Abstract Groupers (Epinephelidae and Serranidae) have attracted special attention to fish farming, and their species offer good opportunities for successful hybridizations. Cytogenetic data allow a better understanding of the role of karyotypic diversification in the acquisition of post-zygotic reproductive isolation (RI). Thus, chromosomal analyses were performed on E. striatus (Caribbean Sea), E. coioides and E. tauvina (Indo-Pacific Region), using standard procedures and mapping of six repetitive DNA classes by the in situ hybridization. The three species have 2n=48 chromosomes. The karyotypes of E. coioides and E. striatus are composed only of acrocentric chromosomes (FN=48), while E. tauvina has 8 submetacentric chromosomes (FN=56). Heterochromatin has a preferential centromeric distribution, and the microsatellite repeats are dispersed throughout the chromosomes of all species. The 18S and 5S rDNA sites are unique but show a colocalization arrangement in E. tauvina and E. striatus. The chromosomal organization suggests that the three species still maintain a significant amount of syntenic regions. The range of the karyotype divergence and the RI levels showed low, but goes turn proportionally greater in relation to the divergence time between the parental species. The slow acquisition of postzygotic RI is consistent with the high karyotype homogeneity presented by Epinephelidae family. Serranidae farming hybridizations post zygotic RI. . (RI) Thus E Caribbean Sea, Sea , Sea) IndoPacific Indo Pacific Region, Region Region) hybridization 2n48 n 2n 48 2n=4 FN=48, FN48 FN FN=48 (FN=48) FN=56. FN56 FN=56 56 (FN=56) distribution S regions low family (RI 2n4 4 2n= FN4 FN=4 (FN=48 FN5 FN=5 5 (FN=56 FN= (FN=4 (FN=5 (FN= (FN

Epinephelidae forma um grupo de espécies de grande interesse biológico e econômico. Seus padrões filogeográficos são pouco conhecidos, principalmente nas populações distribuídas na região oeste do Oceano Atlântico. Entre seus representantes está a pequena espécie Cephalopholis fulva, Coney, a qual apresenta ampla distribuição geográfica, policromia e hermafroditismo, além de estar se tornando um alvo crescente da exploração pesqueira comercial. Os dados genéticos e histórico-demográficos foram obtidos através da análise de sequências parciais da Região Controle de seis localidades do litoral brasileiro, desde o Nordeste até o Sudeste do Brasil, incluindo as ilhas oceânicas do Atol das Rocas e do arquipélago Fernando de Noronha. As amostras analisadas revelaram uma alta variabilidade genética e um forte fluxo gênico entre as localidades amostradas. Além disso, os dados genéticos relevaram expansões populacionais provavelmente relacionadas às mudanças no nível do mar ocorridas durante o Pleistoceno. A ampla conectividade populacional presente em Coney constitui uma condição relevante para a sua conservação biológica.

The Epinephelidae form a group of species of high biological and economical interests. It´s phylogeographic patterns are not well known especially the distributed populations in the western region of the Atlantic Ocean. Among the representatives is a small species called Cephalopholis fulva, Coney, which presents a wide geographical distribution, polychromia, hermaphroditism and is quickly becoming a large target for the exploration of commercial fishing. The genetic and historical demography were obtained through the partial sequence analysis of Control Region from six locations on the coastline of Brazil from the northeast coast to the southwest coast, including the oceanic islands of Rocas Atoll and Fernando de Noronha Archipelago. The analyzed samples revealed a high genetic variability and a strong gene flow among the sampled locations. Additionally, the genetic data revealed that population expansions probably occurred due to the changes in the sea levels that occurred during the Pleistocene. The large population connectivity found in Coney constitutes relevant conditions for their biological conservation.

Mecanismos de acúmulo baseados em deriva centromérica típica ou de cromossomos portadores de inversões pericêntricas mostram-se adequados à diferenciação cariotípica mais ampla nas principais ordens de Actinopterygii. Aqui nós mostramos que a deriva meiótica nos peixes é também apoiada pela fixação preferencial de sistemas de cromossomos sexuais e cromossomos B em ordens com cariótipos predominantemente formados por elementos bi-braquiais. O mosaico de tendências cromossômicas que atuam em nível infra-familiar em peixes poderia ser explicado pela interação do processo direcional de deriva meiótica agindo como pano de fundo, modulada em menor escala por fatores adaptativos ou propriedades cariotípicas específicas de cada grupo, conforme proposto pelo modelo de ortoseleção.

Mechanisms of accumulation based on typical centromeric drive or of chromosomes carrying pericentric inversions are adjusted to the general karyotype differentiation in the principal Actinopterygii orders. Here, we show that meiotic drive in fish is also supported by preferential establishment of sex chromosome systems and B chromosomes in orders with predominantly bi-brachial chromosomes. The mosaic of trends acting at an infra-familiar level in fish could be explained as the interaction of the directional process of meiotic drive as background, modulated on a smaller scale by adaptive factors or specific karyotypic properties of each group, as proposed for the orthoselection model.

Cancer constitutes the second main mortality cause in the world, after cardiovascular diseases. In spite of the progresses in the chemotherapeutics treatments, many patients fail chemotherapy, mainly because of side effects or multi-drugs resistance, proving the need and importance of the research for new molecules with anticancer activity, more effective and with smaller adverse effects. Various compounds derived from plant secondary metabolites are commonly used in the chemotherapy against cancer and the natural products play an important role in the research for new molecules. Among several molecules of natural origin evaluated by MTT assay in murine tumor cell lines [breast (LM3) and lung (LP07)] the quinona-methide triterpenes tingenone and pristimerin showed marked cytotoxic activity presenting IC50 around 2 and 5 µM respectively. The structure-activity relationship suggests that rings A and B containing an α, ß-unsaturated carbonyl group are essential for the observed cytotoxic activity. The interaction between these positions and acetylcisteyne residues suggests a probable mechanism of action. The in vitro mutagenic activity was also evaluated by the Salmonella microsome assay (Ames test) for pristimerin and tingenone with and without metabolic activation (S9) in the strains TA98, TA97a, TA100 and TA102, none of which showed mutagenic potential in any strains. Estrogenic and anti-estrogenic activities were also studied by the e-screen assay in MCF-7 cells with negative results. The present data point to the importance of pristimerin and tingenone as representative of an emerging class of potential anticancer chemicals.

Cytogenetic studies were done on three Pomacentridae species of the genus Chromis. The karyotype of C. multilineata consisted of 48 acrocentric chromosomes (FN = 48), C. insolata had 2n = 46-47 (3-4M+6SM+36-38A; FN = 56) and C. flavicauda had 2n = 39 (9M+6SM+24A; FN = 54). Robertsonian polymorphisms were detected in C. insolata and C. flavicauda. All three species had small heterochromatic blocks restricted to centromeric regions. Nucleolar organizer regions (NORs) were detected in the telomeric position of a medium acrocentric chromosome pair in C. multilineata and in non-homologous chromosomes in both C. flavicauda and C. insolata. FISH with a telomeric probe detected no internal telomeric sequences in C. flavicauda and C. insolata. 5S rRNA genes were observed in a pericentromeric region of two large metacentric chromosome pairs in C. flavicauda and two large acrocentric pairs in C. insolata. The karyotype structure and the number and location of the 5S rDNA loci in these two species indicated that the 5S rRNA-bearing acrocentric chromosomes were directly involved in the origin of the polymorphisms observed. These data reinforce the idea that Robertsonian rearrangements have been involved in molding the karyotype in the subfamily Chrominae.