22 research outputs found

    Global Diversity of Brittle Stars (Echinodermata: Ophiuroidea)

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    This review presents a comprehensive overview of the current status regarding the global diversity of the echinoderm class Ophiuroidea, focussing on taxonomy and distribution patterns, with brief introduction to their anatomy, biology, phylogeny, and palaeontological history. A glossary of terms is provided. Species names and taxonomic decisions have been extracted from the literature and compiled in The World Ophiuroidea Database, part of the World Register of Marine Species (WoRMS). Ophiuroidea, with 2064 known species, are the largest class of Echinodermata. A table presents 16 families with numbers of genera and species. The largest are Amphiuridae (467), Ophiuridae (344 species) and Ophiacanthidae (319 species). A biogeographic analysis for all world oceans and all accepted species was performed, based on published distribution records. Approximately similar numbers of species were recorded from the shelf (n = 1313) and bathyal depth strata (1297). The Indo-Pacific region had the highest species richness overall (825 species) and at all depths. Adjacent regions were also relatively species rich, including the North Pacific (398), South Pacific (355) and Indian (316) due to the presence of many Indo-Pacific species that partially extended into these regions. A secondary region of enhanced species richness was found in the West Atlantic (335). Regions of relatively low species richness include the Arctic (73 species), East Atlantic (118), South America (124) and Antarctic (126)

    Gametogenic cycle of Ophioderma januarii, a common Ophiodermatidae (Echinodermata: Ophiuroidea) in southeastern Brazil

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    Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)This study describes the gametogenic cycle of Ophioderma januarii Luken, 1856, a common species of ophiuroid in Southeastern Brazil. The specimens were collected during the project "Biodiversidade Bentica Marinha no Estado de Sao Paulo-BIOTA/FAPESP-Bentos Marinho" (Marine benthic biodiversity in the State of Sao Paulo-BIOTA/Fapesp-Marine Benthos) which was conducted off the northern coast of the state of Sao Paulo. Specimens were captured monthly between February 2001 and December 2002. Due to the low number of individuals the monthly data was grouped in seasons (spring to winter). A total of 101 specimens were obtained: 33 in spring, 10 in summer, 23 in autumn, and 35 in winter. The gonads of eighty-eight individuals (45 females, 42 males, and one hermaphrodite) were analyzed histologically. The male and female gametogenic cycles were classified into five different gonadal stages, which were analyzed separately. The reproductive pattern could be defined through histological analyses of male and female gonads, together with oocyte diameter frequency. Some general conclusions could also be reached: this is a gonochoric species that reproduces year-round but increases its gonadal activity during summer; based on the size of its mature oocytes, it has lecithotrophic development. Apparently, its recruitment is enhanced in late summer, and smaller individuals are more frequent during autumn and winter.261118126Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [02/04298-0

    Mol. Cell. Biochem.

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    Serotonin is not only a neurotransmitter in the central nervous system, but also a ubiquitous hormone in the periphery involved in vasoconstriction and platelet function. Tryptophan hydroxylase is the rate-limiting enzyme in serotonin biosynthesis. By gene targeting, we have shown that serotonin is synthesized independently by two different tryptophan hydroxylase isoenzymes in peripheral tissues and neurons and identified a neuronal tryptophan hydroxylase isoform. Mice deficient in peripheral tryptophan hydroxylase (TPH1) and serotonin exhibit a reduced risk of thrombosis and thromboembolism. Therefore, we designed several antitph1 hammerhead miniribozymes and tested their cleavage activity against short synthetic Tph1 RNA substrates. In vitro cleavage studies demonstrated site-specific cleavage of Tph1 mRNA that was dependent on substrate/miniribozyme ratio and duration of exposure to miniribozyme. Interestingly, we detected different in vitro cleavage rates after we had cloned the miniribozymes into tRNA expression constructs, and found one with a high cleavage rate. We also demonstrated that this active tRNA–miniribozyme chimera is capable of selectively cleaving native Tph1 mRNA in vivo, with concomitant downregulation of the serotonin biosynthesis. Therefore, this Tph1-specific miniribozyme may provide a novel and effective form of gene therapy that may be applicable to a variety of thrombotic diseases
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