Knowledge of mutation processes is central to understanding virtually all evolutionary phenomena and the underlying nature genetic disorders cancers. However, limitations standard molecular detection methods have historically precluded a genome-wide rates spectra in nuclear genomes multicellular organisms. We applied two high-throughput DNA sequencing technologies identify characterize hundreds spontaneously arising base-substitution mutations 10 Caenorhabditis elegans mutation-accumulation...

Variation among lineages in the mutation process has potential to impact diverse biological processes ranging from susceptibilities genetic disease mode and tempo of molecular evolution. The combination high-throughput DNA sequencing (HTS) with mutation-accumulation (MA) experiments provided a powerful approach genome-wide analysis, though insights into mutational variation have been limited by vast evolutionary distances few species analyzed. We performed HTS analysis MA lines derived four...

Abstract The exceptional diversity of insects is often attributed to the effects specialized relationships between and their hosts. Parasite–host interactions are influenced by current natural selection dispersal, in addition historical that may include past selection, vicariance, random genetic drift. Both events can lead reduced fitness on some If trade‐offs alternate hosts common, adaptation one host prevent another, giving rise differentiation among host‐associated lineages. Previous...

Deleterious mutations are of fundamental importance to all aspects organismal biology. Evolutionary geneticists have expended tremendous effort estimate the genome-wide rate mutation and effects new on fitness, but degree which genomic mutational properties vary within between taxa is largely unknown, particularly in multicellular organisms. Beginning with two highly inbred strains from each three species nematode family Rhabditidae ( Caenorhabditis briggsae , elegans Oscheius myriophila ),...

Genetic and developmental architecture may bias the mutationally available phenotypic spectrum. Although such asymmetries in introduction of variation influence possible evolutionary trajectories, we lack quantitative characterization biases inducible variation, their genotype-dependence, underlying molecular causes. Here quantify accessible spectrum vulval system using mutation accumulation (MA) lines derived from four wild isolates nematodes Caenorhabditis elegans C. briggsae. The results...

Mutation rate often increases with environmental temperature, but establishing causality is complicated. Asymmetry between physiological stress and deviation from the optimal temperature means that are confounded. We allowed mutations to accumulate in two species of Caenorhabditis for approximately 100 generations at 18°C 165 26°C; 26°C stressful elegans not briggsae . report mutation rates a set microsatellite loci estimates per-generation decay fitness (Δ M w ), genomic ( U ) average...

The mutational process varies at many levels, from within genomes to among taxa. Many mechanisms have been linked variation in mutation, but understanding of the evolution is rudimentary. Physiological condition often implicated as a source microbial mutation rate and may contribute multicellular organisms. Deleterious mutations are an ubiquitous condition. We test hypothesis that depends on underlying load two groups Caenorhabditis elegans accumulation (MA) lines differ their starting...

With within-species genetic diversity estimates that span the gamut of seen across entirety animals, Caenorhabditis genus nematodes holds unique potential to provide insights into how population size and reproductive strategies influence gene genome organization evolution. Our study focuses on brenneri, currently known as one most genetically diverse within its and, notably, Metazoa. Here, we present a high-quality, gapless assembly annotation for C. revealing common nematode chromosome...

The importance of genomic structural variants (SVs) is well-appreciated, but much less known about their mutational properties than single nucleotide (SNVs) and short indels. reason simple: the longer mutation, likely it will be covered by a sequencing read, thus harder to map unambiguously unique location. Here we report SV mutation rate estimates from six accumulation (MA) lines two strains C. elegans (N2 PB306) using long-read (PacBio) sequencing. inferred ~1/10 SNV ~1/4 indel rate. We...

It has long been hypothesized that the rate of molecular evolution in birds is slow relative to other tetrapods, particularly mammals, based on small genetic distances between bird taxa (e.g., Prager et al. 1974; Britten 1986). These studies rely heavily, however, accurate dating fossils or biogeographic events estimating taxonomic divergence times. Adachi, Cao, and Hasegawa (1993) used a test, not dependent dating, found significantly slower mitochondrial amino acid substitution chicken...

