Isolation of twelve microsatellite loci,using an enrichment protocol,in the phytopathogenic fungus Puccinia striiformis f.sp. tritici

We report the characterization of 12 microsatellite markers in the biotrophic fungus Puccinia striiformis f.sp. tritici, responsible for yellow rust on wheat. An enrichment protocol was used to isolate microsatellite loci, and polymorphism was explored with 96 isolates from natural populations collected from several French and Chinese locations. Eight primers (67%) showed cross‐amplification when tested with eight isolates of P. triticina.     

Autoantibodies against golgi apparatus induced by arteriviruses.

Members of the genus Arterivirus within the monogeneric family Arteriviridae are lactate dehydrogenase-elvating virus (LDV), porcine reproductive and respiratory syndrome virus (PRRSV), equine arteritis virus (EAV) and simian hemorrhagic fever virus. In LDV-infected mice the appearance of autoantibodies against Golgi-antigen dominated the early immune response. Shared antigenicity between LDV and Golgi-antigen of normal cells could not be demonstrated. Monoclonal antibodies (MAbs) reacted either with LDV or with Golgi-antigen but not with both. Immunization of mice with the porcine arterivirus PRRSV, however, led to the establishment of MAbs that recognized the structural glycoprotein GP3 as well as Golgi-antigen of normal porcine cells indicating molecular mimicry of viral and cellular antigen. In addition to cross-reactive antibodies MAbs solely reactive with Golgi-antigen were observed. After immunization of mice with EAV, the equine arterivirus, clones were isolated producing Golgi-antigen recognizing autoantibodies. Morphogenesis of arteriviruses occurs in the Golgi region. The autoimmune responses following immunization with arteriviruses may offer an approach for determining the mechanism by which such responses develop and become of biologic importance.     

Linkage disequilibrium studies in multiple endocrine neoplasia type 1 (MEN1)

Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant disorder characterised by tumours of the parathyroids, pancreas and anterior pituitary. The MEN1 gene has been localised to a 2-Mb region of chromosome 11q13 by meiotic mapping studies in MEN1 families. Such studies may have a limited resolution of approximately 1 cM (i.e. 1 Mb) and we have therefore investigated 96 MEN1 families (40 British, 17 French, 12 Finnish, 7 Swedish, 7 Dutch, 7 North American, 2 Australian, 1 New Zealand, 1 German, 1 Spanish and 1 Danish) for linkage disequilibrium, in order to facilitate a finer mapping resolution. We have utilised five microsatellite DNA sequence polymorphisms from the candidate region and have accurately determined their allele sizes, which ranged from 161 bp to 272 bp. The heterozygosity and number of alleles (given in brackets), respectively, at the loci were: D11S1883 (76%, 11), D11S457 (55%, 5), PYGM (94%, 18), D11S1783 (10%, 4) and D11S449 (87%, 16). Allelic association was assessed by Chi-square 2 ×n contingency tables, by Fisher exact 2 ×n contingency tables and by a likelihood-based approach. The results of haplotype analysis revealed 91 different affected haplotypes in the 96 families, an identical affected haplotype being observed in no more than two families. These results indicate the absence of an ancestral affected haplotype. Significant linkage disequilibrium (P < 0.005) could be established amongst the microsatellite loci but not between the loci and MEN1 in either the total population or in any of the geographical sub-populations. The absence of linkage disequilibrium between MEN1 and the polymorphic loci is probably the result of the occurrence of multiple different disease-causing mutations in MEN1. Received: 1 April 1997 / Accepted: 25 June 1997     

The measurement in vivo of the rate of unesterified cholesterol exchange between rat plasma and erythrocytes

In order to investigate the rate of unesterified cholesterol exchange between plasma and erythrocytes in vivo, cholesterol labelling in rats was achieved in one of the following ways: intravenous injection of cholesterol-labelled erythrocytes, subcutaneous injection of labelled acetate, feeding of labelled cholesterol. The specific activity of the unesterified cholesterol was measured at intervals up to 24 h and a kinetic analysis of the data was performed. It assumes that both the cholesterol in the erythrocytes and the unesterified cholesterol in the plasma were homogeneous pools. The rate constants obtained for the movements of unesterified cholesterol from erythrocytes to plasma and from plasma to erythrocytes were not significantly different in the three labelling conditions (mean values: 0.26 and 1.5 h-1, respectively).     

