Navegando por Assunto "Tralhoto"

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Acesso aberto (Open Access)
Aspectos reprodutivos de Anableps anableps (Linnaeus, 1758) (Cyprinodontiformes: Anablepidae) no Estuário Amazônico
(Universidade Federal do Pará, 2010) OLIVEIRA, Valéria de Albuquerque; MONTAG, Luciano Fogaça de Assis; http://lattes.cnpq.br/4936237097107099
Acesso aberto (Open Access)
Expressão gênica durante o desenvolvimento ocular e regulação de assimetria de opsinas na espécie Anableps anableps, peixe de quatro olhos
(Universidade Federal do Pará, 2022-11) SOUSA, Daniele Salgado de; SCHNEIDER, Patrícia Neiva Coelho; http://lattes.cnpq.br/9584217233879031
The ocular development is a complex process orchestrated by several events that include: cell specification, morphogenesis and differentiation. All these developmental and functional processes are extremely conserved among living vertebrate species, however, unique adaptations are sometimes observed, such as in fish of the genus Anableps. Unlike most fishes, which use their eyes to explore a submerged world, in Anableps anableps (Anablepidae: Cyprinodontiformes), the eye is adapted for the simultaneous perception of a world above and below the water line. These exceptional adaptations include: duplicated corneas and pupils, as well as a specialized retina region associated with simultaneous aerial and aquatic vision, and which have asymmetrical gene expression. Recently, by transcriptomic analysis of the developing eyes of A. anableps, 20 non-visual opsin genes were identified to be asymmetrically expressed between pre- and post-duplication stages of corneas and pupils. Thus, here, we analyzed by in situ hybridization the gene expression of a bistable opsin (parapinopsin) and a neuropsin (Opn5) in A. anableps larvae. Our data showed that the pattern of gene expression of these opsins is symmetrical between the dorsal and ventral retina, respectively, with expression in the ONL, INL and GCL layers. We also investigated the expression of three non-visual melanopsin genes (opn4x1, opn4x2, opn4m3), one eleost multiple tissue opsin (tmt1b), and two visual opsins (lws and rh2-1) in the dorsal and ventral retinas of juvenile A. anableps, after changing the photic conditions in which the juvenile fish were. Then, we showed that in the transition from an environment of high turbidity to one of clear water, opsins have their expression patterns changed. Additionally, by immunofluorescence, we revealed the expression of Lamin A/C, proteins expressed as part of eye development in A. anableps as well as in other developing organisms, as well as in adult individuals. Therefore, we believe that the information described here elucidates many aspects of the molecular mechanisms behind the development and adaptive plasticity of A. anableps’ eyes.
Acesso aberto (Open Access)
Ontogenia do peixe de quatro olhos Anableps anableps: adaptações ósseas e oculares para a visão simultânea aérea e aquática
(Universidade Federal do Pará, 2015-09-30) PEREZ, Louise Neiva; SCHNEIDER, Patrícia Neiva Coelho; http://lattes.cnpq.br/9584217233879031
The evolution and development of the eye has intrigued developmental biologists for centuries. Aside from partial or complete loss, few vertebrates display substantial modifications to the eye morphology. One example is the Four-eyed fish (Anableps anableps). This species is commonly found from Gulf of Paria in Venezuela to Delta of Parnaíba and reproduces throughout the year. The four-eyed fish consists in a unique model system to study eye Evo-Devo due to its distinctive feature of having divided eye structures, such as pupils and cornea. The retina is a unique structure divided into two regions, dorsal (receives aquatic luminous information) and ventral (receives aerial luminous information). The aim of this study was to describe larval stages of this species, and morphological and molecular description of the retina during eye development. Six larval stages were described. The two earlier stages did not split the cornea and pupil, and from stage three, it is possible to observe this division. It was also described the development and expansion of the frontal bone. The appearance of the frontal bone begins at stage three of development. It has been identified the appearance of an inter-orbital septum cartilaginous, starting four stage of the ocular development. It was observed that the early development of the retinal cellular layers are disorganized and is not possible to distinguish between them, but later during development, these layers become organized, with ventral outer nuclear layer thicker than the dorsal one, and the dorsal inner nuclear layer is thinner than the ventral. The pattern of retinal cell proliferation has been described in three stages of development, before and during ocular division. It was observed that the proliferation is greater at the beginning of the larval development and decreases on later stages. The result of this study will shed light on the molecular basis of this innovative feature.