Immunohistochemical detection of estrogen receptor beta in alveolar bone cells of estradiol-treated female rats: possible direct action of estrogen on osteoclast life span

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Differential vascular adaptive response to stress exposure in male and female rats: Role of gonadal hormones and endothelial cells

Although there are reports concerning a vascular adaptive response to stress in males, this is not yet defined in females. The aim of this study was to delineate functional gender differences in the rat vascular adaptive response to stress and to determine the ability of sex hormones to modulate the stress-induced vascular adaptive response. Responses to noradrenaline were evaluated in aortas, with and without endothelium, from intact, gonadectomized and gonadectomized-hormone-replaced males and females submitted or not to stress (2-h immobilization). Reactivity of the aorta of stressed and non-stressed intact males and females (n = 6-14 per group) was also examined in the presence of L-NAME or indomethacin. Stress decreased and gonadectomy increased maximal responses to noradrenaline in aortas with intact endothelium from both genders. Stress also reduced noradrenaline potency in males. In females, but not males, stress decreased the gonadectomy-induced noradrenaline hyper-reactivity to near that of intact non-stressed rats. Hormone replacement restored the gonadectomy-induced impaired vascular adaptive response to stress. L-NAME, but not indomethacin, abolished the stress-induced decrease in aorta reactivity of males and females. None of the procedures altered reactivity of aortas denuded of endothelium. Conclusion: Stress-induced vascular adaptive responses show gender differences. The magnitude of the adaptive response is dependent on testicular hormones and involves endothelial nitric oxide-system hyperactivity.

Female preferences based on male nutritional chemical traits

Selection favors females that attend to reliable information about male genetic quality and fitness. Male nutritional condition can be a significant sign of mate quality since poor nutrition can be related to reduced sperm quality, low sperm quantity, sexually transmitted diseases, and parasites. We tested whether female Nile tilapia, Oreochromis niloticus, preferred the chemical cues of males that were well fed with high-protein diet over those fed with low-protein diet. Females do not only discriminate between males but also show a preference for well-fed males, discriminating between the odors with respect to nutritional state, suggesting that they were responding to a food-specific chemical cue. It is therefore likely that nutritional condition is related to the production of pheromones in males. Our results suggest that information about male nutritional state can be conveyed in chemical cues and that females attend to these cues during mate choice.

Female pintado catfish choose well-fed males

This study tested the preference of pintado catfish females (Pseudoplatystoma coruscans) for associating with well-fed or food-deprived males in simultaneous choice tests. Females were tested under three different treatments in which: (1) females could choose on the basis of multiple cues from the well-fed or food-deprived males (visual plus chemical); (2) only chemical cues were presented; (3) only visual cues were presented. Females chose well-fed males when chemical cues were presented (either visual + chemical or only chemical cues). When only visual cues were presented, females spent an equal amount of time in the choice apparatus compartments. Chemical signals, either directly through control of pheromone production, or indirectly by excreted metabolites, are likely to be an important source of information about nutritional condition in mating choice.

Search for Genomic Alterations in Monozygotic Twins Discordant for Cleft Lip and/or Palate

Phenotypically discordant monozygotic twins offer the possibility of gene discovery through delineation of molecular abnormalities in one member of the twin pair. One proposed mechanism of discordance is postzygotically occurring genomic alterations resulting from mitotic recombination and other somatic changes. Detection of altered genomic fragments can reveal candidate gene loci that can be verified through additional analyses. We investigated this hypothesis using array comparative genomic hybridization; the 50K and 250K Affymetrix GeneChip (R) SNP arrays and an Illumina custom array consisting of 1,536 SNPs, to scan for genomic alterations in a sample of monozygotic twin pairs with discordant cleft lip and/or palate phenotypes. Paired analysis for deletions, amplifications and loss of heterozygosity, along with sequence verification of SNPs with discordant genotype calls did not reveal any genomic discordance between twin pairs in lymphocyte DNA samples. Our results demonstrate that postzygotic genomic alterations are not a common cause of monozygotic twin discordance for isolated cleft lip and/or palate. However, rare or balanced genomic alterations, tissue-specific events and small aberrations beyond the detection level of our experimental approach cannot be ruled out. The stability of genomes we observed in our study samples also suggests that detection of discordant events in other monozygotic twin pairs would be remarkable and of potential disease significance.

Germ line Cysts and the Formation of the Germinal Epithelium During the Female Gonadal Morphogenesis in Cyprinus Carpio (Teleostei: Ostariophysi: Cypriniformes)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

In utero and lactational exposure to fenvalerate disrupts reproductive function in female rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Reproductive development and function of female rats exposed to di-eta-butyl-phthalate (DBP) in utero and during lactation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Morphology and histology of male and female reproductive systems in the inseminating species Scoloplax distolothrix (Ostariophysi : Siluriformes : Scoloplacidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Male and female reproductive morphology in the inseminating genus Astroblepus (Ostariophysi: Siluriformes: Astroblepidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Assessment of Female Reproductive Endpoints in Sprague-Dawley Rats Developmentally Exposed to Diuron: Potential Ovary Toxicity

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Functional morphology of adult female Culex quinquefasciatus midgut during blood digestion

The adult female Culex quinquefasciatus midgut comprises a narrow anterior and a dilated posterior region, with epithelia composed of a monolayer of adjacent epithelial cells joined at the apical portion by septate junctions. Densely packed apical microvilli and an intricate basal labyrinth characterise each cell pole. Our morphological studies suggest that, during blood digestion, the anterior midgut region also participates in an initial absorptive stage which is probably related to the intake of water, salts and other small molecules. This activity peaked by 6 h after bloodmeal feeding (ABF) and ended approximately 18 h ABF, when the peritrophic membrane was already formed. After this time, absorption only occurred in the posterior region, with morphologic and biochemical evidence of high synthetic activity related to the secretion of proteases. Chymotrypsin, elastase, aminopeptidase, and trypsin reached their maximum activity at around 36 h ABF. Digestion products were apparently absorbed and transported to the basal labyrinth, from where they should be released to the hemolymph. At 72 h ABF, proteolysis had already ended and protein levels had returned to those observed before blood meal. The epithelium of the posterior region, however, did not return to its initial morphology, appearing quite disorganised. Additionally, from 48 h ABF onwards some epithelial cells showed morphological signals of apoptosis. (C) 2002 Elsevier B.V. Ltd. All rights reserved.