Isolation and optimization of a glyphosate-degrading Rhodococcus soli G41 for bioremediation

A widely used herbicide for controlling weeds, glyphosate, is causing environmental pollution. It is necessary to remove it from environment using a cost-effective and eco-friendly method. The aims of this study were to isolate glyphosate-degrading bacteria and to optimize their degradative conditions required for bioremediation. Sixteen bacterial strains were isolated through enrichment and one strain, Rhodococcus soli G41, demonstrated a high removal rate of glyphosate than other strains. Response surface methodology was employed G41 strain to optimize distinct environmental factors on glyphosate degradation of G41 strain. The optimal conditions for the maximum glyphosate degradation were found to have the NH4Cl concentration of 0.663% and glyphosate concentration of 0.115%. Degradation analysis showed 47.1% of glyphosate in soil was degraded by G41 strain after 14 days. The presence of soxB gene in G41 strain indicates that the glyphosate is degraded via the eco-friendly sarcosine pathway. The results indicated that G41 strain has the potential to serve as an in-situ candidate for bioremediation of glyphosate polluted environments.

Drosophila Neuroblast Selection Gated by Notch, Snail, SoxB and EMT Gene Interplay

SUMMARYIn the developing Drosophila central nervous system neural progenitor (neuroblast; NB) selection is gated by lateral inhibition, controlled by Notch signalling and proneural genes. However, proneural mutants only display partial NB reduction, indicating the existence of additional genes with proneural activity. In addition, recent studies reveal involvement of key epithelial-mesenchymal transition (EMT) genes in NB selection, but the regulatory interplay between Notch signalling and the EMT machinery is unclear. We find that the SoxB gene SoxNeuro and the Snail gene worniou are integrated with the Notch pathway, and constitute the missing proneural genes. Notch signalling, the proneural, SoxNeuro, and worniou genes regulate key EMT genes to orchestrate the NB specification process. Hence, we uncover an expanded lateral inhibition network for NB specification, and demonstrate its link to key players in the EMT machinery. Because of the evolutionary conservation of the genes involved, the Notch-SoxB-Snail-EMT network may control neural progenitor selection in many other systems.

A SoxB gene acts as an anterior gap gene and regulates posterior segment addition in a spider

Sox genes encode a set of highly conserved transcription factors that regulate many developmental processes. In insects, the SoxB gene Dichaete is the only Sox gene known to be involved in segmentation. To determine if similar mechanisms are used in other arthropods, we investigated the role of Sox genes during segmentation in the spider Parasteatoda tepidariorum. While Dichaete does not appear to be involved in spider segmentation, we found that the closely related Sox21b-1 gene acts as a gap gene during formation of anterior segments and is also part of the segmentation clock for development of the segment addition zone and sequential addition of opisthosomal segments. Thus, we have found that two different mechanisms of segmentation in a non-mandibulate arthropod are regulated by a SoxB gene. Our work provides new insights into the function of an important and conserved gene family, and the evolution of the regulation of segmentation in arthropods.

A SoxB gene acts as an anterior gap gene and regulates posterior segment addition in the spider Parasteatoda tepidariorum

SummaryThe Sox gene family encode a set of highly conserved HMG domain transcription factors that regulate many key processes during metazoan embryogenesis. In insects, the SoxB gene Dichaete is the only Sox gene known to be involved in embryonic segmentation. To determine if similar mechanisms are used in other arthropods, we investigated the role of Sox genes during segmentation in the spider Parasteatoda tepidariorum. While Dichaete does not appear to be involved in spider segmentation, RNAi knockdown of the closely related Sox21b-1 gene results in a gap like phenotype in the developing prosoma and also perturbs the sequential addition of opisthosomal segments. We show that this is in part due to a role for Sox21b-1 in regulating the expression of Wnt8 and influencing Delta-Notch signalling during the formation of the segment addition zone. Thus, we have found that two different mechanisms for segmentation in a non-mandibulate arthropod are regulated by a Group B Sox gene. Our work provides new insights into the function of an important and conserved gene family across arthropods, and the evolution of the regulation of segmentation in these animals.