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Fish puberty

Yun Liu, Haipei Tang, Rui Xie, Shuisheng Li, Xiaochun Liu, Haoran Lin, Yong Zhang, Christopher H K Cheng
It is generally believed that kisspeptin and gonadotropin-releasing hormone (GnRH) are required for reproduction in vertebrates. In this study, we generated gnrh3-null zebrafish and found that gnrh3 mutation did not impair gonad development and reproductive capacity. Moreover, zebrafish triple knockout mutant lacking gnrh3 and the 2 kiss1s genes undergo normal puberty and gonad maturation. The expression of follicle-stimulating hormone beta (fshβ) and luteinizing hormone beta (lhβ) was not significantly altered whereas the expression of neuropeptide Y (npy), tachykinin 3 (tac3), and secretogranin-II (sgII) was significantly increased in the triple knockout mutant, suggesting that compensation mechanisms exist to stimulate the reproductive axis in the absence of kiss and gnrh...
March 1, 2017: Endocrinology
Sanny David Pacheco Lumayno, Hirofumi Ohga, Sethu Selvaraj, Mitsuo Nyuji, Akihiko Yamaguchi, Michiya Matsuyama
The gonadotropin-releasing hormone (GnRH) is essential during pubertal onset, for its regulation of the synthesis and release of pituitary gonadotropins. Its action is mediated by GnRH receptors (GnRHRs) in the pituitary gonadotrophs. Our previous study demonstrated that the chub mackerel brain expresses three GnRH forms (gnrh1, gnrh2, and gnrh3), and that only GnRH1 neurons innervate anterior pituitary regions. Furthermore, chub mackerel gnrh1 mRNA exhibited a significant increase at pubertal onset. The present study aimed to isolate the functional GnRHR form involved in chub mackerel puberty...
January 30, 2017: General and Comparative Endocrinology
Huayu Song, Mengxun Wang, Zhongkai Wang, Jinxiang Liu, Jie Qi, Quanqi Zhang
Reproduction allows organisms to produce offspring. Animals shift from immature juveniles into mature adults and become capable of sexual reproduction during puberty, which culminates in the first spermiation and sperm hydration or ovulation. Reproduction is closely related to the precise control of the hypothalamic-pituitary-gonadal (HPG) axis. Kisspeptin peptides are considered as the important regulator of HPG axis in mammalian. However, the current understanding of kisspeptin in flatfish is not comprehensive...
December 24, 2016: Fish Physiology and Biochemistry
José A Paullada-Salmerón, Guillaume Henri Loentgen, Mairi Cowan, María Aliaga-Guerrero, María Del Carmen Rendón-Unceta, José A Muñoz-Cueto
The role of rearing temperature on fish development, sex differentiation and puberty has been largely addressed, but the impact of water temperature on the ontogeny of the main neuroendocrine systems controlling reproduction has received little attention. Gonadotropin-inhibitory hormone (GnIH) has been shown to act on gonadotropin-releasing hormone (GnRH) neurons and on the pituitary to inhibit gonadotropin release and synthesis in vertebrates, including sea bass, Dicentrarchus labrax. In the present study we investigated the effects of rearing temperature during the thermosensitive period (5-60days post-fertilization, dpf) on the expression of the GnIH gene (gnih) and its receptor (gnihr)...
January 18, 2017: Comparative Biochemistry and Physiology. Part A, Molecular & Integrative Physiology
L Lauritzen, S E Eriksen, M F Hjorth, M S Nielsen, S F Olsen, K D Stark, K F Michaelsen, C T Damsgaard
Dietary long-chain n-3 PUFA (n-3 LCPUFA) in infancy may have long-term effects on lifestyle disease risk. The present follow-up study investigated whether maternal fish oil (FO) supplementation during lactation affected growth and blood pressure in adolescents and whether the effects differed between boys and girls. Mother-infant pairs (n 103) completed a randomised controlled trial with FO (1·5 g/d n-3 LCPUFA) or olive oil (OO) supplements during the first 4 months of lactation; forty-seven mother-infant pairs with high fish intake were followed-up for 4 months as the reference group...
December 2016: British Journal of Nutrition
Daniel A F Villagómez, Tamas Revay, Brendan Donaldson, Samira Rezaei, Alain Pinton, Manuel Palomino, Awang Junaidi, Ali Honaramooz, W Allan King
Few sex-autosome chromosome abnormalities have been documented in domestic animal species. In humans, Y-autosome chromosome abnormalities may occur at a rate of 1/2,000 live births, whereas in the domestic pig only 2 Y-autosome reciprocal translocations have been previously described. During a routine cytogenetic screening of young boars, we identified a new Y-autosome translocation carrier, which after puberty showed semen devoid of sperm and testicular hypoplasia with spermatogenesis arrest. Whole chromosome painting by FISH analysis corroborated the reciprocal nature of the chromosomal exchanges between the Y chromosome and SSC13...
