CENTA funded – The evolution of cell-diversity in ctenophores

Project highlights

• Ctenophores 
• Neurons  
• Genomics 

Overview

Ctenophores, or comb jellies, are a mysterious group of non-bilaterian animals that stand out for their unusual nervous system and neurons (Burkhardt et al., 2023; Sachkova et al., 2021;Moroz et al., 2014). Recent evidence, based on phylogenetic, molecular studies, and morphological studies suggests that ctenophores may have developed their neurons independently from other animals (Burkhardt et al., 2023; Moroz et al., 2014; Schultz et al., 2021). This means that their nervous system might represent a separate evolutionary path, unlike the neurons found in other groups like bilaterians and cnidarians.  

By examining the gene expression of individual cells using single‐cell RNA sequencing (Tanay and Regev, 2017) (scRNA-seq) researchers can test whether neurons across species share a common set of regulatory genes. If ctenophore neurons evolved independently, we would expect them to express a unique combination of regulatory genes not found in the neurons of other animal lineages. 

However, current studies using scRNA-seq on ctenophores did not identify cell-type with a distinct neuronal gene expression signatures (Sebé-Pedrós et al., 2018). On the other hand, Hayakawa et al., (2022) have identified cells in ctenophores expressing typical neuronal markers. Thereby a big question remains: are the neurons in ctenophores homologous to those in bilaterians? 

To clarify this, in this project we will combine comparative genomics, scRNA-seq and molecular biology.  

This area of research presents a captivating challenge for prospective PhD students who are eager to tackle fundamental questions about the evolution of the nervous system. By using cutting-edge molecular and genomics techniques, you could be part of the effort to uncover one of biology’s greatest mysteries. 

Objectives 

The objective of this proposal is to understand how many times the neurons evolved in animals by integrating cutting-edge molecular biology, machine learning and phylogenetic methods. 

Methodology

This PhD will use state-of-the-art techniques in molecular biology (i.e. single-cell RNA seq) and computational methods (e.g. machine learning and phylogenetic methods) to test whether neurons evolved once or multiple times. Specifically, the PhD student will: 

1. Field visit to collect comb jellies and culturing animals. 
2. Generate single-cell RNA-seq data for Pleurobrachia pileus. 
3. Use machine learning to classify cell-types and validate them using in-situ hybridization methods. 
4. Reconstruct the evolutionary origin of neuronal modules and genes in animals using phylogenetic methods. 

Enquiries to Dr Roberto Feuda – [email protected]

To apply see our website https://le.ac.uk/study/research-degrees/funded-opportunities/centa-phd-studentships

Study start September 2025