PhD defence and trial lecture: Sowmya Ramachandran

Doctoral candidate Sowmya Ramachandran will hold a trial lecture and defend her thesis for the degree Philosophiae Doctor (PhD) at the Faculty of Biosciences and Aquaculture (Bodø), Nord University.

Start date:

16 December 2022 10:15

End date:

16 December 2022 15:00

Location:

A5 Petter Thomassen


PhD candidate Sowmya Ramachandran

Trial lecture topic

tba​

Thesis title

Ribosomal RNA, ribose methylation, and box C/D snoRNAs during embryonic development of teleosts zebrafish (Danio rerio) and medaka (Oryzias latipes)

Evaluation Committee​

- Research Director Benoît Masquida, University of Strasbourg, France​
- Professor Eivind Dale Valen, Department of Informatics, University of Bergen 
- Professor Monica Fengsrud Brinchmann, FBA, Nord University

Supervisory Committee​​

Main supervisor: Professor Igor​ Babiak​​, FBA, Nord University
Co-supervisors: - Professor Steinar Daae Johansen, FBA, Nord University
                        ​     - Professor Henrik Nielsen, University of Copenhagen , Denmark

About the thesis

Zebrafish (Danio rerio) and medaka (Oryzias latipes), are model organisms for human biology and diseases. Even though an abundance of information about the DNA and RNA of zebrafish and medaka is readily available, a functional understanding of many biological mechanisms is lacking, especially with respect to the early stages of embryonic development. Ribosomal RNA (rRNA) structure and composition are highly conserved across most organisms with variable modifications such as ribose methylations. Zebrafish has been shown to possesses two types of rRNA, one of which is only observed during early embryonic development. 

The purpose of this study was to investigate the structure and modification profile of the two rRNA types and to compare the results with that of medaka, a distant evolutionary relative of zebrafish. We used the sequencing-based RiboMeth-seq method to study the ribose methylation (2'-O-Me) profile in zebrafish and medaka during select stages of embryonic development. 

The results showed that the two rRNA types in zebrafish differed in structure and modification profile while medaka only expressed one rRNA type that was most similar to the rRNA of other known vertebrates. We also propose a new investigative strategy to study the RNA that guide 2'-O-Me modifications. Overall, this study leads to question whether the two rRNA types seen in zebrafish is restricted to a specific sub-group of fish and if medaka could indeed be the better model to study early embryonic development.      ​

Trial lecture: 10:15 - 11:05
PhD defence: 12:15 - 15:00​​​

Start date:

16 December 2022 10:15

End date:

16 December 2022 15:00

Location:

A5 Petter Thomassen
The PhD trial lecture and defence are open to the public. The thesis is available upon request. Please contact Jeanett Stegen.