Biology subjects

Paps, J.

Publications and source records attributed to Paps, J..

4 recordsLinked to original sources

bioRxiv2024

The Hydractinia cell atlas reveals cellular and molecular principles of cnidarian coloniality

Coloniality is a widespread growth form in cnidarians, tunicates, and bryozoans, among others. Despite being modular, composed of multiple zooids and supporting tissues, colonies function as a single physiological unit. A major question in the biology of colonies is the cellular mechanism of generating structurally and functionally distinct colony parts. The cnidarian Hydractinia establishes colonies with different types of zooids (polyps), interconnected by a gastrovascular system that is attached to the substrate and known as stolons. We obtained single cell transcriptomic profiles of [~]200K Hydractinia cells, including isolated stolons and two polyp types. We characterised the major Hydractinia cell types and quantified their abundance across colony parts. Overall, we find that distinct colony parts are characterised primarily by distinct combinations of shared cell types and to a lesser extent by part-specific cell types. Therefore, we propose that both cell type combinations, as well as rarer cell type innovations, have been the main mechanism in the evolution of coloniality in cnidarians. We identified cell type-specific transcription factors (TFs) and gene networks expressed within these cell types. Notably, we discovered a previously unidentified, stolon-specific cell type, which expresses enzymes related to biomineralization and chitin synthesis, reminiscent of molluscan shell matrix proteins that may represent a crucial adaptation to the animals habitat. In summary, the Hydractinia cell atlas elucidates the fundamental cellular and molecular mechanisms underlying coloniality.

systems biology↗

bioRxiv2023

Hagfish genome illuminates vertebrate whole genome duplications and their evolutionary consequences

Whole genome duplications (WGDs) are major events that drastically reshape genome architecture and are causally associated with organismal innovations and radiations1. The 2R Hypothesis suggests that two WGD events (1R and 2R) occurred during early vertebrate evolution2, 3. However, the veracity and timing of the 2R event relative to the divergence of gnathostomes (jawed vertebrates) and cyclostomes (jawless hagfishes and lampreys) is unresolved4-6 and whether these WGD events underlie vertebrate phenotypic diversification remains elusive7. Here we present the genome of the inshore hagfish, Eptatretus burgeri. Through comparative analysis with lamprey and gnathostome genomes, we reconstruct the early events in cyclostome genome evolution, leveraging insights into the ancestral vertebrate genome. Genome-wide synteny and phylogenetic analyses support a scenario in which 1R occurred in the vertebrate stem-lineage during the early Cambrian, and the 2R event occurred in the gnathostome stem-lineage in the late Cambrian after its divergence from cyclostomes. We find that the genome of stem-cyclostomes experienced two additional, independent genome duplications (herein CR1 and CR2). Functional genomic and morphospace analyses demonstrate that WGD events generally contribute to developmental evolution with similar changes in the regulatory genome of both vertebrate groups. However, appreciable morphological diversification occurred only after the 2R event, questioning the general expectation that WGDs lead to leaps of morphological complexity7.

genomics↗

bioRxiv2019

Genomic adaptations to aquatic and aerial life in mayflies and the origin of wings in insects

The first winged insects underwent profound morphological and functional transformations leading to the most successful animal radiations in the history of earth. Despite this, we still have a very incomplete picture of the changes in their genomes that underlay this radiation. Mayflies (Ephemeroptera) are one of the extant sister groups of all other winged insects and therefore are at a key phylogenetic position to understand this radiation. Here, we describe the genome of the cosmopolitan mayfly Cloeon dipterum and study its expression along development and in specific organs. We discover an expansion of odorant-binding proteins, some expressed specifically in the breathing gills of aquatic nymphs, suggesting a novel sensory role for gills. In contrast, as flying adults, mayflies make use of an enlarged set of opsins and utilise these visual genes in a sexually dimorphic manner, with some opsins expressed only in males. Finally, to illuminate the origin of wings, we identify a core set of deeply conserved wing-specific genes at the root of the pterygote insects. Globally, this is the first comprehensive study of the structure and expression of the genome of a paleopteran insect and shows how its genome has kept a record of its functional adaptations.

evolutionary biology↗

bioRxiv2018

Metabarcoding analysis on European coastal samples reveals new molecular metazoan diversity

Although animals are among the best studied organisms, we still lack a full description of their diversity, especially for microscopic taxa. This is partly due to the time-consuming and costly nature of surveying animal diversity through morphological and molecular studies of individual taxa. A powerful alternative is the use of high-throughput environmental sequencing, providing molecular data from all organisms sampled. We here address the unknown diversity of animal phyla in marine environments using an extensive dataset designed to assess eukaryotic ribosomal diversity among European coastal locations. A multi-phylum assessment of marine animal diversity that includes water column and sediments, oxic and anoxic environments, and both DNA and RNA templates, revealed a high percentage of novel 18S rRNA sequences in most phyla, suggesting that marine environments have not yet been fully sampled at a molecular level. This novelty is especially high among Platyhelminthes, Acoelomorpha, and Nematoda, which are well studied from a morphological perspective and abundant in benthic environments. We also identified based on molecular data a potentially novel group of widespread tunicates. Moreover, we recovered a high number of reads for Ctenophora and Cnidaria in the smaller fractions suggesting their gametes might play a greater ecological role than previously suspected.

microbiology↗