Round gobies (Neogobius melanostomus) in the River Rhine: Population genetic support for invasion via two different routes.

The round goby, Neogobius melanostomus, is a successful invasive fish species. Originating from the Caspian and Black Sea, it is now distributed widely within European fresh- and brackish waters. The River Rhine was colonized in 2008 only a few years after the opening of the Rhine-Main-Danube canal and only four years after N.

Influence of salinity on the thermal tolerance of aquatic organisms.

Aquatic organisms are challenged by changes in their external environment, such as temperature and salinity fluctuations. If these variables interacted with each other, the response of organisms to temperature changes would be modified by salinity and vice versa. We tested for potential interaction between temperature and salinity effects on freshwater, brackish, and marine organisms, including algae, macrophytes, heterotrophic protists, parasites, invertebrates, and fish.

Field application of de novo transcriptomic analysis to evaluate the effects of sublethal freshwater salinization on Gasterosteus aculeatus in urban streams.

Freshwater salinization poses global challenges for aquatic organisms inhabiting urban streams, impacting their physiology and ecology. However, current salinization research predominantly focuses on mortality endpoints in limited model species, overlooking the sublethal effects on a broader spectrum of organisms and the exploration of adaptive mechanisms and pathways under natural field conditions. To address these gaps, we conducted high-throughput sequencing transcriptomic analysis on the gill tissue of the euryhaline fish Gasterosteus aculeatus, investigating its molecular response to salinity stress in the highly urbanized river Boye, Germany.

The Asymmetric Response Concept explains ecological consequences of multiple stressor exposure and release.

Our capacity to predict trajectories of ecosystem degradation and recovery is limited, especially when impairments are caused by multiple stressors. Recovery may be fast or slow and either complete or partial, sometimes result in novel ecosystem states or even fail completely. Here, we introduce the Asymmetric Response Concept (ARC) that provides a basis for exploring and predicting the pace and magnitude of ecological responses to, and release from, multiple stressors.

Burnout in medical students.

Only a small number of studies have examined the relationship between medical students and burnout syndrome. In Salzburg, Paracelsus Private Medical University (PMU) offers a 5‑year medical program instead of the regular 6 years of medical studies. Due to the tight schedule and heavy workload, the stress level of students is high.

Linking local movement and molecular analysis to explore philopatry and population connectivity of the southern stingray Hypanus americanus.

Limited data pertaining to life history and population connectivity of the data-deficient southern stingray (Hypanus americanus) are available. To determine potential vulnerabilities of their populations, this study aimed to analyse their movement patterns and genetic variability. A population of southern stingrays encompassing nine sites around Cape Eleuthera, the Bahamas, has been monitored using mark-recapture, spanning a 2.

Red Queen revisited: Immune gene diversity and parasite load in the asexual Poecilia formosa versus its sexual host species P. mexicana.

In accordance with the Red Queen hypothesis, the lower genotypic diversity in clonally reproducing species should make them easier targets for pathogen infection, especially when closely related sexually reproducing species occur in close proximity. We analyzed two populations of clonal P. formosa and their sexual parental species P.

Oxygen concentration drives local adaptation in the greenlip abalone (Haliotis laevigata).

Understanding adaptation has become one of the major biological questions especially in the light of rapid environmental changes induced by climate change. Ocean temperatures are rising which triggers massive changes in water chemistry and thereby alters the living environment of all marine organisms. Studying adaptation, however, can be tricky because spatial genetic patterns might also occur due to random effects, for example, genetic drift.

Clonal polymorphism and high heterozygosity in the celibate genome of the Amazon molly.

The extreme rarity of asexual vertebrates in nature is generally explained by genomic decay due to absence of meiotic recombination, thus leading to extinction of such lineages. We explore features of a vertebrate asexual genome, the Amazon molly, Poecilia formosa, and find few signs of genetic degeneration but unique genetic variability and ongoing evolution. We uncovered a substantial clonal polymorphism and, as a conserved feature from its interspecific hybrid origin, a 10-fold higher heterozygosity than in the sexual parental species.

Increase of prostaglandin E2 in the reversal of fetal ductal constriction after polyphenol restriction.

Objective: Anti-inflammatory substances that inhibit the synthesis of prostaglandins, such as non-steroidal anti-inflammatory drugs (NSAIDs) and polyphenol-rich foods, can cause constriction of the fetal ductus arteriosus. This study aimed to test the hypothesis that reversal of fetal ductal constriction after maternal restriction of polyphenol-rich foods, in the third trimester of pregnancy, is accompanied by increased plasma levels of prostaglandin E2 (PGE2).

Methods: This was a controlled clinical trial of women with singleton pregnancy ≥ 28 weeks undergoing fetal echocardiography.

Polyphenol supplementation inhibits physiological increase of prostaglandin E2 during reproductive period - A randomized clinical trial.

Anti-inflammatory property of polyphenols and their effect on the metabolism of prostaglandins is not established in healthy humans. This study aimed to evaluate the effect of polyphenol supplementation in plasma levels of prostaglandin E and other markers of inflammation and oxidative stress in women using contraceptives. In this randomized double-blind clinical trial, women aged 25-35 years were selected.

