Mutant redundancy

Eehner In mammalian cells there is more genetic redundancy. We are not sure to what extent the other D-type cyclins compensate when we are looking at cyclin D1 or D2 knockouts. The same is true for Cdk4 knockouts Cdk6 may compensate. There are many different mutant combinations that have not yet been analysed. 

A detailed analysis of ethylene receptor mutants has shown functional redundancy between them. However, in Arabidopsis, subfamily 1 members cannot be replaced by subfamily 2 members, in contrast to tomato in which functional redundancy between subfamily 1 and subfamily 2 members was reported. " " It seems that there exists some degree of plasticity among different plant species within the ethylene signaling pathway. 

DNMT3a and DNMT3b double ES mutants exhibit no de novo methylase activity double-mutant mice fail to develop beyond gastrulation. This observation, taken together with the ability of single mutants to support de novo methylation, show redundancy between the two genes. 

Todd, J.L., Haynes, K.F. and Baker, T. C. (1992). Antennal neurones specific for redundant pheromone components in normal and mutant Trichoplusia ni males. Physiological Entomology 17 183-192. 

Studies with knockout mutant mice lacking one or another of the retinoid receptors suggest that there is some degree of redundancy or overlap between the receptor subtypes, and that RARy is especiallyimportant in the teratogenic actions of retinoids (Section 2.5.1.1 Mark et al., 1999 Maden, 2000) ... 

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