Fixation of genetic variation and optimization of gene expression: The speed of evolution in isolated lizard populations undergoing Reverse Island Syndrome

The ecological theory of island biogeography suggests that mainland populations should be more genetically divergent from those on large and distant islands rather than from those on small and close islets. Some island populations do not evolve in a linear way, but the process of divergence occurs more rapidly because they undergo a series of phenotypic changes, jointly known as the Island Syndrome. A special case is Reversed Island Syndrome (RIS), in which populations show drastic phenotypic changes both in body shape, skin colouration, age of sexual maturity, aggressiveness, and food intake rates. The populations showing the RIS were observed on islets nearby mainland and recently raised, and for this they are useful models to study the occurrence of rapid evolutionary change. We investigated the timing and mode of evolution of lizard populations adapted through selection on small islets. For our analyses, we used an ad hoc model system of three populations: wild-type lizards from the mainland and insular lizards from a big island (Capri, Italy), both Podarcis siculus siculus not affected by the syndrome, and a lizard population from islet (Scopolo) undergoing the RIS (called P. s. coerulea because of their melanism). The split time of the big (Capri) and small (Scopolo) islands was determined using geological events, like sea-level rises. To infer molecular evolution, we compared five complete mitochondrial genomes for each population to reconstruct the phylogeography and estimate the divergence time between island and mainland lizards. We found a lower mitochondrial mutation rate in Scopolo lizards despite the phenotypic changes achieved in approximately 8,000 years. Furthermore, transcriptome analyses showed significant differential gene expression between islet and mainland lizard populations, suggesting the key role of plasticity in these unpredictable environments

The diet of otters (Lutra lutra) on the Agri river system, one of the most important presence sites in Italy: A molecular approach

Background. The Eurasian otter (Lutra lutra) underwent a strong decline in large areas of the Central-Western part of its distribution range, during the second half of the twentieth century. In Italy, only residual fragmented nuclei survive in the Central- Southern part of the peninsula. Nowadays, the otter is one of the most endangered mammals in Italy, and increasing the knowledge about the ecology of this species is a key step in defining fitting management strategies. Here we provide information about the diet of otter on the Agri river system, one of the most important presence sites in Italy, to understand both the species' food requirements and the impact on fish communities. Methods. DNA metabarcoding and High Throughput Sequencing were used on DNA extracted from spraints. We amplified DNA with a primer set for vertebrates, focusing efforts on the bulk of the otter's diet (fishes and amphibians). Results. Our findings showed that the diet of the otter was dominated by cyprinids (97.77%, and 99.14% of fishes), while amphibians represented 0.85% of the sequences analyzed. Results are in general accordance with previous studies based on morphological characterization; however, molecular analyses allow the resolving of some morphological uncertainties. Although the study area offers a very wide range of available prey, the diet of the otters shows marked selectivity. We highlighted a variation in prey consumed, in accordance with the typology of water system (i.e., river, lake, tributary). Some of the preys found in the diet were alien species introduced by man for sport fishing. Our findings could help define strategies useful for the conservation of the otter population in Southern Italy, suggesting management actions directed at avoiding fish community alterations through illegal stockings without severe controls on their taxonomic status. These introductions could result in a general reduction in the diversity of the otter's preys, affecting its predatory behavior

Traditional Free-Ranging Livestock Farming as a Management Strategy for Biological and Cultural Landscape Diversity: A Case from the Southern Apennines

Mediterranean mountain landscapes are undergoing a widespread phenomenon of abandonment. This brings, as a consequence, the loss of traditional land use practices, such as transhumant pastoralism, as well as shrub and wood encroachment, with repercussions on the biodiversity associated with semi-open, human-managed landscapes. In this study, we focus on a mountain pasture from the Southern Apennines (Italy), where free-ranging transhumant grazing is still carried out, to quantify the effects of grazing presence and exclusion on arthropod diversity, and to qualitatively characterize the plant communities of grazed and ungrazed areas. Using field sampling, remote sensing, and semi-structured interviews, we assessed the validity of traditional cattle farming as a landscape management tool. Indeed, high diversity grasslands excluded from grazing were characterized by significantly less even and more dominated arthropod communities, as well as fewer plant species and families. Moreover, in areas that have been consistently grazed over the years, we found no forest encroachment from 1955 to 2019. However, rural communities are experiencing difficulties in keeping local traditions alive, even with current agri-environmental schemes. Thus, traditional livestock grazing can be a valuable management tool to maintain high biological and cultural diversity, even if stronger cooperation and attention to local needs is necessary

Cognitive stimulation induces differential gene expression in octopus vulgaris: The key role of protocadherins

Octopuses are unique invertebrates, with sophisticated and flexible behaviors controlled by a high degree of brain plasticity, learning, and memory. Moreover, in Octopus vulgaris, it has been demonstrated that animals housed in an enriched environment show adult neurogenesis in specific brain areas. Firstly, we evaluated the optimal acclimatization period needed for an O. vulgaris before starting a cognitive stimulation experiment. Subsequently, we analyzed differential gene expression in specific brain areas in adult animals kept in tested (enriched environment), wild (naturally enriched environment), and control conditions (unenriched environment). We selected and sequenced three protocadherin genes (PCDHs) involved in the development and maintenance of the nervous system; three Pax genes that control cell specification and tissue differentiation; the Elav gene, an earliest marker for neural cells; and the Zic1 gene, involved in early neural formation in the brain. In this paper, we evaluated gene expression levels in O. vulgaris under different cognitive stimulations. Our data shows that Oct-PCDHs genes are upregulated in the learning and lower motor centers in the brain of both tested and wild animals (higher in the latter). Combining these results with our previous studies on O. vulgaris neurogenesis, we proposed that PCDH genes may be involved in adult neurogenesis processes, and related with their cognitive abilities

