Search results for "GENETICS"
showing 10 items of 12494 documents
Sexual selection in a wolf spider: Male drumming activity, body size, and viability
1996
Females are often believed to actively choose highly ornamented males (males with extravagant morphological signals or intense sexual display), and ornaments should be honest signals of male viability. However, this belief is relying only on some pieces of empirical evidence from birds. Our study reports active female choice on sexual display that indicates male viability in spiders. We established trials in which we studied female choice in relation to male courtship drumming activity and body size. Females chose the most actively drumming males as mating partners, but the body size of the males did not seem to be selected. Male drumming activity turned out to be a good predictor of male v…
Viability selection creates negative heterozygosity–fitness correlations in female Black Grouse Lyrurus tetrix
2017
There is widespread interest in the relationship between individual genetic diversity and fitness–related traits (heterozygosity–fitness correlations, HFC). Most studies found weak continuous increases of fitness with increasing heterozygosity while negative HFC have rarely been reported. Negative HFC are expected in cases of outbreeding depression and outbreeding is rare in natural populations; but negative HFC may also arise through viability selection acting on low heterozygosity individuals at an early stage producing a skew in the heterozygosity distribution leading to negative HFCs. We tested this idea using survival and clutch parameters (egg mass, egg volume, chick mass, clutch size…
Give me a sample of air and I will tell which species are found from your region : Molecular identification of fungi from airborne spore samples
2017
Fungi are a megadiverse group of organisms, they play major roles in ecosystem functioning and are important for human health, food production and nature conservation. Our knowledge on fungal diversity and fungal ecology is however still very limited, in part because surveying and identifying fungi is time demanding and requires expert knowledge. We present a method that allows anyone to generate a list of fungal species likely to occur in a region of interest, with minimal effort and without requiring taxonomical expertise. The method consists of using a cyclone sampler to acquire fungal spores directly from the air to an Eppendorf tube, and applying DNA barcoding with probabilistic specie…
Host dispersal shapes the population structure of a tick-borne bacterial pathogen
2020
Birds are hosts for several zoonotic pathogens. Because of their high mobility, especially of longdistance migrants, birds can disperse these pathogens, affecting their distribution and phylogeography. We focused on Borrelia burgdorferi sensu lato, which includes the causative agents of Lyme borreliosis, as an example for tick-borne pathogens, to address the role of birds as propagation hosts of zoonotic agents at a large geographical scale. We collected ticks from passerine birds in 11 European countries. B. burgdorferi s.l. prevalence in Ixodes spp. was 37% and increased with latitude. The fieldfare Turdus pilaris and the blackbird T. merula carried ticks with the highest Borrelia prevale…
Clonal populations of Clavibacter michiganensis subsp michiganensis are responsible for the outbreaks of bacterial canker in greenhouse tomatoes in I…
2015
Clavibacter michiganensis subsp. michiganensis (Cmm) strains, collected in greenhouses from 17 farms during tomato bacterial canker outbreaks occurring between 2005 and 2008 in Sicily, were analysed by a multiphasic approach. Population studies were conducted to investigate the possible sources of inocula. Cmm strains were characterized by PCR assays targeting virulence genes, fingerprinting techniques, metabolic profiles and virulence. These strains were comparatively analysed with Cmm strains isolated in other parts of Italy over a period of 15 years. Chromosomal genes encoding virulence determinants tomA, ppaA, chpC, and the plasmid-encoded genes pat-1 and celA were detected by PCR in al…
Environmental DNA effectively captures functional diversity of coastal fish communities.
2020
Robust assessments of taxonomic and functional diversity are essential components of research programmes aimed at understanding current biodiversity patterns and forecasting trajectories of ecological changes. Yet, evaluating marine biodiversity along its dimensions is challenging and dependent on the power and accuracy of the available data collection methods. Here we combine three traditional survey methodologies (underwater visual census strip transects [UVCt], baited underwater videos [BUV] and small-scale fishery catches [SSFc]), and one novel molecular technique (environmental DNA metabarcoding [eDNA]-12S rRNA and cytochrome oxidase subunit 1 [COI]) to investigate their efficiency and…
Specimens at the Center: An Informatics Workflow and Toolkit for Specimen-level analysis of Public DNA database data
2016
Pham, Kasey K. [et al.]
Multiple mechanisms of cryptic female choice act on intraspecific male variation in Drosophila simulans
2016
Postcopulatory sexual selection can arise when females mate with multiple males and is usually mediated by an interaction between the sexes. Cryptic female choice (CFC) is one form of postcopulatory sexual selection that occurs when female morphology, physiology, or behavior generates a bias in fertilization success. However, its importance in nonrandom reproductive success is poorly resolved due to challenges distinguishing the roles of females and males in generating patterns of fertilization bias. Nevertheless, two CFC mechanisms have recently been documented and characterized in Drosophila simulans within the context of gametic isolation in competitive hybrid matings with Drosophila mau…
Essentiality Is a Strong Determinant of Protein Rates of Evolution during Mutation Accumulation Experiments in Escherichia coli
2016
[EN] The Neutral Theory of Molecular Evolution is considered the most powerful theory to understand the evolutionary behavior of proteins. One of the main predictions of this theory is that essential proteins should evolve slower than dispensable ones owing to increased selective constraints. Comparison of genomes of different species, however, has revealed only small differences between the rates of evolution ofessential and nonessential proteins. In some analyses, these differences vanish once confounding factors are controlled for, whereas in other cases essentiality seems to have an independent, albeit small, effect. It has been argued that comparing relatively distant genomes may entai…
Genetic Basis of Body Color and Spotting Pattern in Redheaded Pine Sawfly Larvae (Neodiprion lecontei)
2018
Abstract Pigmentation has emerged as a premier model for understanding the genetic basis of phenotypic evolution, and a growing catalog of color loci is starting to reveal biases in the mutations, genes, and genetic architectures underlying color variation in the wild. However, existing studies have sampled a limited subset of taxa, color traits, and developmental stages. To expand the existing sample of color loci, we performed QTL mapping analyses on two types of larval pigmentation traits that vary among populations of the redheaded pine sawfly (Neodiprion lecontei): carotenoid-based yellow body color and melanin-based spotting pattern. For both traits, our QTL models explained a substan…