Effects of neonatal castration and androgenization on sexual dimorphism in bone, leptin and corticosterone secretion

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Dimorphism, thermal tolerance, virulence and Heat shock protein 70 transcription in different isolates of Paracoccidioides brasiliensis

The mycelia-to-yeast (M-Y) transition, thermal tolerance and virulence profiles were evaluated for nine isolates of Paracoccidioides brasiliensis, including samples from two of the three recently discovered cryptic species, as well as their relation to the partial sequence and transcription of the hsp70 gene. The isolates Bt84 and T10 (from PS2 species) took more time to convert to yeast form and presented elongated yeast cells at 36 degrees C. Arthroconidia production was also observed during the M-Y transition for some isolates. Our data confirm that the hsp70 transcription may be associated with thermal tolerance, but this does not seem to be directly related to high virulence profiles. The partial sequencing of this gene allowed the separation of our isolates into two clusters that correspond to the two sympatric cryptic species occurring in an area hyperendemic for PCM (Botucatu, SP, Brazil).

Achene dimorphism in Bidens pilosa L. (Asteraceae) as determined by germination test

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

Discrete dimorphism among castes of the bald-faced hornet Dolichovespula maculata (Hymenoptera: Vespidae) in different phases of the colony cycle

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

Sexual dimorphism in Ceraeochrysa cubana (Neuroptera : Chrysopidae)

Sexual dimorphism of green lacewings is discussed, citing previously known examples of this structural phenomenon on the frons, antennal scape, and forewings. Newly recognized dimorphism is cited in Ceraeochrysa cubana for the vertex and abdominal spiracles.

Sexual dimorphism in Ramphastos toco and Ramphastos dicolorus (Piciformes, Aves)

Phenotypic sexual dimorphism seems to be rare in the Ramphastidae family, except in Pteroglossus viridis and in the genus Selenidera. Many breeders of wild birds believe that specimens of Ramphastos toco can be sexed using bill characteristics. In this study, various discriminant phenotypic variables were analyzed in birds which were sexed cytogenetically. Fifty-one specimens of R. toco and 20 R. dicolorus were studied. The statistically significant parameters which served to distinguish the sex in these species were the length of the culmen and tomium, length of the lower corneous beak and the cloaca. Using these parameters, capitive bird breeders can determine sex of R. toco specimens by phenotypic analysis and form breeding couples more quickly.

Evidence for the role of calcineurin in morphogenesis and calcium homeostasis during mycelium-to-yeast dimorphism of Paracoccidioides brasiliensis

Paracoccidioides brasiliensis is a dimorphic fungus that causes paracoccidioidomycosis, the most prevalent human deep mycosis in Latin America. The dimorphic transition from mycelium to yeast (M-Y) is triggered by a temperature shift from 25°C to 37°C and is critical for pathogenicity. Intracellular Ca 2+ levels increased in hyphae immediately after temperature-induced dimorphism. The chelation of Ca 2+ with extracellular (EGTA) or intracellular (BAPTA) calcium chelators inhibited temperature-induced dimorphism, whereas the addition of extracellular Ca 2+ accelerated dimorphism. The calcineurin inhibitor cyclosporine A (CsA), but not tacrolimus (FK506), effectively decreased cell growth, halted the M-Y transition that is associated with virulence, and caused aberrant growth morphologies for all forms of P. brasiliensis. The difference between CsA and FK506 was ascribed by the higher levels of cyclophilins contrasted to FKBPs, the intracellular drug targets required for calcineurin suppression. Chronic exposure to CsA abolished intracellular Ca 2+ homeostasis and decreased mRNA transcription of the CCH1 gene for the plasma membrane Ca 2+ channel in yeast-form cells. CsA had no detectable effect on multidrug resistance efflux pumps, while the effect of FK506 on rhodamine excretion was not correlated with the transition to yeast form. In this study, we present evidence that Ca 2+/calmodulin-dependent phosphatase calcineurin controls hyphal and yeast morphology, M-Y dimorphism, growth, and Ca 2+ homeostasis in P. brasiliensis and that CsA is an effective chemical block for thermodimorphism in this organism. The effects of calcineurin inhibitors on P. brasiliensis reinforce the therapeutic potential of these drugs in a combinatory approach with antifungal drugs to treat endemic paracoccidioidomycosis. Copyright © 2008, American Society for Microbiology. All Rights Reserved.

Allometry for Sexual Size Dimorphism in Stoneflies Defies the Rensch's Rule

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Linear Versus Geometric Morphometric Approaches for the Analysis of Head Shape Dimorphism in Lizards

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Size-Dependent Selective Mechanisms on Males and Females and the Evolution of Sexual Size Dimorphism in Frogs

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

Sexual dimorphism and phenotypic plasticity in the antennal lobe of a stingless bee, Melipona scutellaris

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

Population structure and growth of the hermit crab Pagurus brevidacylus (Anomura : Paguridae) from the northern coast of São Paulo, Brazil

The hermit crab Paguras brevidactylus (Crustacea: Anomura: Paguridea) from the infralittoral area of Anchieta Island, Ubatuba, was characterized by population Structure (size, sex ratio, reproduction and recruitment) and growth. Animals were collected monthly during 1999 by SCUBA diving. A total of 1525 individuals was collected (633 males and 892 females), 695 of them were ovigerous females. Overall sex ratio was 0.7:1 in favour of females. The crabs showed a unimodal distribution with males significantly larger than females. Ovigerous females were collected during all months and in high percentages from 1.0 mm of shield length, demonstrating intense and Continuous reproduction. The longevity was approximately 24 months for males and 18 for females, which showed larger growth rate and reached sexual maturity earlier (two months) than males. The low number of males in this Population may be due to the longer life span. Moreover, the sexual dimorphism favours males during the intra- and interspecific fights by shell, food, reproduction and territory. Females demonstrated a short life cycle and intense reproduction.

Canine lacrimal and third eyelid superficial glands macroscopic and morphometric characteristics

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Sex-related macrostructural organization of the deer's brachial plexus

We describe the morphological organization of the deer brachial plexus in order to supply data to veterinary neuroclinics and anaesthesiology. The deer (Mazama gouazoubira) brachial plexus is composed of four roots: three cervical (C6, C7 and C8) and one thoracic (T1). Within each sex group, no variations are observed between the left and the right brachial plexus, though sex-related differences are seen especially in its origin. The origin of axillary and radial nerves was: C6, C7, C8 and T1 in males and C8-T1 (radial nerve) and C7, C8 and T1 (axillary nerve) in females; musculocutaneous nerve was: C6-C7 (males) and C8-T1 (females); median and ulnar nerves was: C8-T1 (males) and T1 (females); long thoracic nerve was: C7 (males) and T1 (females); lateral thoracic nerve was: C6, C7, C8 and T1 (males) and T1 (females); thoracodorsal nerve was: C6, C7, C8 and T1 (males) and C8-T1 (females); suprascapular nerve was: C6-C7 (males) and C6 (females) and subscapular nerve was: C6-C7 (males) and C7 (females). This study suggests that in male deer the origin of the brachial plexus is more cranial than in females and the origin of the brachial plexus is slightly more complex in males, i.e. there is an additional number of roots (from one to three). This sexual dimorphism may be related to specific biomechanical functions of the thoracic limb and electrophysiological studies may be needed to shed light on this morphological feature.