ABSTRACT
Abstract The Cerrado is one of the most threatened biomes in Brazil. It is estimated that much of its original vegetation has been replaced by some type of human use. This is quite worrying, mainly in the northern part where the number of wildlife inventories is insufficient and creates the false impression of low diversity in the region. The Parque Estadual do Mirador-PEM, located in the south-central region of the state of Maranhão, presents vegetation typical of the Cerrado biome and corresponds to one of 46 priority areas for conservation in the state. Herein, we describe the species richness and composition of the anurofauna from the PEM and analyze the influence of different types of vegetation in its formation. Our inventory was conducted from December 2013 to February 2015, using the active search and auditory census methods on breeding sites in different water bodies of the park. We recorded 31 anuran species belonging to five families (species number in parentheses): Leptodactylidae (14), Hylidae (12), Bufonidae (3), Microhylidae (1) and Phyllomedusidae (1). The rarefaction curve and species richness estimators indicated that the sampling effort was enough to record most of the species in the region. The richness of anurans in the PEM was higher than reported by other authors for several areas of Cerrado. Most species have a wide distribution in Brazil or are strongly associated with the Caatinga or Amazon biomes. Only about 19% are endemic to the Cerrado biome. This study is the first to inventory the anurans species of the south-central region of state of Maranhão and provides important data on amphibian communities from the northern part of the Brazilian Cerrado.
Resumo O Cerrado é um dos biomas mais ameaçados do Brasil. Estima-se que grande parte da cobertura vegetal original deste bioma tenha sido substituída por alguma forma de utilização humana. Este fato é bastante preocupante, principalmente na porção norte, onde o número de inventários faunísticos é insuficiente e gera a falsa impressão de baixa diversidade na região. O Parque Estadual do Mirador-PEM, localizado na região centro-meridional do Maranhão, apresenta vegetação típica do Cerrado e corresponde a uma das 46 áreas prioritárias para conservação no estado. Aqui, nós descrevemos a riqueza e a composição da anurofauna no PEM, analisando a influência dos diferentes tipos vegetacionais na sua formação. Inventariamos a anurofauna de dezembro de 2013 a fevereiro de 2015, utilizando métodos de procura ativa e censo auditivo em sítios reprodutivos de diferentes corpos d'água do parque. Registramos 31 espécies de anuros, pertencentes a cinco famílias (números de espécies entre parênteses): Leptodactylidae (14), Hylidae (12), Bufonidae (3), Microhylidae (1) e Phyllomedusidae (1). A curva de rarefação e os estimadores de riqueza indicaram que o esforço amostral foi suficiente para registrar a maior parte das espécies da região. A riqueza de anuros no PEM foi maior que a registrada por outros autores em diversas áreas de Cerrado. A maioria das espécies possuem ampla distribuição no Brasil ou são fortemente associadas aos biomas Caatinga ou Amazônia. Somente cerca de 19% são endêmicas do bioma Cerrado. O presente trabalho representa o primeiro estudo a inventariar as espécies de anfíbios anuros na região Centro-Sul do Maranhão e fornece dados importante sobre as comunidades de anfíbios da porção norte do Cerrado brasileiro.
ABSTRACT
Eight new peptides were isolated from the skin secretion of the frog Leptodactylus pustulatus and their amino acid sequences determined by de novo sequencing and by cDNA cloning. Structural similarities between them and other antimicrobial peptides from the skin secretion of Leptodactylus genus frogs were found. Ocellatins-PT1 to -PT5 (25 amino acid residues) are amidated at the C-terminus, while ocellatins-PT6 to -PT8 (32 amino acid residues) have free carboxylates. Antimicrobial activity, hemolytic tests, and cytotoxicity against a murine fibroblast cell line were investigated. All peptides, except for ocellatin-PT2, have antimicrobial activity against at least one Gram-negative strain. Ocellatin-PT8 inhibited the growth of Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, and Salmonella choleraesuis strains with MICs in the 60-240 µM range. No significant effect was observed in human erythrocytes and in a murine fibroblast cell line after exposure to the peptides at MICs. A comparison between sequences obtained by both direct HPLC-MS de novo sequencing and cDNA cloning demonstrates the secretion of mature peptides derived from a pre-pro-peptide structure.
