Somatolactin Transcription during Oogenesis in Female Blue Gourami (<i>Trichogaster trichopterus</i>)

Abstract

Somatolactin (SL), a specific pituitary hormone belonging to the prolactin (PRL) super family, is involved in background adaptation, osmoregulation, reproduction and fatty acid metabolism. The goal of this study was to examine the gene transcription of SL changes in the ovary of blue gourami females (Trichogaster trichopterus) during oogenesis by quantitative real-time polymerase chain reaction (Real-Time PCR). Somatolactin in the pituitary was higher in females at low vitellogenesis compared to females with oocytes in maturation, and the difference was significant (p < 0.05). No significant differences were found in mRNA levels between low and high vitellogenesis, and high vitellogenesis and maturation. The findings of this and previous studies demonstrate that SL, growth hormone (GH) and PRL are involved in oogenesis in blue gourami; however, considerably more studies are required in order to separate the functions of these hormones.

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

“…The brain of Anabantoidei fish contains neurons secreting hormones that are involved in growth and reproduction control and the interactions between them, which is very complex and is summarized in Figure 2 . The environment, pheromones, sexual behavior, and hormones are involved in oogenesis and the interactions between the two axes of blue gourami, BPG and BPLB, as is presented in Figure 2 and supported by relatively many studies [ 9 , 10 , 11 , 12 , 13 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 ].…”

“…Detailed studies have been carried out on hormones in the pituitary of blue gourami using histological methods based on light and electron microscopy [ 49 ], as well as molecular methods [ 9 , 10 , 30 , 39 , 50 ], which might help in understanding the control of oogenesis in this specific group in which blue gourami is represented. FSH and LH mRNA levels are very high during advanced vitellogenesis and maturation, and both are involved in two different stages [ 39 ] ( Figure 6 and Figure 7 ).…”

“… The interactions between the two axes, BPG and BPLB, of female blue gourami control oogenesis based on the review and unpublished data [ 9 , 10 , 11 , 12 , 13 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 ]. Gonadotropin-releasing hormone 1 and 3 (GnRH1 and 3), follicle-stimulating hormone (FSH), luteinizing hormone (LH), pituitary adenylate cyclase-activating polypeptide (PACAP) and its related peptide (PRP), growth hormone (GH), prolactin (PRL), 17β-estradiol (E2), testosterone (T), 17α,20β- dihydroxy-4-pregnen-3-one (17,20P), vitellogenin (VTG), insulin-like growth factor 1 (IGF1).…”

Immunohistochemical study of gonadotropin-releasing hormone and somatolactin during induced spawning of Liza ramada

“…Activated SL cells identified immunohistochemically, were seen also in spawning of Oncorhynchus nerka, O. keta and O. tshawytscha [19,30] , M. cephalus [18] and in L. niloticus [12] . Also, Somatolactin in the pituitary of blue gourami (Trichogaster trichopterus) was higher in females at low vitellogenesis compared to females with oocytes in maturation [22] . Moreover, our immunohistochemical results are in agreement with the biochemical studies, which revealed increase of SL levels during the spawning migration of chum salmon Oncorhynchus keta [54] .…”

“…SL is a pituitary hormone closely related to GH and is only found in fish. SL is involved in the regulation of different physiological processes, including reproduction [17][18][19][20][21][22] , acid-base and calcium regulation [13,23,24] , phosphate and fat metabolism [25,26] , and background adaptation [27][28][29] . SL has also been linked to fish reproduction.…”