Evolutionary dynamics of rRNA gene clusters in cichlid fish

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

The evolutionary dynamics of the Helena retrotransposon revealed by sequenced Drosophila genomes

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

Taxonomic and evolutionary analysis of Zaprionus indianus and its colonization of Palearctic and Neotropical regions

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Evolutionary dynamics of retrotransposable elements Rex1, Rex3 and Rex6 in neotropical cichlid genomes

Background: Transposable elements (TEs) have the potential to produce broad changes in the genomes of their hosts, acting as a type of evolutionary toolbox and generating a collection of new regulatory and coding sequences. Several TE classes have been studied in Neotropical cichlids; however, the information gained from these studies is restricted to the physical chromosome mapping, whereas the genetic diversity of the TEs remains unknown. Therefore, the genomic organization of the non-LTR retrotransposons Rex1, Rex3, and Rex6 in five Amazonian cichlid species was evaluated using physical chromosome mapping and DNA sequencing to provide information about the role of TEs in the evolution of cichlid genomes. Results: Physical mapping revealed abundant TE clusters dispersed throughout the chromosomes. Furthermore, several species showed conspicuous clusters accumulation in the centromeric and terminal portions of the chromosomes. These TE chromosomal sites are associated with both heterochromatic and euchromatic regions. A higher number of Rex1 clusters were observed among the derived species. The Rex1 and Rex3 nucleotide sequences were more conserved in the basal species than in the derived species; however, this pattern was not observed in Rex6. In addition, it was possible to observe conserved blocks corresponding to the reverse transcriptase fragment of the Rex1 and Rex3 clones and to the endonuclease of Rex6. Conclusion: Our data showed no congruence between the Bayesian trees generated for Rex1, Rex3 and Rex6 of cichlid species and phylogenetic hypothesis described for the group. Rex1 and Rex3 nucleotide sequences were more conserved in the basal species whereas Rex6 exhibited high substitution rates in both basal and derived species. The distribution of Rex elements in cichlid genomes suggests that such elements are under the action of evolutionary mechanisms that lead to their accumulation in particular chromosome regions, mostly in heterochromatins. © 2013 Schneider et al.; licensee BioMed Central Ltd.

The Developing Left Superior Cervical Ganglion of Pacas (Agouti Paca)

In this study the main question investigated was the number and size of both binucleate and mononucleate superior cervical ganglion (SCG) neurons and, whether post-natal development would affect these parameters. Twenty left SCGs from 20 male pacas were used. Four different ages were investigated, that is newborn (4 days), young (45 days), adult (2 years), and aged animals (7 years). By using design-based stereo-logical methods, that is the Cavalieri principle and a physical disector combined with serial sectioning, the total volume of ganglion and total number of mononucleate and binucleate neurons were estimated. Furthermore, the mean perikaryal (somal) volume of mononucleate and binucleate neurons was estimated using the vertical nucleator. The main findings of this study were a 154% increase in the SCG volume, a 95% increase in the total number of mononucleate SCG neurons and a 50% increase in the total volume of SCG neurons. In conclusion, apart from neuron number, different adaptive mechanisms may coexist in the autonomic nervous system to guarantee a functional homeostasis during ageing, which is not always associated with neuron losses. Anat Rec, 292:966-975, 2009. (C) 2009 Wiley-Liss, Inc.

Nandrolone Decanoate and Physical Effort: Histological and Morphometrical Assessment in Adult Rat Uterus

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

O processo evolutivo: uma análise semiótica

Esta pesquisa é uma Análise Semiótica da Biologia Evolutiva, utilizando-se para tanto o quadro categorial de Charles S. PEIRCE (1853-1914). Questões como Diversidade, Acaso e Relações Ambientais são discutidas através de relações sígnicas.

Area of Rests of Malassez in Young and Adult Rat Molars: Evidences in the Formation of Large Rests

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

Aquaporin 9 (AQP9) localization in the adult dog testis excurrent ducts by immunohistochemistry

Aquaporins (AQPs) are small, intrinsic membrane proteins that are present in many cell types involved in fluid transport. AQP9 is a major apical water channel that is expressed throughout the efferent ducts, epididymis, and vas deferens, as well as in other regions of the human and rodent male reproductive tract. The target of this study was to examine the expression of AQP9 in epithelial cells in the adult dog efferent ducts, epididymis, and vas deferens. Samples of dog male reproductive tract comprising fragments of the testis; initial segment, caput, corpus, and cauda of the epididymis; and vas deferens were obtained from eight adult mongrel dogs. Immunohistochemistry and Western blotting procedures were used to show AQP9 localization and distribution. AQP9 expression was not detected either in dog seminiferous tubules or rete testis. However, apical labeling for AQP9 was detected in the different regions of epididymis and vas deferens, with the reaction being less intense in the caput epididymis. Thus, AQP9 is abundantly expressed in dog male reproductive tract, in which it is an important apical pathway for transmembrane flow of water and neutral solutes.

High-Intensity Resistance Training with Insufficient Recovery Time Between Bouts Induce Atrophy and Alterations in Myosin Heavy Chain Content in Rat Skeletal Muscle

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Differential MMP-2 and MMP-9 Activity and Collagen Distribution in Skeletal Muscle from pacu (Piaractus mesopotamicus) During Juvenile and Adult Growth Phases

Here, we evaluated collagen distribution and matrix metalloproteinases (MMPs) MMP-2 and MMP-9 activities in skeletal muscle of pacu (Piaractus mesopotamicus) during juvenile and adult growth phases. Muscle samples from juvenile and adult fishes were processed by histochemistry for collagen system fibers and for gelatin-zymography for MMP-2 and MMP-9 activities analysis. Picrosirius staining revealed a myosept, endomysium, and perimysium-like structures in both growth phases and muscle types, with increased areas of collagen fibers in adults, mainly in red muscle. Reticulin staining showed that reticular fibers in the endomysium-like structure were thinner and discontinuous in the red muscle fibers. The zymography revealed clear bands of the pro-MMP-9, active-MMP-9, intermediate-MMP-2, and active-MMP-2 forms in red and white muscle in both growth phases. MMP-2 activity was more intense in juvenile than adult muscle fibers. Comparing the red and white muscle types, MMP-2 activity was significantly higher in red muscle in adult phase only. The activity of MMP-9 forms was similar in juvenile red and white muscles and in the adult red muscle, without any activity in adult white muscle. In conclusion, our results show that, in pacu, the higher activities of MMP-2 and -9 are associated with the rapid muscle growth in juvenile age and in adult fish, these activities are related with a different red and white muscle physiology. This study may contribute to the understanding muscle growth mechanisms and may also contribute to analyse red and the white muscle parameters of firmness and softness, respectively, of the commercial product. Anat Rec, 292:387-395, 2009. (C) 2009 Wiley-Liss, Inc.

The evolution of jumping performance in anurans: morphological correlates and ecological implications

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

Calcaneal Tendon Regions Exhibit Different MMP-2 Activation After Vertical Jumping and Treadmill Running

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

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)

Chromosome spreading of associated transposable elements and ribosomal DNA in the fish Erythrinus erythrinus. Implications for genome change and karyoevolution in fish

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