Since its inception in 1973 the slightly deleterious model of molecular evolution, aka the Nearly Neutral Theory of molecular evolution, remains a central model to explain the main patterns of DNA polymorphism in natural populations. This is not to say that the quantitative fit to data is perfect. In a recent study CO_SCPLOWASTELLANOC_SCPLOW et al. (2018) used polymorphism data from D. melanogaster to test whether, as predicted by the Nearly Neutral Theory, the proportion of effectively neutral mutations...
Thu Jun 27, 2019 03:00
mRNA secondary structure assumes a critical role in gene regulation, especially for translational efficiency. Previous studies have a growing appreciation of purifying selection for the conserved mRNA structure across lineages of different species. However, the effect of mRNA structure on positive evolution remains unclear. Here, we construct a large-scale dataset of single nucleotide polymorphisms (SNPs) at synonymous sites in the population of Saccharomyces cerevisiae, combined with the experimental...
Thu Jun 27, 2019 03:00
Thanks to the development of high-throughput sequencing technologies, target enrichment sequencing of nuclear ultraconserved DNA elements (UCEs) now allows routinely inferring phylogenetic relationships from thousands of genomic markers. Recently, it has been shown that mitochondrial DNA (mtDNA) is frequently sequenced alongside the targeted loci in such capture experiments. Despite its broad evolutionary interest, mtDNA is rarely assembled and used in conjunction with nuclear markers in capture-based...
Thu Jun 27, 2019 03:00
Supernumerary (B) chromosomes are dispensable genomic elements found in most kinds of eukaryotic genomes. Many show drive mechanisms that give them an advantage in transmission, but how they achieve it remains a mystery. The recent finding of protein-coding genes in B chromosomes has opened the possibility that their evolutionary success is based on their genetic content. Using a protocol based on mapping genomic DNA Illumina reads from B-carrying and B-lacking individuals on the coding sequences...
Thu Jun 27, 2019 03:00
Plasticity and evolution are two processes enabling individuals to respond to environmental change, but how both are related and impact each other is still controversial. We studied plastic and evolutionary responses in gene expression of Tribolium castaneum after exposure to new environments that differed from ancestral conditions in temperature, humidity or both. Using experimental evolution with ten replicated lines per condition, we were able to demonstrate adaptation after 20 generations. We...
Thu Jun 27, 2019 03:00
The complex geological history and tropical climate of Mesoamerica create a rich source of biodiversity from which we can study evolutionary processes. Here, we discuss highly divergent forms of lake-dwelling fishes distributed across southern Mexico and Central America, originally recognized as members of different genera (Astyanax and Bramocharax). Recent phylogenetic studies suggest these morphotypes group within the same genus and readily hybridize. Despite genetic similarities, Bramocharax morphs...
Thu Jun 27, 2019 03:00
Hydrogen gas, H2, is generated in alkaline hydrothermal vents from reactions of iron containing minerals with water during a geological process called serpentinization. It has been a source of electrons and energy since there was liquid water on the early Earth, and it fuelled early anaerobic ecosystems in the Earth's crust. H2 is the electron donor for the most ancient route of biological CO2 fixation, the acetyl-CoA (or Wood-Ljungdahl) pathway, which unlike any other autotrophic pathway simultaneously...
Thu Jun 27, 2019 03:00
From publicly available next-gen sequencing datasets of non-model organisms, such as marine protists, arise opportunities to explore their evolutionary relationships. In this study we explored the effects that dataset and model selection have on the phylogenetic inference of the Gonyaulacales, single celled marine algae of the phylum Dinoflagellata with genomes that show extensive paralogy. We developed a method for identifying and extracting single copy genes from RNA-seq libraries and compared...
Thu Jun 27, 2019 03:00
A loss of sex is hypothesized to decrease the ability of hosts to evolve defenses against parasites, but no study of plants has tested how this affects genome-wide patterns of molecular evolution. Here, we test whether repeated losses of sex in the genus Oenothera alter the molecular evolution of defense genes against herbivores and pathogens. Using transcriptomes from 32 Oenothera species, we determined the function of 2431 orthologs. Phylogenetic Analysis by Maximum Likelihood was used to test...
Thu Jun 27, 2019 03:00
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Medicine by Alexandros G. Sfakianakis,Anapafseos 5 Agios Nikolaos 72100 Crete Greece,00302841026182,00306932607174,alsfakia@gmail.com,