Histological description of the larval development of Brycon gouldingi Lima, 2004 (Teleostei, Characidae)

Piabanha, Brycon gouldingi, is an endemic species in the Tocantins-Araguaia basin. It has aroused the interest of both fish farmers, who started its creation in confinement, and riverine people who appreciate it as a food source. In order to provide information about organic systems of B. gouldingi larvae, a histological description was performed after capturing adult specimens in the Rio das Mortes (Mato Grosso, Brazil), adapted to captivity and induced to spawn at Buriti Fisheries (Nova Mutum, MT, Brazil). The collection of samples took place at pre-defined moments after hatching, and the processes relating to morphological differentiation of digestive, excretory, cardiorespiratory, nervous/sensory systems and gas bladder were characterized. At the hatching were found: undifferentiated digestive system; pronephros (primitive kidney), rudimentary heart, central nervous system characterized by primary vesicles, optic vesicle forming the optic cup and crystalline lens. In the course of ontogeny, these organic systems were developed and at the time of the total absorption of the yolk at 55 hours post-hatching were found: the digestive system consisting of the head gut, foregut, midgut and hindgut; two heart chambers and branching of gill arches; three regions of the brain (forebrain, midbrain and hindbrain), neuromasts, olfactory cavity, taste buds; eye consisting of well-defined layers; presence of gas bladder. The results of this study may be useful in providing support for the captive breeding of B. gouldingi during the larval stage

Structural and ultrastructural characterization of the embryonic development of Pseudoplatystoma spp. hybrids

The hybrid fish Pseudoplatystoma spp. has been raised on a large scale by several fish farmers, despite the fact that little is known about its biology. This is because it presents a number of zootechnical advantages over the parental species. In order to provide information about the early morphology of this important species, we analyzed the fertilization and embryonic development of the hybrid between spotted females and barred males of sorubim specimens by light microscopy and by scanning (SEM) and transmission electron microscopy (TEM) after induced spawning. Samples were collected at pre-established moments up to larval hatching. Seven distinct stages of hybrid embryonic development were identified: zygote, cleavage, morula, blastula, gastrula, histogenesis and organogenesis, and hatching. Under SEM, we observed spermatozoa at the micropyle entrance, the formation of a fertilization cone in the eggs, the differentiation of cephalic and caudal regions, the neural tube and embryo growth along the cephalo-caudal axis, as well as rudimentary optic vesicle and barbels. Under light microscopy, cytoplasmic movement was apparent with the consequent formation of animal and vegetative poles in eggs, in addition to epiboly movements and a small notochord portion. Under TEM, the oocyte chorion and eggs presented a sieve-like aspect in transversal cuts, coupled with the rupture of cortical alveoli and chorion elevation, thus enlarging the perivitelline space. Several mitochondria in the cortical cytoplasm were detected in both oocytes and eggs. Overall, we observed that the larvae hatched without visible morphological alterations, and seemed to be as viable in captive systems as they are in the natural environment

Resveratrol, by Modulating RNA Processing Factor Levels, Can Influence the Alternative Splicing of Pre-mRNAs

Alternative pre-mRNA splicing defects can contribute to, or result from, various diseases, including cancer. Aberrant mRNAs, splicing factors and other RNA processing factors have therefore become targets for new therapeutic interventions. Here we report that the natural polyphenol resveratrol can modulate alternative splicing in a target-specific manner. We transfected minigenes of several alternatively spliceable primary mRNAs into HEK293 cells in the presence or absence of 1, 5, 20 and 50 µM resveratrol and measured exon levels by semi-quantitative PCR after separation by agarose gel electrophoresis. We found that 20 µg/ml and 50 µg/ml of resveratrol affected exon inclusion of SRp20 and SMN2 pre-mRNAs, but not CD44v5 or tau pre-mRNAs. By Western blotting and immunofluorescence we showed that this effect may be due to the ability of resveratrol to change the protein level but not the localization of several RNA processing factors. The processing factors that increased significantly were ASF/SF2, hnRNPA1 and HuR, but resveratrol did not change the levels of RBM4, PTBP1 and U2AF35. By means of siRNA-mediated knockdown we depleted cells of SIRT1, regarded as a major target of resveratrol, and showed that the effect on splicing was not dependent on SIRT1. Our results suggest that resveratrol might be an attractive small molecule to treat diseases in which aberrant splicing has been implicated, and justify more extensive research on the effects of resveratrol on the splicing machinery

