An intragenic mutagenesis strategy in Physcomitrella patens to preserve intron splicing.

Gene targeting is a powerful reverse genetics technique for site-specific genome modification. Intrinsic homologous recombination in the moss Physcomitrella patens permits highly effective gene targeting, a characteristic that makes this organism a valuable model for functional genetics. Functional characterization of domains located within a multi-domain protein depends on the ability to generate mutants harboring genetic modifications at internal gene positions while maintaining the reading-frames of the flanking exons. In this study, we designed and evaluated different gene targeting constructs for targeted gene manipulation of sequences corresponding to internal domains of the DEFECTIVE KERNEL1 protein in Physcomitrella patens. Our results show that gene targeting-associated mutagenesis of introns can have adverse effects on splicing, corrupting the normal reading frame of the transcript. We show that successful genetic modification of internal sequences of multi-exon genes depends on gene-targeting strategies which insert the selection marker cassette into the 5' end of the intron and preserve the nucleotide sequence of the targeted intron.

In vitro Evaluation of Eclipta alba against Serogroups of Leptospira interrogans.

Leptospirosis is now acknowledged as the most widespread zoonoses in the world. Hundreds of cases occur in India every year accounting for considerable morbidity and sizable mortality. Several studies have delineated the epidemiology, pathology and variable clinical features of this condition. The present study comprises the importance and utilization of traditional based medicines to overcome the adverse reaction by conventional drugs and standardize the technology. The antileptospiral activity of Eclipta alba L. was well studied by both tube dilution and micro dilution techniques and the result showed better inhibitory action against various serogroups of Leptospira interrogans. L. australis, L. autumnalis and L. grippotyphosa are inhibited by both water and ethanol extract by tube dilution technique. The MIC level observed are 50 µg and 100 µg respectively. Similarly acetone extract, Icterohaemorrhagiae was responded to 200 µg/ml as MIC whereas in petroleum ether extract, no inhibition was observed. In the case of micro dilution technique, the entire inhibition rates are supported to the tube dilution technique. It showed that the micro dilution technique is the best method where we obtained the results within 30 minutes; at the same time tube dilution technique takes minimum of 7 days to provide the result.