کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5918078 1163825 2008 17 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Organization, structure and evolution of 41 kb of genomic DNA spanning the D-J-C region of the sheep TRB locus
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شناسی مولکولی
پیش نمایش صفحه اول مقاله
Organization, structure and evolution of 41 kb of genomic DNA spanning the D-J-C region of the sheep TRB locus
چکیده انگلیسی
A genomic region of 41,045 bp encompassing the 3′-end of the sheep T cell receptor beta chain was sequenced. Extensive molecular analysis has revealed that this region retains a unique structural feature for the presence of a third D-J-C cluster, never detected in any other mammalian species examined so far. A total of 3 TRBD, 18 TRBJ and 3 substantially identical TRBC genes were identified in about 28 kb. At 13 kb, downstream from the last TRBC gene, in an inverted transcriptional orientation, lies a TRBV gene. Sequence comparison and phylogenetic analyses have demonstrated that the extra D-J-C cluster originated from an unequal crossing over between the two ancestral TRBC genes. Interspersed repeats spanning 22.2% of the sequence, contribute to the wider size of the sheep TRB locus with respect to the other mammalian counterparts, without modifying the general genomic architecture. The nucleotide and predicted amino acid sequences from peripheral T cells cDNA clones indicated that the genes from cluster 3 are fully implicated in the beta chain recombination machinery. Closer inspections of the transcripts have also shown that inter-cluster rearrangements and splice variants, involving the additional cluster, increase the functional diversity of the sheep beta chain repertoire.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Molecular Immunology - Volume 45, Issue 2, January 2008, Pages 493-509
نویسندگان
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