First record of second-generation facultative parthenogenesis in a vertebrate species, the whitespotted bambooshark Chiloscyllium plagiosum.

In this study, two parthenogenetic events within a family of the whitespotted bambooshark Chiloscyllium plagiosum are reported. A captive female produced multiple parthenogens. Unexpectedly, a single specimen of a total of nine parthenogens displayed external claspers characterizing the male sex in chondrichthyans.

More than one genotype: how common is intracolonial genetic variability in scleractinian corals?

In recent years, a few colonial marine invertebrates have shown intracolonial genetic variability, a previously unreported phenomenon. Intracolonial genetic variability describes the occurrence of more than a single genotype within an individual colony. This variability can be traced back to two underlying processes: chimerism and mosaicism.

Single-male paternity in coelacanths.

Latimeria chalumnae, a 'living fossil,' is of great scientific interest, as it is closely related to the aquatic ancestors of land-living tetrapods. Latimeria show internal fertilization and bear live young, but their reproductive behaviour is poorly known. Here we present for the first time a paternity analysis of the only available material from gravid females and their offspring.

Development and validation of a food frequency questionnaire for consumption of polyphenol-rich foods in pregnant women.

Previous studies have shown that maternal consumption of polyphenol-rich foods after the third trimester of pregnancy may interfere with the anatomical and functional activity of the fetal heart as, to our knowledge, there are no validated instruments to quantify total polyphenols in pregnant women. The aim of this study was evaluate the reproducibility and validity of a food frequency questionnaire (FFQ), with 52 items, to assess the intake of polyphenol-rich foods in pregnant women in Brazil. This cross-sectional study included 120 pregnant women who participated in nutritional interviews in two moments.

Exploring Pandora's box: potential and pitfalls of low coverage genome surveys for evolutionary biology.

High throughput sequencing technologies are revolutionizing genetic research. With this "rise of the machines", genomic sequences can be obtained even for unknown genomes within a short time and for reasonable costs. This has enabled evolutionary biologists studying genetically unexplored species to identify molecular markers or genomic regions of interest (e.

Population divergence in East African coelacanths.

The coelacanth, Latimeria chalumnae, occurs at the Eastern coast of Africa from South Africa up to Kenya. It is often referred to as a living fossil mainly because of its nearly unchanged morphology since the Middle Devonian. As it is a close relative to the last common ancestor of fish and tetrapods, molecular studies mostly focussed on their phylogenetic relationships.

Induction of male production in clones of Daphnia pulex by the juvenoid hormone methyl farnesoate under short photoperiod.

The juvenile hormone, methyl farnesoate (MF), and its analog insecticides have been used successfully to induce the production of males in cladocerans under long-day conditions in the laboratory. However, without hormone addition Daphnia do not usually produce male offspring under long photoperiods, while short photoperiods are a stimulus for the induction of males. We used 21 clones of Daphnia pulex differing in their propensity to produce males under short-day conditions to test whether the treatment with MF would result in an additive effect of shifting the sex ratio towards males.

Are shoals of minnow Phoxinus phoxinus formed by close kin?

A molecular analysis examining the level of relatedness in shoaling minnows Phoxinus phoxinus was conducted. The results revealed that individuals from within the same shoal were not more closely related to each other than to individuals from other shoals. This led to the conclusion that Schreckstoff may be less likely to have evolved in the context of kin selection.

Monophyletic origin of multiple clonal lineages in an asexual fish (Poecilia formosa).

Despite the advantage of avoiding the costs of sexual reproduction, asexual vertebrates are very rare and often considered evolutionarily disadvantaged when compared to sexual species. Asexual species, however, may have advantages when colonizing (new) habitats or competing with sexual counterparts. They are also evolutionary older than expected, leaving the question whether asexual vertebrates are not only rare because of their 'inferior' mode of reproduction but also because of other reasons.

Determination of onset of sexual maturation and mating behavior by melanocortin receptor 4 polymorphisms.

Polymorphisms in reproductive strategies are among the most extreme and complex in nature. A prominent example is male body size and the correlated reproductive strategies in some species of platyfish and swordtails of the genus Xiphophorus. This polymorphism is controlled by a single Mendelian locus (P) that determines the onset of sexual maturity of males.

A little bit is better than nothing: the incomplete parthenogenesis of salamanders, frogs and fish.

A re-examination of the mitochondrial genomes of unisexual salamander lineages, published in BMC Evolutionary Biology, shows them to be the oldest unisexual vertebrates known, having been around for 5 million years. This presents a challenge to the prediction that lack of genetic recombination is a fast track to extinction. See research article http://www.

Major histocompatibility complex variability in the clonal Amazon molly, Poecilia formosa: is copy number less important than genotype?

The evolution of sex is still a major unsolved puzzle in biology. One of the most promising theoretical models to answer this question is the Red Queen hypothesis. The Red Queen hypothesis proposes a fast adaptation of pathogens to common genotypes and therefore a negative frequency-dependent selection against common genotypes.