Process of Apoptosis in the Soil Worm Caenorhabditis elegans (Campbell Biology)
The molecular mechanisms of apoptosis were worked out by researchers studying embryonic development of a small soil worm, a nematode called Caenorhabditis elegans. Because the adult worm has only about 1,000 cells, the researchers were able to work out the entire ancestry of each cell. The timely suicide of cells occurs exactly 131 times during normal development of C. elegans, at precisely the same points in the cell lineage of each worm. In worms and other species, apoptosis is triggered by signals that activate a cascade of “suicide” proteins in the cells destined to die.– What is a small, free-living, nematode worm, which has become established as a standard model organism for a great variety of genetic investigations, being especially useful for studying developmental biology, cell biology and neurobiology?
Genetic research on C. elegans initially revealed two key apoptosis genes, called ced-3 and ced-4 (ced stands for “cell death”), which encode proteins essential for apoptosis. The proteins are called Ced-3 and Ced-4, respectively. These and most other proteins involved in apoptosis are continually present in cells, but in inactive form; thus, regulation in this case occurs at the level of protein activity rather than through gene activity and protein synthesis. In C. elegans, a protein in the outer mitochondrial membrane, called Ced-9 (the product of the ced-9 gene), serves as a master regulator of apoptosis, acting as a brake in the absence of a signal promoting apoptosis. When a death signal is received by the cell, signal transduction involves a change in Ced-9 that disables the brake, and the apoptotic pathway activates proteases and nucleases, enzymes that cut up the proteins and DNA of the cell. The main proteases of apoptosis are called caspases; in the nematode, the chief caspase is the Ced-3 protein.– What are a family of protease enzymes playing essential roles in programmed cell death including apoptosis, pyroptosis and necroptosis and also playing role in inflammation?
Urry, Lisa A.. Campbell Biology. Pearson Education. Kindle Edition. https://www.pearson.com/us/higher-education/series/Campbell-Biology-Series/2244849.html
Research Article: Evolution of Susceptibility to Ingested Double-Stranded RNAs in Caenorhabditis Nematodes
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Research Article: Phenotypic Covariance of Longevity, Immunity and Stress Resistance in the Caenorhabditis Nematodes
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Date Published: January 23, 2012 Publisher: Public Library of Science Author(s): František Zedek, Petr Bureš, Conrad A. Nieduszynski. http://doi.org/10.1371/journal.pone.0030496 Abstract: In monocentric organisms with asymmetric meiosis, the kinetochore proteins, such as CENH3 and CENP-C, evolve adaptively to counterbalance the deleterious effects of centromere drive, which is caused by the expansion of centromeric satellite repeats. The selection … Continue reading
Research Article: A Streamlined System for Species Diagnosis in Caenorhabditis (Nematoda: Rhabditidae) with Name Designations for 15 Distinct Biological Species
Date Published: April 11, 2014 Publisher: Public Library of Science Author(s): Marie-Anne Félix, Christian Braendle, Asher D. Cutter, Bob Goldstein. http://doi.org/10.1371/journal.pone.0094723 Abstract: The rapid pace of species discovery outstrips the rate of species description in many taxa. This problem is especially acute for Caenorhabditis nematodes, where the naming of distinct species would greatly improve their … Continue reading