02749nas a2200265 4500008004100000022001400041245009700055210006900152260001500221300000900236490000800245520197300253653001902226653001402245653001402259653000902273653001202282653001802294100002102312700002102333700002202354700001902376700002102395856006702416 2020 eng d a0038-071700aRelease of greenhouse gases from millipedes as related to food, body size, and other factors0 aRelease of greenhouse gases from millipedes as related to food b c28/02/2020 a1-100 v1443 a

The release of greenhouse gases from millipede digestive tracts warrants study because of its potential effect on climate change and also as an indicator of microbial processes that transform organic matter during passage through the gut of these animals. Gas chromatography was used to quantify the release of methane (CH4), carbon dioxide (CO2), and nitrous oxide (N2O) from living millipedes in laboratory conditions. The effect of four food types (leaf litter of alder, oak, and maple, and rotten wood) on the release of CH4, CO2, and N2O by 12 species was also assessed. In addition, two julid species were fed pure cellulose to test the ability of these millipedes to obtain energy from cellulose and to determine the effect of this diet on gas production.

All of the tested millipede species produced CO2 and some produced CH4. Stable and substantial CH4 emission was restricted to the large millipedes in the tropical orders Spirobolida and Spirostreptida. This asymmetrical phylogenetic distribution of CH4 production may be related to body size and the presence of gut commensals, but these factors may influence each other and depend upon geographic distribution of species. The quality of the food and feeding regime can also affect CH4 production in that CH4 release was significantly higher when millipedes were fed alder leaf litter rather than oak or maple leaf litter. CO2 production from millipedes mainly reflected the metabolic response of the animals. Traces of N2O were only occasionally emitted by millipedes; this release evidently depends on the N content in the food and seems to be restricted to members of the Glomeridae family. Based on gas production, the tested species of millipedes were unable to obtain their energy needs from a diet of pure cellulose.

10aCarbon dioxide10aCellulose10aDiplopoda10aFood10aMethane10aNitrous oxide1 aŠustr, Vladimir1 aŠimek, Miloslav1 aFaktorová, Lucie1 aMacková, Jana1 aTajovský, Karel uhttps://linkinghub.elsevier.com/retrieve/pii/S003807172030062602624nas a2200229 4500008004100000022001400041245006100055210006100116260001500177300000900192490000800201520194600209653001902155653002702174653001802201653002302219653001902242100002002261700002402281700002202305856006702327 2020 eng d a0965-174800aDiversity and evolution of the P450 family in arthropods0 aDiversity and evolution of the P450 family in arthropods c22/10/2020 a1-220 v1273 a

The P450 family (CYP genes) of arthropods encodes diverse enzymes involved in the metabolism of foreign compounds and in essential endocrine or ecophysiological functions. The P450 sequences (CYPome) from 40 arthropod species were manually curated, including 31 complete CYPomes, and a maximum likelihood phylogeny of nearly 3000 sequences is presented. Arthropod CYPomes are assembled from members of six CYP clans of variable size, the CYP2, CYP3, CYP4 and mitochondrial clans, as well as the CYP20 and CYP16 clans that are not found in Neoptera. CYPome sizes vary from two dozen genes in some parasitic species to over 200 in species as diverse as collembolans or ticks. CYPomes are comprised of few CYP families with many genes and many CYP families with few genes, and this distribution is the result of dynamic birth and death processes. Lineage-specific expansions or blooms are found throughout the phylogeny and often result in genomic clusters that appear to form a reservoir of catalytic diversity maintained as heritable units. Among the many P450s with physiological functions, six CYP families are involved in ecdysteroid metabolism. However, five so-called Halloween genes are not universally represented and do not constitute the unique pathway of ecdysteroid biosynthesis. The diversity of arthropod CYPomes has only partially been uncovered to date and many P450s with physiological functions regulating the synthesis and degradation of endogenous signal molecules (including ecdysteroids) and semiochemicals (including pheromones and defense chemicals) remain to be discovered. Sequence diversity of arthropod P450s is extreme, and P450 sequences lacking the universally conserved Cys ligand to the heme have evolved several times. A better understanding of P450 evolution is needed to discern the relative contributions of stochastic processes and adaptive processes in shaping the size and diversity of CYPomes.

10aDetoxification10aEcdysteroid metabolism10aGene clusters10aOrthologous groups10aP450 Evolution1 aDermauw, Wannes1 aVan Leeuwen, Thomas1 aFeyereisen, René uhttps://linkinghub.elsevier.com/retrieve/pii/S096517482030179X