Dr Hasan Alnaser

Biography

I use budding yeast (Saccharomyces cerevisiae) to study how cells form, process and repair programmed DNA double-strand breaks (DSBs) during meiosis, and how these processes contribute to accurate chromosome segregation.

I completed my BSc in Biotechnology at the University of Sharjah, UAE, in 2014. During my degree I did a training placement in molecular biology techniques at the University of Sheffield. I then took an MSc in Human and Molecular Genetics at Sheffield, graduating in 2015, and stayed on for a PhD in Molecular Biology. My PhD looked at protein phosphorylation during yeast meiosis and its links to the DNA damage response.

After my PhD I started postdoctoral work with Dr Bin Hu, and moved with the lab to the University of Aberdeen in 2020. I now work in Dr Hajime Murakami’s laboratory on meiotic recombination and chromosome biology.

Research Overview

• Yeast meiosis
• Cell-cycle checkpoint
• Chromosome segregation 
• DNA Repair 
• Protein post-translational modifications 

Current Research

During meiosis, a single diploid cell divides twice to produce four genetically distinct haploid gametes. Recombination begins when Spo11 creates programmed DSBs across the genome. These breaks are resected to expose 3′ single-stranded DNA, which then searches for a homologous template. Their repair produces crossovers, which both generate genetic diversity and physically link homologous chromosomes so they separate correctly. Errors at any of these steps can cause aneuploidy and infertility.

In Dr Murakami’s laboratory, I use TurboID proximity labelling and quantitative mass spectrometry to map the protein environment of the DSB-formation machinery during meiosis. By comparing mutant backgrounds that stall cells at different stages of recombination, I aim to understand how DSB formation is coordinated with the steps that follow. I also use genome-wide sequencing methods, including ChIP-seq and S1-seq, to map protein binding, DSB distribution and resection across the yeast genome.

Past Research

In my previous post with Dr Bin Hu, I studied the regulation of Exonuclease 1 (Exo1), the nuclease responsible for long-range resection of meiotic DSBs. Using mass spectrometry, I identified meiosis-specific phosphorylation sites on Exo1 that depend on Tel1 and the MRX complex. I also characterised how Exo1 is recruited to Spo11-induced break sites.

Knowledge Exchange

I developed Yeast Meiosis Gene Viewer (pachytene.com), a free online tool for exploring gene expression across a meiotic time course in budding yeast. I built it to make meiosis research more accessible, both to students and to anyone curious about how cells make gametes. It needs no specialist software or bioinformatics skills. Users can look up any gene and see how its expression changes as cells move through meiosis. 

The tool is designed for both teaching and research. In teaching, students can use it to explore how gene activity is coordinated across the stages of meiosis. In research, it offers a quick way to check the meiotic expression profile of a gene of interest, or to find candidates for further study.

Teaching Responsibilities

I supervise undergraduate (BSc) and postgraduate taught (MSc) students on research projects in the Murakami laboratory. I support them through each stage of their projects, from experimental design and training in laboratory techniques to data analysis and dissertation writing. I also help the laboratory’s PhD students with their experimental work and research.