Senescence associated genes

JOHN, C.F., MORRIS, K., JORDAN, B.R., Ultraviolet-B exposure leads to up-regulation of senescence-associated genes in Arabidopsis thaliana, J. Exp. Bot., 2001, 52, 1367-1373. 

Falk, J., KrauiJ, N., Dahnhardt, D. Kmpinska, K. (2002). The senescence associated gene of barley encoding 4-hydroxyphenylpymvate dioxygenase is expressed during oxidative stress. J. Plant Phys., 159, 1245-1253. 

The first involved testing for the existence of a life cycle process or producing a description of such a process. Five examples discussed here include (a) demonstration of in vitro colony division in P. pouchetii (CDWP) (b) description of in vitro change in colony shape for P. pouchetii associated with senescence (CSWP) (c) determining which life stage of P. pouchetii, solitary cells or colonies, is vulnerable to viral infection and lysis (VIL) (d) demonstration of potential benthic involvement in the P. pouchetii life cycle (CFBI) (e) demonstration of differential gene expression in solitary versus colonial cells of P. globosa (DGE). 

Plasmids are also encountered in eukaryotes, although less commonly than in bacteria. Examples are the 2- x circle in yeast, the senescence (aging) plasmids in the fungus Neurospora and the plasmids associated with male sterility in corn. In addition, there are many other extrachromosomal genomes such as those from mitochondria, chloroplasts and viruses. In addition, colony hybridization type experiments can be carried out on single genes or on transcripts and may resemble in situ hybridization, except for the transfer to membranes. 

The best-known association between FEI-1 and human tumors relates to its fusion with the EWS gene on chromosome 22 (22ql2) in many examples of Ewing s sarcoma/ primitive neuroectodermal tumor (PNET).i An associated fusion protein results from that event, which probably plays a role in the evasion of cellular senescence. 

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