Molecular phylogeny of the tribe Philodryadini Cope, 1886 (Dipsadidae: Xenodontinae): Rediscovering the diversity of the South American Racers

Abstract South American racers of the tribe Philodryadini are a widespread and diverse group of Neotropical snakes with a complex taxonomic and systematic history. Recent studies failed to present a robust phylogenetic hypothesis for the tribe, mainly due to incomplete taxon sampling. Here we provide the most extensive molecular phylogenetic analysis of Philodryadini available so far, including 20 species (83% of the known diversity) from which six were not sampled previously. Our results reveal that Philodryadini is not monophyletic, but instead includes a central Andean clade formed by Philodryas simonsii, P. tachymenoides, and P. amaru, and a southern and cis-Andean clade including all remaining philodryadines. This discovery requires resurrection of two genera as well as erection of a new tribe of Xenodontinae for the central Andean clade. Within the southern and cis-Andean radiation, our analyses resolve a basal dichotomy separating two main lineages: Clade A, containing the Common Green Racers P. laticeps and P. viridissima and the South American Vine snakes P. georgeboulengeri and P. argentea; and Clade B, including the remaining species of Philodryas sensu stricto. We resurrect the genera Chlorosoma and Xenoxybelis to better represent the monophyly of lineages within the southern and cis-Andean clade.

Molecular phylogeny of the tribe Philodryadini Cope, 1886 (Dipsadidae: Xenodontinae): Rediscovering the diversity of the South American Racers

South American racers of the tribe Philodryadini are a widespread and diverse group of Neotropical snakes with a complex taxonomic and systematic history. Recent studies failed to present a robust phylogenetic hypothesis for the tribe, mainly due to incomplete taxon sampling. Here we provide the most extensive molecular phylogenetic analysis of Philodryadini available so far, including 20 species (83% of the known diversity) from which six were not sampled previously. Our results reveal that Philodryadini is not monophyletic, but instead includes a central Andean clade formed by Philodryas simonsii, P. tachymenoides, and P. amaru, and a southern and cis-Andean clade including all remaining philodryadines. This discovery requires resurrection of two genera as well as erection of a new tribe of Xenodontinae for the central Andean clade. Within the southern and cis-Andean radiation, our analyses resolve a basal dichotomy separating two main lineages: Clade A, containing the Common Green Racers P. laticeps and P. viridissima and the South American Vine snakes P. georgeboulengeri and P. argentea; and Clade B, including the remaining species of Philodryas sensu stricto. We resurrect the genera Chlorosoma and Xenoxybelis to better represent the monophyly of lineages within the southern and cis-Andean clade.

Molecular phylogeny of the tribe Philodryadini Cope, 1886 (Dipsadidae: Xenodontinae): Rediscovering the diversity of the South American Racers

South American racers of the tribe Philodryadini are a widespread and diverse group of Neotropical snakes with a complex taxonomic and systematic history. Recent studies failed to present a robust phylogenetic hypothesis for the tribe, mainly due to incomplete taxon sampling. Here we provide the most extensive molecular phylogenetic analysis of Philodryadini available so far, including 20 species (83% of the known diversity) from which six were not sampled previously. Our results reveal that Philodryadini is not monophyletic, but instead includes a central Andean clade formed by Philodryas simonsii, P. tachymenoides, and P. amaru, and a southern and cis-Andean clade including all remaining philodryadines. This discovery requires resurrection of two genera as well as erection of a new tribe of Xenodontinae for the central Andean clade. Within the southern and cis-Andean radiation, our analyses resolve a basal dichotomy separating two main lineages: Clade A, containing the Common Green Racers P. laticeps and P. viridissima and the South American Vine snakes P. georgeboulengeri and P. argentea; and Clade B, including the remaining species of Philodryas sensu stricto. We resurrect the genera Chlorosoma and Xenoxybelis to better represent the monophyly of lineages within the southern and cis-Andean clade.(AU)

