The study reports a genetic screen for mutations that affect microtubule-dependent mRNA localisation in developing oocytes of the fruit fly Drosophila melanogaster. The team identified ten novel mutation groups that disrupt gurken mRNA localisation and other aspects of oogenesis. Their findings revealed a quality control mechanism in which overexpression of transposons—foreign mobile genetic elements in the genome—leads to defective egg follicle formation and eventual germline loss. The study also suggests a possible role for double-stranded RNA recognition in transposon silencing. 

The genetic screen was conducted during Hayashi’s postdoctoral time at Cancer Research UK, London (2010–2013), as part of the first author Sophie Liddell’s Ph.D. project. The subsequent characterisation of the genetic mutations was completed with the help of three Honours and master’s students who worked with Hayashi at ANU. The four main contributors of the study have since taken different career paths yet share a fond memory of the long and painstaking fly ovary dissections that defined their collaboration. 

The study is published here: A second genetic screen for gurken mRNA mislocalisation uncovers novel phenotypes of piRNA pathway mutants in Drosophila

I carried out my PhD between 2009-2013, in David Ish-Horowicz’s lab at the Cancer Research UK London Research Institute. I was very lucky to have wonderful colleagues and BBC Radio 4 to keep me company through hours and years of fly screening, looking for mutations disrupting gurken RNA localisation. 

While I remain in awe of those who dedicate their life to the pursuit of knowledge, I chose to cross to the other side to research funders. I’ve worked for Wellcome and the UK Medical Research Council and am now Head of Research Infrastructure at the Engineering and Physical Sciences Research Council. Although my day job is supporting supercomputers and research software engineers, I am still a developmental biologist at heart and will never forget the thrill of spotting a beautiful mutant amongst thousands of wildtypes. 

Sejal Sathe, ANU Master student between 2018 and 2019 

During my master’s study I investigated the effect of transposon upregulation on ovarian somatic tissue development in Drosophila. The most enjoyable part of the project for me was to dissect pupal ovaries and visualise the beautiful basal stalk structures under a confocal microscope. This project provided my foundational skills in critical thinking and precision technique. 

Following my master's, my career took a pivotal turn in molecular diagnostics. I worked in India, at the National Institute of Virology, performing whole genome sequencing of SARS-CoV-2 for WHO’s COVID-19 surveillance initiative. That high-stakes experience led me to my current role as a Medical Scientist at Peter MacCallum Cancer Centre in Melbourne. Here, in Pathology-Clinical Trials, I now utilize advanced molecular tools like Next Generation Sequencing to screen patients for various malignancies, helping them get onto relevant clinical trials. 

Rahnya Taghi, ANU Honours student from 2022 to 2023 

I discovered my passion for biology and genetics in high school, which led me to pursue further studies at the Australian National University. During my Honours year in the Hayashi lab, I investigated transposons and their genetic regulation in Drosophila. Most of my time was spent delicately dissecting ovaries from pupal fruit flies (a task far more challenging than it sounds!) and staining them to examine piRNA pathway expression. It was meticulous, hands-on work that I remember with fondness. 

Since graduating, my career has been a whirlwind. I've worked across various parts of the public service, gaining diverse experience and insights, and now find myself in the Clean Energy sector. The skills and perspectives I developed during my Honours year continue to shape how I approach new challenges. That formative time in the lab remains one of the most rewarding chapters of my professional journey. 

Jessie Siling Li, ANU Master student from 2024 to 2025 

My master’s study focused on uncovering the molecular mechanisms of somatic transposon activity in the female reproductive system, especially basal stalk cell formations in mid ovary development, using Drosophila melanogaster pupa as a model. My work involved live-tissue dissection and fixation, mosaic analysis with repressive cell markers (MARCM) systems, and applying immunofluorescent microscopy to visualize ovarian development patterns critical for cellular function. Through this research, I developed a strong technical foundation in cellular biology and molecular genetics, along with a deep appreciation for the role of fundamental science in driving medical advances. Inspired by this experience, I am pursuing a career as a research technician in the public health system, where I hope to contribute to biomedical innovations that directly improve patient care and community health, as well as strengthen the communication of fundamental biological research to the broader public.