Project description:The transcriptome signature of peripheral blood mononuclear cells (PBMCs) of Ladakhi cattle adapted to high altitude vis a vis Sahiwal cattle adapted to the arid/semi-arid region at mean sea level was established using bovine expression microarray chips. The transcriptome analysis of PBMCs from these cattle types living at two distinct altitudes, resulted in identification of several hundred differentially expressed genes, biological processes, molecular functions and pathways.
Project description:Biological soil crusts (BSCs) are cyanobacteria-dominated microbial communities that cover extensive portions of the world’s arid and semi-arid deserts. The infrequent periods of hydration are often too short to allow for dormancy strategies based on sporulation; consequently, survival is based on the unique capabilities of vegetative cells to resuscitate from and re-enter a stress resistant dormant state, one of which is migration within the crust layers in response to hydration. In this study, we sought to characterize the events that govern the emergence of the dominant cyanobacterium from dormancy, its subsequent growth, and the events triggered by re-desiccation and a transition back to dormant state. We performed a 48 hour laboratory wetting experiment of a desert BSC and tracked the response of Microcoleus vaginatus using a whole genome transcriptional time-course including night/day periods. This allowed the identification of genes with a diel expression pattern, genes involved uniquely in the signaling after hydration and those that contribute primarily to desiccation preparation.
Project description:1. The heartwood of A. auriculiformis contains a typical mixture of analogues consisting of three isomeric flavan-3,4-diols, a dihydroflavonol, flavanone, flavonol and chalcone based on the 4',7,8-trihydroxyl pattern. These were resolved by preparative paper chromatography and preparative paper ionophoresis. 2. Crystalline (-)-teracacidin [(2R,3R,4R)-4',7,8-trihydroxy-2,3-cis-flavan-3,4-cis-diol] was obtained in high (10%) yield, and a new crystalline derivative of (-)-isoteracacidin [(-)-2,3-cis-3,4-trans isomer] was isolated. The crystalline methyl ether of a new (+)-2,3-trans-3,4-cis isomer was isolated. 3. The absolute configurations of (-)-isoteracacidin (2R,3R,4S) and of the (+)-2,3-trans-3,4-cis isomer (2R,3S,4S) were tentatively assigned on the basis of nuclear-magnetic-resonance spectroscopy, paper ionophoresis and paper-chromatographic comparison with the epimerization products of (-)-teracacidin. 4. Possible reasons for the absence of polymeric leuco-anthocyanidin tannins are discussed. 5. (+/-)-4',7,8-Trihydroxydihydroflavonol and (+/-)-4',7,8-trihydroxyflavanone were isolated for the first time. 6. The bark polyphenols consist mainly of polymeric leuco-delphinidins and leuco-cyanidins which redden exceptionally rapidly to light. The mechanism of this phenomenon is discussed.