Desenvolvimento embrionário e larval de Brycon gouldingi (Teleostei, Characidae)

Brycon gouldingi é uma espécie endêmica da Bacia Tocantins-Araguaia e estudos acerca de sua biologia e desenvolvimento ontogenético não se encontram na literatura. Analises morfométrica e morfológica dos períodos embrionário e larval desta espécie contribuirão para o conhecimento de sua biologia e potencial para o cultivo. Para este trabalho, foram capturados exemplares adultos da espécie, provenientes do Rio das Mortes - MT, principal afluente do Rio Araguaia e adaptados em cultivo por cerca de sete meses. Dez coletas foram realizadas na Piscicultura Buriti, Nova Mutum — MT, nos meses de dezembro de 2007 e janeiro de 2008, apos a reprodução induzida dos exemplares, sendo feitas amostragens nos seguintes tempos: extrusão, fertilização (tempo zero), 10, 20 e 30 segundos, 1 min, 1 min e 30s, a cada minuto ate completar 10min, a cada 5min ate atingir 30min, aos 45min, de hora em hora ate completar 24 horas, a cada 2 horas ate completar 48 horas e a cada 3 horas ate a absorção total do vitelo. Ovócitos, ovos, embriões e larvas foram observados em estereomicroscópio, microscopia eletrônica de varredura e microscopia de luz. Foi realizada também a morfometria dos ovócitos liberados por cada fêmea e das larvas desde o momento da eclosão ate a absorção total do vitelo, registrando-se valores de comprimento total da larva, altura e comprimento do saco vitelínico. A temperatura media da água nas incubadoras foi de 26,4±1,12 °C. 0 diâmetro dos ovócitos foi de 1,13±0,06 mm e 54% deles possuíam entre 1,11 e 1,20 mm. 0 período embrionário teve uma duração media de 13,9±0,06 horas pós-fertilização (hpf) sendo dividido em sete fases (zigoto,'1. clivagem, mórula, blástula, gástrula, histogênese/organogênese...Brycon gouldingi is an endemic species of Tocantins-Araguaia basin and studies about its biology and ontogenetic development are not available in the literature. Morphometric and morphological analyses of embryonic and larval stages of this species will increase the knowledge about its biology and aquaculture potential. To perform this work, adult specimens from Mortes River- MT, the main tributary of Araguaia River were collected and adapted to captivity for seven months. Ten collections were carried out at Buriti Fishculture, Nova Mutum — MT, between December 2007 and January 2008, after induced spawning, comprising samplings in the following periods: extrusion, fertilization (time zero), 10, 20 and 30 seconds, lmin, lmin e 30s, at each minute up to 10min, each 5min up to 30min, at 45min, each hour up to 24 hours, each 2 hours up to 48 hours and each 3 hours up to total yolk absorption. Oocytes, eggs, embryos and larvae were observed under stereomicroscope, scanning electron microscope and light microscope. Morphometry analyses were also performed in the oocytes released by each female and in the oocytes up to total yolk absorption taking into account total larval length, yolk sac height and length values. The mean water temperature in the incubators was 26.4±1.12 °C. The oocyte diameter was equal to 1.13±0.06 mm and 54% of them were between 1.11 and 1.20 mm. The mean duration of the embryonic period was 13.9±0.06 hours post-fertilization (hpf) being divided into seven stages (zygote, cleavage, blastula, gastrula, histogenesis/organogenesis and hatching). At hatching, the total larval length was equal to 3.40±0.07 mm and the yolk sac volume was 0.46±0.081.iL. During the larval development, the appearance of adhesive organs on the cephalic dorsal region plus heart... (Complete abstract click electronic access below)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Parâmetros seminais, ultraestruturais, criopreservação e androgênese de espécies do gênero Brycon ameaçadas de extinção

