Sex differences in the distribution of the steroid receptor coactivator SRC-1 in the song control nuclei of male and female canaries

in Brain Research (2003), 959(2), 263-274

The steroid receptor coactivator SRC-1 modulates ligand-dependent transactivation of several nuclear receptors, including the receptors for sex steroid hormones. The distribution of SRC-1 transcripts was ... [more ▼]

The steroid receptor coactivator SRC-1 modulates ligand-dependent transactivation of several nuclear receptors, including the receptors for sex steroid hormones. The distribution of SRC-1 transcripts was analyzed here by in situ hybridization in coronal sections through the brain of male and female canaries. A broad but heterogeneous distribution of SRC-1 transcripts was observed with high numbers of densely labeled cells being present in many steroid-sensitive areas including the medial preoptic nucleus, several hypothalamic nuclei, five song control nuclei (HVc, the lateral and medial portion of the magnocellular nucleus of the anterior neostriatum, area X and the nucleus uvaeformis) and several catecholaminergic areas (area ventralis of Tsai, substantia nigra, locus coeruleus). The volume of two song control nuclei, HVc and area X were reconstructed based on the boundaries of the cell groups exhibiting a denser SRC-1 expression as compared to the surrounding areas. Sex differences in the expression of SRC-1 were also detected in several song control nuclei. In particular, the volume of HVc based on the high density of SRC-1 expression was significantly larger in males than in females. The effect of steroids on the song control system could be, at least in part, indirect and result from a modulation by steroids of the catecholaminergic inputs to the song control nuclei. The presence of the steroid receptor coactivator SRC-1 in the telencephalic song control nuclei and in the catecholaminergic cell groups that innervate the song system supports the idea that SRC-1 expression could play an active role in the control of singing behavior by modulating estrogen and androgen receptor action at both locations. (C) 2002 Elsevier Science B.V. All rights reserved. [less ▲]

Sex differences in the distribution of the steroid receptor-coactivator-1 in the canary brain

in Hormones & Behavior (2002), 41

Sex differences in the rapid control of aromatase activity in the quail preoptic area.

in Journal of Neuroendocrinology (2011), 23(5), 424-34

Adult male quail show high levels of aromatase activity in the preoptic area-hypothalamus (POA-HYP), which parallels the high number of aromatase-immunoreactive cells and elevated mRNA concentrations ... [more ▼]

Adult male quail show high levels of aromatase activity in the preoptic area-hypothalamus (POA-HYP), which parallels the high number of aromatase-immunoreactive cells and elevated mRNA concentrations detected in this brain region by in situ hybridisation. Interestingly, females display considerably lower aromatase activity than males but have almost equal numbers of aromatase-immunoreactive cells and express similar levels of aromatase mRNA. Aromatase activity in the male POA-HYP can be rapidly regulated by calcium-dependent phosphorylations, in the absence of changes in enzyme concentration. In the present study, we investigated whether aromatase activity is differentially regulated by phosphorylations in males and females. A linear increase in accumulation of aromatisation products was observed in both sexes as a function of time but the rate of conversion was slower in females. Saturation analysis confirmed the lower maximum velocities (V(max) ) in females but indicated a similar affinity (K(m) ) in both sexes. Aromatase activity in females reacted differentially to manipulations of intracellular calcium. In particular, chelating calcium with ethylene glycol tetraacetic acid (EGTA) resulted in a larger increase of enzymatic activity in males than in females, especially in the presence of ATP. A differential reaction to kinase inhibitors was also observed between males and females (i.e. a larger increase in aromatase activity in females than in males after exposure to specific inhibitors). These findings suggest that the nature of aromatase is conserved between the sexes, although the control of its activity by calcium appears to be different. Additional characterizations of intracellular calcium in both sexes would therefore be appropriate to better understand aromatase regulation. [less ▲]

