scholarly journals Photoperiodic light pulse induces ovarian development in the catfish, Mystus cavasius: Possible roles of dopamine and melatonin in the brain

2021 ◽  
Vol 227 ◽  
pp. 112941
Author(s):  
Muhammad Badruzzaman ◽  
Chayon Goswami ◽  
Md. Abu Sayed
Keyword(s):  
Light Pulse ◽  
Ovarian Development ◽  
The Brain

scholarly journals Two cytochrome P450 aromatase genes in the hermaphrodite ricefield eel Monopterus albus: mRNA expression during ovarian development and sex change

2008 ◽  
Vol 199 (2) ◽  
pp. 317-331 ◽  
Author(s):  
Yang Zhang ◽  
Weimin Zhang ◽  
Huiyi Yang ◽  
Wenliang Zhou ◽  
Chaoqun Hu ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Ovarian Development ◽  
Sex Change ◽  
Mature Stage ◽  
Rt Pcr ◽  
Monopterus Albus ◽  
P450 Aromatase ◽  
Mrna Tissue Distribution ◽  
Cytochrome P450 Aromatase ◽  
The Brain

Previously, the ricefield eel (Monopterus albus) was speculated to have only one cytochrome p450 aromatase gene. In this study, however, the cDNAs encoding two distinct cytochrome p450 aromatases, cyp19a1a and cyp19a1b, were isolated. The genomic organizations of both cyp19 genes were conserved when compared with other teleosts. Northern blot detected an abundant expression of cyp19a1a in the ovary, and cyp19a1b in the hypothalamus. RT-PCR coupled with Southern blot showed that cyp19a1a was expressed predominantly in the gonads of both sexes, with higher levels in the ovary than testis, while cyp19a1b was expressed in all the tissues examined in the male, but only in the brain and pituitary in the female. The levels of cyp19a1a mRNA in the ovary were increased significantly during vitellogenesis, but decreased significantly at mature stage. The levels of cyp19a1b mRNA in the brain and pituitary did not vary significantly during vitellogenesis. As ovarian development shifted from vitellogenesis to maturation, the levels of cyp19a1b mRNA was decreased significantly in the brain, but increased significantly in the pituitary. During natural sex change from female to male, the levels of cyp19a1a mRNA in the gonad were significantly decreased. The levels of cyp19a1b mRNA in the hypothalamus were significantly increased at the early intersexual phase, whereas the expression levels in the pituitary were significantly decreased at the intersexual phases. Taken together, these results showed a novel sexual dimorphism of cyp19a1b mRNA tissue distribution, and both CYP19 genes were associated with the ovarian development and natural sex change of the ricefield eel.

The influence of the brain hormone on retention of blood in the mid-gut of the mosquito Aedes aegypti (L.) III. The involvement of the ovaries and ecdysone

1979 ◽  
Vol 205 (1160) ◽  
pp. 411-421 ◽  
Keyword(s):  
Aedes Aegypti ◽  
Blood Meal ◽  
Ovarian Development ◽  
Neurosecretory Cells ◽  
Direct Result ◽  
Corpus Cardiacum ◽  
Egg Development ◽  
The Brain

Most female mosquitoes require a blood-meal in order to produce mature oöcytes. An egg development neurosecretory hormone (EDNH), which is produced in the medial neurosecretory cells (m. n. c.) of the brain and stored in the corpus cardiacum, is released into the haemolymph following the ingestion of blood and is essential for the promotion of ovarian development to maturity. It has been shown that a factor from the m. n. c., presumably EDNH, is necessary if the blood-meal is to be retained in the mid-gut until the oöcytes approach maturity. The present paper shows that retention is not a direct result of the action of EDNH, but is dependent on the ovaries and may well involve ecdysone. Removal of the ovaries before a blood-meal leads to early haem-defaecation, but delay can be restored by injection of ecdysterone. Sub-threshold feeders and mosquitoes decapitated immediately after the intake of blood, each of which would be expected to eliminate the blood-meal early, also show a delay in the onset of haem-defaecation when injected with ecdysterone. Further, both in ovariectomized insects and sub-threshold feeders the time of onset of haem-defaecation is associated with the dose of ecdysterone given.

scholarly journals Hormonal and Pheromonal Regulation of Reproduction in the Bumble Bee Bombus terrestris

1994 ◽  
Author(s):  
Abraham Hefetz ◽  
Gene Robinson
Keyword(s):  
Ovarian Development ◽  
Bombus Terrestris ◽  
Worker Reproduction ◽  
Colony Development ◽  
Social Species ◽  
Before And After ◽  
High Aggression ◽  
Total Body ◽  
Virgin Queens ◽  
The Brain

