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261.
WILSON J. E. M. COSTA SERGIO M. Q. LIMA RENATA BARTOLETTE 《Biological journal of the Linnean Society. Linnean Society of London》2010,99(2):344-349
Kryptolebias marmoratus is an important experimental fish, and is considered to represent the only vertebrate species comprising self‐fertilizing hermaphroditic individuals. Subsequent to the discovery of this unusual mode of reproduction, approximately 50 years ago, K. marmoratus has been the focus of a series of studies. However, little is known about the evolution of this rare reproduction mode, and data on the biology of closely related species are still unavailable. The present study aimed to histologically analyse the gonads of three K. marmoratus congeners (i.e. Kryptolebias ocellatus, Kryptolebias caudomarginatus, and Kryptolebias brasiliensis) to check the distribution of features related to hermaphroditism that are useful for forming hypotheses about the origin and evolution of the self‐fertilization mode of reproduction through the available phylogenies. The data obtained demonstrate that populations of K. caudomarginatus consist of males and hermaphrodites, which supports the hypothesis that hermaphroditism arose at the base of the clade containing K. caudomarginatus, K. marmoratus, and K. ocellatus as a first step towards a more advanced condition, uniquely shared by both K. marmoratus and K. ocellatus, in which males are rare or absent in natural populations, with the subsequent occurrence of self‐fertilization. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 99 , 344–349. 相似文献
262.
Graziele Mendes Vívian N Gon?alves Elaine M Souza-Fagundes Markus Kohlhoff Carlos A Rosa Carlos L Zani Betania B Cota Luiz H Rosa Susana Johann 《Memórias do Instituto Oswaldo Cruz》2016,111(3):209-217
Fungi of the genus Paracoccidioides are responsible for
paracoccidioidomycosis. The occurrence of drug toxicity and relapse in this disease
justify the development of new antifungal agents. Compounds extracted from fungal
extract have showing antifungal activity. Extracts of 78 fungi isolated from rocks of
the Atacama Desert were tested in a microdilution assay against
Paracoccidioides brasiliensis Pb18. Approximately 18% (5) of the
extracts showed minimum inhibitory concentration (MIC) values≤ 125.0
µg/mL. Among these, extract from the fungus UFMGCB 8030 demonstrated the best
results, with an MIC of 15.6 µg/mL. This isolate was identified as
Aspergillus felis (by macro and micromorphologies, and internal
transcribed spacer, β-tubulin, and ribosomal polymerase II gene analyses) and was
grown in five different culture media and extracted with various solvents to optimise
its antifungal activity. Potato dextrose agar culture and dichloromethane extraction
resulted in an MIC of 1.9 µg/mL against P. brasiliensis and did not
show cytotoxicity at the concentrations tested in normal mammalian cell (Vero). This
extract was subjected to bioassay-guided fractionation using analytical
C18RP-high-performance liquid chromatography (HPLC) and an antifungal assay using
P. brasiliensis. Analysis of the active fractions by HPLC-high
resolution mass spectrometry allowed us to identify the antifungal agents present in
the A. felis extracts cytochalasins. These results reveal the
potential of A. felis as a producer of bioactive compounds with
antifungal activity. 相似文献
263.
The gene polymorphisms interferon-gamma (IFN-γ) +874 T/A and interleukin (IL)-4 −590 C/T have been associated with the altered production of cytokines. Therefore, they might be indicative of the occurrence of Paracoccidioidomycosis (PCM) caused by Paracoccidioides brasiliensis. The analysis of single nucleotide polymorphism (SNP) at position +874 IFN-γ showed an increase occurrence of A/T genotype in both PCM patients and healthy individuals as control (HIC) (56% and 45%, respectively), while the allelic distribution showed 82% of A allele in the patients and 80% in the controls. The SNP of −590 IL-4 showed that C/T genotype was significantly (p < 0.05) more prevalent (39%) in PCM group compared to the HIC group (19%), while IL-4 C/C genotype was significantly less frequent (59%) in the patient group compared to the control group (81%). Otherwise, 41% of PCM patients and 19% of HIC individuals carried the IL-4 T allele. Stimulation of peripheral blood mononuclear cells (PBMC) from PCM patients with cell extract antigenic preparations (PbAg) as well as secreted and surface antigens (MEXO) of P. brasiliensis evidenced that there is no difference in the IFN-γ production related to A and T alleles between PCM and HIC individuals. However, with IL-4 production, PCM patients classified as C phenotype showed two times more IL-4 production than PCM patients classified as T phenotype and HIC controls. In conclusion, our results suggest that functional genetic variants in the IL-4 promoter could influence the production of IL-4 in PCM. 相似文献