Background Kinetoplastids are a flagellated group of protists, including some parasites, such as Trypanosoma and Leishmania species, that can cause diseases in humans and other animals. The genomes of these species enclose a fraction of retrotransposons including VIPER and TATE , two poorly studied transposable elements that encode a tyrosine recombinase (YR) and were previously classified as DIRS elements. This study investigated the distribution and evolution of VIPER and TATE in kinetoplastids to understand the relationships of these elements with other retrotransposons. Results We observed that VIPER and TATE have a discontinuous distribution among Trypanosomatidae, with several events of loss and degeneration occurring during a vertical transfer evolution. We were able to identify the terminal repeats of these elements for the first time, and we showed that these elements are potentially active in some species, including T. cruzi copies of VIPER . We found that VIPER and TATE are strictly related elements, which were named in this study as VIPER-like . The reverse transcriptase (RT) tree presented a low resolution, and the origin and relationships among YR groups remain uncertain. Conversely, for RH, VIPER-like grouped with Hepadnavirus , whereas for YR, VIPER-like sequences constituted two different clades that are closely allied to Crypton . Distinct topologies among RT, RH and YR trees suggest ancient rearrangements/exchanges in domains and a modular pattern of evolution with putative independent origins for each ORF. Conclusions Due to the presence of both elements in Bodo saltans, a nontrypanosomatid species, we suggested that VIPER and TATE have survived and remained active for more than 400 million years or were reactivated during the evolution of the host species. We did not find clear evidence of independent origins of VIPER-like from the other YR retroelements, supporting the maintenance of the DIRS group of retrotransposons. Nevertheless, according to phylogenetic findings and sequence structure obtained by this study and other works, we proposed separating DIRS elements into four subgroups: DIRS-like, PAT-like, Ngaro-like, and VIPER-like. Electronic supplementary material The online version of this article (10.1186/s13100-019-0175-2) contains supplementary material, which is available to authori...
O consumismo e a agressão ao meio ambiente são algumas ações antrópicas emergentes da dicotomia ser humano-natureza, reforçada ao longo da nossa história. Compreendendo que as aves podem promover uma reaproximação ao meio, essencial na formação efetiva de um sujeito ecológico, este estudo - qualitativo, teórico e descritivo - busca discutir, a partir de um levantamento de pesquisas anteriores, como a observação e o estudo das aves podem servir de subsídios para uma Educação Ambiental que reaproxime os pares, em espaços formais e não-formais. Nessa posição, a observação de aves se destaca como uma atividade contextualizada, e potencial, na promoção de uma necessária (re)sensibilização em relação ao meio ambiente.
The foraging efficiency of birds may vary according to local conditions as a result of the balance between energy consumption and expenditure. The foraging efficiency of Egretta thula (adults n=11) and Egretta caerulea (adults n=69 and juveniles n= 17) was compared in Paranaguá city estuary, in Paraná, Brazil. In 14 hours of observation divided into 2 minutes sessions per individual, were recorded foraging site (mud or shallow water), number of steps, total peckings and successful peckings, and were calculated the success rates, energy effort and capture efficiency. In shallow water E.thula was more efficient than E. caerulea. There was no intraspecific differences in E. thula regarding environments. Adults of E. caerulea were more efficient than juveniles, with greater efficiency in mud than in shallow waters environments. Differences in foraging efficiency between species may be related to the type of foraging according to feeding location.
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