Bombus terrestris constitute important pollinators of greenhouse crops. In Israel the species utilized is, whose colonies are reared commercially. This is a primitively social species with a particular colony development. It encompasses two social phases: a eusocial phase in which the queen dominates reproduction, and a competition phase in which workers compete with the queen for the parentage of males. These workers are distinguished by accelerated ovarian development, high production of JH, and elevated levels of dopamine in the brain. Queen-worker conflict is also manifested in overt aggression among all members of the nest. High aggression is correlated with dominance status of the bees and is also correlated with octopamine levels in the brain. After verifying that JH III is the only JH produced by the bees and validating the assay for its measurements (RCA & RIA), we used JH as an indicator of worker reproduction. Queens taken from colonies both before and after the competition phase were equally effective in inhibiting worker reproduction. Moreover, there is only a narrow window, around the competition point, in which workers may have the opportunity to initiate reproduction. Before that point they are inhibited by the dominant queen, while after that point both the queen and those workers with accelerated ovarian development exert strong inhibition on worker nest mates. Thus, "queen dominance deterioration" is not the primary cause in eliciting the queen-worker conflict. Queens convey their presence by means of a chemical signal that is extractable in organic solvent and that is normally spread on the cuticle. Total body extract and body washes, applied on dead virgin queens, were able to inhibit the release of JHin vitro in queenless workers. However, none of the prominent exocrine gland investigated mimicked this function. It is possible that the source of the putative pheromone is an unknown gland, or that it emanates from an assembly of glands. Chemical analyses of the prominent glands revealed a plethora of compounds the function of which should be further investigated. Understanding the social behavior of B. terrestris paves the way to facilitate colony manipulation and to adjust the colonies for specific pollination requirements.

Regulation of female brain aromatase activity during the reproductive cycle of the dove

1992 ◽  
Vol 134 (3) ◽  
pp. 385-396 ◽  
Author(s):  
R. E. Hutchison ◽  
A. W. Wozniak ◽  
J. B. Hutchison
Keyword(s):  
Reproductive Cycle ◽  
Ovarian Development ◽  
Preoptic Area ◽  
Ovarian Follicles ◽  
Substrate Affinity ◽  
Aromatase Activity ◽  
Oestrogen Treatment ◽  
Female Brain ◽  
Brain Aromatase ◽  
The Brain

ABSTRACT Oestrogen is formed in the female dove brain. The aim of this study was to determine whether (a) the catalytic properties of the brain aromatase are similar to the ovarian enzyme and (b) aromatase activity in the female brain changes during the reproductive cycle and is influenced by steroids and environmental stimuli. The results show that female preoptic aromatase has a higher substrate affinity than the enzyme in ovarian follicles (apparent Km: preoptic area, 7 nmol/l; ovarian follicles, 29 nmol/l), but a lower activity in the preoptic area (Vmax: preoptic area, 290 fmol/mg tissue per h; ovarian follicles, 843 fmol/mg tissue per h). In intact females with developing follicles, oestradiol-17β formation was higher in the posterior hypothalamus than the preoptic area. Females in a later stage of reproductive development (yolked follicles) had a different distribution of oestrogen formation with increased aromatase activity in the preoptic area. Preoptic and posterior hypothalamic aromatase activity of females paired with males for 10 days was positively correlated (r = 0·84, P = 0·0001; r = 0·75, P = 0·001 respectively) with ovarian development. Females with undeveloped ovaries which interacted with males had higher preoptic aromatase activity than visually isolated females with similar ovarian development, suggesting that behavioural stimuli have direct effects on brain aromatase activity which are independent of the ovary. Oestradiol benzoate treatment increased preoptic and posterior hypothalamic aromatase activity in intact and ovariectomized females, and testosterone propionate treatment increased anterior hypothalamic aromatase activity, but did not affect other areas, indicating that the distribution of induced aromatase activity is steroid-specific. Oestrogen treatment in ovariectomized or intact females did not replicate the maximal hypothalamic aromatase activity seen when the ovary contained yolked follicles. We conclude that brain aromatase activity is related directly to ovarian condition during the reproductive cycle of the female dove. As in the male, steroids have a role in the regulation of oestrogen formation in the female hypothalamus; behavioural stimuli are also likely to be involved in the control of the brain enzyme. Journal of Endocrinology (1992) 134, 385–396

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