MT1-MMP and its potential role in the vertebrate intestinal morphogenesis.

Membrane type 1-matrix metalloproteinase (MT1-MMP) is involved in numerous biological processes, including morphogenesis. However, the role of MT1-MMP in the development of the vertebrate intestine is poorly understood. This study aimed to evaluate the expression of MT1-MMP in the intestine of rats and chickens along the embryonic and postnatal periods using immunohistochemistry. Results revealed a remarkable spatiotemporal correlation between MT1-MMP expression and intestinal villi morphogenesis in both vertebrates. However, the villi morphogenesis process was found to be different in chickens to that of rats. Moreover, extensive MT1-MMP labeling was observed in the entire villus epithelium from birth until the complete maturation of the small intestinal mucosa in both vertebrates. From these results, we suggest that MT1-MMP contributes to intestinal development, particularly to villi morphogenesis, in both vertebrates. However, further studies are necessary to confirm the role of MT1-MMP in this cellular process. In addition, we performed validation of the primary antibody against human MT1-MMP for adult chickens.

Development of Loxosceles intermedia Mello-Leitão (1934) (Araneae, Sicariidae) genital tract.

We examined the post-embryonic development of the male and female genital apparatus of the brown spider, Loxosceles intermedia. The development of the genital apparatus for both sexes begins with the appearance of inner structures. In the male genital apparatus, formation of the testes occurs first, followed by differentiation of the duct, ampulla and vas deferens, and finally the formation of the genital opening and differentiation of the copulatory organ (secondary sexual characteristic). Similarly, the development of the female genital apparatus begins with the formation of the ovaries, followed by the appearance of oocytes in vitellogenesis, then the development of oviducts and uterus internus and, finally, the spermatheca. These data may be very important in further comparative studies on the development of the reproductive system of spiders.

Evaluation of fixative solutions for ultrastructural analysis of brown spider Loxosceles intermedia (araneae: sicariidae) tissues

In view of the widely varying compositions of fixative solutions used for studying spiders, five different fixative formulas were tested for fixing male brown-spider (Loxosceles intermedia) gonad tissues. The brown spider represents a public health problem in Curitiba (Paraná State, Brazil). Morphological study of its gonads may aid in understanding the reproductive strategies of this species, and possibly in developing a reproduction control program. The fixatives tested contained glutaraldehyde alone or combined with paraformaldehyde, and the buffers cacodylate or phosphate, with or without the addition of sucrose or sodium chloride as osmolytes. Those containing 2.5 percent glutaraldehyde and 2 percent paraformaldehyde in 100 mM phosphate buffer with 200 mM sucrose, or in 200 mM sodium cacodylate, satisfactorily preserved mitochondria, the Golgi apparatus, and the membranes in general. These formulas were nearly isosmotic (439 mOsm/kg H2O and 455 mOsm/kg H2O respectively) to brown spider hemolymph (478 mOsm/kg H2O). With respective to the fixative agents, a glutaraldehyde-paraformaldehyde combination resulted in optimal fixation of Loxosceles intermedia cells. For other species of spiders, hemolymph osmolality should be considered, but the fixative formulas cited above would also probably yield good results.

Dada a variabilidade na composição de soluções fixadoras utilizadas em aranhas, cinco diferentes fixadores foram elaborados para a análise ultra-estrutural dos tecidos da aranha marrom Loxosceles intermedia. A aranha marrom representa um problema de saúde pública na cidade de Curitiba, e o estudo morfológico de suas gônadas pode auxiliar na compreensão de suas estratégias reprodutivas e, possivelmente, no desenvolvimento de um programa de controle da sua população. As fórmulas usadas continham glutaraldeído com ou sem paraformaldeído, tampão cacodilato ou fosfato, e NaCl ou sacarose como osmólitos. As soluções fixadoras compostas por 2.5 por cento glutaraldeído e 2 por cento paraformaldeído, em tampão fosfato com adição de sacarose ou em 200 mM cacodilato de sódio, preservaram bem estruturas como mitocôndrias, aparelho de Golgi e membranas em geral. Os tampões são praticamente isosmóticos (439 mOsm/kg H2O e 455 mOsm/kg H2O, respectivamente) à hemolinfa da aranha marrom (478 mOsm/kg H2O). Ainda, com relação aos agentes fixadores, a combinação do glutaraldeído e paraformaldeído levou a uma melhor preservação das células. Para outras espécies de aranhas, a osmolalidade da hemolinfa deve ser medida e considerada, mas as fórmulas acima citadas podem ser testadas, com chance de sucesso.

Evaluation of fixative solutions for ultrastructural analysis of brown spider Loxosceles intermedia (Araneae: Sicariidae) tissues.

In view of the widely varying compositions of fixative solutions used for studying spiders, five different fixative formulas were tested for fixing male brown-spider (Loxosceles intermedia) gonad tissues. The brown spider represents a public health problem in Curitiba (Paraná State, Brazil). Morphological study of its gonads may aid in understanding the reproductive strategies of this species, and possibly in developing a reproduction control program. The fixatives tested contained glutaraldehyde alone or combined with paraformaldehyde, and the buffers cacodylate or phosphate, with or without the addition of sucrose or sodium chloride as osmolytes. Those containing 2.5% glutaraldehyde and 2% paraformaldehyde in 100 mM phosphate buffer with 200 mM sucrose, or in 200 mM sodium cacodylate, satisfactorily preserved mitochondria, the Golgi apparatus, and the membranes in general. These formulas were nearly isosmotic (439 mOsm/kg H2O and 455 mOsm/kg H2O respectively) to brown spider hemolymph (478 mOsm/kg H2O). With respective to the fixative agents, a glutaraldehyde-paraformaldehyde combination resulted in optimal fixation of Loxosceles intermedia cells. For other species of spiders, hemolymph osmolality should be considered, but the fixative formulas cited above would also probably yield good results.