Search results for "Systematics"
showing 10 items of 6702 documents
The effect of a temperature-sensitive prophage on the evolution of virulence in an opportunistic bacterial pathogen.
2022
https://doi.org/10.1111/mec.16638 Abstract Viruses are key actors of ecosystems and have major impacts on global biogeochemical cycles. Prophages deserve particular attention as they are ubiquitous in bacterial genomes and can enter a lytic cycle when triggered by environmental conditions. We explored how temperature affects the interactions between prophages and other biological levels by using an opportunistic pathogen, the bacterium Serratia marcescens, that harbours several prophages and that had undergone an evolution experiment under several temperature regimes. We found that the release of one of the prophages was temperature-sensitive and malleable to evolutionary changes. We furthe…
Genome degeneration and adaptation in a nascent stage of symbiosis
2014
Symbiotic associations between animals and microbes are ubiquitous in nature, with an estimated 15% of all insect species harboring intracellular bacterial symbionts. Most bacterial symbionts share many genomic features including small genomes, nucleotide composition bias, high coding density, and a paucity of mobile DNA, consistent with long-term host association. In this study, we focus on the early stages of genome degeneration in a recently derived insect-bacterial mutualistic intracellular association. We present the complete genome sequence and annotation of Sitophilus oryzae primary endosymbiont (SOPE). We also present the finished genome sequence and annotation of strain HS, a close…
Spatial variation in the evolutionary potential and constraints of basal metabolic rate and body mass in a wild bird
2023
An organism's energy budget is strongly related to resource consumption, performance, and fitness. Hence, understanding the evolution of key energetic traits, such as basal metabolic rate (BMR), in natural populations is central for understanding life-history evolution and ecological processes. Here we used quantitative genetic analyses to study evolutionary potential of BMR in two insular populations of the house sparrow (Passer domesticus). We obtained measurements of BMR and body mass (Mb) from 911 house sparrows on the islands of Leka and Vega along the coast of Norway. These two populations were the source populations for translocations to create an additional third, admixed ‘common ga…
Biological and Mechanical Characterization of the Random Positioning Machine (RPM) for Microgravity Simulations
2021
The rapid improvement of space technologies is leading to the continuous increase of space missions that will soon bring humans back to the Moon and, in the coming future, toward longer interplanetary missions such as the one to Mars. The idea of living in space is charming and fascinating; however, the space environment is a harsh place to host human life and exposes the crew to many physical challenges. The absence of gravity experienced in space affects many aspects of human biology and can be reproduced in vitro with the help of microgravity simulators. Simulated microgravity (s-μg) is applied in many fields of research, ranging from cell biology to physics, including cancer biology. In…
Fatty acid composition as biomarkers of freshwater microalgae: analysis of 37 strains of microalgae in 22 genera and in seven classes
2013
The fatty acid (FA) composition of algae is an important determinant of their food quality for consumers, and FAs can also be used as biomarkers for biochemical and energetic pathways in food webs. FA analyses of 7 freshwater algal classes and 37 strains showed clear similarity within classes and strong differences amongst classes. Class was a dominant factor (66.4%) explaining variation in FA signatures of microalgae. The 7 algal classes comprised 4 separate groups according to their FA profiles: (1) Chlorophyceae and Trebouxiophyceae, (2) Bacillariophyceae, (3) Cryptophyceae, Chrysophyceae, and Raphidophyceae, and (4) Euglenophyceae. Each group had a characteristic FA composition, althoug…
Catalogue of the Diptera (Insecta) of Morocco— an annotated checklist, with distributions and a bibliography
2022
The faunistic knowledge of the Diptera of Morocco recorded from 1787 to 2021 is summarized and updated in this first catalogue of Moroccan Diptera species. A total of 3057 species, classified into 948 genera and 93 families (21 Nematocera and 72 Brachycera), are listed. Taxa (superfamily, family, genus and species) have been updated according to current interpretations, based on reviews in the literature, the expertise of authors and contributors, and recently conducted fieldwork. Data to compile this catalogue were primarily gathered from the literature. In total, 1225 references were consulted and some information was also obtained from online databases. Each family was reviewed and the c…
Measuring, comparing and interpreting phenotypic selection on floral scent
2022
Natural selection on floral scent composition is a key element of the hypothesis that pollinators and other floral visitors drive scent evolution. The measure of such selection is complicated by the high-dimensional nature of floral scent data and uncertainty about the cognitive processes involved in scent-mediated communication. We use dimension reduction through reduced-rank regression to jointly estimate a scent composite trait under selection and the strength of selection acting on this trait. To assess and compare variation in selection on scent across species, time and space, we reanalyse 22 datasets on six species from four previous studies. The results agreed qualitatively with prev…
Subtropical streams harbour higher genus richness and lower abundance of insects compared to boreal streams, but scale matters
2018
Aim: Biological diversity typically varies between climatically different regions, and regions closer to the equator often support higher numbers of taxa than those closer to the poles. However, these trends have been assessed for a few organism groups, and the existing studies have rarely been based on extensive identical surveys in different climatic regions. Location: We conducted standardized surveys of wadeable streams in a boreal (western Finland) and a subtropical (south-eastern Brazil) region, sampling insects identically from 100 streams in each region and measuring the same environmental variables in both regions. Taxon: Aquatic insects. Methods: Comparisons were made at the scale…
First insights into female sperm storage duration in tardigrades.
2022
Female sperm storage is ubiquitous in the animal kingdom and it has been shown to be linked to several evolutionary processes, from postcopulatory sexual selection to dispersal. Here we report, for the first time, long-term sperm storage in females of the tardigrade Macrobiotus polonicus. Females, isolated after a short contact with a male, were able to use the stored sperm for up to 5 weeks (mean of 2 weeks), which translates to a considerable proportion of female post-mating longevity under controlled laboratory conditions (60% on average). Our study provides the first insights into the duration of sperm storage, an underexplored feature of the reproductive biology of tardigrades. Additio…
New genera, species and records of Phaneropterinae (Orthoptera, Phaneropteridae) from sub-Saharan Africa
2015
The results of the study of many specimens preserved in different European museums are reported. The tribe Terpnistrini Brunner von Wattenwyl, 1878 is resurrected. The distribution of the following species is enhanced: Pardalotaasymmetrica Karsch, 1896, Diogenadenticulata Chopard, 1954, Diogenafausta (Burmeister, 1838), Plangiopsisadeps Karsch, 1896, Poreuomenasanghensis Massa, 2013 and Tylopsiscontinua (Walker, 1869). Further, for their peculiar characteristics, two African representatives of the American genus Symmetropleura Brunner von Wattenwyl, 1878 are included in two new genera: Symmetrokarschiaafricana (Brunner von Wattenwyl, 1878), comb. n. and Symmetroraggeadirempta (Karsch, 1889)…