Project description:Proteins are ubiquitous macromolecules displaying a vast repertoire of chemical and enzymatic functions making them suitable candidates for chemosignals used in intraspecific communication. Proteins are present in skin gland secretions of vertebrates but their identity, and especially, their functions, remain largely unknown. Many species of lizards possess femoral glands, i.e. epidermal organs primarily involved in the production and secretion of chemosignals playing a pivotal role in mate choice and intrasexual communication. The lipophilic fraction of femoral glands has been well studied in lizards. In contrast, proteins have been the focus of only a handful of investigations. Here, we study the identity, inter-individual expression patterns and functionality of proteins present in femoral glands of sand lizards (Lacerta agilis) by applying mass-spectrometry proteomics. Our results showed that the total number of proteins varied substantially among individuals. None of the identified femoral gland proteins could be directly linked to chemical communication in lizards, although this result hinges on protein annotation in databases in which squamate semiochemicals are poorly represented. In contrast to our expectations, proteins consistently expressed across individuals were related to immune system, antioxidant activity and lipid metabolism as the main functions, adding support to the hypothesis that proteins in reptilian epidermal glands have other functions besides chemical communication. Interestingly, we found that major histocompatibility complex class I (MHC) expression is enriched in femoral gland secretions. Previously, MHC was hypothesized to have been coopted to serve a semiochemical function in sand lizards, specifically in partner recognition. We speculate with the possibility that MHC proteins could be linked to semiochemical function in sand lizards.
Project description:RNAsequening revolutionized the bacterial gene expression analysis. The objective of this study was to identify the genes involved in metabolism of Inulin in Ligilactobacillus agilis. We have obtained a list of genes upregulated in Ligilactobacillus agilis when it is grown in 1% Inulin
Project description:BACKGROUND:Present-day climate change has altered the phenology (the timing of periodic life cycle events) of many plant and animal populations worldwide. Some of these changes have been adaptive, leading to an increase in population fitness, whereas others have been associated with fitness decline. Representing short-term responses to an altered weather regime, hitherto observed changes are largely explained by phenotypic plasticity. However, to track climatically induced shifts in optimal phenotype as climate change proceeds, evolutionary capacity in key limiting climate- and fitness-related traits is likely to be crucial. In order to produce realistic predictions about the effects of climate change on species and populations, a main target for conservation biologists is thus to assess the potential of natural populations to respond by these two mechanisms. In this study we use a large 15-year dataset on an ectotherm model, the Swedish sand lizard (Lacerta agilis), to investigate how higher spring temperature is likely to affect oviposition timing in a high latitude population, a trait strongly linked to offspring fitness and survival. RESULTS:With an interest in both the short- and potential long-term effect of rising temperatures, we applied a random regression model, which yields estimates of population-level plasticity and among-individual variation in the average, as well as the plastic, response to temperature. Population plasticity represents capacity for short-term adjustments whereas variation among individuals in a fitness-related trait indicates an opportunity for natural selection and hence for evolutionary adaptation. The analysis revealed both population-level plasticity and individual-level variation in average laying date. In contrast, we found no evidence for variation among females in their plastic responses to spring temperature, which could demonstrate a similarity in responses amongst females, but may also be due to a lack of statistical power to detect such an effect. CONCLUSION:Our findings indicate that climate warming may have positive fitness effects in this lizard population through an advancement of oviposition date. This prediction is consistent over shorter and potentially also longer time scales as the analysis revealed both population-level plasticity and individual-level variation in average laying date. However, the genetic basis for this variation would have to be examined in order to predict an evolutionary response.
Project description:Our studies conducted on reptilian limb muscle development revealed, for the first time, early forelimb muscle differentiation at the morphological and molecular level. Sand lizard skeletal muscle differentiation in the early forelimb bud was investigated by light, confocal, and transmission electron microscopy as well as western blot. The early forelimb bud, filled with mesenchymal cells, is surrounded by monolayer epithelium cells. The immunocytochemical analysis revealed the presence of Pax3- and Lbx-positive cells in the vicinity of the ventro-lateral lip (VLL) of the dermomyotome, suggesting that VLL is the source of limb muscle progenitor cells. Furthermore, Pax3- and Lbx-positive cells were observed in the dorsal and ventral myogenic pools of the forelimb bud. Skeletal muscle development in the early limb bud is asynchronous, which is manifested by the presence of myogenic cells in different stages of differentiation: multinucleated myotubes with well-developed contractile apparatus, myoblasts, and mitotically active premyoblasts. The western blot analysis revealed the presence of MyoD and Myf5 proteins in all investigated developmental stages. The MyoD western blot analysis showed two bands corresponding to monomeric (mMyoD) and dimeric (dMyoD) fractions. Two separate bands were also detected in the case of Myf5. The observed bands were related to non-phosphorylated (Myf5) and phosphorylated (pMyf5) fractions of Myf5. Our investigations on sand lizard forelimb myogenesis showed that the pattern of muscle differentiation in the early forelimb bud shares many features with rodents and chicks.