Conjoint Prof. Keith Jones

Biography

Meiosis is the name given to the two cell divisions germ cells go through following DNA replication in order to produce haploid gametes. Our research focuses on mammalian female meiosis where we use imaging based techniques (Fluorescent Protein chimeras) to explore this process in real-time. We argue that this is an important strategy when examining a dynamic process such as the meiotic cell cycle.

Meiosis is important to study because of its unique cell division; in terms of understanding a fundamental cellular developmental biology process; and also because errors in meiotic division lead to aneuploid embryos, the leading cause of early pregnancy loss in humans and the cause of Down's Syndrome.

Research Highlights: The mammalian oocyte spends most of its life arrested at prophase of the first meiotic division and we found that APCcdh1 activity was necessary in order to achieve this arrest (Reis et al., Nature Cell Biology, 2006). Recently we extended these observations to show that APCcdh1 also functioned in prometaphase to prevent aneuploidy in maturing oocytes (Reis et al., Nature Cell Biology, 2007). In the first meiotic division chromosome homologues are separated, a unique cell division, and in 2006 we found that during this division separase is needed to inhibit MPF activity (Gorr et al., Nature Cell Biology, 2006. See Nature Cell Biology, News & Views). Following exit from the first meiotic division the egg re-arrests at metaphase of the second meiotic division until sperm break this arrest with a cytosolic calcium signal. Re-arrest at metaphase of the second meiotic division requires the APC inhibitor Emi2 (Madgwick et al., Journal of Cell Biology, 2006). At fertilization the sister chromatids are separated. Another unequal cell division occurs, and the second polar body is extruded. The fertilized oocyte completes meiosis and forms a zygote.

We are very much interested in how the two meiotic divisions are controlled at a molecular level. Our approach is to over-express and visualise gene products by tagging them with a toolkit of Fluorescent Proteins (Cyan; Cerulean; Yellow, Green; Venus; and Red Fluorescent Proteins) and knock them out using antisense morpholinos.

Qualifications

• Doctor of Philosophy, University of Liverpool - UK, 1994
• Bachelor of Science, University of Leeds - UK, 1989

Research

Research keywords

• Cell Cycle
• Cell Division
• Chromosomes
• Female Fertility
• Meiosis
• Mitosis
• Oocytes
• Ovarian Biology
• Reproductive Biology

Research expertise

Mammalian reproductive biology, especially female reproduction with emphasis on oocytes and the meiotic divisions. Cell division and early embryo development, such as the transition from meiosis to mitosis, and the embryonic divisions leading up to implantation. Mitotic cell divisions of cultured cells, and the control of M-phase. Mis-segregation of chromosomes that lead to aneuploidy. Control of the meiotic divisions of oocytes with focus on the mechanisms that control faithful chromosome segregation such as the Spindle Assembly Checkpoint.

Fields of Research

Centres and Groups

Centre

Group