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A new genus and species of troglobitic buthid scorpion are described on the basis of a single specimen collected in Brazil. This is the first cavernicolous scorpion ever found in Brazil, and only the second to be found in South America. Some considerations on troglobitic scorpions are proposed. 相似文献
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Pasteurella multocida toxin (PMT) stimulates and subsequently uncouples phospholipase C (PLC) signal transduction through its selective action on the Gq subunit. This review summarizes what is currently known about the molecular action of PMT on Gq and the resulting cellular effects. Examples are presented illustrating the use of PMT as a powerful tool for dissecting the molecular mechanisms involving pertussis toxin (PT)-insensitive heterotrimeric G proteins. 相似文献
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Verjovski-Almeida S Leite LC Dias-Neto E Menck CF Wilson RA 《Trends in parasitology》2004,20(7):304-308
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Bogani D Warr N Elms P Davies J Tymowska-Lalanne Z Goldsworthy M Cox RD Keays DA Flint J Wilson V Nolan P Arkell R 《Genesis (New York, N.Y. : 2000)》2004,40(2):109-117
Dominantly acting mutations that produce visible phenotypes are frequently recovered, either during routine maintenance of colonies or from mutagenesis experiments. We have studied 12 dominant mouse mutations that cause a tail dysmorphology, a coat spotting phenotype, or a combination of these. The majority of these mutations act in a semidominant manner with the homozygous state associated with embryonic lethality and a visible phenotype at or before midgestation. The homozygous phenotypes include axis truncation and neural crest cell defects, as may be expected from the heterozygous phenotypes. The majority of mutations, however, also produced other phenotypes that include neural tube closure defects and aberrant heart looping. In one coat spotting mutant the homozygous condition is lethal before neural crest cell production commences. The mutated genes often function in processes additional to those alluded to by the heterozygous phenotype. 相似文献
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Early steps in the development of the forebrain 总被引:2,自引:0,他引:2
The tremendous complexity of the adult forebrain makes it a challenging task to elucidate how this structure forms during embryonic development. Nevertheless, we are beginning to understand how a simple epithelial sheet of ectoderm gives rise to the labyrinthine network of cells that constitutes the functional forebrain. Here, we discuss early events in forebrain development--those that lead to the establishment of the anterior neural plate and the regional subdivision of this territory into the different domains of the prospective forebrain. 相似文献
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