Gene duplication networks

Homo sapiens (compared to Drosophila melanogaster) Large-scale gene duplications with substantial expansion of genes involved in acquired immune response (B cells, T cells, major histocompatibility complex genes, cytokines, chemokines and their receptors), plasma proteases (complement and hemostatic proteins), proteins associated with apoptotic regulation and proteins related to neuronal network formation and electrical coupling... 

Wagner, A. (1994) Evolution of gene networks by gene duplications A mathematical model and its implications on genome organization. Proc Natl Acad Sci USA 91 4387. 

Bifunctional (double-headed) inhibitors of proteases, traditionally, belong to the family Bowman-Birk inhibitors. Bifunctional inhibitors are assumed to have arisen by duplication of an ancestral single headed inhibitor gene and subsequently diverged into different classes and with a network of highly conserved disulfide bridges (Odani et al., 1983 Qi et al., 2005). However, interest bifunctional inhibitors active against both proteases and amylases (Table 2). 

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