Gene expression evolvability

RNAi probably evolved initially in primitive organisms in order to protect their genomes from viruses, transposons and additional insertable genetic elements, and to regulate gene expression. The RNAi pathway was first discovered in plants, but it is now known to function in most, if not all, eukaryotes. 

In a related application of this approach, Ferea et al. (1999) examined variations in gene expression of progeny during adaptive evolution. The yeast genomes were monitored in evolving strains subjected to growth under... 

HNLs comprise a heterogenous enzyme family, since hydroxynitrile lyase activity has evolved in different structural frames by convergent evolution [17, 18]. Thus, (S) -specific HNLs based on an a/P-hydrolase fold framework from Manihot esculmta (cassava) [19-21], Hevea hrasilensis (rubber tree) [22-26], and Sorghum hicolor (millet) [27-33] have been described. (R)-specific HNLs based on the structural framework of oxidoreductases were isolated from Linum usitatissimum (flax) [30, 34-37] and Rosaceae (e.g., bitter almonds) [31, 38]. Despite their potential in biocatalysis only few HNLs (from cassava and rubber tree) are available by recombinant gene expression, which is a prerequisite for their technical application [20, 24]. Thus, cloning, recombinant expression, and... 

Two general approaches of gene expression related to toxicology and safety assessment have evolved, either of which can be deployed depending on the nature of the investigation being carried out. 

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