[
1985]
At first sight the inclusion of a chapter on Caenorhabditis elegans in a volume on cell biology may seem unusual. However this nematode has been a superb model system for a number of cell biology studies as well as a useful model of aging. This widespread interest in C. elegans is engendered in large part by its genetic system and its optical clarity in Nomarski phase-contrast optics. Nematodes have long been a system in wide use among experimental gerontologists, and with the introduction of C. elegans by Brenner in 1974, this species has become the nematode of choice for most aging studies. We concentrate primarily on C. elegans in this review although a number of other speices, including Caenorhabditis briggsae, Turbatrix aceti, and Panagrellus redivivus, have been used in aging studies also. Other reviews on aging in C. elegans have appeared recently, including a more detailed review in another volume of this series.
[
1987]
Since the last review in this series [Johnson, 1985], many papers have appeared dealing directly with the aging process in both Caenorhabditis elegans and Turbatrix aceti. We will review this work and also briefly review other areas of C. elegans research that may impact on the study of aging. C. elegans has become a major biological model; four "News" articles in Science [Lewin, 1984a,b; Marx, 1984a,b] and inclusion as one of three developmental genetics models in a recent text [Wilkins, 1986] indicate its importance. Recent work has verified earlier results and has advanced progress toward new goals, such as routine molecular cloning. The aging studies reviewed here, together with new findings from other areas of C. elegans research, lay the groundwork for rapid advances in our understanding of aging in nematodes. Several areas of research in C. elegans have been reviewed recently: the genetic approach to understanding the cell lineage [Sternberg and Horvitz, 1984] and a brief summary of cell lineage mutants [Hedgecock, 1985]. The specification of neuronal development and neural connectivity has been a continuing theme in C. elegans research and reviews of these areas have also appeared [Chalfie, 1984; White, 1985]. A major genetic advance is the development of reliable, if not routine, mosaic analysis [Herman, 1984; Herman and Kari, 1985], which is useful for the genetic analysis of tissue-limited gene expression. Hodgkin [1985] reviews studies on a series of mutants involved in the specification of sex. These include her mutations that cause XO worms (normally males) to develop as hermaphrodites and tra mutations that change XX hermaphrodites into phenotypic males. The work on the structure and development of nematode muscle has been summarized by Waterston and Francis [1985]. A comprehensive review of aging research, containing useful reference material on potential biomarkers, has appeared [Johnson and Simpson, 1985], as well as a review including