Search results for "specificity"
showing 10 items of 2234 documents
Sex-specific responses to cold in a very cold-tolerant, northern Drosophila species
2021
Funding: This work was supported by Academy of Finland projects 268214 and 322980 to MK and a NERC (UK) grant NE/P000592/1 to MGR. Organisms can plastically alter resource allocation in response to changing environmental factors. For example, in harsh conditions, organisms are expected to shift investment from reproduction toward survival; however, the factors and mechanisms that govern the magnitude of such shifts are relatively poorly studied. Here we compared the impact of cold on males and females of the highly cold-tolerant species Drosophila montana at the phenotypic and transcriptomic levels. Although both sexes showed similar changes in cold tolerance and gene expression in response…
Successive Invasion-Mediated Interspecific Hybridizations and Population Structure in the Endangered Cichlid Oreochromis mossambicus.
2013
Hybridization between invasive and native species accounts among the major and pernicious threats to biodiversity. The Mozambique tilapia Oreochromis mossambicus, a widely used freshwater aquaculture species, is especially imperiled by this phenomenon since it is recognized by the IUCN as an endangered taxon due to genetic admixture with O. niloticus an invasive congeneric species. The Lower Limpopo and the intermittent Changane River (Mozambique) drain large wetlands of potentially great importance for conservation of O. mossambicus, but their populations have remained unstudied until today. Therefore we aimed (1) to estimate the autochthonous diversity and population structure among genet…
ENDEMIC HANTAVIRUS INFECTION IMPAIRS THE WINTER SURVIVAL OF ITS RODENT HOST
2007
The influence of pathogens on host fitness is one of the key questions in infection ecology. Hantaviruses have coevolved with their hosts and are generally thought to have little or no effect on host survival or reproduction. We examined the effect of Puumala virus (PUUV) infection on the winter survival of bank voles (Myodes glareolus), the host of this virus. The data were collected by monitoring 22 islands over three consecutive winters (a total of 55 island populations) in an endemic area of central Finland. We show that PUUV infected bank voles had a significantly lower overwinter survival probability than antibody negative bank voles. Antibody negative female bank voles from low-densi…
Sex-pairing pheromones and reproductive isolation in three sympatric Cornitermes species (Isoptera, Termitidae, Syntermitinae)
2011
International audience; The species-specificity of pairing has been studied in three sympatric Neotropical termites: Cornitermes bequaerti, Cornitermes cumulans and Cornitermes silvestrii (Termitidae, Syntermitinae). Bioassays showed that sex attraction was highly species-specific between C. bequaerti and C cumulans but not between C. cumulans and C. silvestrii. The sex-pairing pheromone of the three species is secreted by the tergal glands of female alates. It consists of a common compound (3Z,6Z,8E)-dodeca-3,6,8-trien-1-ol. In C. bequaerti, this polyunsaturated alcohol is the only compound of the sex-pairing pheromone, whereas it is associated with the oxygenated sesquiterpene (E)-nerolid…
Widespread vertical transmission and associated host sex–ratio distortion within the eukaryotic phylum Microspora
2004
Vertical transmission (VT) and associated manipulation of host reproduction are widely reported among prokaryotic endosymbionts. Here, we present evidence for widespread use of VT and associated sex-ratio distortion in a eukaryotic phylum. The Microspora are an unusual and diverse group of eukaryotic parasites that infect all animal phyla. Following our initial description of a microsporidian that feminizes its crustacean host, we survey the diversity and distribution of VT within the Microspora. We find that vertically transmitted microsporidia are ubiquitous in the amphipod hosts sampled and that they are also diverse, with 11 species of microsporidia detected within 16 host species. We f…
Description of a new genus of Euliina with unique coupling adaptations of the male and female (Lepidoptera: Tortricidae: Tortricinae: Cochylini)
2017
Ancoruncus langeri, new genus and new species, is described and illustrated from the Neotropics (Bolivia). It is assigned to the tribe Cochylini (subtribe Euliina) in the family Tortricidae. Ancoruncus langeri is characterized by an unusual, strongly developed uncus, distally expanded into an anchor-like, bilobed apical process and a complex gnathos in male genitalia, as well as an unusual configuration of the anterior lobes of the papillae anales, and tergum 8 with the anterior area bearing a double pocket in the female genitalia. The hypothetical dorsal coupling mechanism of the male and female genitalia is discussed.
Identifying a key host in an acanthocephalan-amphipod system.
2015
SUMMARYTrophically transmitted parasites may use multiple intermediate hosts, some of which may be ‘key-hosts’, i.e. contributing significantly more to the completion of the parasite life cycle, while others may be ‘sink hosts’ with a poor contribution to parasite transmission. Gammarus fossarum and Gammarus roeseli are sympatric crustaceans used as intermediate hosts by the acanthocephalan Pomphorhynchus laevis. Gammarus roeseli suffers higher field prevalence and is less sensitive to parasite behavioural manipulation and to predation by definitive hosts. However, no data are available on between-host differences in susceptibility to P. laevis infection, making it difficult to untangle the…
Flexible parental care: Uniparental incubation in biparentally incubating shorebirds
2017
The relative investment of females and males into parental care might depend on the population’s adult sex-ratio. For example, all else being equal, males should be the more caring sex if the sex-ratio is male biased. Whether such outcomes are evolutionary fixed (i.e. related to the species’ typical sex-ratio) or whether they arise through flexible responses of individuals to the current population sex-ratio remains unclear. Nevertheless, a flexible response might be limited by the evolutionary history of the species, because one sex may have lost the ability to care or because a single parent cannot successfully raise the brood. Here, we demonstrate that after the disappearance of one pare…
Sex Differences in Age-Associated Type 2 Diabetes in Rats—Role of Estrogens and Oxidative Stress
2019
Females live longer than males, and the estrogens are one of the reasons for this difference. We reported some years ago that estrogens are able to protect rats against oxidative stress, by inducing antioxidant genes. Type 2 diabetes is an age-associated disease in which oxidative stress is involved, and moreover, some studies show that the prevalence is higher in men than in women, and therefore there are sex-associated differences. Thus, the aim of this study was to evaluate the role of estrogens in protecting against oxidative stress in type 2 diabetic males and females. For this purpose, we used Goto-Kakizaki rats, which develop type 2 diabetes with age. We found that female diabetic ra…
Circulating miRNAs as diagnostic biomarkers for adolescent idiopathic scoliosis
2018
AbstractThe aetiology of adolescent idiopathic scoliosis (AIS) has been linked to many factors, such as asymmetric growth, neuromuscular condition, bone strength and genetic background. Recently, epigenetic factors have been proposed as contributors of AIS physiopathology, but information about the molecular mechanisms and pathways involved is scarce. Regarding epigenetic factors, microRNAs (miRNAs) are molecules that contribute to gene expression modulation by regulating important cellular pathways. We herein used Next-Generation Sequencing to discover a series of circulating miRNAs detected in the blood samples of AIS patients, which yielded a unique miRNA biomarker signature that diagnos…