesis (VTL); and 17α,20β- dihydroxy-4-pregnen-3-one (17,20P). A proposed quality model is presented regarding the brain control oogenesis in blue gourami that has a Labyrinth organ about which relatively little information has been published. This paper summarizes the complex various factors involved in the interactions between external and internal elements affecting the brain of fish reproduction in the Anabantiform order. It is suggested to study in the future the involvement of receptors of hormones, pheromones, and genome changes in various organs belonging to the reproduction system during the reproduction cycles about which little is known.

Fish species composition in the Kaliotik River, Lamongan Regency, Indonesia

“…The species is characterized by a specific organ located above its gills for the respiration of atmospheric oxygen. This feature functions in a specific adaptation to low oxygen levels (Degani, 2020;Sukmono & Margaretha, 2017). Likewise, T. trichopterus is also a labyrinth fish species (Muslim, 2019) resistant to living in humid waters with a low pH level.…”

Markers of Genetic Variation in Blue Gourami (Trichogaster trichopterus) as a Model for Labyrinth Fish

“…Information on the molecular variation of species belonging to the Anabantoidei in the order Perciformes (perch-like-fishes) is very limited [ 2 , 15 , 16 ]. Polymorphisms in several enzymes can be utilized as a genetic marker for these Anabantoidei species belonging to the Perciformes [ 5 , 17 ].…”

“…Somatolactin (SL), a specific pituitary hormone belonging to the PRL superfamily, is involved in environmental adaptation, osmoregulation, reproduction, and fatty acid metabolism. The cDNA of SL from blue gourami was cloned and subjected to DNA sequence analysis [ 44 , 45 ]. The partial cDNA sequence of SL was compared to those of other fish species ( Figure 22 ).…”

A Qualitative Model of the Interaction of Sexual Behavior and Hormone Gene Transcription in Male Blue Gourami during Reproduction

“…In blue gourami, as a model Labyrinithici fish for hormonal control of reproduction, the male's sexual behavior [10] and pheromones [11] [12] affect the gonadotropic axis-the brain-pituitary-gonadal (BPG) axis [9] [13], and the somatotropic axis-the brain-pituitary-liver and body (BPLB) axis. These axes are very complex and they control gametogenesis [1] [10] [14].…”

“…The two habitats, with high and low densities of males. (a) At high density, the male does not build a nest; (b) At low density, the male builds a nest and sexual behavior[1] [5] [8][9]…”