Biology subjects

Boscaro, V.

Publications and source records attributed to Boscaro, V..

3 recordsLinked to original sources

bioRxiv2025

Regulated development of cannibalistic supergiant cells

Virtually all paradigms in developmental biology apply to differentiating cells and tissues within multicellular animals and plants. However, unicellular eukaryotes, which must simultaneously perform all roles necessary for organismal function, also form complex and specialized structures, using processes that take place exclusively within the confines of a single cell. Here, we describe a ciliate (Euplotes gigatrox sp. nov.) undergoing drastic morphological transformations within a genetically uniform population, the most spectacular being the appearance of "supergiants" that increase in size, change shape, and modify their locomotion and feeding behaviour to cannibalize clonal relatives. We explore supergiant formation from the perspective of life cycle, ecological strategy, and gene expression, demonstrating that supergiants are distinct, regulated, transcriptionally unique stages. These reversibly differentiated cells require both external and internal triggers to develop and have evolved regulatory loops to ensure coupling between environmental and physiological conditions. This system provides a blueprint for approaching both cell differentiation and functional ecology in unicellular organisms, which might open new avenues for the generalization and contextualization of known morphogenetic mechanisms, as well as the discovery of new ones.

cell biology↗

bioRxiv2025

Phylogenetic position and mitochondrial genome evolution of 'orphan' eukaryotic lineages

The phylogenetic tree of eukaryotes is divided into a handful of highly diverse supergroups; only a few so-called orphan lineages branch in uncertain positions outside of these large clades. We found that the mitochondrial genome of one such lineage, the telonemids, is considerably gene-rich, a feature observed in other orphans as well, raising the possibility that these organisms share a common history. On the contrary, our phylogenomic analyses show that orphans with gene-rich mitochondria branch into two different positions: telonemids actually belong to the established supergroup Haptista, while provorans and meteorids form a strongly supported clade with hemimastigophorans, in a novel ancient supergroup that we dub here Promethea. Comparative genomics shows that this split reflects differences between mitochondrial gene sets. Thanks to the increased number of available representatives analyzed together, our results further simplify and illuminate the evolutionary relationships between eukaryotes.

microbiology↗

bioRxiv2018

EukRef: phylogenetic curation of ribosomal RNA to enhance understanding of eukaryotic diversity and distribution

Environmental sequencing has greatly expanded our knowledge of micro-eukaryotic diversity and ecology by revealing previously unknown lineages and their distribution. However, the value of these data is critically dependent on the quality of the reference databases used to assign an identity to environmental sequences. Existing databases contain errors, and struggle to keep pace with rapidly changing eukaryotic taxonomy, the influx of novel diversity, and computational challenges related to assembling the high-quality alignments and trees needed for accurate characterization of lineage diversity. EukRef (eukref.org) is a community driven initiative that addresses these challenges by bringing together taxonomists with expertise spanning the complete eukaryotic tree of life and microbial ecologists that actively use environmental sequencing data for the purpose of developing reliable reference databases across the diversity of microbial eukaryotes. EukRef organizes and facilitates rigorous sequence data mining and annotation by providing protocols, guidelines and tools to do so.

microbiology↗