scholarly journals Gnrh mRNA expression in the brain of cooperatively breeding female Damaraland mole-rats

Reproduction ◽  
2017 ◽  
Vol 153 (4) ◽  
pp. 453-460 ◽  
Author(s):  
Cornelia Voigt ◽  
Nigel C Bennett
Keyword(s):  
Mrna Expression ◽  
Anterior Hypothalamus ◽  
Subterranean Rodent ◽  
Mole Rat ◽  
Hybridisation Signal ◽  
Reproductive Females ◽  
Caudal Level ◽  
The Brain ◽  
Social Suppression

The Damaraland mole-rat (Fukomys damarensis) is a eusocial, subterranean rodent, in which breeding is limited to a single reproductive pair within each colony. Non-reproductive females, while in the confines of the colony, exhibit socially induced infertility. Anovulation is thought to be caused by a disruption in the normal gonadotropin-releasing hormone (GNRH) secretion from the hypothalamus. To assess whether social suppression is associated with alteredGnrhmRNA expression in the brain, we investigated the distribution and gene expression levels by means ofin situhybridization in female breeders and non-breeders from field captured colonies of the Damaraland mole-rat. We found expression ofGnrhmRNA as a loose network in several forebrain areas of female Damaraland mole-rats with the majority of labelling in the preoptic and anterior hypothalamus. The distribution matched previous findings using immunocytochemistry in this and other social mole-rat species. Quantification of the hybridisation signal revealed no difference between breeding and non-breeding females in the average optical density of the hybridization signal and the size of the total area covered byGnrhmRNA. However, analysis along the rostro-caudal axis revealed significantly elevatedGnrhmRNA expression in the rostral preoptic region of breeders compared to non-breeders, whereas the latter had increasedGnrhmRNA expression at the caudal level of the anterior hypothalamus. This study indicates that social suppression affects the expression ofGnrhmRNA in female Damaraland mole-rats. Furthermore, differential regulation occurs within different neuron subpopulations.

scholarly journals Physiological consequences of social descent: studies in Astatotilapia burtoni

2006 ◽  
Vol 190 (1) ◽  
pp. 183-190 ◽  
Author(s):  
Victoria N Parikh ◽  
Tricia Clement ◽  
Russell D Fernald
Keyword(s):  
Mrna Expression ◽  
Reproductive Capacity ◽  
Plasma Testosterone ◽  
Complete Regression ◽  
Mrna Levels ◽  
Short Term ◽  
Reproductive Regulation ◽  
Astatotilapia Burtoni ◽  
The Brain ◽  
Social Suppression

In many species, social interactions regulate reproductive capacity, although the exact mechanisms of such regulation are unclear. Since social stress is often related to reproductive regulation, we measured the physiological signatures of change in reproductive state as they relate to short-term stress and the stress hormone cortisol. We used an African cichlid fish, Astatotilapia burtoni, with two distinct, reversible male phenotypes: dominant (territorial, T) males that are larger, more brightly colored, more aggressive, and reproductively competent and non-dominant males (non-territorial, NT) that are smaller, camouflage colored, and have regressed gonads. Male status, and hence reproductive competence, depends on social experience in this system. Specifically, if a T male is placed among larger male fish, it quickly becomes NT in behavior and coloration, but complete regression of its reproductive axis takes ca. 3 weeks (White et al. 2002). Reproduction in all vertebrates is controlled by the hypothalamic–pituitary–gonadal axis in which the key signaling molecule from the brain to the pituitary is GnRH1. Here, we subjected T males to territory loss, a social manipulation which results in status descent. We measured the effects of this status change in levels of circulating cortisol and testosterone as well as mRNA levels of GnRH1 and GnRH receptor-1 (GnRH-R1) in the brain and pituitary, respectively. Following short-term social suppression (4 h), no change was observed in plasma cortisol level, GnRH1 mRNA expression, GnRH-R1 mRNA expression, or plasma testosterone level. However, following a somewhat longer social suppression (24 h), cortisol and GnRH1 mRNA levels were significantly increased, and testosterone levels were significantly decreased. These results suggest that in the short run, deposed T males essentially mount a neural ‘defense’ against loss of status.

Is the Mahali mole-rat (Cryptomys hottentotus mahali) a spontaneous or induced ovulator?

2020 ◽  
Vol 98 (5) ◽  
pp. 299-305
Author(s):  
D.W. Hart ◽  
K. Medger ◽  
B. van Jaarsveld ◽  
N.C. Bennett
Keyword(s):  
Direct Contact ◽  
Physical Contact ◽  
Corpora Lutea ◽  
Reproductive Suppression ◽  
Subterranean Rodent ◽  
Breeding Female ◽  
Mole Rat ◽  
Cooperatively Breeding ◽  
Reproductive Females ◽  
Unrelated Male