Reprodução em crotalíneos: Uterine Muscular Twisting in vivo

Algumas serpentes necessitam obrigatoriamente estocar espermatozoides nos ovidutos para que os oócitos sejam fecundados, isso porque nessas espécies o período de cópula é distinto do período de ovulação. Em geral essa estocagem ocorre em receptáculos de estocagem encontrados na região infundibular. Em Crotalíneos a estocagem tem sido descrita como ocorrendo na região caudal dos ovidutos (junção útero-vaginal) em uma estrutura chamada de Uterine Muscular Twisting (UMT). Essa estrutura tem sido descrita como um twisting que se forma após a cópula e permanece presente até o momento da ovulação. Aqui demonstramos que a UMT não é formado por uma torção (twist) do oviduto e sim por uma helicoide formada pelas camadas internas da junção útero-vaginal. A UMT está presente em fêmeas ao longo de todo o ano, e não somente no período pós-cópula. Nós observamos que a UMT tem diferentes graus de formação, podendo ser forte, fraca ou ausente. A UMT forte é encontrada no periodo reprodutivo da fêmea (outono e inverno austrais) e está presente independentemente de haver espermatozoides nessa região. A UMT fraca é encontrada em todas as fêmeas maduras fora do período reprodutivo. Já a ausencia de UMT é encontrada nas fêmeas prenhes e nas imaturas. Nossos resultados mostram que a UMT é formada mesmo em fêmeas ovariectomizadas com níveis basais de estradiol e que a progesterona é responsável pelo relaxamento da musculatura lisa do oviduto tornando a UMT ausente nas fêmeas.

Some snakes need must store sperm in the oviduct so that the oocytes are fertilized, that because these species the mating period is distinct from ovulation period. Usually this occurs in receptacles found in the infundibular region. In pitvipers the storage has been described as occurring in the caudal region of oviduct (uterus-vaginal junction) in a structure named Uterine Muscular Twisting (UMT). This structure has been described as a twisting formed after mating and remains present until the time of ovulation. Here we demonstrate that the UMT is not formed by a twist (rotation around its own axis) of the oviduct but by a helicoid formed by the inner layers of the uterus-vaginal junction. The UMT is present in females throughout the whole year, not only in the post-copulation period. We note that the UMT has different degrees of shaping, can be strong, weak or absent. Strong UMT is found in the female reproductive period (austral autumn and winter) and is present regardless of whether sperm cells in this region. Weak UMT is found in all mature females outside the breeding season. Already the absence of UMT is found in pregnant females and the immature ones. Our results show that the UMT is formed even in ovariectomized with basal levels of estradiol and progesterone is responsible for relaxation of smooth muscle of the oviduct making UMT absent in females.

Food habits of Anilius scytale (Serpentes: Aniliidae) in the Brazilian Amazonia

Information on the diet of Anilius scytale is provided based on the analysis of 162 specimens from the Brazilian Amazonia. Amphisbaenians (Aulura anomala Barbour, 1914; Leposternon polystegumn [Duméril, 1951] and Amphisbaena sp.), which are highly specialized for a fossorial life, accounted for 81.25% of the recorded items, followed by snakes - Anilius scytale (Linnaeus, 1758), and Tantilla melanocephala (Linnaeus, 1758): 12.5% - and caecilians - Caecilia cf. gracilis Shaw, 1802: 6.25%. We found a positive, although not significant, relationship between the snout-vent length of A. scytale and the total length of the prey and a tendency for smaller specimens to ingest proportionately larger prey. Anilius scytale forages mainly on the ground, at night, as well as in aquatic environments. The non-selective capture of either proportionately large or small prey by A. scytale may reflect the opportunistic nature of the encounters. A tendency of the juveniles of this species to ingest proportionately larger prey may be associated with either a low availability of prey with a size compatible to that of the juveniles, or with their inexperience in selecting prey. Ingestion of prey headfirst may be an attempt to minimize the risk of injury the prey could cause through their rigid, pointed and sharp structures or powerful bites.

Food habits of Anilius scytale (Serpentes: Aniliidae) in the Brazilian Amazonia

Information on the diet of Anilius scytale is provided based on the analysis of 162 specimens from the Brazilian Amazonia. Amphisbaenians (Aulura anomala Barbour, 1914; Leposternon polystegumn [Duméril, 1951] and Amphisbaena sp.), which are highly specialized for a fossorial life, accounted for 81.25% of the recorded items, followed by snakes - Anilius scytale (Linnaeus, 1758), and Tantilla melanocephala (Linnaeus, 1758): 12.5% - and caecilians - Caecilia cf. gracilis Shaw, 1802: 6.25%. We found a positive, although not significant, relationship between the snout-vent length of A. scytale and the total length of the prey and a tendency for smaller specimens to ingest proportionately larger prey. Anilius scytale forages mainly on the ground, at night, as well as in aquatic environments. The non-selective capture of either proportionately large or small prey by A. scytale may reflect the opportunistic nature of the encounters. A tendency of the juveniles of this species to ingest proportionately larger prey may be associated with either a low availability of prey with a size compatible to that of the juveniles, or with their inexperience in selecting prey. Ingestion of prey headfirst may be an attempt to minimize the risk of injury the prey could cause through their rigid, pointed and sharp structures or powerful bites.

