HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Parra, Z. E. Articles by Miller, R. D. Search for Related Content PubMed PubMed Citation Articles by Parra, Z. E. Articles by Miller, R. D.

TCRµ Recombination and Transcription Relative to the Conventional TCR during Postnatal Development in Opossums¹

Zuly E. Parra^*, Michelle L. Baker^*, April M. Lopez^*, Jonathan Trujillo^*, Joseph M. Volpe and Robert D. Miller^2,*

^* Center for Evolutionary & Theoretical Immunology and Department of Biology, The University of New Mexico, Albuquerque, NM 87131; and Center for Computational Immunology, Duke University Medical Center, Durham, NC 27705

Marsupials are a distinct lineage of mammals notable for giving birth to highly altricial (relatively less developed) young. The recent discovery of a unique TCR chain in marsupials, TCRµ, raises questions about its possible role in early development. Here we compare the timing of V(D)J recombination and appearance of TCRµ transcripts relative to the conventional TCR, β, , and mRNA during postnatal development in the opossum. There are two TCRµ transcript isoforms, TCRµ1.0 and TCRµ2.0. TCRµ1.0, which uses prejoined V(D)J segments, is detectable as early as day 1, when the thymus is primarily undifferentiated epithelium. The other isoform, TCRµ2.0, which requires V(D)J recombination and contains an unusual double V configuration, is not detectable until day 13 when the thymus is histologically mature. Surprisingly, we were able to detect TCR, β, and mRNA transcribed from loci that had completed V(D)J recombination as early as day 1 as well. At this early age there is apparent evidence for preference in the V segments used in the TCR and β genes. In the case of V this preference appears to be associated with position in the TCR/ locus. In Vβ, however, preference may be due to the use of microhomology in the V, D, and J segments. Mature TCR transcripts were not detected until day 8, suggesting that, in contrast to eutherian mammals, in the opossum β T cell development precedes T cell development. The results support that there may be differences in T cell subset development between marsupials and placental mammals.

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.

¹ This publication was made possible by support from the National Institutes of Health Initiative for Maximizing Student Diversity (to Z.E.P. and J.T.) and Institutional Development Award (IDeA) program of the National Center for Research Resources (to M.L.B. and R.D.M.), as well as awards from the National Science Foundation (to R.D.M.) and the Robert C. McNair program (to A.M.L.).

² Address correspondence and reprint requests to Dr. Robert D. Miller, Department of Biology, MSC03 2020, 1 University of New Mexico, Albuquerque, NM 87131-001. E-mail address: rdmiller{at}unm.edu

³ Abbreviation used in this paper: Vµj, prejoined Vµ gene.