We combine big data ‘omics with developmental biology approaches to investigate the control and evolution of spiral cleavage. Additionally, we investigate how genome evolution played a role in animal diversification.
Axis specification in spiral cleaving annelids
Spiral cleavage is an early mode of development found in at least seven invertebrate animal groups, including annelids, molluscs, flatworms, and nemerteans. It is presumably the ancestral defining character to Spiralia, one of the three major groups of animals with bilateral symmetry.
During spiral cleavage, the axial information and cellular fates that define the animal body plan emerge either conditionally – through cell-cell interactions – or autonomously – through maternal factors. In annelids, most studies have focused on autonomous cleaving species, limiting our understanding of how these two modes of development evolved. We are combining live microscopy, transcriptomics, gene expression analyses, and functional approaches to disentangle the mechanisms of axis specification and cell fate commitment in conditional cleaving annelids, using as main research species the palaeannelid worm Owenia fusiformis.
Epigenetics of spiral cleavage
Conditional and autonomous spiral cleaving embryos differ in the timing and mode of specification of their progenitor cells. Epigenetic changes ultimately control cell fate acquisition, but our understanding of this process is still very limited in spiralians, and in particular during spiral cleavage.
We are characterising the genome-wide dynamics of cis-regulation during annelid development to dissect the control and evolution of conditional and autonomous spiral cleavage. Combining latest techniques in epigenomic profiling, such as ATAC-seq, CUT&Tag and WGBS, with high resolution RNA-seq, we are starting decipher how genome regulation influence gene dynamics and changes in transcriptional profiles that ultimately reflect in changes of cell fate and developmental trajectory.
Comparative annelid genomics
Annelids are one of the most diverse animal groups on Earth, with over 16,000 described species. They display a vast diversity of adult morphologies and lifestyles, and have colonised marine, freshwater and terrestrial environments. Yet how this biodiversity is encoded at the genomic level is still largely unexplored.
To start filling this knowledge gap and provide a better understanding of the morphological and ecological evolution of this animal group, we recently decoded the compact genome of the meiobenthic worm Dimorphilus gyrociliatus. Now, we are combining long-read sequencing, optical mapping and HiC approaches to generate gold-standard assemblies for key annelid species, such as Owenia fusiformis, our main model experimental system.
In addition, we collaborate with labs worldwide to explore the genomic diversity of marine invertebrate groups.