Thursday, January 8, 2009
The life of a cell
All living organisms are formed from millions of micrometric units, the cells, which are constantly growing, reproducing and dying throughout the lifetime of an organism. The cell cycle is divided into the interphase – the time between divisions – and the mitotic phase, in which the cell divides physically. The interphase is formed by the growth stage (G1), the duplication stage (S), during which the cell duplicates its DNA, and the maturity stage (G2). After G2, the mitotic phase, which can be divided into 2 stages, begins. The first stage is mitosis, in which the chromosomes are shared between the two daughter cells. The second stage is cytokinesis, during which the mother cell divides physically. The cell cycle is ordered and strictly regulated. This regulation is essential, since the chaos of the cell cycle is the main cause of cancer: when there are errors in the cycle, the cells don’t stop dividing and the tumour grows.
At the PRBB centres there are many groups performing research into different aspects of the cell cycle. Among them are Dr. Gil’s group (IMIM), who focus on the biochemical connection between programmed cell death and the cell cycle regulation in mice, and the groups of Dr. Hidalgo’s and Dr. Ayté’s from the CEXS-UPF, who are trying to understand the control of the cell cycle in yeast, a model organism widely used in this field. Dr. Posas (CEXS-UPF) also uses yeast to study the control of cell progression by the protein Hog1 MAPK, whilst Dr. Muñoz (CRG) is interested in the role of MAPKs in the control of proliferation and differentiation of the muscle. Another group is Dr. Vernos’ (CRG), who study the chromosomes sharing during mitosis in frogs.