The doctoral thesis consisted of three main chapters besides the “General Introduction”, which includes a bibliographic review of the species studied and the topics discussed, and the “Final Remarks”. Scientific research articles will be published from the data of the three chapters in the scientific journals listed in the index. The first scientific article (Chapter I) describes the seminal parameters and the spermatozoa structure of Brycon vermelha, “vermelha” (Characiformes, Characidae). The semen of the Brycon vermelha is viscous and contains, in average, 4.34 ± 0.75x1010 spermatozoa.mL-1. Spermatozoa motility was of short duration when activated with distilled water, 46.48 ± 0.07 seconds until 100% of spermatozoa lost their motility. Scanning transmission electron microscopy (STEM) of spermatozoa revealed three distinctive parts: head, middle piece and tail (flagellum). Each part was analysed in detail by transmission electron microscopy (TEM). The characteristics observed suggest that the spermatozoa of B. vermelha posses ancestral characteristics of fish that reproduce by external fertilization, and can thus be classified as “uniflagellate anacrosomal aquasperms”, or aquasperms Type I. These are the first reports on B. vermelha semen and spermatozoa and, therefore, could be used as a reference and benchmark for research studies using biotechniques such as cryopreservation and androgenesis. The second scientific article (Chapter II) describes the ultrastructural alterations of Brycon orbignyanus, “piracanjuba” (Characiformes, Characidae) spermatozoa after cryopreservation. Spermatozoa were cryopreserved for 1 day, 1 month or 1 year in solutions containing DMSO, methyl glycol and methanol. The ultrastructural analysis of the frozen-thawed spermatozoa revealed alterations varying from small damages to the different parts of the cell to total destruction of spermatozoa ...A Tese de Doutorado foi estruturada em três capítulos, além da “Introdução Geral”, que abrange uma revisão bibliográfica das espécies em estudo e dos temas abordados, e das “Considerações Finais”. Os três capítulos darão origem a artigos científicos em revistas indexadas. O primeiro artigo (Capítulo I) descreve os parâmetros seminais e a ultraestrutura dos espermatozoides de Brycon vermelha, “vermelha” (Characiformes, Characidae). O sêmen da B. vermelha possuiu consistência viscosa, e concentração espermática média de 4,34 ± 0,75x1010 espermatozoides.mL-1. O tempo de motilidade espermática, quando ativado com água destilada, foi curto, sendo necessários 46,48 ± 0,07 segundos para perda da motilidade de 100% dos espermatozoides. A análise dos espermatozoides por MEV revelou três regiões distintas: cabeça, peça intermediária e flagelo, sendo cada região caracterizada detalhadamente em MET. Tais características sugerem que os espermatozoides de B. vermelha apresentam características ancestrais próprias de peixes com fecundação externa classificando-os como “espermatozoides aquáticos uniflagelados anacrossomais”, ou seja, aquasperm do Tipo I. Estas informações são as primeiras em relação ao sêmen e espermatozoides de B. vermelha, podendo ser uma referência para futuros estudos, embasando especialmente pesquisas que adotem biotécnicas, como a criopreservação e androgênese. O segundo artigo (Capítulo II) descreve, ultraestruturalmente, as alterações dos espermatozoides da Brycon orbignyanus, “piracanjuba” (Characiformes, Characidae) durante o processo de criopreservação. O exame ultraestrutural dos espermatozoides descongelados criopreservados em soluções contendo DMSO, metilglicol e metanol, em três tempos de armazenamento (1 dia, 1 mês e 1 ano), revelou a presença de alterações no espermatozoide, variando desde ..

Brycon gouldingi (Teleostei, Characidae): aspects of the embryonic development in a new fish species with aquaculture potential

Brycon gouldingi is an endemic species from Tocantins-Araguaia basin, used as a food source by riverine communities and relevant to aquaculture. Information about the initial morphology of B. gouldingi, a recently described species, is absent. In the present study, we analysed the fertilization and the embryonic development of this species based on light and scanning electron microscopy. After collection of adult specimens in Mortes River - Mato Grosso, Brazil, adaptation to captivity and induced spawning at Buriti Fishculture, Nova Mutum - Mato Grosso, Brazil, in December 2007 and January 2008, samples were collected at pre-defined periods from egg extrusion up to larval hatching, which occurred at 13.9 +/- 0.06 h post-fertilization (hpf) in average. At the moment of extrusion, the eggs were slightly ovoid bearing a single micropyle per oocyte with a funnel-shaped micropyle canal and vestibule covered with longitudinal folds, typical of the genus Brycon. The embryonic development of B. gouldingi was characterized by six stages with distinct features: zygote (from fertilization up to formation of egg-cell); cleavage (cell divisions resulting in blastomeres, including the morula phase); blastula (several embryonic cells in a cup shape, without distinction of cell boundaries); gastrula (cell movement); histogenesis/organogenesis (formation of tissues and organs); and hatching (larval chorion rupture). Right after hatching, the larvae presented neither swimming abilities nor visual accuracy, and the digestive trait was undifferentiated. The present study is the first report on biological features of embryogenesis in B. gouldingi, providing relevant information to several approaches, mainly related to taxonomy, ecology, conservation and captive rearing of this new Brycon species.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Fertilização e desenvolvimento embrionário: Morfometria e análise estereomicroscópica dos ovos dos híbridos de surubins (pintado, Pseudoplatystoma corruscans x cachara, Pseudoplatystoma fasciatum)