Recent evidence suggests that mutation rates are fitness-dependent, broadening our view of the impacts on genetic health populations.

Important clues about natural selection can be gleaned from discrepancies between the properties of segregating genetic variants and mutations accumulated experimentally under minimal selection, provided mutational process is same in laboratory as nature. The base-substitution spectrum differs C. elegans mutation accumulation (MA) experiments standing site-frequency spectrum, which has been argued to part owing increased oxidative stress environment. Using genome sequence data MA lines...

Abstract It is often assumed that the mutation rate an evolutionarily optimized property of a taxon. The relevant for mutations affect fitness, U, but strength selection on depends average effect mutation. Determination U complicated by possibility mutational effects depend particular environmental context in which organism exists. has been suggested deleterious are typically magnified stressful environments, most studies confound genotype with environment, so it unclear to what extent...

Mitochondrial DNA (mtDNA) mutations underlie a variety of human genetic disorders and are associated with the aging process. mtDNA polymorphisms widely used in evolutionary applications. Although mutation spectra known to differ between distantly related model organisms, extent which processes vary more closely species within remains enigmatic. We analyzed divergence two sets 250-generation Caenorhabditis briggsae mutation-accumulation (MA) lines, each derived from different natural isolate...

Variation in rates of molecular evolution has been attributed to numerous, interrelated causes, including metabolic rate, body size, and generation time. Speculation concerning the influence rate on often invokes putative mutagenic effects oxidative stress. To isolate stress germline from time, other factors, we allowed mutations accumulate under relaxed selection for 125 generations two strains nematode Caenorhabditis elegans, canonical wild-type strain (N2) a mutant with elevated...

Abstract The distribution of fitness effects (DFE) for new mutations is one the most theoretically important but difficult to estimate properties in population genetics. A crucial challenge inferring DFE from natural genetic variation sensitivity site frequency spectrum factors like size change, substructure, genome structure, and nonrandom mating. Although inference methods aim control changes, influence mating remains incompletely understood, despite being a common feature many species. We...

Abstract.— Tradeoffs in performance or fitness across environments have important implications regarding the nature of evolutionary constraints. It remains controversial whether tradeoffs such as these reflect genetic correlations that are genuine However, if long‐term constraints do exist, they must be due to underlying pleiotropy alleles confer high one environment invariably low another. The distribution within and among populations can provide insight about existence pleiotropic...

Mutational bias is a potentially important agent of evolution, but it difficult to disentangle the effects mutation from those natural selection. Mutation-accumulation experiments, in which mutations are allowed accumulate at very small population size, thus minimizing efficiency selection, best way separate Body size varies greatly among species nematode family rhabditidae; mutational biases both potential cause and consequence that variation. We report data on cumulative affect body three...

The evolution of canalization, the robustness phenotype to environmental or genetic perturbation, has attracted considerable recent interest. A key step toward understanding any is characterizing rate at which mutation introduces variation for trait (the mutational variance, VM) and average directional effects mutations on mean (ΔM). In this study, parameters canalization productivity body volume are quantified in two sets accumulation lines nematodes genus Caenorhabditis compared with...

Understanding the evolutionary processes responsible for shaping genetic variation within and between species requires separating effects of mutation selection. Differences patterns observed in nature when mutations are allowed to accumulate relative absence selection can reveal biases imposed by We characterize at dinucleotide microsatellite repeats four sets 250-generation accumulation (MA) lines, two Caenorhabditis briggsae elegans, compare mutational with standing those species. also...

Mutation rate may be condition dependent, whereby individuals in poor condition, perhaps from high mutation load, have higher rates than good condition. Agrawal (J. Evol. Biol.15, 2002, 1004) explored the basic properties of fitness-dependent (FDMR) infinite populations and reported some heuristic results for finite populations. The key parameter governing how evolve under FDMR is curvature (k) relationship between fitness rate. We extend Agrawal's analysis to consider dominance epistasis....