Mitochondrial Variation of Bottlenose Dolphins (Tursiops truncatus) from the Canary Islands Suggests a Key Population for Conservation with High Connectivity within the North-East Atlantic Ocean.

In recent decades, worldwide cetacean species have been protected, but they are still threatened. The bottlenose dolphin (Tursiops truncatus) is a vulnerable keystone species and a useful bioindicator of the health and balance of marine ecosystems in oceans all over the world. The genetic structure of the species is shaped by their niche specialization (along with other factors), leading to the classification of two ecotypes: coastal and pelagic. In this study, the genetic diversity, population structure, and ecotypes of bottlenose dolphins from the Canary Islands were assessed through the analysis of 49 new samples from biopsies and from stranded animals using the 636 bp portion of the mitochondrial control region and 343 individuals from databases (n = 392). The results reveal high genetic diversity in Canarian bottlenose dolphins (Hd = 0.969 and π = 0.0165) and the apparent lack of population genetic structure within this archipelago. High genetic structure (Fst, Φst) was found between the Canary Islands and coastal populations, while little to no structure was found with the pelagic populations. These results suggest that Canarian bottlenose dolphins are part of pelagic ecotype populations in the North Atlantic. The studied Special Areas of Conservation in the Canary Islands may correspond to a hotspot of genetic diversity of the species and could be a strategic area for the conservation of the oceanic ecotype of bottlenose dolphins.

Biomarkers of Oxidative Stress in Healthy Infants within the First Three Days after Birth.

The clinical relevance of stress biomarkers in newborns is well established. Currently, oxidative stress (OS) parameters are seen to play an important role in neonatal resuscitation guidelines, and a link has been observed between the amount of oxygen delivered and the level of OS and the development of various pathologies. The aim of the current study was to investigate changes in neonatal plasma and urine OS status during the first hours after birth. A lower antioxidant capacity (TAC) and higher levels of malondialdehyde in blood were observed in newborns at the time of birth compared with results 48 h postnatally. The urine revealed a significant and progressive increase in TAC and creatinine during the first 36 h of life, with a progressive decline thereafter. Meanwhile, malondialdehyde in urine samples showed no significant differences over time. Overall, the correlation between blood and urine parameters was poor, except for the relationship between umbilical vein glutathione reduced/oxidized ratio and urine malondialdehyde (r = 0.7; p = 0.004) and between TAC in the umbilical artery and urine (r = -0.547; p = 0.013). The biomarkers evaluated in this study could be established as reference values for neonatal OS.

Detection of SARS-CoV-2 Based on Nucleic Acid Amplification Tests (NAATs) and Its Integration into Nanomedicine and Microfluidic Devices as Point-of-Care Testing (POCT).

The coronavirus SARS-CoV-2 has highlighted the criticality of an accurate and rapid diagnosis in order to contain the spread of the virus. Knowledge of the viral structure and its genome is essential for diagnosis development. The virus is still quickly evolving and the global scenario could easily change. Thus, a greater range of diagnostic options is essential to face this threat to public health. In response to the global demand, there has been a rapid advancement in the understanding of current diagnostic methods. In fact, innovative approaches have emerged, leveraging the benefits of nanomedicine and microfluidic technologies. Although this development has been incredibly fast, several key areas require further investigation and optimization, such as sample collection and preparation, assay optimization and sensitivity, cost effectiveness, scalability device miniaturization, and portability and integration with smartphones. Addressing these gaps in the knowledge and these technological challenges will contribute to the development of reliable, sensitive, and user-friendly NAAT-based POCTs for the diagnosis of SARS-CoV-2 and other infectious diseases, facilitating rapid and effective patient management. This review aims to provide an overview of current SARS-CoV-2 detection methods based on nucleic acid detection tests (NAATs). Additionally, it explores promising approaches that combine nanomedicine and microfluidic devices with high sensitivity and relatively fast 'time to answer' for integration into point-of-care testing (POCT).

Development and validation of eDNA markers for the detection of Crepidula fornicata in environmental samples.

