Biology subjects

Furni, F.

Publications and source records attributed to Furni, F..

4 recordsLinked to original sources

bioRxiv2025

Towards an archaeological workflow for sedaDNA sample collection: methods and best practices for minimizing surface contamination

SedaDNA has been successfully recovered from diverse contexts, enabling researchers to address paleoenvironmental questions such as ecosystem changes and climatic shifts, along with archaeological questions related to past human activities, diet, health, and interactions with their environment. Despite its potential, the reliability of sedaDNA data heavily depends on proper sampling and handling practices. Contamination remains a significant challenge in ancient DNA research, profoundly impacting data integrity and interpretation. Consequently, numerous studies have underscored the importance of minimizing contamination levels. Nonetheless, a challenge arises in implementing this in daily archaeological practice, as a specialized DNA expert is not always available. This study suggests two customised workflows of commonly used sedaDNA sampling techniques, redesigned for archaeologists without sedaDNA expertise. We test their effectiveness in the field. To benchmark these protocols, we applied artificial DNA contaminants onto sediment surfaces before sampling. Subsequently, we evaluate archaeologists effectiveness in reducing surface contamination by quantifying the level of artificial DNA detected. Finally, we compare results between samples taken by archaeologists with and without sedaDNA expertise. Our results demonstrate that existing sampling protocols, when slightly adapted to the needs of archaeologists, significantly minimize surface contamination to the point that they provide high-quality extraction. Additionally, our findings suggest that subsampling sediments with minimal surface contamination from previously collected materials is viable, emphasizing the potential of archived sediment collections for sedaDNA analysis.

genomics↗

bioRxiv2024

Dosage compensation and sexual conflict in female heterogametic methylomes

DNA methylation (DNAm) suppresses gene expression and contributes to dosage compensation in mammals but whether DNAm plays a similar role in female ZW chromosome heterogametic species remains unresolved. We assessed chromosome-level DNAm using whole genome bisulphite sequencing in two avian species, zebra finches and jackdaws. Dosage compensation by DNAm would result in higher and more variable DNAm level in males relative to females on the Z chromosome. However, we found that the level of DNAm and its variance on the Z chromosome was lower in males. Moreover, male Z chromosome-based gene promoters were more frequently hypomethylated compared to females, indicating absence of upregulation on a gene-by-gene basis across the female Z chromosome. We suggest our findings reveal mitigation of an intra-genomic sexual conflict, with females suppressing expression of Z chromosome-based genes that benefit male but not female fitness. W was the most methylated chromosome, but hypermethylation on the W chromosome was mostly confined to intergenic regions, presumably resulting in the downregulation of transposable elements known to comprise a large part of the W chromosome. Thus, DNAm is involved in the development of sex-dependent phenotypes, but dosage compensation is achieved through other mechanisms.

evolutionary biology↗

bioRxiv2024

Sex-chromosome-dependent aging in female heterogametic methylomes

Recent research in humans and both model and non-model animals has shown that DNA methylation (DNAm), an epigenetic modification, is one of the mechanisms underlying the aging process. DNAm-based indices predict mortality and provide valuable insights into biological aging mechanisms. Although sex-dependent differences in lifespan are ubiquitous and sex chromosomes are thought to play an important role in sex-specific aging, they have been largely ignored in epigenetic aging studies. We characterized the genome-wide distribution of age-related CpG sites from longitudinal samples in two avian species (zebra finch and jackdaw), including for the first time the avian sex chromosomes (Z and the female-specific, haploid W). In both species, we find a small fraction of the CpG sites to show age-related changes in DNAm with the majority of them being located on the haploid, female-specific W chromosome where DNAm levels predominantly decrease with age. Age-related CpG sites were overrepresented on the zebra finch but underrepresented on the jackdaw Z chromosome. Our results highlight distinct age-related changes in sex chromosome DNAm compared to the rest of the genome in two avian species, suggesting this previously understudied feature of sex chromosomes may be instrumental in sex-dependent aging. Moreover, studying the DNAm of sex chromosomes might be particularly useful in aging research, facilitating the identification of shared (sex-dependent) age-related pathways and processes between phylogenetically diverse organisms.

evolutionary biology↗

bioRxiv2022

Direct estimation of genome mutation rates from pedigrees in free-ranging baleen whales

Current low germline mutation rate () estimates in baleen whales have greatly influenced research ranging from assessments of whaling impacts to evolutionary cancer biology. However, the reported rates were subject to methodological errors and uncertainty. We estimated directly from pedigrees in natural populations of four baleen whale species and the results were similar to primates. The implications of revised values include pre-exploitation population sizes at 14% of previous genetic diversity-based estimates and the conclusion that in itself is insufficient to explain low cancer rates in gigantic mammals (i.e., Petos Paradox). We demonstrate the feasibility of estimating from whole genome pedigree data in natural populations, which has wide-ranging implications for the many ecological and evolutionary inferences that rely on .

genetics↗