Genome-wide strengthening of evolutionary constraint across the volvocine multicellularity gradient
Abstract
The evolutionary cost of maintaining somatic cell populations has been hypothesised to drive proteome-wide strengthening of constraint on coding sequence at the origin of multicellularity. Prior work on the volvocine clade has reported lower d_N/d_S in colonial than in unicellular relatives on 55 chloroplast genes (Hu et al. 2019) and on 105 nuclear single-copy orthogroups across colonial species (Hu et al. 2020), but a nuclear genome-wide branch-model analysis together with per-species phylogenetic regression, an orthogonal amino-acid branch-length analysis with non-independence-corrected significance, a functional-category breakdown, and within-clade replication has been lacking. Here, ten volvocine green algae spanning the unicellular Chlamydomonas reinhardtii, the colonial intermediates Tetrabaena, Gonium, the independently evolved partial-soma lineage Astrephomene gubernaculifera (Goniaceae), Yamagishiella, Eudorina, Pleodorina, and three species of Volvox (V. carteri, V. africanus, V. reticuliferus) were analysed by branch-model d_N/d_S on 1,755 single-copy nuclear orthogroups (845 retained after quality control), an order of magnitude larger than the closest prior nuclear analysis (Hu et al. 2020). Foreground (multicellular) omega was lower than background (Chlamydomonas) omega in 88.6 % of orthogroups (median omega_fg = 0.046, median omega_bg = 0.117); the pattern occurred across all 20 COG functional categories analysed (range 78-100 % per category). Independent…
Read the paper
Related studies
- eggNOG 5.0: a hierarchical, functionally and phylogenetically annotated orthology resource based on 5090 organisms and 2502 viruses
- Online Survival Analysis Software to Assess the Prognostic Value of Biomarkers Using Transcriptomic Data in Non-Small-Cell Lung Cancer
- OptiType: precision HLA typing from next-generation sequencing data
- Nicotinic Cholinergic System and COVID-19: In Silico Identification of an Interaction between SARS-CoV-2 and Nicotinic Receptors with Potential Therapeutic Targeting Implications
- Saccharomyces cerevisiae cells have three Omega class glutathione S-transferases acting as 1-Cys thiol transferases
- Hemolysis at low blood flow rates: in-vitro and in-silico evaluation of a centrifugal blood pump
Go deeper in Evidence Hub
Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.