Rho GTPase function in flies: insights from a developmental and organismal perspective.

Morphogenesis is a key event in the development of a multicellular organism and is reliant on coordinated transcriptional and signal transduction events. To establish the segmented body plan that underlies much of metazoan development, individual cells and groups of cells must respond to exogenous signals with complex movements and shape changes. One class of proteins that plays a pivotal role in the interpretation of extracellular cues into cellular behavior is the Rho family of small GTPases. These molecular switches are essential components of a growing number of signaling pathways, many of which regulate actin cytoskeletal remodeling. Much of our understanding of Rho biology has come from work done in cell culture. More recently, the fruit fly Drosophila melanogaster has emerged as an excellent genetic system for the study of these proteins in a developmental and organismal context. Studies in flies have greatly enhanced our understanding of pathways involving Rho GTPases and their roles in development

Microbial phytase-induced calcium-phosphate precipitation: A potential soil stabilization method

Two hypotheses were tested: (1) microbial dephosphorylation of phytate in the presence of Ca2+ ions will result in the precipitation of hydroxyapatite-like crystals and (2) precipitation of calcium-phosphate crystals on and between sand-like particles can cause cementation. A growing culture of the dimorphic phytase-active yeast Arxula adeninivorans was introduced into a column filled with quartz particles and subsequently a liquid growth medium amended with calcium phytate was pumped through the column resulting in increased strength and stiffness of the quartz particle matrix. Environmental scanning electron microscope analysis combined with energy-dispersive X-ray measurement revealed cementation of the quartz particles by calcium-phosphate crystals. This microbial mineralization process could provide a novel approach to improving the mechanical properties like strength and stiffness of sandy soils.BT/BiotechnologyApplied Science