Follistatin-like 3 (FSTL3) mediated silencing of transforming growth factor (TGF ) signaling is essential for testicular aging and regulating testis size

Follistatin-like 3 (FSTL3) is a glycoprotein that binds and inhibits the action of TGFβ ligands such as activin. The roles played by FSTL3 and activin signaling in organ development and homeostasis are not fully understood. The authors show mice deficient in FSTL3 develop markedly enlarged testes that are also delayed in their age-related regression. These FSTL3 knockout mice exhibit increased Sertoli cell numbers, allowing for increased spermatogenesis but otherwise showing normal testicular function. The data show that FSTL3 deletion leads to increased AKT signaling and SIRT1 expression in the testis. This demonstrates a cross-talk between TGFβ ligand and AKT signaling and leads to a potential mechanism for increased cellular survival and antiaging. The findings identify crucial roles for FSTL3 in limiting testis organ size and promoting age-related testicular regression

A dança como expressão do imaginário

Este artigo sintetiza as conclusões obtidas em pesquisa etnográfica realizada no ano de 2009, que deu origem à dissertação de mestrado intitulada As tessituras do movimento: dança, tribalismo e imaginário no cotidiano de um grupo de alunos de uma escola pública de Araraquara, defendida na Universidade Estadual Paulista - Faculdade de Ciências e Letras de Araraquara, São Paulo. O objetivo da pesquisa foi levantar pistas para um método de análise dos movimentos tendo como referência a Antropologia do Imaginário de Gilbert Durand e os estudos dos esforços (effort shape) em Rudolf Laban. Para isso, identificaram-se os principais movimentos da dança break praticada por um grupo de adolescentes que frequenta a escola aos finais de semana. O inventário dos movimentos desta dança nos conduziu a um pensar gestual e rítmico, para além da racionalização da educação do corpo

CORPO E ESCOLA:: O “CUIDADO DE SI” COMO “ATITUDE MODERNA”

Apresentamos os resultados dos nossos estudos entre os processos educacionais e processos de subjetivação. Associamos este fato com a dificuldade dos educadores deslocarem o corpo do lugar de quem ensina para o lugar de quem aprende. Estudamos as implicações do corpo nos processos educacionais e sugerimos uma “atitude moderna” a partir do “cuidado de si”, apoiados em Foucault, como a ação do educador que “toma partido” do educando

BMP Signaling in the Human Fetal Ovary is Developmentally Regulated and Promotes Primordial Germ Cell Apoptosis

Primordial germ cells (PGCs) are the embryonic precursors of gametes in the adult organism, and their development, differentiation, and survival are regulated by a combination of growth factors collectively known as the germ cell niche. Although many candidate niche components have been identified through studies on mouse PGCs, the growth factor composition of the human PGC niche has not been studied extensively. Here we report a detailed analysis of the expression of components of the bone morphogenetic protein (BMP) signaling apparatus in the human fetal ovary, from postmigratory PGC proliferation to the onset of primordial follicle formation. We find developmentally regulated and reciprocal patterns of expression of BMP2 and BMP4 and identify germ cells to be the exclusive targets of ovarian BMP signaling. By establishing long-term cultures of human fetal ovaries in which PGCs are retained within their physiological niche, we find that BMP4 negatively regulates postmigratory PGC numbers in the human fetal ovary by promoting PGC apoptosis. Finally, we report expression of both muscle segment homeobox (MSX)1 and MSX2 in the human fetal ovary and reveal a selective upregulation of MSX2 expression in human fetal ovary in response to BMP4, suggesting this gene may act as a downstream effector of BMP-induced apoptosis in the ovary, as in other systems. These data reveal for the first time growth factor regulation of human PGC development in a physiologically relevant context and have significant implications for the development of cultures systems for the in vitro maturation of germ cells, and their derivation from pluripotent stem cells

3640 Unique EST Clusters from the Medaka Testis and Their Potential Use for Identifying Conserved Testicular Gene Expression in Fish and Mammals

BACKGROUND: The fish medaka is the first vertebrate capable of full spermatogenesis in vitro from self-renewing spermatogonial stem cells to motile test-tube sperm. Precise staging and molecular dissection of this process has been hampered by the lack of suitable molecular markers. METHODOLOGY AND PRINCIPAL FINDINGS: We have generated a normalized medaka testis cDNA library and obtained 7040 high quality sequences representing 3641 unique gene clusters. Among these, 1197 unique clusters are homologous to known genes, and 2444 appear to be novel genes. Ontology analysis shows that the 1197 gene products are implicated in diverse molecular and cellular processes. These genes include markers for all major types of testicular somatic and germ cells. Furthermore, markers were identified for major spermatogenic stages ranging from spermatogonial stem cell self-renewal to meiosis entry, progression and completion. Intriguingly, the medaka testis expresses at least 13 homologs of the 33 mouse X-chromosomal genes that are enriched in the testis. More importantly, we show that key components of several signaling pathways known to be important for testicular function in mammals are well represented in the medaka testicular EST collection. CONCLUSIONS/SIGNIFICANCE: Medaka exhibits a considerable similarity in testicular gene expression to mammals. The medaka testicular EST collection we obtained has wide range coverage and will not only consolidate our knowledge on the comparative analysis of known genes' functions in the testis but also provide a rich resource to dissect molecular events and mechanism of spermatogenesis in vivo and in vitro in medaka as an excellent vertebrate model

Mechanically Induced Chromatin Condensation Requires Cellular Contractility in Mesenchymal Stem Cells

This work was supported by the National Institutes of Health (R01 AR056624, R01 EB02425, T32 AR007132, and P30 AR050950). Additional support was provided by a Montague Research Award from the Perelman School of Medicine and a University of Pennsylvania University Research Foundation Award