The invasive Crepidula fornicata caused major problems along the European Atlantic coast, especially in France and Netherlands where high densities leads on changes in the habitat, disturb native marine wildlife as well as it originates competition for space and food. Despite its dangerous invasive nature, regular monitoring to alert about its presence in risk areas, like the south Bay of Biscay (Spain and south France), is not done yet. Here, we developed a species-specific marker to detect the presence of C. fornicata in environmental samples (eDNA) of seawater. The novel C. fornicata specific primers amplified a region of 239 bp within the COI gen. We employed this tool to check its presence in 6 estuaries of the Cantabrian Sea, an area comprised between the Spanish and French limits of the previously reported presence of this limpet in the south Bay of Biscay. The presence of C. fornicata was confirmed in A Coruña (Galicia, Spain), Eo and Villaviciosa estuaries (Asturias, Spain) while it was not detected in Santander, Bilbao (Spain), and Bayonne (France). This new method to detect C. fornicata could be easily implemented in regular monitoring to prevent and manage future invasions of this species.

Marine litter and public involvement in beach cleaning: Disentangling perception and awareness among adults and children, Bay of Biscay, Spain.

Coastal litter abundance and its effects have increased for years. Waste reduction is the most effective countermeasure to fight against this problem. Littering attitudes may have an effect on people's involvement in coastal cleanups. In this study, coastal litter perception, awareness about its impact and likely sources were investigated in local population from south Bay of Biscay, Spain. People of different age groups and commitment levels regarding litter were interviewed and their answers compared with data from the area. Results showed differences in perception between volunteers and non-volunteers, but not between children and adults. Interaction effect of age was found for awareness. Volunteers and children tended to erroneously attribute the main litter origin to beachgoers, more than non-volunteers or adults. Our results suggest that encouraging local population to clean beaches would contribute to improve their perception of the problem and their attitudes toward taking action.

Stress related epigenetic changes may explain opportunistic success in biological invasions in Antipode mussels.

Different environmental factors could induce epigenetic changes, which are likely involved in the biological invasion process. Some of these factors are driven by humans as, for example, the pollution and deliberate or accidental introductions and others are due to natural conditions such as salinity. In this study, we have analysed the relationship between different stress factors: time in the new location, pollution and salinity with the methylation changes that could be involved in the invasive species tolerance to new environments. For this purpose, we have analysed two different mussels' species, reciprocally introduced in antipode areas: the Mediterranean blue mussel Mytilus galloprovincialis and the New Zealand pygmy mussel Xenostrobus securis, widely recognized invaders outside their native distribution ranges. The demetylathion was higher in more stressed population, supporting the idea of epigenetic is involved in plasticity process. These results can open a new management protocols, using the epigenetic signals as potential pollution monitoring tool. We could use these epigenetic marks to recognise the invasive status in a population and determine potential biopollutants.

Marine litter in south Bay of Biscay: Local differences in beach littering are associated with citizen perception and awareness.

Marine litter is often left by beachgoers. Thus, understanding beachgoers' perception and awareness is important. In this study, the amount and type of litter was measured from nine beaches of central south Bay of Biscay (Spain), and a survey about perception and awareness of the beach littering was conducted among beachgoers. The region could be considered moderately littered compared with other studies, with significant differences among beaches for litter amount and types. Plastic was the most abundant item, followed by fishing gear. Differences among beaches for awareness and litter perception correlated significantly with differences in litter amount. Perception was positively correlated with beach frequentation. Significant gender differences were found, males taking more actions against litter than females regardless how much litter they perceived. These results could be employed for designing campaigns of beach litter treatment and awareness raising, by taking into account local differences detected in this study.

eDNA for detection of five highly invasive molluscs. A case study in urban rivers from the Iberian Peninsula.

Biological invasions are an important threat to biodiversity especially in aquatic ecosystems, and their frequency is generally higher near urban areas. Potentially invasive non-indigenous molluscs were deliberately introduced into European waters for food (Corbicula fluminea) and biocontrol (Melanoides tuberculata), and unintentionally introduced by ballast water (Mytilopsis leucophaeata, Corbicula fluminea), stock contamination (Sinanodonta woodiana), accidental escapes from aquaculture (Sinanodonta woodiana), aquarium trade releases (Melanoides tuberculata) and even attached to aquatic birds (Corbicula fluminea). Three rivers from the Iberian Peninsula were monitored near the three most populated inland cities to evaluate the presence of these invasive molluscs through PCR amplification using taxon-specific primers from eDNA. New primers were designed within 16S rRNA and cytochrome oxidase subunit I genes, tested in silico from BLAST methodology and experimentally in vitro before application in the field. C. fluminea was found in Ebro River (near Zaragoza); M. leucophaeata in Guadalquivir River (near Sevilla). M. tuberculata and S. woodiana were found from enclosed areas (lake and reservoir respectively) upstream, respectively, Zaragoza and Madrid. The new tools are ready to be used in other regions where these species are also invasive.

