PhD defence: Md. Golam Rbbani

Thesis title​​​:

Characterization of Circular RNAs in Nile Tilapia Muscle and Thermal Modulation of their Expression in Relation to Growth

Trial lecture topic:

Gene-regulation in teleosts - with a focus on epigenetic and post-transcriptional events

Evaluation Committee:

• Associate Professor Christian Kroun Damgaard, Aarhus University, Denmark
• Associate Professor Alessia Giannetto, University of Messina, Italy
• Associate Professor Jens Mortansson Jelstrup Nolsøe, Nord University

Supervisory Committee:

• Main supervisor: Professor Jorge Manuel de Oliveira, Nord University
• Co-supervisor: Professor Artem Nedoluzhko, European University at St. Petersburg, Russia
• Co-supervisor: Professor Joost Andre M Raeymaekers, Nord University
• Co-supervisor: Researcher Jorge Galindo-Villegas, Nord University

Thesis summary​:

Fish muscle is a focal point in the aquaculture industry due to its commercial importance as the edible portion of fish. Muscle development and growth are intricately influenced by genetic and environmental factors, including temperature. Currently, our understanding of the molecular mechanisms governing these processes remains incomplete. Thus, this thesis explores the complex regulatory network of circular RNAs (circRNAs) in fish muscle growth and investigates the relationship between the thermal developmental plasticity of circRNA expression and muscle growth.

For this purpose, we utilized an integrative omics approach, precisely quantifying and comparing circRNA, miRNA, and mRNA expression profiles within the fast muscle of Nile tilapia while also manipulating embryonic temperatures to discern the influence of circRNA expression on long-term growth. Our findings elucidate the pivotal role of circRNA-miRNA-mRNA networks in enhancing muscle growth. Furthermore, we observed that circRNA expression patterns vary with embryonic temperature, significantly correlating with growth at the juvenile stage.

This thesis signifies a substantial advancement in our understanding of circRNA regulatory networks in muscle growth in Nile tilapia. It emphasizes the potential of circRNAs as growth-related molecular markers, laying the foundation for evaluating and monitoring fish responses to temperature fluctuations—a critical aspect in the context of global climate change.