What is C. elegans?
A quick peek at a plate of C. elegans
About this movie:
Hermaphrodites can self-fertilize or cross with males. However, hermaphrodites cannot fertilize another hermaphrodite. Males can only cross with hermaphrodites. Crossing between a male and hermaphrodite produces more progenyG than the self-fertilization of a hermaphrodite (about 350 progeny).
C. elegans has five pairs of autosomesG and one pair of sex chromosomeG. Sexual determination in C. elegans is similar to Drosophila; the ratio of sex chromosomes to autosomes determines its sex. If the 6th chromosome pair is XX, then C. elegans will be a hermaphrodite. A XO combination in the 6th chromosome pair will produce a male. XO combination in male is the spontaneous loss of X chromosome (XX -> XO). When a male crosses with a hermaphrodite, the progeny will be half males and half hermaphrodites.
Life Cycle & Life Span
Its life cycle and life span are about 3 days and 3 weeks, respectively.
"Worm" is its nickname. Researchers working with worm call themselves as "worm people" and form the "worm community" of research.
1. A Worm eating (Paul Muhlrad, 02/14/2001, The Ward Lab, Retrieved 12/13/04, from http://www.mcb.arizona.edu/wardlab/gallery.html)
2. Hermaphrodite and male: Wood, W. B. (Ed.). (1988). The nematode Caenorhabditis elegans. New York, NY: Cold Spring Harbor Laboratory Press.
3. Hermaphrodite colored image: WormAtlas, access 03/30/05
4. C. elegans nothanks drawing (Hernan Espinoza, 7/17/1999, web page no longer available)
Chromosome: in eukaryotes, the structural unit of the genetic material consisting of a single, linear double-stranded DNA molecule and associated proteins. During mitosis, chromosomes condense into compact structures visible in the light microscope. In prokaryotes, a single circular double-stranded DNA molecule constitutes the bulk of the genetic material. (Molecular Cell Biology/Harvey Lodish [et al.] – 4th)
Hermaphrodite: hermaphrodite is the form that can make both sperm and oocytes and can self-fertilize. C. elegans has both hermaphrodites and males. The male can mate with hermaphrodites to produce cross progeny.
Nematode: nematodes, or roundworms, are generally slender worms, circular in cross section. They are remarkably uniform in structure but vary a lot in size and way of life. Some live as parasites in other animals; some are parasites of plants and some live free in soil, marine mud and decaying organic matter.