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Biology subjects

Buzan, E.

Publications and source records attributed to Buzan, E..

6 recordsLinked to original sources

High-quality reference genome of the African hermit spider, Nephilingis cruentata, and sex chromosome evolution in spiders

Background: Chromosome-level genome assemblies are increasingly enabling tests of chromosome evolution, conserved synteny, and sex chromosome conservation across diverse animal lineages, including spiders. Results: Here, we present a chromosome-level genome assembly for the African hermit spider, Nephilingis cruentata, a species with extreme female-biased sexual size dimorphism and a cytogenetically inferred XX2 sex chromosome system. The final Hi-C-assisted assembly spans 1.72 Gbp, with 99.5% of bases assigned to 13 pseudochromosomes, a scaffold N50 of 131.6 Mbp, and a BUSCO completeness score of 98.8%. We annotated 20,021 protein-coding genes, and repetitive elements accounted for 42.7% of the genome. Sex-specific whole-genome resequencing identified Chr02 and Chr07 as candidate X chromosomes based on reduced male coverage, consistent with the expected XX2 system. Using comparative whole-genome alignments across existing chromosome-scale spider assemblies, we also show that sex-linked chromosomes retain broad homologous identity across sampled spider lineages but exhibit lower synteny conservation and greater chromosome-length divergence than autosomes. Conclusions: These results suggest that spider sex chromosomes are conserved in homologous identity but more labile in structure, providing a comparative framework for studying sex chromosome conservation and divergence across Araneae.

genomics↗

First insight into genetic diversity of two sympatric marten species between the Alps and Adriatic islands

Closely related species occupying the same geographical area may exhibit markedly different genetic patterns due to differences in evolutionary history, ecology and behaviour. In this study, a landscape genetics approach is applied to investigate the genetic structure, diversity, and connectivity of two sympatric carnivore species, i.e. the European pine marten (Martes martes) and the stone marten (Martes foina) in Croatia and Slovenia. We analysed mitochondrial DNA sequences for both species and additionally used nuclear microsatellite markers for the pine marten. A total of 211 individuals (29 pine martens and 182 stone martens) from both mainland and island populations were analysed. For pine marten, we found a significant genetic structuring, with pronounced differentiation between island and mainland populations, and a further substructure within the mainland. No significant isolation by distance was detected (Mantel test, p = 0.15), suggesting that genetic differentiation is driven more by habitat discontinuities and anthropogenic barriers rather than geographical distance alone. In contrast, stone marten exhibited weak genetic structure and high genetic diversity, indicating gene flow and potential landscape permeability for this more synanthropic species. These contrasting patterns underscore species-specific responses to landscape fragmentation and highlight the need to tailor management strategies accordingly.

zoology↗

ERGA-BGE genome of Coenonympha oedippus: an IUCN endangered European butterfly species occurring in two ecotypes

The reference genome of the False ringlet (Coenonympha oedippus) will serve as a valuable resource for uncovering the genetic mechanism underlying the species' adaptability to two ecologically distinct habitats. Through this genome we might be able to determine whether (i) each ecotype is monophyletic, indicating that the ecological divergence represents an early stage of speciation, (ii) the ecotypes have evolved through divergent evolution of habitat preference, or (iii) the differences between ecotypes are solely due to phenotypic plasticity or epigenetic variation. This reference genome is also a prerequisite for the planning, design, and implementation of conservation measures for this endangered species, taking into account its intraspecific diversity. Furthermore, it holds broader implications for population genomic studies of the species-rich genus Coenonympha, which includes some of the most endangered butterfly taxa in Europe. The complete genome sequence was assembled into 30 contiguous chromosomal pseudomolecules (sex chromosomes included). This chromosome-level assembly encompasses 0.39 Gb, composed of 385 contigs and 62 scaffolds, with contig and scaffold N50 values of 2.8 Mb and 14.2 Mb, respectively.

genomics↗

ERGA-BGE Reference Genome of the Striped Field Mouse (Apodemus agrarius), a Widespread and Abundant Species in Central and Eastern Europe

The reference genome of Apodemus agrarius provides a valuable resource for phylogenetic studies of rodents, particularly mice, and for understanding factors that influence the geographical distribution of the species across East Asia and East Europe. A total of 25 contiguous chromosomal pseudomolecules were assembled from the genome sequence (23 autosomes and 2 sex chromosomes). This chromosome-level assembly encompasses 2.6 Gb, composed of 242 contigs and 60 scaffolds, with contig and scaffold N50 values of 35 Mb and 119 Mb, respectively.

genomics↗

ERGA-BGE Reference Genome of the Northern chamois (Rupicapra rupicapra): Europe's most abundant mountain ungulate

The reference genome of Rupicapra rupicapra (subsp. rupicapra) provides insights into the genetic makeup that enabled this iconic mountain ungulate to adapt to its harsh environment, including its ability to survive in extreme weather and high altitudes--factors that are increasingly important in the face of climate change. A total of 29 contiguous chromosomal pseudomolecules were assembled from the genome sequence. This chromosome-level assembly encompasses 2.62 Gb, composed of 124 contigs and 76 scaffolds, with contig and scaffold N50 values of 77 Mb and 101 Mb, respectively.

genomics↗

Conserving genetic diversity during climate change:Niche marginality and discrepant monitoring capacity in Europe

Genetic monitoring of populations currently attracts interest in the context of the Convention on Biological Diversity but needs long-term planning and investments. Genetic diversity has been largely neglected in biodiversity monitoring, and when addressed is treated separately, detached from other conservation issues, such as habitat alteration due to climate change. Genetic monitoring supports the conservation and management of fisheries, game, and threatened populations. It also can contribute to the assessment of predicted and realized impacts of climate change, and their management. We report the first accounting of genetic monitoring efforts among countries in Europe (their genetic monitoring capacity, GMC) to determine where GMC suggests the combination of national infrastructure, political support and resources for continued and expanded monitoring. Overlaying GMC with areas where species ranges approach current and future climate niche limits (i.e., niche marginality) helps identify whether GMC coincides with anticipated climate change effects on biodiversity. Our analysis suggests that country area extent, financial resources, and conservation policy influence GMC, high values of which inconsistently match joint species patterns of climate niche marginality. Populations at niche margins likely hold genetic diversity that is important to adaptation to changing climate, and our results illuminate the need in Europe for expanded genetic monitoring across the climate gradients occupied by species, a need arguably greatest in southeastern European countries.

ecology↗