Food habits of Anilius scytale (Serpentes: Aniliidae) in the Brazilian Amazonia

Information on the diet of Anilius scytale is provided based on the analysis of 162 specimens from the Brazilian Amazonia. Amphisbaenians (Aulura anomala Barbour, 1914; Leposternon polystegumn [Duméril, 1951] and Amphisbaena sp.), which are highly specialized for a fossorial life, accounted for 81.25% of the recorded items, followed by snakes - Anilius scytale (Linnaeus, 1758), and Tantilla melanocephala (Linnaeus, 1758): 12.5% - and caecilians - Caecilia cf. gracilis Shaw, 1802: 6.25%. We found a positive, although not significant, relationship between the snout-vent length of A. scytale and the total length of the prey and a tendency for smaller specimens to ingest proportionately larger prey. Anilius scytale forages mainly on the ground, at night, as well as in aquatic environments. The non-selective capture of either proportionately large or small prey by A. scytale may reflect the opportunistic nature of the encounters. A tendency of the juveniles of this species to ingest proportionately larger prey may be associated with either a low availability of prey with a size compatible to that of the juveniles, or with their inexperience in selecting prey. Ingestion of prey headfirst may be an attempt to minimize the risk of injury the prey could cause through their rigid, pointed and sharp structures or powerful bites.

Estudo do potencial citotóxico do veneno da serpenteCrotalus Durissus Cascavella em adenocarcinoma ovariano – OVCAR-88

Nas últimas décadas o câncer alcançou grande dimensão, sendo considerado um problema de saúde publica a nível mundial, representando uma das principais causas de morte no mundo. As serpentes do gênero Crotalus vêm ganhando espaço significativo no campo científico, pois pesquisas realizadas com seu veneno estão demostrando que este apresenta mecanismos envolvidos em atividades citotóxicas em linhagens tumorais. Logo, o objetivo deste trabalho foi analisar o efeito citotóxico do veneno bruto da serpente Crotalus durissus cascavella (Cdcasca), in vitro, em linhagens tumorais, bem como, os mecanismos de morte celular induzidos por este veneno. Os efeitos citotóxicos da Cdcasca foram avaliados nas linhagens de carcinoma ovariano, carcinoma de próstata, carcinoma de mama e glioblastoma. Foram realizados também avaliação de alterações no DNA, integridade da membrana celular, ciclo celular e atividade das Caspases 3 e 7. Os resultados demostraram relevante citotoxicidade apresentando valores de CI50 de 2.4 até 6.7 ?g/mL, para as cinco linhagens testadas. As células tratadas com o Cdcasca demostraram alterações morfológicas de forma dosedependente, apresentando redução no volume celular, fragmentação nuclear e formação de corpos apoptóticos. A atividade anti-proliferativa e integridade de membrana celular foi confirmada, com uma significante redução do número de células para a concentração do veneno de 4 ?g/mL. A ocorrência de apoptose foi confirmada através da ativação de Caspases 3 e 7. Em conclusão, o veneno da Crotalus durissus cascavella demostrou efeito citotóxico dose-dependente em diversas linhagens tumorais, demonstrando diversas alterações morfológicas em especial as células de linhagem de carcinoma ovariano, causando morte celular.

