Being mammals ourselves it is not surprising that the immune system of this phylogenetic group holds our special interest and has been studied to the greatest extent. However, the immensely complex immune system we observe in mammals arose through the stepwise accumulation of small changes over billions of years. Whilst some form of innate immunity has been found in all species thus far examined, adaptive immunity, centered upon highly antigen-specific receptors generated via somatic recombination, emerged after the divergence of the vertebrates. The cartilaginous fishes (chimera, sharks, skates and rays) are the oldest phylogenetic lineage to have a mammalian-like adaptive immune system based upon immunoglobulin super-family domains (immunoglobulins, T cell receptors and major histocompatibility complex) which are somatically recombined by the RAG proteins. Their location at this pivotal point in phylogeny means that the cartilaginous fishes are vital in furthering our understanding regarding the evolution of the immune system in general and the emergence of adaptive immunity specifically. In this chapter I will discuss some of the findings regarding immunity in the cartilaginous fishes and other non-human species which have improved our understanding regarding the evolution of the immune system.
|Title of host publication||Immunobiology of the Shark|
|Editors||Sylvia Smith, Bob Simm, Martin Flajnik|
|Publisher||Taylor & Francis Group|
|Number of pages||25|
|Publication status||Published - Dec 2014|