Project description:D. grimshawi microarray used to text for gene expression differences between two populations subjected to control or low-intensity heat for one week during maturation Anthropogenic influences on global processes and climatic conditions are increasingly affecting ecosystems throughout the world. Hawaii Island’s native ecosystems are well-studied and local long-term climatic trends well-documented, making these ecosystems ideal for evaluating how native taxa may respond to a warming environment. This study documents adaptive divergence of populations of a Hawaiian picture wing Drosophila, D. sproati, that are separated by only 7km and 365m in elevation. Representative laboratory populations show divergent behavioral and physiological responses to an experimental low-intensity increase in ambient temperature during maturation. The significant interaction of source population by temperature treatment for behavioral and physiological measurements indicates differential adaptation to temperature for the two populations. Significant differences in gene expression among males were mostly explained by the source population, with eleven genes in males also showing a significant interaction of source population by temperature treatment. The combined behavior, physiology, and gene expression differences between populations illustrates the potential for local adaptation to occur over a fine spatial scale and exemplifies nuanced response to climate change.
Project description:Comparative RNA-sequencing of the developmental leaf zones in Brachypodium distachyon wild type and bdmute mutants that do not form stomatal subsidiary cells was performed. The aim was to identify genes relevant for subsidiary cell formation in B. distachyon.
Project description:Comparative RNA-sequencing of the mature leaf zones in Brachypodium distachyon wild type and bdmute mutants that do not form stomatal subsidiary cells was performed. The aim was to identify genes relevant for subsidiary cell function in B. distachyon.
Project description:Affymetrix single nucleotide polymorphism (SNP) array data were used to study genes that underlie human adaptation to climatic stress, with a focus on genetic changes that lead to long-term cold tolerance. Siberia provides the best opportunity to investigate the genetic mechanisms of cold resistance because of the long-term ancestry of indigenous populations in some of the coldest climates on earth. While much of northern Europe was under ice throughout the last glacial period, Siberia remained relatively ice free, and archaeological evidence suggests that people inhabited this region for more than 40,000 years. We gathered SNP data from ~200 individuals from 15 indigenous Siberian populations that inhabit a range of arctic climates and compare their patterns of genetic variation with those from other world populations from warmer climates.Particular attention is paid to regions containing genes that have been previously implicated in cold adaptation or that function in known pathways connected to energy metabolism or cold adapted phenotypes (e.g., those involved in basal metabolic rate and brown adipose tissue function).
Project description:In the growth plate, the reserve and perichondral zones have been hypothesized to have similar functions, but their exact functions are poorly understood. Our hypothesis was that significant differential gene expression exists between perichondral and reserve chondrocytes that may differentiate the respective functions of these two zones. Normal Sprague-Dawley rat growth plate chondrocytes from the perichondral zone (PC), reserve zone (RZ), proliferative zone (PZ), and hypertrophic zone (HZ) were isolated by laser microdissection and then subjected to microarray analysis. In order to most comprehensively capture the unique features of the two zones, we analyzed both the most highly expressed genes and those that were most significantly different from the proliferative zone (PZ) as a single comparator. Keywords: cell specific expression profiles
Project description:The bacterium, Sinorhizobium meliloti, interacts symbiotically with leguminous plants such as Medicago truncatula to form nitrogen-fixing root nodules. During symbiosis, plant and bacterial cells differentiate in a coordinated manner, resulting in specialized plant cells that contain nitrogen-fixing bacteroids. Medicago nodules are organized in structurally distinct tissue zones, representing different stages of bacterial and plant differentiation. We used laser-capture microdissection (LCM) to analyze bacterial and plant gene expression in four root nodule regions. In parallel, we analyzed gene expression in nodules formed by wild type bacteria on six plant mutants with nitrogen fixation deficiencies (dnf). We found that bacteroid metabolism is drastically remodeled during bacteroid differentiation. Many processes required for bacterial growth are down-regulated in the nitrogen fixation zone. The overall transcriptional changes are similar to those occurring during nutrient limitation by the stringent response. We also observed differential expression of bacterial genes involved in nitrogen fixation, cell envelope homeostasis, cell division, stress response and polyamine biosynthesis at distinct stages of nodule development. In M. truncatula we observed the differential regulation of several host processes that may trigger bacteroid differentiation and control bacterial infection. We analyzed plant and bacterial gene expression simultaneously, which allowed us to correlate processes in both organisms.
Project description:In Sub-Saharan Africa, Anopheles gambiae Giles (Diptera: Culicidae) largely contributes to malaria transmission, in direct relation to environmental conditions influencing the vector ecology. Therefore, our study aimed to compare the proteomes of An. gambiae according to varying insecticide pressures associated to cotton crops also integrating different population origins from two climatic regions of Burkina Faso.