DNA in a bottle-Rapid metabarcoding survey for early alerts of invasive species in ports.

Biota monitoring in ports is increasingly needed for biosecurity reasons and safeguarding marine biodiversity from biological invasion. Present and future international biosecurity directives can be accomplished only if the biota acquired by maritime traffic in ports is controlled. Methodologies for biota inventory are diverse and now rely principally on extensive and labor-intensive sampling along with taxonomic identification by experts. In this study, we employed an extremely simplified environmental DNA (eDNA) sampling methodology from only three 1-L bottles of water per port, followed by metabarcoding (high-throughput sequencing and DNA-based species identification) using 18S rDNA and Cytochrome oxidase I as genetic barcodes. Eight Bay of Biscay ports with available inventory of fouling invertebrates were employed as a case study. Despite minimal sampling efforts, three invasive invertebrates were detected: the barnacle Austrominius modestus, the tubeworm Ficopomatus enigmaticus and the polychaete Polydora triglanda. The same species have been previously found from visual and DNA barcoding (genetic identification of individuals) surveys in the same ports. The current costs of visual surveys, conventional DNA barcoding and this simplified metabarcoding protocol were compared. The results encourage the use of metabarcoding for early biosecurity alerts.

An Easy Phylogenetically Informative Method to Trace the Globally Invasive Potamopyrgus Mud Snail from River's eDNA.

Potamopyrgus antipodarum (New Zealand mud snail) is a prosobranch mollusk native to New Zealand with a wide invasive distribution range. Its non-indigenous populations are reported from Australia, Asia, Europe and North America. Being an extremely tolerant species, Potamopyrgus is capable to survive in a great range of salinity and temperature conditions, which explains its high invasiveness and successful spread outside the native range. Here we report the first finding of Potamopyrgus antipodarum in a basin of the Cantabrian corridor in North Iberia (Bay of Biscay, Spain). Two haplotypes already described in Europe were found in different sectors of River Nora (Nalon basin), suggesting the secondary introductions from earlier established invasive populations. To enhance the surveillance of the species and tracking its further spread in the region, we developed a specific set of primers for the genus Potamopyrgus that amplify a fragment of 16S rDNA. The sequences obtained from PCR on DNA extracted from tissue and water samples (environmental DNA, eDNA) were identical in each location, suggesting clonal reproduction of the introduced individuals. Multiple introduction events from different source populations were inferred from our sequence data. The eDNA tool developed here can serve for tracing New Zealand mud snail populations outside its native range, and for inventorying mud snail population assemblages in the native settings if high throughput sequencing methodologies are employed.

Interspecific Hybridization in Pilot Whales and Asymmetric Genetic Introgression in Northern Globicephala melas under the Scenario of Global Warming.

Pilot whales are two cetacean species (Globicephala melas and G. macrorhynchus) whose distributions are correlated with water temperature and partially overlap in some areas like the North Atlantic Ocean. In the context of global warming, distribution range shifts are expected to occur in species affected by temperature. Consequently, a northward displacement of the tropical pilot whale G. macrorynchus is expected, eventually leading to increased secondary contact areas and opportunities for interspecific hybridization. Here, we describe genetic evidences of recurrent hybridization between pilot whales in northeast Atlantic Ocean. Based on mitochondrial DNA sequences and microsatellite loci, asymmetric introgression of G. macrorhynchus genes into G. melas was observed. For the latter species, a significant correlation was found between historical population growth rate estimates and paleotemperature oscillations. Introgressive hybridization, current temperature increases and lower genetic variation in G. melas suggest that this species could be at risk in its northern range. Under increasing environmental and human-mediated stressors in the North Atlantic Ocean, it seems recommendable to develop a conservation program for G. melas.