In the last decades cancer has reached a great dimension being considered a worldwide public health problem, representing a major cause of death in world. Snakes from the genus Crotalus has gained significant space in the scientific field, since researches with their venom show that its mechanisms are involved in the cytotoxic activity.Therefore, the aim of the present study was to analyze the crude venom of Crotalus durissus cascavella (Cdcasca) cytotoxic activity in vitro against tumor cell lines, as well as, the mechanism of cell death induced by this venom. . The cytotoxic effects of Cdcasca were evaluated on ovarian cell carcinoma, prostate carcinoma, breast carcinoma and glioblastoma. Evaluations to DNA fragmentation, cell membrane integrity, cell cycle and the activity of Caspases 3 and 7 were also present in this study. Results showed relevant cytotoxicity presenting values of CI50 of 2.4 to 6.7 μg/mL on the five lineages tested. The cells treated with Cdcasca showed morphologic alterations in a dose - dependent way, presenting reduction on the cell volume, nuclear fragmentation and presence of apoptotic bodies. The antiprolifer active activity and the membrane integrity were confirmed, with a significant reduction of the number of cells to the concentration of the venom of μg/mL. The occurrence of apoptosis was confirmed trough the activation of Caspases 3 and 7. In conclusion, the venom of Crotalus durissus cascavella showed a dose-dependent cytotoxic effect in several tumor cell lines, presenting several morphological alterations, especially to the ovarian cell carcinoma, causing cell death.

Estudo do potencial citotóxico do veneno da serpenteCrotalus Durissus Cascavella em adenocarcinoma ovariano OVCAR-88

Nas últimas décadas o câncer alcançou grande dimensão, sendo considerado um problema de saúde publica a nível mundial, representando uma das principais causas de morte no mundo. As serpentes do gênero Crotalus vêm ganhando espaço significativo no campo científico, pois pesquisas realizadas com seu veneno estão demostrando que este apresenta mecanismos envolvidos em atividades citotóxicas em linhagens tumorais. Logo, o objetivo deste trabalho foi analisar o efeito citotóxico do veneno bruto da serpente Crotalus durissus cascavella (Cdcasca), in vitro, em linhagens tumorais, bem como, os mecanismos de morte celular induzidos por este veneno. Os efeitos citotóxicos da Cdcasca foram avaliados nas linhagens de carcinoma ovariano, carcinoma de próstata, carcinoma de mama e glioblastoma. Foram realizados também avaliação de alterações no DNA, integridade da membrana celular, ciclo celular e atividade das Caspases 3 e 7. Os resultados demostraram relevante citotoxicidade apresentando valores de CI50 de 2.4 até 6.7 ?g/mL, para as cinco linhagens testadas. As células tratadas com o Cdcasca demostraram alterações morfológicas de forma dosedependente, apresentando redução no volume celular, fragmentação nuclear e formação de corpos apoptóticos. A atividade anti-proliferativa e integridade de membrana celular foi confirmada, com uma significante redução do número de células para a concentração do veneno de 4 ?g/mL. A ocorrência de apoptose foi confirmada através da ativação de Caspases 3 e 7. Em conclusão, o veneno da Crotalus durissus cascavella demostrou efeito citotóxico dose-dependente em diversas linhagens tumorais, demonstrando diversas alterações morfológicas em especial as células de linhagem de carcinoma ovariano, causando morte celular. (AU)

In the last decades cancer has reached a great dimension being considered a worldwide public health problem, representing a major cause of death in world. Snakes from the genus Crotalus has gained significant space in the scientific field, since researches with their venom show that its mechanisms are involved in the cytotoxic activity.Therefore, the aim of the present study was to analyze the crude venom of Crotalus durissus cascavella (Cdcasca) cytotoxic activity in vitro against tumor cell lines, as well as, the mechanism of cell death induced by this venom. . The cytotoxic effects of Cdcasca were evaluated on ovarian cell carcinoma, prostate carcinoma, breast carcinoma and glioblastoma. Evaluations to DNA fragmentation, cell membrane integrity, cell cycle and the activity of Caspases 3 and 7 were also present in this study. Results showed relevant cytotoxicity presenting values of CI50 of 2.4 to 6.7 μg/mL on the five lineages tested. The cells treated with Cdcasca showed morphologic alterations in a dose - dependent way, presenting reduction on the cell volume, nuclear fragmentation and presence of apoptotic bodies. The antiprolifer active activity and the membrane integrity were confirmed, with a significant reduction of the number of cells to the concentration of the venom of μg/mL. The occurrence of apoptosis was confirmed trough the activation of Caspases 3 and 7. In conclusion, the venom of Crotalus durissus cascavella showed a dose-dependent cytotoxic effect in several tumor cell lines, presenting several morphological alterations, especially to the ovarian cell carcinoma, causing cell death.(AU)