Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published May 15, 2004 | public
Journal Article

Evolutionary Origins of Lymphocytes: Ensembles of T Cell and B Cell Transcriptional Regulators in a Cartilaginous Fish

Abstract

The evolutionary origins of lymphocytes can be traced by phylogenetic comparisons of key features. Homologs of rearranging TCR and Ig (B cell receptor) genes are present in jawed vertebrates, but have not been identified in other animal groups. In contrast, most of the transcription factors that are essential for the development of mammalian T and B lymphocytes belong to multigene families that are represented by members in the majority of the metazoans, providing a potential bridge to prevertebrate ancestral roles. This work investigates the structure and regulation of homologs of specific transcription factors known to regulate mammalian T and B cell development in a representative of the earliest diverging jawed vertebrates, the clearnose skate (Raja eglanteria). Skate orthologs of mammalian GATA-3, GATA-1, EBF-1, Pax-5, Pax-6, Runx2, and Runx3 have been characterized. GATA-3, Pax-5, Runx3, EBF-1, Spi-C, and most members of the Ikaros family are shown throughout ontogeny to be 1) coregulated with TCR or Ig expression, and 2) coexpressed with each other in combinations that for the most part correspond to known mouse T and B cell patterns, supporting conservation of function. These results indicate that multiple components of the gene regulatory networks that operate in mammalian T cell and B cell development were present in the common ancestor of the mammals and the cartilaginous fish. However, certain factors relevant to the B lineage differ in their tissue-specific expression patterns from their mouse counterparts, suggesting expanded or divergent B lineage characteristics or tissue specificity in these animals.

Additional Information

© 2004 The American Association of Immunologists, Inc. Received for publication November 11, 2003. Accepted for publication February 27, 2004. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact. This work was supported by National Aeronautics and Space Administration Grants NAG2-1370 and NAG2-1588 (to M.K.A. and E.V.R.), and National Institutes of Health Grant R37 AI2338 (to G.W.L.). M.K.A. was supported in part by the Stowers Institute for Medical Research. A.L.M. was supported in part by the Institute for Biomolecular Science, University of South Florida. C.A.L. received partial support through grants from the Vernal W. and Florence H. Bates Foundation and the Disney Wildlife Conservation Fund. We thank the Caltech DNA Sequencing Facility for technical assistance.

Additional details

Created:
August 19, 2023
Modified:
October 24, 2023