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Journal of Biomedicine and Biotechnology
Volume 2011, Article ID 809765, 8 pages
Research Article

Role of Positive Selection in Functional Divergence of Mammalian Neuronal Apoptosis Inhibitor Proteins during Evolution

1Department of Immunology & Laboratory Immunology, Center of Clinical Medicine and Laboratory, Jiangsu University, Zhenjiang, Jiangsu 212013, China
2Department of Stomatology, The Affiliated People’s Hospital of Jiangsu University, Zhenjiang 212008, China
3Department of Laboratory, Zhenjiang Entry-Exit Inspection and Quarantine Bureau, Jiangsu 212001, China

Received 16 February 2011; Revised 28 June 2011; Accepted 26 August 2011

Academic Editor: Patrick Matthias

Copyright © 2011 Fanzhi Kong et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Neuronal apoptosis inhibitor proteins (NAIPs) are members of Nod-like receptor (NLR) protein family. Recent research demostrated that some NAIP genes were strongly associated with both innate immunity and many inflammatory diseases in humans. However, no similar phenomena have been reported in other mammals. Furthermore, some NAIP genes have undergone pseudogenization or have been lost during the evolution of some higher mammals. We therefore aimed to determine if functional divergence had occurred, and if natural selection had played an important role in the evolution of these genes. The results showed that NAIP genes have undergone pseudogenization and functional divergence, driven by positive selection. Positive selection has also influenced NAIP protein structure, resulting in further functional divergence.