Climatic niche breadth determines the response of bumblebees (<Emphasis Type="Italic">Bombus</Emphasis> spp.) to climate warming in mountain areas of the Northern Iberian Peninsula

Studies examining species range shifts in the face of climate change have consistently found that response patterns are complex and varied, suggesting that ecological traits might be affecting species response. However, knowledge of how the traits of a species determine its response to climate change is still poorly understood. Here we investigate the role of species-specific climate niche breadth in forecasting bumblebee (Bombus spp.) responses to regional climate warming in the Cantabrian Range (north-western Iberian Peninsula). Climate niche breadth was defined using known data for occurrences of specific species at their continental (i.e., European) scale of distribution. For each bumblebee species, climate niche breadth was found to be related to (1) the elevational range shifts of species between their historical (1988–1989) and recent (2007–2009) distribution and (2) the variation in the climatic conditions of the localities they inhabited (i.e., the local climate space) between both study periods. Our results show a strong relationship between climate niche breadth, particularly thermal niche breadth, and the response of bumblebee species to climate warming, but only when this response was determined as variations in local climate space. The main conclusions of our work are thus twofold. First, variations in the climatic conditions underlying range shifts are useful in making accurate assessments of the impact of climate change on species distributions. Second, climate niche breadth is a particularly informative ecological trait for forecasting variations in species responses to climate change.     

Rapid specialization of counter defenses enables two-spotted spider mite to adapt to novel plant hosts

Genetic adaptation, occurring over a long evolutionary time, enables host-specialized herbivores to develop novel resistance traits and to efficiently counteract the defenses of a narrow range of host plants. In contrast, physiological acclimation, leading to the suppression and/or detoxification of host defenses, is hypothesized to enable broad generalists to shift between plant hosts. However, the host adaptation mechanisms used by generalists composed of host-adapted populations are not known. Two-spotted spider mite (TSSM; Tetranychus urticae) is an extreme generalist herbivore whose individual populations perform well only on a subset of potential hosts. We combined experimental evolution, Arabidopsis thaliana genetics, mite reverse genetics, and pharmacological approaches to examine mite host adaptation upon the shift of a bean (Phaseolus vulgaris)-adapted population to Arabidopsis. We showed that cytochrome P450 monooxygenases are required for mite adaptation to Arabidopsis. We identified activities of two tiers of P450s: general xenobiotic-responsive P450s that have a limited contribution to mite adaptation to Arabidopsis and adaptation-associated P450s that efficiently counteract Arabidopsis defenses. In approximately 25 generations of mite selection on Arabidopsis plants, mites evolved highly efficient detoxification-based adaptation, characteristic of specialist herbivores. This demonstrates that specialization to plant resistance traits can occur within the ecological timescale, enabling the TSSM to shift to novel plant hosts.

Mites can evolve highly efficient detoxification-based adaptation in approximately 25 generations on an initially unfavorable plant host, revealing that specialization can occur within the ecological timescale.     

Bioinspiration as a method of problem‐based STEM education: A case study with a class structured around the COVID‐19 crisis

Bioinspiration is a promising lens for biology instruction as it allows the instructor to focus on current issues, such as the COVID‐19 pandemic. From social distancing to oxygen stress, organisms have been tackling pandemic‐related problems for millions of years. What can we learn from such diverse adaptations in our own applications? This review uses a seminar course on the COVID‐19 crisis to illustrate bioinspiration as an approach to teaching biology content. At the start of the class, students mind‐mapped the entire problem; this range of subproblems was used to structure the biology content throughout the entire class. Students came to individual classes with a brainstormed list of biological systems that could serve as inspiration for a particular problem (e.g., absorptive leaves in response to the problem of toilet paper shortages). After exploration of relevant biology content, discussion returned to the focal problem. Students dug deeper into the literature in a group project on mask design and biological systems relevant to filtration and transparency. This class structure was an engaging way for students to learn principles from ecology, evolution, behavior, and physiology. Challenges with this course design revolved around the interdisciplinary and creative nature of the structure; for instance, the knowledge of the participants was often stretched by engineering details. While the present class was focused on the COVID‐19 crisis, a course structured through a bioinspired approach can be applied to other focal problems, or subject areas, giving instructors a powerful method to deliver interdisciplinary content in an integrated and inquiry‐driven way.