Corre, P. | Search bioRxiv

bioRxiv2026

A pan-eukaryotic analysis of mitochondrial ribosomes uncovers major evolutionary transitions

Mitochondrial ribosomes (mitoribosomes) have diverged extensively both from their bacterial ancestors and across eukaryotes, and while many general trends have been identified, fundamental features of their evolution remain unclear. We analyzed sequences from 85 eukaryotes to chart protein composition across the evolution of mitochondrial translation. We both reconstruct the LECA mitoribosomal proteome as containing nearly the full bacterial protein complement and at least 23 proteins recruited after -proteobacterial endosymbiosis and describe the subsequent extensive but lineage-specific remodeling post LECA. We further uncover previously unrecognized homologies among several mitoribosomal proteins and unify and update the mitoribosomal nomenclature. Our data also support protein retargeting between organellar ribosomes, documenting remarkable intercompartmental structural compatibility. Together, these findings highlight the exceptional evolutionary plasticity of mitoribosomes and provide a comprehensive reference framework for future analysis.

evolutionary biology↗

bioRxiv2023

Coordinated multiple cellular processes in tongue development

Dysfunction of primary cilia leads to genetic disorder, ciliopathies, which shows various malformations in many vital organs such as brain. Multiple tongue deformities including cleft, hamartoma and ankyloglossia are also seen in ciliopathies, which yield difficulties in fundamental functions such as mastication and vocalization. Here, we found these tongue anomalies in mice with mutation of ciliary protein. Abnormal cranial neural crest-derived cells (CNCC) failed to evoke Hh signal for differentiation of mesoderm-derived cells into myoblasts, which resulted in abnormal differentiation of mesoderm-derived cells into adipocytes. The ectopic adipose subsequently arrested migration of other mesoderm-derived cells and CNCC. Some aberrant CNCC abnormally differentiated into osteoblasts due to the lack of Hh signal, which migrated into tongue to form ectopic bone. Ankyloglossia was caused by aberrant cell migration due to lack of non-canonical Wnt signaling. In addition to ciliopathies, these tongue anomalies are often observed as non-familial condition in human. We found that these tongue deformities could be reproduced in wild-type mice by simple mechanical manipulations in CNCC to disturb cellular processes which were disrupted in mutant mice. Thus, tongue development requires coordinated multiple cellular processes (cell-cell contact, migration and differentiation). Our results provide hints for possible future treatment in ciliopathies.

developmental biology↗