This study aimed to analyze the morphometry of hybrids' eggs under stereomicroscopy. The induced reproduction was carried out in specimens of pintado's females (P. corruscans) and cachara's males (P. fasciatum) from Cepta - Ibama, Pirassununga, state of São Paulo, Brazil. Samples were collected in extrusion moment, during the fertilization, in times of 10 and 30 seconds, 1, 2, 5, 8, 10, 15, 20, 30 and 45 minutes, 1 hour, at every 15 minutes until completing 2 hours, and afterwards, at every hour until the larval hatching. Oocytes and eggs' external morphology were observed, photographed and 30 samples from each moment were measured in stereomicroscopy. Oocytes, in the time of extrusion, and the eggs presented a spherical form and yellowish color. Characteristics such as wide perivitelinic space, somites, presence of optical vesicle and the main phases of embryonic development as egg-cell (blastodisc), 2, 4, 8, 16, 32 and 64 blastomeres, morula, blastula, gastrula, epiboly movements, formation and larvae hatching were verified

Fertilização e desenvolvimento embrionário: morfometria e análise estereomicroscópica dos ovos dos híbridos de surubins (pintado, Pseudoplatystoma corruscans x cachara, Pseudoplatystoma fasciatum) = Fertilization and embrionary development: morphometry and stereomicroscopic analysis of hybrids’ eggs from surubins (pintado, Pseudoplatystoma corruscans and cachara, Pseudoplatystoma fasciatum)

O objetivo deste estudo foi analisar a morfometria dos ovos dos híbridos sob estereomicroscópio. Foi realizada a reprodução induzida em exemplares de fêmeas de pintado (P. corruscans) e de machos de cachara (P. fasciatum) do Cepta - Ibama, Pirassununga, Estado de São Paulo, Brasil. As amostras foram coletadas no momento da extrusão, durante a fertilização, nos tempos 10 e 30 segundos, 1, 2, 5, 8, 10, 15, 20, 30 e 45 minutos, 1 hora, a cada 15 minutos até completar 2 horas e depois a cada hora até a eclosão da larva. Ovócitos e ovos foram observados quanto à morfologia externa, fotografados e 30 amostras de cada momento foram medidas em estereomicroscópio. Os ovócitos, no momento da extrusão, eos ovos apresentaram formato esférico e coloração amarelada. As características observadas foram: amplo espaço perivitelínico, somitos, presença da vesícula. As principais fases do desenvolvimento embrionário como célula-ovo (blastodisco), 2, 4, 8, 16, 32 e 64 blastômeros, mórula, blástula, gástrula e eclosão da larva também foram verificadas.This study aimed to analyze the morphometry of hybrids’ eggs under stereomicroscopy. The induced reproduction was carried out in specimens of pintado’s females (P. corruscans) and cachara’smales (P. fasciatum) from Cepta - Ibama, Pirassununga, state of São Paulo, Brazil. Samples were collected in extrusion moment, during the fertilization, in times of 10 and 30 seconds, 1, 2, 5, 8, 10, 15, 20, 30 and 45 minutes, 1 hour, at every 15 minutes until completing 2hours, and afterwards, at every hour until the larval hatching. Oocytes and eggs’ external morphology were observed, photographed and 30 samples from each moment were measured in stereomicroscopy. Oocytes, in the time of extrusion, and the eggs presented aspherical form and yellowish color. Characteristics such as wide perivitelinic space, somites, presence of optical vesicle and the main phases of embryonic development as egg-cell (blastodisc), 2, 4, 8, 16, 32 and 64 blastomeres, morula, blastula, gastrula, epibolymovements, formation and larvae hatching were verified