Development

Development is the process of temporal and spatial control of gene expression that gives rise to a fully functional adult form of the organism. Studies of development in C. elegans have traced every cell from birth to final differentiated state in the developing nematode. These studies have elucidated cellular, genetic, and molecular mechanisms that control the division, growth, differentiation and morphogenesis of cells giving rise to tissues and organs in the nematode body. While most terminally differentiated cells can be traced by lineage back to a founder cell, there still remains a few cells types in the nematode with stochastic identity, relying on signals from the environment for their final identity.

Mitosis

Mitosis is part of the eukaryotic cell cycle and results in the production of two daughter cells each with a copy of the genome. The cell cycle itself is comprised of an interphase (made up of three stages G1, S, and G2) and the M (mitotic) phase. Cell growth, active transcription and translation, and DNA replication occur during interphase. During M phase duplicated DNA (chromatin) condense into sister chromatids (prophase); the nuclear envelop breaks down, kinetochore microtubles attach to the chromosomes and centrosomes are pushed to the poles of the growing spindle (prometaphase); the chromosomes are lined up on the metaphase plate (metaphase); sister chromatids are pulled to spindle poles at opposite ends of the cell (anaphase); the nuclear envelop is reformed and the chromatids decondense to chromatin (telophase); and the cell is cleaved into two by a contractile ring and the resolution of a cleavage furrow (cytokinesis). In some variant cell cycles nuclear division may not be followed by cell division, or G1 and G2 phases may be absent.