Laboratory of Gene Function

About our research

Purpose of our research

Every higher eukaryote reproduces by fusing two gametes: oocytes and sperm. In contrast to a typical eukaryotic cell that contains a diploid genome, a gamete only contains one haploid genome. To differentiate into haploid gametes, diploid primordial germ cells must go through meiosis, a special type of cell division, which halves the number of chromosomes. Meiosis is one of the most fundamental biological events and is conserved from unicellular eukaryotes such as yeast through to mammals, including humans. However, many enigmas about meiosis remain. We are trying to clarify the molecular mechanisms underlying meiosis.

Features of our research

We use the fission yeast Schizosaccharomyces pombe as a model organism to study the molecular mechanisms of meiosis because of the genetic tractability and easy induction of meiosis. We have been able to characterize several pivotal regulators of meiosis and the molecular processes in which these factors are involved.

Expected fields of application

Much effort has been devoted to the understanding of meiosis in the fields of basic biology and medicine. Using the biological simplicity of fission yeast, and the genetic and biochemical methods used to study it, we can begin to understand the common molecular bases of meiosis that are shared by eukaryotes.

Our research projects

1. Signaling pathways that regulate the onset of sexual differentiation and meiosis.

We are trying to elucidate how fission yeast cells switch the cell cycle mode from mitotic to meiotic. We have focused on highly conserved kinase complexes, known as TOR complexes, which play key roles in the recognition of nutrition and the onset of sexual differentiation.

2. The molecular mechanisms that establish the meiosis-specific transcription profile.

Hundreds of genes are upregulated during meiosis. We found that control of mRNA stability, which is orchestrated by the interplay between RNA-binding proteins and a long non-coding RNA, contributes to meiosis-specific gene expression. Understanding the detailed mechanisms underlying the control of meiotic mRNA stability will shed light on the timely regulation of gene expression.

3. Meiosis-specific cell cycle regulation.

In both mitosis and meiosis, the accumulation and activation of M-phase promoting factor (MPF) is required before nuclear division. When cells exit from mitosis and enter the next phase of the cell cycle, MPF levels must be reduced. How are MPF levels regulated between meiosis I and meiosis II, when two sequential nuclear divisions take place? We are interested in the molecular mechanisms underlying cell cycle progression from meiosis I to meiosis II.

Publications