Gut microbiota plasticity in insular lizards under reversed island syndrome

Animals living on small islands are more drastically exposed to environmental changes, such as food or water starvation, and rapid temperature shifts. Facing such conditions, and probably thank to adaptive plasticity mechanisms, some animals display a Reversed Island Syndrome (RIS), a suite of traits, including skin pigmentation, voracity, sexual dimorphism, showed differently from mainland relatives. Here, we analyse a so far poorly explored aspect of RIS: the effect of this on the microbiota composition of host Italian wall lizard (Podarcis siculus), strongly influenced by the animal's lifestyle, and conditioning the same. We compare mainland and island populations, assessing the difference between their microbial communities and their response under unexpected food, experimentally provided. Our observations showed a significant difference in microbiota communities between island and mainland groups, depended mainly from changes in relative abundance of the shared genera (difference due to decrease/increase). Exposure to experimental diet regimes resulted into significative reshaping of bacterial composition of microbiota and a greater variation in body mass only in the island population. Our results could be an evidence that gut microbial community contributes to adaptive plasticity mechanisms of island lizards under RIS to efficiently respond to unexpected changes

Population genomic, olfactory, dietary, and gut microbiota analyses demonstrate the unique evolutionary trajectory of feral pigs

Domestication is an intriguing evolutionary process. Many domestic populations are subjected to strong human-mediated selection, and when some individuals return to the wild, they are again subjected to selective forces associated with new environments. Generally, these feral populations evolve into something different from their wild predecessors and their members typically possess a combination of both wild and human selected traits. Feralisation can manifest in different forms on a spectrum from a wild to a domestic phenotype. This depends on how the rewilded domesticated populations can readapt to natural environments based on how much potential and flexibility the ancestral genome retains after its domestication signature. Whether feralisation leads to the evolution of new traits that do not exist in the wild or to convergence with wild forms, however, remains unclear. To address this question, we performed population genomic, olfactory, dietary, and gut microbiota analyses on different populations of Sus scrofa (wild boar, hybrid, feral and several domestic pig breeds). Porcine single nucleotide polymorphisms (SNPs) analysis shows that the feral population represents a cluster distinctly separate from all others. Its members display signatures of past artificial selection, as demonstrated by values of FST in specific regions of the genome and bottleneck signature, such as the number and length of runs of homozygosity. Generalised FST values, reacquired olfactory abilities, diet, and gut microbiota variation show current responses to natural selection. Our results suggest that feral pigs are an independent evolutionary unit which can persist so long as levels of human intervention remain unchanged

Clinical registry of dental outcomes in head and neck cancer patients (OraRad): rationale, methods, and recruitment considerations

Background Most head and neck (H&N) cancer patients receive high-dose external beam radiation therapy (RT), often in combination with surgery and/or chemotherapy. Unfortunately, high-dose RT has significant adverse effects on the oral and maxillofacial tissues, some of which persist for the life of the patient. However, dental management of these patients is based largely on individual and expert opinion, as few studies have followed patients prospectively to determine factors that predict adverse oral sequelae. In addition, many previous studies were conducted before wide-spread adoption of intensity-modulated radiation therapy (IMRT) and concurrent chemotherapy. The objective of this multi-center study is to systematically evaluate the oral health of subjects for 2 years after commencement of RT, with the goal of identifying risk factors that predict adverse oral outcomes post-RT. Methods This is a prospective multi-center longitudinal cohort study of H&N cancer patients who receive high-dose RT with curative intent. Planned enrollment is 756 subjects at 6 primary clinical sites (and their affiliated sites) in the USA. A baseline visit is conducted prior to the beginning of RT. Follow-up visits are conducted at 6, 12, 18 and 24 months from the start of RT. The primary outcome measure is the 2-year rate of tooth loss in patients who have received at least one session of external beam RT for H&N cancer. Secondary outcome measures include the incidence of exposed intraoral bone; incidence of post-extraction complications; change in Decayed Missing and Filled Surfaces (DMFS); change in periodontal measures; change in stimulated whole salivary flow rates; change in mouth opening; topical fluoride utilization; chronic oral mucositis incidence; changes in RT-specific quality of life measures; and change in oral pain scores. Discussion This study will contribute to a better understanding of the dental complications experienced by these patients. It will also enable identification of risk factors associated with adverse outcomes such as tooth loss and osteoradionecrosis. These findings will support the development of evidence-based guidelines and inform the planning of future interventional studies, with the goal of advancing improvements in patient care and outcomes. Trial registration ClinicalTrials.gov Identifier NCT02057510 , registered 5 February 2014

Differential Diagnosis and Clinical Management of a Case of COVID-19 in a Patient With Stage III Lung Cancer Treated With Radio-chemotherapy and Durvalumab

none14nononeGuerini A.E.; Borghetti P.; Filippi A.R.; Bonu M.L.; Tomasini D.; Greco D.; Imbrescia J.; Volpi G.; Triggiani L.; Borghesi A.; Maroldi R.; Pasinetti N.; Buglione M.; Magrini S.M.Guerini, A. E.; Borghetti, P.; Filippi, A. R.; Bonu, M. L.; Tomasini, D.; Greco, D.; Imbrescia, J.; Volpi, G.; Triggiani, L.; Borghesi, A.; Maroldi, R.; Pasinetti, N.; Buglione, M.; Magrini, S. M