Model system: the fruit fly Drosophila melanogaster
Germ cells reside in the reproductive tissues, the testes and ovaries. These cells undergo specialised cell divisions, such as meiosis, to ultimately give rise to gametes (eggs and sperm). Defects in egg and sperm development lead to reduced fertility or sterility. Understanding how cell division is controlled in germ cells is critical, as this information can impact on the diagnosis and treatment of human or animal infertility.
A field of fruit fly spermatocytes in which an ATP synthase subunit is depleted leading to defects in DNA organization, imaged using wide field microscopy (DNA is shown in green).
Four fruit fly egg chambers containing germline stem cells, imaged using high resolution confocal microscopy.
Located on each chromosome within the cell nucleus, the centromere plays a key role in cell division. It is the site where the kinetochore assembles to ensure proper chromosome segregation. Rather than DNA sequence, the histone variant CENP-A specifies centromere identity and function in an epigenetic manner. Compared to somatic cells, CENP-A assembly in germ cells displays unique properties. For example, in spermatocytes undergoing meiosis and germline stem cells undergoing asymmetric divisions, CENP-A is assembled at unique cell cycle times or in unexpected amounts.
A key research question in the laboratory is to understand how CENP-A is targeted to and reproducibly incorporated at centromeres during meiosis. To address this question, we use male meiosis in the fruit fly Drosophila melanogaster as a model developmental system, combing genetics, cell biology and biochemical approaches. A second major focus of the laboratory is to investigate mechanisms of centromere assembly and maintenance in germ line stem cells and to understand how this might impact on cell fate. We use the germ line stem cell niche in both Drosophila melanogasterfemales and males as model systems, combining genetics with high resolution fixed and live imaging approaches.
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