2017: Sexual Development: Genetics, Molecular Biology, Evolution, Endocrinology, Embryology, and Pathology of Sex Determination and Differentiation
M Oswaldo Tovar Bohórquez, Alejandro S Mechaly, Lily C Hughes, Daniela Campanella, Guillermo Ortí, Luis F Canosa, Gustavo M Somoza
In vertebrates, kisspeptins and their receptors are known to be related to puberty onset and gonadal maturation, however, there are few studies concerning their role in early development. Here, we characterize the kisspeptin system in the pejerrey, Odontesthes bonariensis, a fish with strong temperature-dependent sex determination. We reconstructed the phylogenetic history of the two ligands (kiss1 and kiss 2) and two receptors (kissr2 and kissr3) in pejerrey in the context of recent classifications of bony fishes, determined their tissue distribution and documented the early expression pattern of these ligands and receptors...
February 2017: Comparative Biochemistry and Physiology. Part A, Molecular & Integrative Physiology
X Y Qin, W K Dong, W Wang, Z Y Dong, Y Xiao, W L Lu, D F Wang
Objective: To explore the clinical manifestations and molecular features of 46, XX male syndrome. Method: The clinical and molecular data of five 46, XX male syndrome cases treated in the Department of Pediatrics of Shanghai Ruijin Hospital form August 2010 to August 2014 were retrospectively analyzed. Result: The five patients were all sociopsychologically males and came to hospital respectively for short stature, ambiguous genitalia or gynecomastia. They were all below the normal male's average height, and their karyotype was all 46, XX...
November 2, 2016: Zhonghua Er Ke za Zhi. Chinese Journal of Pediatrics
Alfheidur Haraldsdottir, Laufey Steingrimsdottir, Unnur A Valdimarsdottir, Thor Aspelund, Laufey Tryggvadottir, Tamara B Harris, Lenore J Launer, Lorelei A Mucci, Edward L Giovannucci, Hans-Olov Adami, Vilmundur Gudnason, Johanna E Torfadottir
Background: Little is known about fish intake throughout the life course and the risk of breast cancer.Methods: We used data on the first residence of 9,340 women born 1908 to 1935 in the Reykjavik Study as well as food frequency data for different periods of life from a subgroup of the cohort entering the Age, Gene/Environment Susceptibility (AGES)-Reykjavik Study (n = 2,882).Results: During a mean follow-up of 27.3 years, 744 women were diagnosed with breast cancer in the Reykjavik Study. An inverse association of breast cancer was observed among women who lived through the puberty period in coastal villages, compared with women residing in the capital area [HR, 0...
March 2017: Cancer Epidemiology, Biomarkers & Prevention
Shubo Jin, Dajiang Sun, Qingkai Xi, Xiaoli Dong, Dan Song, Hongtuo Fu, Ying Zhang
Kisspeptin plays an important role in the reproduction and onset of puberty in vertebrates through stimulation of gonadotropin-releasing hormone (GnRH). However, the mechanisms whereby kisspeptin-related genes regulate sexual differentiation in teleosts are poorly understood. We aimed to study the relationship between the hypothalamus-pituitary-gonad (HPG) axis and sexual differentiation in relation to kisspeptin in the sturgeon Acipenser schrenckii. We performed comparative transcriptomic analysis of the brains of sturgeons treated with KISS1-10 during the gonadal sex-differentiation-sensitive period (170-210days post-hatching (dph)) using an Illumina sequencing platform...
December 20, 2016: Gene
F J Schaefer, B Hermelink, P Husmann, W Meeus, J Adriaen, S Wuertz
A rearing experiment was conducted to test whether temperature protocols that differed from a simulation of natural conditions might induce maturation after isothermal grow-out in burbot Lota lota. Lota lota were acclimated to two different temperature regimes: low temperature (LT), close to natural temperature at 4·0° C and elevated, high temperature (HT) at 8·5° C over 40 and 27 days respectively, with all fish then wintered for 47 days. Every second fish was treated with a gonadotropin-releasing hormone analogue...
November 2016: Journal of Fish Biology
Hirofumi Ohga, Daisuke Hirata, Kojiro Matsumori, Hajime Kitano, Naoki Nagano, Akihiko Yamaguchi, Michiya Matsuyama
Leptin directly regulates kisspeptin neurons in the hypothalamus and gonadotropin secretion from the pituitary, making it a central player in the onset of mammalian puberty. Recently, we identified two leptin genes (lepa and lepb) and a single leptin receptor (lepr) in the marine perciform fish chub mackerel; however, the expression of these genes did not correlate with the expression of important reproductive genes or ovarian stage during female puberty. Here, we expand upon these initial observations by evaluating the expression of lepa, lepb, and lepr during pubertal transition and under differential feeding conditions in the male chub mackerel...
January 2017: Comparative Biochemistry and Physiology. Part A, Molecular & Integrative Physiology
F Espigares, A Rocha, A Gómez, M Carrillo, S Zanuy
The onset of puberty is characterized by activation of the brain-pituitary-gonad axis. However, the molecular and endocrine mechanism involved in the process of puberty and the influence of environmental conditions, such as photoperiod signalling, are not well understood in fish. In this study, 1-year-old male European sea bass (Dicentrarchus labrax) were exposed to photoperiod manipulation in combination with size-sorting. Two treatment groups, a puberty accelerating photoperiod (AP) group and a continuous light (LL) group, were studied from August to February...
