Fig. 1. A simplified phylogenetic tree depicting the general relationships of the major bilaterian phyla and chordate subphyla, highlighting select species that use different somatic mechanisms of immune receptor diversification. Red dots designate animal groups where the vast majority of immune data have been derived. Solid black dots denote taxa in which species have been the subject of extensive molecular immune research. Circles denote phyla where some molecular data are available. Color variation (see key) over specific phyla denotes the presence of a major somatic mechanism of receptor diversification in at least one representative member (6) and is not intended to be mutually exclusive. In the case of somatic variation, shade intensity indicates the level of empirically established diversity. Innate immune receptors, including TLRs, are likely present in all of the phyla. Numbers given beside taxa names are approximate estimates of species diversity and are presented to underscore the immense variety of immune mechanisms that have not yet been investigated [primarily taken from the Tree of Life Web project (44)]. Cnidarians (e.g., jellyfishes and sea anemones) are shown as an outgroup to the Bilateria. This view is not intended to represent all known species in which immune-type mediators have been identified. [View Larger Version of this Image (179K JPEG file)]

[PowerPoint download feature is available to paid individual subscribers and to registered users at subscribing institutions (register for free).]

You may download the image(s) above for non-profit educational presentation use only, provided no modifications are made to the content. Any use, publication, or distribution of the image(s) beyond that permitted in the sentence above or beyond that allowed by the "Fair Use" limitations (sections 107 and 108) of the US Copyright law requires the prior written permission of AAAS. This permission does not apply to images that are credited to non-AAAS sources. For images credited to non-AAAS entities, you will need to obtain permission from the entity listed in the legend or credit line before making any use of the image(s).

To Advertise   |   Find Products