Bragghildebrandt4293

Homing endonucleases (HE) are enzymes capable of cutting DNA at highly specific target sequences, the repair of the generated double-strand break resulting in the insertion of the HE-encoding gene ("homing" mechanism). HEs are present in all three domains of life and viruses; in eukaryotes, they are mostly found in the genomes of mitochondria and chloroplasts, as well as nuclear ribosomal RNAs. We here report the case of a HE that accidentally integrated into a telomeric region of the nuclear genome of the fungal maize pathogen Ustilago maydis. https://www.selleckchem.com/products/litronesib.html We show that the gene has a mitochondrial origin, but its original copy is absent from the U. maydis mitochondrial genome, suggesting a subsequent loss or a horizontal transfer from a different species. The telomeric HE underwent mutations in its active site and lost its original start codon. A potential other start codon was retained downstream, but we did not detect any significant transcription of the newly created open reading frame, suggesting that the inserted gene is not functional. Besides, the insertion site is located in a putative RecQ helicase gene, truncating the C-terminal domain of the protein. The truncated helicase is expressed during infection of the host, together with other homologous telomeric helicases. This unusual mutational event altered two genes The integrated HE gene subsequently lost its homing activity, while its insertion created a truncated version of an existing gene, possibly altering its function. As the insertion is absent in other field isolates, suggesting that it is recent, the U. maydis 521 reference strain offers a snapshot of this singular mutational event.The worldwide biodiversity crisis with the resulting need to increase species protection has led researchers to pursue and select survey methods that guarantee the best quality of data and produce the least negative effects on wild animals. Plethodontids are the most diverse family of salamanders; all species are very sensitive to human handling and noninvasive, but accurate, measurement methods are needed to reduce researchers' impact. Here, we tested the reliability of a noninvasive post hoc method in estimating the snout-vent length (SVL) from photographs showing salamanders' dorsal view. The correlation between the estimated snout-vent length (SVLe) and the conventional SVL was high (R2 m = .81), and no significant difference occurred between operators with different experience. Finally, we list the numerous advantages for the use of SVLe in terms of data quality and in reducing the stress caused to wild animals.Closely related species are often assumed to be functionally similar. Phylogenetic information is thus widely used to infer functional diversity and assembly of communities. In contrast, evolutionary processes generating functional similarity of phylogenetically distinct taxa are rarely addressed in this context.To investigate the impact of convergent evolution on functional diversity (FD) and phylogenetic diversity (PD), we reconstructed the phylogenetic structure of carabid trophic groups. We then analyzed the mandible shapes using geometric morphometrics to link specialization in functional morphology with feeding specialization among herbivores, generalist carnivores, and specialized consumers of Collembola.Our results show that carabid feeding groups are paraphyletic. Herbivory evolved at least twice and specialization to Collembola predation at least three times. Species within feeding groups share a remarkably similar mandible morphology, which evolved convergently. While specialized mandibles of herbivores and collembolan specialists represent an adaptation to their main food source, the particular mandible morphologies do not necessarily reflect the degree of food specialization within feeding groups. Only a few species with a specialized herbivorous mandible may occasionally feed on animals, but the range of specific food resources in generalist carnivore species is large, despite an almost identical mandible shape.Thus, convergent evolution in specialized feeding groups reverses the relationship between PD and functional similarity compared with generalist carnivores. We conclude that phylogenetic relationship is a poor proxy of FD in carabids. Moreover, the inconsistencies between relatedness, morphological adaptation, and ecological function require caution in the characterization of functional groups. Rather than assuming general relationships between PD and FD, we suggest integrating the analysis of evolutionary processes into functional community analyses.As populations differentiate across geographic or host-association barriers, interpopulation fertility is often a measure of the extent of incipient speciation. The bed bug, Cimex lectularius L., was recently found to form two host-associated lineages within Europe one found with humans (human-associated, HA) and the other found with bats (bat-associated, BA). No unequivocal evidence of contemporary gene flow between these lineages has been found; however, it is unclear whether this is due to an inability to produce viable "hybrid" offspring. To address this question and determine the extent of compatibility between host-associated lineages, we set up mating crosses among populations of bed bugs based on both their host association (human-HA vs. bat-BA) and geographic origin (North America vs. Europe). Within-population fecundity was significantly higher for all HA populations (>1.7 eggs/day) than for BA populations (92% egg hatch rates. Contrary to previous reports, in all interlineage crosses, successful matings occurred, fertile eggs were oviposited, and the F1 "hybrid" generation was found to be reproductively viable. In addition, we evaluated interpopulation genetic variation in Wolbachia among host-associated lineages. We did not find any clear patterns related to host association, nor did we observe a homogenization of Wolbachia lineages across populations that might explain a breakdown of reproductive incompatibility. These results indicate that while the HA and BA populations of C. lectularius represent genetically differentiated host-associated lineages, possibly undergoing sympatric speciation, this is in its incipient stage as they remain reproductively compatible. Other behavioral, physiological, and/or ecological factors likely maintain host-associated differentiation.