An analysis of translocations and rearrangements within the alpha chain of the human T cell receptor

Abstract

The alpha chain of the human T cell receptor (Tcr-$\alpha$), located at band 14q11, previously had been shown to be interrupted by chromosomal translocations in certain malignancies. In this report, two leukemic patient samples with the t(11;14) (p13;q11) translocation were studied to determine the precise sites of chromosomal breakage. More than 120 kilobases of the genomic locus of Tcr-$\alpha$ was isolated and mapped using phage libraries. The locations of the two translocations were identified and characterized by restriction mapping, Southern blotting and sequencing. Multiple rearrangements of the Tcr-$\alpha$ locus in these samples were also detected and analyzed. As a continuation of these studies, localization of several unique Tcr-$\alpha$ joining regions (J$\alpha$) within the locus was performed using oligonucleotide mapping with genomic clones. The results of these studies reveal that the translocation events in the two t(11;14) (p13;q11) samples involve the delta chain of the T cell receptor (Tcr-$\delta$), not Tcr-$\alpha$. The rearrangements of Tcr-$\alpha$ on the untranslocated chromosomes 14 in these samples indicate a pattern of internal deletion within the locus. Finally, the oligonucleotide mapping of J$\alpha$ has greatly improved the understanding of the organization of these gene segments within Tcr-$\alpha$. The significance of each of these findings is discussed.

Subject Area

Genetics|Molecular biology|Immunology

Recommended Citation

Harvey, Richard Carl, "An analysis of translocations and rearrangements within the alpha chain of the human T cell receptor" (1992). Dissertations available from ProQuest. AAI9308588.
https://repository.upenn.edu/dissertations/AAI9308588

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