The outstanding biodiversity of the Guiana Shield has raised many questions about its origins and evolution. Frogs of the genera Adelastes, Otophryne and Synapturanus form an ancient lineage distributed mostly across this region. These genera display strikingly disparate morphologies and life-history traits. Notably, Synapturanus is conspicuously adapted to fossoriality and is the only genus within this group to have dispersed further into Amazonia. Moreover, morphological differences among Synapturanus species suggest different degrees of fossoriality that might be linked to their biogeographical history. Through integrative analysis of genetic, morphometric and acoustic data, we delimited 25 species in this clade, representing a fourfold increase. We found that the entire clade started to diversify ~55 Mya and Synapturanus ~30 Mya. Members of this genus probably dispersed three times out of the Guiana Shield both before and after the Pebas system, a wetland ecosystem occupying most of Western Amazonia during the Miocene. Using a three-dimensional osteological dataset, we characterized a high morphological disparity across the three genera. Within Synapturanus, we further characterized distinct phenotypes that emerged concomitantly with dispersals during the Miocene and possibly represent adaptations to different habitats, such as soils with different physical properties.

Summary Specimens of 4 marine fish species 3 from genus Trachinotus, T. carolinus, T. falcatus, T. goodei, and 1 from genus Selene, S. vomer belonging to the family Carangidae (Perciformes) were analyzed. All the specimens analyzed inhabit the South/Southeast coast of Brazil, and were sampled from the locality São Sebastião, SP. The 4 species presented 2nϭ48 chromosomes, being the chromosome formula for Selene vomer 46Aϩ2ST, T. carolinus 8MSMϩ40A, T. falcatus 38Aϩ10MSM and T. goodei 4MSMϩ44A chromosomes. The 4 species presented 1 pair of NORs. Small blocks of heterochromatin were found in these 4 species. The karyotypic characteristics of these species were discussed in comparison with other species and populations of Perciformes already analysed. The cytogenetic analysis of fish species is well advanced for the freshwater fish that inhabit Brazilian rivers, and a growing number of species is being analyzed, so that an expressive amount of information is currently available for this group. This fact results in a great amount of data about the evolutionary relationship of species and genera of freshwater species. In some cases, the cytogenetic information associated with molecular markers was used in the description of new species (Albert et al. 1999). When compared with the amount of data available for freshwater fish species from the Neotropical region, the cytogenetic information about marine fishes from the Brazilian coast is still incipient. Key wordsIn a preliminary analysis of Trachinotus carried out by Zeinad and Almeida-Toledo (1994) the chromosome number and morphology for T. carolinus and T. falcatus were established. Pauls et al. (1998) and Netto et al. (1998) described respectively the karyotype of T. goodei and the chromosome number and formula of Selene volmer. All these analysis were performed using conventional Giemsa staining. However, no data about the C-banding pattern of heterochromatin or nucleolus or-

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is caused by a respiratory virus with a wide range of manifestations, varying from asymptomatic to fatal cases, with a generally short outcome. However, some individuals present long-term viral shedding. We monitored 38 individuals who were mildly affected by the SARS-CoV-2 infection. Out of the total studied population, three (7.9%) showed atypical events regarding the duration of positivity for viral RNA detection. In one of these atypical cases, a previously HIV-positive male patient presented a SARS-CoV-2 RNA shedding and subgenomic RNA (sgRNA) detected from the upper respiratory tract, respectively, for 232 and 224 days after the onset of the symptoms. The SARS-CoV-2 B.1.1.28 lineage, one of the most prevalent in Brazil in 2020, was identified in this patient in three serial samples. Interestingly, the genomic analyses performed throughout the infectious process showed an increase in the genetic diversity of the B.1.1.28 lineage within the host itself, with viral clearance occurring naturally, without any intervention measures to control the infection. Contrasting widely spread current knowledge, our results indicate that potentially infectious SARS-CoV-2 virus might be shed by much longer periods by some infected patients. This data call attention to better adapted non-pharmacological measures and clinical discharge of patients aiming at preventing the spread of SARS-CoV-2 to the population.

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Deixo registrado aqui os meus mais sinceros agradecimentos a todos que, direta ou indiretamente, contribuíram para a realização deste trabalho. Foram muitas as pessoas que participaram ou colaboraram de alguma forma na execução deste, as quais sou muito grata, seja pelo apoio técnico e científico, ou ainda pelo incentivo, amizade e carinho, por vezes tão necessários! E desde já aviso que a lista é grande... À Prof. a Dr a Lurdes Foresti de Almeida-Toledo, por tudo que resume nossos sete anos de convivência. Pelo acolhimento, pela disposição e orientação, mas sobretudo, pela confiança e pela oportunidade. Aos professores do Departamento de Genética e Biologia Evolutiva e do Departamento de Zoologia, agora que minha vida passou a ser dividida por essas duas grandes áreas do conhecimento, agradeço pela minha formação científica, pela qualidade do programa de Pós-graduação da USP e pelos ensinamentos, tanto profissional quanto pessoal. Em especial, agradeço ao Prof. Dr. Miguel Trefaut U. Rodrigues e Prof. Dr. Antônio Carlos Marques, meus chefes diretos no Departamento de Zoologia, principalmente pela compreensão com o meu estado de doutoranda. E ao Prof. Dr. Fernando Portella de Luna Marques por tantas coisas... desde a fase inicial de excecução do projeto, pela ajuda com o desenho experimental de primers, otimização das reações de amplificação e seqüenciamento, pela paciência com minhas discussões sobre os métodos de análises, disponibilização do cluster, enfim, do começo ao fim desse projeto sua ajuda foi inestimável.

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This work aimed to study the role of different SARS-CoV-2 lineages in the epidemiology of multiple waves of the COVID-19 pandemic in Ribeirão Preto (São Paulo state), with comparison within Brazil and globally. Viral genomic sequencing was combined with clinical and sociodemographic information of 2,379 subjects at a large Brazilian hospital. On the whole 2,395 complete SARS-CoV-2 genomes were obtained from April 2020 to January 2022. We report variants of concern (VOC) and interest (VOI) dynamics and the role of Brazilian lineages. We identified three World Health Organization VOCs (Gamma, Delta, Omicron) and one VOI (Zeta), which caused distinct waves in this cohort. We also identified 47 distinct Pango lineages. Consistent with the high prevalence of Gamma in Brazil, Pango lineage P.1 dominated infections in this cohort for half of 2021. Each wave of infection largely consisted of a single variant group, with each new group quickly and completely rising to dominance. Despite increasing vaccination in Brazil starting in 2021, this pattern was observed throughout the study and is consistent with the hypothesis that herd immunity tends to be SARS-CoV-2 variant-specific and does not broadly protect against COVID-19.