Sex in the media

in Scientist (Philadelphia, Pa.) (2004), 18

Sex steroid dynamics during embryogenesis and sexual differentiation in Eurasian perch, Perca fluviatilis

in Theriogenology (2007), 67(5), 1046-1052

It is widely accepted that sex steroid hormones play an important and a specific role during the process of sex differentiation in fish. In order to describe the role of the three main sex steroid ... [more ▼]

It is widely accepted that sex steroid hormones play an important and a specific role during the process of sex differentiation in fish. In order to describe the role of the three main sex steroid hormones (testosterone--T, 17beta-estradiol--E2 and 11keto-testosterone--11KT) during embryogenesis and sex differentiation in Eurasian perch, Perca fluviatilis, eggs, larvae and juveniles originating from two mixed-sex and two all-female progenies were regularly sampled from fertilization to hatching (D0) and from hatching to day 70 post-hatching (D70). Just after spawning, a significant amount of sex steroids [T (1634.2pgg(-1)), E2 (554.4pgg(-1)) and 11KT (1513.2pgg(-1))] was measured in non-fertilised eggs suggesting a maternal transmission of these steroids. From D2 to D70 post-hatching, E2 levels were significantly higher in mixed-sex progenies (median: 725.7pgg(-1)) than in all-female progenies (156.2pgg(-1)) and significantly increased after the onset of the histological differentiation of the gonad in both progenies (D35). Levels of 11KT were significantly higher in mixed-sex (median: 431.5pgg(-1)) than in all-female progenies (below the limit of assay detection) and significantly increased at D35 in all-female progenies (median value: 343.2pgg(-1)). Mean 11KT to E2 ratio was six-fold higher in mixed-sex progenies (1.35) than in all-female progenies (0.24). The data suggest that the 11-oxygenated androgen (11KT) plays a major role in the male differentiation process, and that sex differentiation in Eurasian perch is probably determined by the 11KT to E2 ratio. [less ▲]

Sex, gender und Altersdiskurs in Thomas Manns „Die Betrogene“: Peinliches Begehren

in Bidwell-Steiner; Wozonig, Karin S. (Eds.) Gender & Generation. Gendered Subjects. (2005)

Sex-specific effect of pool desiccation on the movement of Alpine newts, Mesotriton alpestris (Laurenti, 1768), among breeding sites (Caudata: Salamandridae)

in Herpetozoa (2011), 24(3/4), 127-134

In unpredictable habitats, it is advantageous to amphibians to reduce the risk of weather-induced offspring mortality by utilization of several reproductive patches. In european deciduous forest ... [more ▼]

In unpredictable habitats, it is advantageous to amphibians to reduce the risk of weather-induced offspring mortality by utilization of several reproductive patches. In european deciduous forest landscapes, ruts caused by vehicular traffic, typically comprising small vernal or ephemeral pools with variable hydroperiod, are at times used as breeding habitats by some species of amphibians. Previous research shows that in such systems newts move between ruts within a single reproductive season. The aim was to characterize such movements by means of a capture-mark-recapture study of the alpine Newt Mesotriton alpestris (laureNti, 1768), during two years differing in water availability, and to detect possible sex-specific differences. Movement between ruts differed between years according to sex. In the year with higher pool drying frequency, more females changed ruts than in the year when stable conditions prevailed. Among the adults that moved between ruts, however, the mean number of aquatic patches visited was higher in males. These results show that the sexes can react differently to environmental correlates and that alpine Newts are well adapted to utilize networks of temporary pools. [less ▲]

Le sexe, élément d'appréciation du risque ?

in Rogge, Jean (Ed.) Discrimination, différenciation hommes/femmes et assurances - Discriminatie, geslachtsdifferentie en verzekeringen (2007, March)

La sexologie clinique en Belgique

Conference (2006, October 07)

Le point sur la formation et la reconnaissance légale des sexologues et des sexologues cliniciens en belgique (2006)

Sexual abuse: is regression in borderline functioning a risk factor for acting out within the interfamilial system?

Poster (2012, May 11)