January 1, 2017: General and Comparative Endocrinology
Jin Woo Park, Ye Hwa Jin, Sung-Yong Oh, Joon Yeong Kwon
It has been suggested that kisspeptin influences reproduction and onset of puberty in fishes. Unlike mammals, which produce only one kisspeptin (Kiss1), some teleosts have two, Kiss1 and Kiss2, both thought to be involved in the stimulation of gonadotropin (GTH) secretion. In Nile tilapia (Oreochromis niloticus), however, only Kiss2 has been identified so far. The effect of Kiss2 on GTH release varies significantly depending on species and reproductive stage. Furthermore, its physiological function in this species is not clearly defined...
December 2016: Comparative Biochemistry and Physiology. Part B, Biochemistry & Molecular Biology
Vidar Berg, Marianne Kraugerud, Rasoul Nourizadeh-Lillabadi, Pål A Olsvik, Janneche U Skåre, Peter Alestrøm, Erik Ropstad, Karin Elisabeth Zimmer, Jan L Lyche
A series of studies have assessed the occurrence, levels, and potential adverse effects of persistent organic pollutants (POP) in fish from Lake Mjøsa. In this lake, high levels of various POP were detected in biota. Fish from the nearby Lake Losna contain background levels of POP and served as reference (controls) in these studies. Significantly higher prevalence of mycobacteriosis and pathological changes were documented in burbot (Lota lota) from Mjøsa compared to burbot from Losna. Further, transcriptional profiling identified changes in gene expression in burbot from Mjøsa compared to burbot from Losna associated with drug metabolism enzymes and oxidative stress...
2016: Journal of Toxicology and Environmental Health. Part A
Olivia Smith Spicer, Ten-Tsao Wong, Nilli Zmora, Yonathan Zohar
Gnrh is the major neuropeptide regulator of vertebrate reproduction, triggering a cascade of events in the pituitary-gonadal axis that result in reproductive competence. Previous research in mice and humans has demonstrated that Gnrh/GNRH null mutations result in hypogonadotropic hypogonadism and infertility. The goal of this study was to eliminate gnrh3 (the hypophysiotropic Gnrh form) function in zebrafish (Danio rerio) to determine how ontogeny and reproductive performance are affected, as well as factors downstream of Gnrh3 along the reproductive axis...
2016: PloS One
Johan Svensson, Arshi Mustafa, Jerker Fick, Monika Schmitz, Björn Brunström
Progestins are aquatic contaminants that in low concentrations can impair fish reproduction. The mechanisms are likely multiple since different progestins interact with other steroid receptors in addition to progesterone receptors. Puberty is the process when animals first acquire the capability to reproduce and it comprises maturation of sperm and eggs. In zebrafish, puberty is initiated around 45days post fertilization (dpf) in females and around 53-55 dpf in males, and is marked by increased production of pituitary gonadotropins...
August 2016: Aquatic Toxicology
Prakash Sharma, Song Tang, Gregory D Mayer, Reynaldo Patiño
Thyroid hormone reportedly induces masculinization of genetic females and goitrogen treatment delays testicular differentiation (ovary-to-testis transformation) in genetic males of Zebrafish. This study explored potential molecular mechanisms of these phenomena. Zebrafish were treated with thyroxine (T4, 2nM), goitrogen [methimazole (MZ), 0.15mM], MZ (0.15mM) and T4 (2nM) (rescue treatment), or reconstituted water (control) from 3 to 33days postfertilization (dpf) and maintained in control water until 45dpf...
September 1, 2016: General and Comparative Endocrinology
F Moreira, Z M G Cheuiche, G Rizzoto, M Q Santos, M S Schuch, M J Flach, B G Gasperin, I Bianchi, T Lucia
Polyunsaturated fatty acids may benefit reproductive performance of female swine. This study evaluated metabolic and reproductive parameters of prepubertal finishing gilts fed with fish oil as a natural source of omega-3 fatty acids (6.88g/d) (n=12) over a period of 45 d. Gilts in the control group were fed soybean oil (n=13). Body weight and backfat were determined at 15-d intervals. Serum levels of leptin, IGF-1, insulin, cholesterol and triglycerides were measured at the beginning (D0) and at the end of the period (D45)...
July 2016: Animal Reproduction Science
Sebastián Escobar, Alicia Felip, Silvia Zanuy, Manuel Carrillo
Previous works on European sea bass have determined that long-term exposure to restrictive feeding diets alters the rhythms of some reproductive/metabolic hormones, delaying maturation and increasing apoptosis during gametogenesis. However, exactly how these diets affect key genes and hormones on the brain-pituitary-gonad (BPG) axis to trigger puberty is still largely unknown. We may hypothesize that all these signals could be integrated, at least in part, by the kisspeptin system. In order to capture a glimpse of these regulatory mechanisms, kiss1 and kiss2 mRNA expression levels and those of their kiss receptors (kiss1r, kiss2r) were analyzed in different areas of the brain and in the pituitary of pubertal male sea bass during gametogenesis...
September 2016: Comparative Biochemistry and Physiology. Part A, Molecular & Integrative Physiology
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