Biology subjects

Scarcelli, N.

Publications and source records attributed to Scarcelli, N..

6 recordsLinked to original sources

bioRxiv2026

Managing the genetic diversity of Dioscorea yams for adaptation to climate change

Understanding adaptation to environmental variation is fundamental to climate-resilient agriculture. Here, we analyzed a georeferenced collection of 167 Dioscorea accessions spanning a wide range of bioclimatic and biophysical variation, from dry sahelian environment to rainforest environment. Genome-wide association analyses revealed that the genetic architecture of environmental adaptation is largely driven by large-effect loci, although precipitation-related traits were associated with many small-effect loci. This mixed architecture could lead to multiple breeding strategies, including marker-assisted backcrossing and the targeted use of wild and semi-wild relatives. We identified a core collection of accessions that captures much of the genetic and environmental diversity, and highlighted accessions as potential parents for abiotic stress tolerance. Projections under future climate scenarios using genomic offset identified regions and accessions at elevated risk of maladaptation, as well as others with broad adaptive potentiality. Maximizing the use of available material may facilitate the development of climate-resilient cultivars.

plant biology↗

bioRxiv2025

Influence of past climate changes and human-mediated introduction on patterns of genetic diversity distribution of the Papuan nutmeg (Myristica argentea) Warb.

Understanding the distribution of genetic diversity of endemic food tree species holds significant importance for conservation planning and the formulation of effective management strategies. Natural and anthropogenic factors can influence species geographic range and distribution of genetic diversity. Here, we tested the relative influence of barriers to gene flow (rivers, mountains and past climate change) and recent human activities on the evolutionary history of an endemic species from Fakfak district, Papua Island, Myristica argentea Warb (Myristicaceae), better known as Papuan nutmeg. Myristica argentea is a spice tree species used by local populations since centuries/millennia. The species has been introduced in other locations from the region. Fourteen microsatellite markers (nSSRs), whole chloroplast (cp) genome, and nuclear-targeted sequence genes (nrDNA sequence) were used to characterize the genetic diversity, population structure, and demographic history of the species across its distribution range (native and introduced populations). We found that native populations of the species in Fakfak present higher levels of genetic diversity than introduced populations. We further detected the presence of a moderate genetic structure (FST = 0.143), and the presence of three intraspecific genetic clusters. Additionally, our findings indicate that population fragmentation within the native range of the species in Fakfak, may have been influenced by the presence of riparian networks, mountain ranges and by Pleistocene climatic fluctuations. Our results suggest that all introduced populations were sourced mainly from the native population of Raduria, in the South of Fakfak region. Given the population genetic variation across the ranges of Papuan nutmeg, management plans should not treat them as single populations, but rather consider the broader genetic diversity within its range.

evolutionary biology↗

bioRxiv2024

Picturing plant biodiversity from airborne environmental DNA.

While eDNA approaches have gained interest over the past decades all types of organisms have not been addressed evenly. In particular terrestrial plants have been the subject of less attention. Here we address the possibility to represent plant biodiversity from airborne environmental DNA (eDNA) sampling and metabarcoding. We collected air using a biological air sampler in the Botanical Garden of Montpellier (France) and compared the list of revealed plant species to the botanical inventory of the Garden. Ninety-two plant species could be detected from three sampling points across the 4,6 ha of the Garden, after one hour sampling allowing to filter 9 m3 of air. We recorded the plants carrying flowers at the time of the experiment, which allowed us to estimate that plants flowering at the time of the sampling could be detected 10 times more easily than plants that were not, given the number of plants carrying flowers. However, flowering is far from being required as a vast majority of plants still was detected without flowering. We also show that not all species orders are detected with the same probability, tree species being better represented in the sample than herbal plants, given the number of trees present in the garden. Finally using diagnostic species, present only once in the garden, we estimate that the maximum sampling distance allowed by the biological air sampler is at least 110 m. Our study underlines that air sampling is a promising method for monitoring terrestrial plant biodiversity and highlights the parameters that should be adjusted to optimize the approach.

genetics↗

bioRxiv2021

Hypothalamic perineuronal nets are regulated by sex and dietary interventions

Perineuronal nets (PNNs) are widely present in the hypothalamus, and are thought to provide physical protection and ion buffering for neurons, and regulate their synaptic plasticity and intracellular signaling. Recent evidence indicates that PNNs in the mediobasal hypothalamus plays an important role in the regulation of glucose homeostasis. However, whether and how hypothalamic PNNs are regulated are not fully understood. In the present study, we examined whether PNNs in various hypothalamic regions in mice can be regulated by sex, gonadal hormones, dietary interventions, or their interactions. We demonstrated that gonadal hormones are required to maintain normal PNNs in the arcuate nucleus of hypothalamus in both male and female mice. In addition, PNNs in the terete hypothalamic nucleus display a sexual dimorphism with females higher than males, and high-fat diet feeding increases terete PNNs only in female mice but not in male mice. On the other hand, PNNs in other hypothalamic regions are not influenced by sex, gonadal hormones or dietary interventions. In summary, we demonstrated that hypothalamic PNNs are regulated in a region-specific manner and these results provide a framework to further investigate the potential functions of PNNs in regulating energy/glucose homeostasis at the interplay of sex, gonadal hormones and diets.

neuroscience↗

bioRxiv2020

Fonio millet genome unlocks African orphan crop diversity for agriculture in a changing climate

Sustainable food production in the context of climate change necessitates diversification of agriculture and a more efficient utilization of plant genetic resources. Fonio millet (Digitaria exilis) is an orphan African cereal crop with a great potential for dryland agriculture. Here, we established high-quality genomic resources to facilitate fonio improvement through molecular breeding. These include a chromosome-scale reference assembly and deep re-sequencing of 183 cultivated and wild Digitaria accessions, enabling insights into genetic diversity, population structure, and domestication. Fonio diversity is shaped by climatic, geographic, and ethnolinguistic factors. Two genes associated with seed size and shattering showed signatures of selection. Most known domestication genes from other cereal models however have not experienced strong selection in fonio, providing direct targets to rapidly improve this crop for agriculture in hot and dry environments.

plant biology↗

bioRxiv2018

Adaptive introgression: an untapped evolutionary mechanism for crop adaptation

Global environmental changes strongly impact wild and domesticated species biology and their associated ecosystem services. For crops, global warming has led to significant changes in terms of phenology and/or yield. To respond to the agricultural challenges of this century, there is a strong need for harnessing the genetic variability of crops and adapting them to new conditions. Gene flow, from either the same species or a different species, may be an immediate primary source to widen genetic diversity and adaptions to various environments. When the incorporation of a foreign variant leads to an increase of the fitness of the recipient pool, it is referred to as \"adaptive introgression\". Crop species are excellent case studies of this phenomenon since their genetic variability has been considerably reduced over space and time but most of them continue exchanging genetic material with their wild relatives. In this paper, we review studies of adaptive introgression, presenting methodological approaches and challenges to detecting it. We pay particular attention to the potential of this evolutionary mechanism for the adaptation of crops. Furthermore, we discuss the importance of farmers knowledge and practices in shaping wild-to-crop gene flow. Finally, we argue that screening the wild introgression already existing in the cultivated gene pool may be an effective strategy for uncovering wild diversity relevant for crop adaptation to current environmental changes and for informing new breeding directions.

evolutionary biology↗