Controlling populations of invasive pygmy mussel (Xenostrobus securis) through citizen science and environmental DNA.

Early detection of dangerous exotic species is crucial for stopping marine invasions. The New Zealand pygmy mussel Xenostrobus securis is a problematic species in coasts of temperate regions in the northern hemisphere. In this study we have controlled a population of this invader that recently expanded in a north Iberian estuary with both a participatory approach involving researchers and citizens, and employing a sensitive eDNA-based tool to monitor the population expansion in the estuary. Results demonstrate successful eradication of pygmy mussels in the outer part of the estuary with citizen science and the practical utility of eDNA for controlling biological invasions.

Detection and characterisation of the biopollutant Xenostrobus securis (Lamarck 1819) Asturian population from DNA Barcoding and eBarcoding.

DNA efficiently contributes to detect and understand marine invasions. In 2014 the potential biological pollutant pygmy mussel (Xenostrobus securis) was observed for the first time in the Avilés estuary (Asturias, Bay of Biscay). The goal of this study was to assess the stage of invasion, based on demographic and genetic (DNA Barcoding) characteristics, and to develop a molecular tool for surveying the species in environmental DNA. A total of 130 individuals were analysed for the DNA Barcode cytochrome oxidase I gene in order to determine genetic diversity, population structure, expansion trends, and to inferring introduction hits. Reproduction was evidenced by bimodal size distributions of 1597 mussels. High population genetic variation and genetically distinct clades might suggest multiple introductions from several source populations. Finally, species-specific primers were developed within the DNA barcode for PCR amplification from water samples in order to enabling rapid detection of the species in initial expansion stages.

DNA Re-EvolutioN: a game for learning molecular genetics and evolution.

Evolution is a main concept in biology, but not many students understand how it works. In this article we introduce the game DNA Re-EvolutioN as an active learning tool that uses genetic concepts (DNA structure, transcription and translation, mutations, natural selection, etc.) as playing rules. Students will learn about molecular evolution while playing a game that mixes up theory and entertainment. The game can be easily adapted to different educational levels. The main goal of this play is to arrive at the end of the game with the longest protein. Students play with pawns and dices, a board containing hypothetical events (mutations, selection) that happen to molecules, "Evolution cards" with indications for DNA mutations, prototypes of a DNA and a mRNA chain with colored "nucleotides" (plasticine balls), and small pieces simulating t-RNA with aminoacids that will serve to construct a "protein" based on the DNA chain. Students will understand how changes in DNA affect the final protein product and may be subjected to positive or negative selection, using a didactic tool funnier than classical theory lectures and easier than molecular laboratory experiments: a flexible and feasible game to learn and enjoy molecular evolution at no-cost. The game was tested by majors and non-majors in genetics from 13 different countries and evaluated with pre- and post-tests obtaining very positive results.

Interspecific introgression in cetaceans: DNA markers reveal post-F1 status of a pilot whale.

Visual species identification of cetacean strandings is difficult, especially when dead specimens are degraded and/or species are morphologically similar. The two recognised pilot whale species (Globicephala melas and Globicephala macrorhynchus) are sympatric in the North Atlantic Ocean. These species are very similar in external appearance and their morphometric characteristics partially overlap; thus visual identification is not always reliable. Genetic species identification ensures correct identification of specimens. Here we have employed one mitochondrial (D-Loop region) and eight nuclear loci (microsatellites) as genetic markers to identify six stranded pilot whales found in Galicia (Northwest Spain), one of them of ambiguous phenotype. DNA analyses yielded positive amplification of all loci and enabled species identification. Nuclear microsatellite DNA genotypes revealed mixed ancestry for one individual, identified as a post-F1 interspecific hybrid employing two different Bayesian methods. From the mitochondrial sequence the maternal species was Globicephala melas. This is the first hybrid documented between Globicephala melas and G. macrorhynchus, and the first post-F1 hybrid genetically identified between cetaceans, revealing interspecific genetic introgression in marine mammals. We propose to add nuclear loci to genetic databases for cetacean species identification in order to detect hybrid individuals.