RESUMO
Polyploids are cells or organisms with a genome consisting of more than two sets of homologous chromosomes. Polyploid plants have important traits that facilitate speciation and are thus often model systems for evolutionary, molecular ecology and agricultural studies. However, due to their unusual mode of inheritance and double-reduction, diploid models of population genetic analysis cannot properly be applied to autopolyploids. To overcome this problem, we developed a software package entitled vcfpop to perform a variety of population genetic analyses for autopolyploids, such as parentage analysis, analysis of molecular variance, principal coordinates analysis, hierarchical clustering analysis and Bayesian clustering. We used three data sets to evaluate the capability of vcfpop to analyse large data sets on a desktop computer. This software is freely available at http://github.com/huangkang1987/vcfpop.
RESUMO
A wash-free and label-free colorimetric biosensor for the amplified detection of aflatoxin B1 (AFB1) has been constructed by the integration of an ingenious hairpin DNA probe with exonuclease III (Exo III)-assisted signal amplification. The presence of the AFB1 activates the continuous cleavage reactions by Exo III toward a hairpin probe, resulting in the autonomous accumulation of numerous free G-quadruplex sequences, which can catalyze the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) by H2O2 to produce a colorimetric response. The naked-eye biosensor is ultrasensitive, enabling the visual detection of trace amounts of AFB1 as low as 1â¯pM without instrumentation. The sensor is robust and can work even when challenged with complex sample matrices such as peanut samples. With the advantages of simple operation, wash-free and label-free format, visible and intuitive output, and low cost, the naked-eye based colorimetric biosensor is expected to have potential applications for in-field detection of AFB1.