The Mahali mole-rat (Cryptomys hottentotus mahali (Roberts, 1913)) is a social, cooperatively breeding subterranean rodent that breeds aseasonally. Only one female in a colony breeds and the remaining females are reproductively suppressed. When the opportunity arises, these non-reproductive females disperse from the natal colony to escape reproductive suppression and pair up with an unrelated male to start a new colony. This study set out to determine whether female Mahali mole-rats are induced or spontaneous ovulators once separated from the reproductive suppression of the breeding female. Fifteen separated females were subjected to three treatments: housed separately without a male (A), allowed chemical, but not physical, contact with a vasectomised male (NPC), and placed in direct contact with a vasectomised male (PC). Urine was collected from all females under each treatment every 2 days for 40 days. Only females housed in the PC treatment exhibited heightened progesterone concentrations and corpora lutea of ovulation in the ovaries. Furthermore, males possessed epidermal spines on the shaft of the penises that may be used to stimulate the cervix of the female during copulation. These findings suggest that the Mahali mole-rat is an induced ovulator.

scholarly journals Changes in GAD67 mRNA expression evidenced by in situ hybridization in the brain of R6/2 transgenic mice

2003 ◽  
Vol 86 (6) ◽  
pp. 1369-1378 ◽  
Author(s):  
I. Gourfinkel-An ◽  
K. Parain ◽  
A. Hartmann ◽  
L. Mangiarini ◽  
A. Brice ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Transgenic Mice ◽  
Mrna Expression ◽  
The Brain

Substituted N,N-Dimethyl-3-(phenylthio)- and -4-(phenylthio)benzylamines

1992 ◽  
Vol 57 (1) ◽  
pp. 194-203 ◽  
Author(s):  
Karel Šindelář ◽  
Vojtěch Kmoníček ◽  
Marta Hrubantová ◽  
Zdeněk Polívka
Keyword(s):  
Serotonin Receptors ◽  
Hydrobromic Acid ◽  
Antidepressant Activity ◽  
Benzoic Acids ◽  
Lithium Aluminium Hydride ◽  
Acid Chlorides ◽  
Activity Inhibition ◽  
Lithium Aluminium ◽  
The Brain

(Arylthio)benzoic acids IIa - IIe and VIb - VId were transformed via the acid chlorides to the N,N-dimethylamides which were reduced either with diborane "in situ" or with lithium aluminium hydride to N,N-dimethyl-(arylthio)benzylamines Ia - Ie and Vb - Vd. Leuckart reaction of the aldehydes IX and X with dimethylformamide and formic acid afforded directly the amines Va and Ve. Demethylation of the methoxy compounds Ia and Ve with hydrobromic acid resulted in the phenolic amines If and Vf. The most interesting N,N-dimethyl-4-(phenylthio)benzylamine (Va) hydrochloride showed affinity to cholinergic and 5-HT2 serotonin receptors in the rat brain and some properties considered indicative of antidepressant activity (inhibition of serotonin re-uptake in the brain and potentiation of yohimbine toxicity in mice).

PPARα and PPARγ Signaling Is Enhanced in the Brain of the Naked Mole-Rat, a Mammal that Shows Intrinsic Neuroprotection from Oxygen Deprivation

2021 ◽  
Author(s):  
Melissa R. Pergande ◽  
Vince G. Amoroso ◽  
Thu T. A. Nguyen ◽  
Wenping Li ◽  
Emily Vice ◽  
...  
Keyword(s):  
Oxygen Deprivation ◽  
Mole Rat ◽  
Naked Mole Rat ◽  
The Brain

Expression of transforming growth factor alpha during development

1988 ◽  
Vol 66 (8) ◽  
pp. 1113-1121 ◽  
Author(s):  
V. K. M. Han ◽  
A. J. D'Ercole ◽  
D. C. Lee
Keyword(s):  
In Situ Hybridization ◽  
Growth Factor ◽  
Mrna Expression ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Alpha ◽  
Egf Receptors ◽  
Hybridization Histochemistry ◽  
In Situ Hybridization Histochemistry ◽  
Factor Alpha

Transforming growth factors (TGFs) are polypeptides that are produced by transformed and tumour cells, and that can confer phenotypic properties associated with transformation on normal cells in culture. One of these growth-regulating molecules, transforming growth factor alpha (TGF-α), is a 50 amino acid polypeptide that is related to epidermal growth factor (EGF) and binds to the EGF receptor. Previous studies have shown that TGF-α is expressed during rodent embryogenesis between 7 and 14 days gestation. To investigate the cellular sites of TGF-α mRNA expression during development, we have performed Northern analyses and in situ hybridization histochemistry on the conceptus and maternal tissues at various gestational ages. Contrary to previous reports, both Northern analyses and in situ hybridization histochemistry indicate that TGF-α mRNA is predominantly expressed in the maternal decidua and not in the embryo. Decidual expression is induced following implantation, peaks at day 8, and declines through day 15 when the decidua is being resorbed. In situ hybridization revealed that expression of TGF-α mRNA is highest in the region of decidua adjacent to the embryo and is low or nondetectable in the uterus, placenta, and embryo. In addition, we could not detect TGF-α mRNA expression in other maternal tissues, indicating that the induction of TGF-α transcripts in the decidua is tissue specific, and not a pleiotropic response to changes in hormonal milieu that occur during pregnancy. The developmentally regulated expression of TGF-α mRNA in the decidua, together with the presence of EGF receptors in this tissue, suggests that this peptide may stimulate mitosis and angiogenesis locally by an autocrine mechanism. Because EGF receptors are also present in the embryo and placenta, TGF-α may act on these tissues by a paracrine or endocrine mechanism.

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