Pampeno C, Meruelo D
Department of Pathology, New York University Medical Center, NY 10016.
Immunogenetics. 1988;28(4):247-54. doi: 10.1007/BF00345501.
A retrovirus element (TLev1) is located within the Thymus leukemia antigen (Tla) locus of the C57BL/10 mouse major histocompatibility complex. Low-copy probes have been isolated from sequences flanking the TLev1 integration site to examine the distribution of TLev1 among inbred mouse strains having genotypically determined variations in TL-antigen expression. It was found that the low-copy probes cross-hybridize to regions within the Tla locus in a genotype-specific manner. Although a strong association was found between TL mouse strains and TLev1, the presence or absence of the TLev1 locus did not exclusively correlate with expression or nonexpression of TL antigens. Analysis of different Mus subspecies indicates that TLev1 integrated into a common ancestor of the species Mus musculus. It is suggested that the loss of the TLev1 locus from certain mouse genomes reflects evolutionary rearrangements in the TL region; the resulting diversity may relate to the differential expression of TL antigens among mouse strains. The probes described here provide a useful tool for examining the genomic expansions and contractions which have occurred during the evolution of the Tla locus.
一种逆转录病毒元件（TLev1）位于C57BL/10小鼠主要组织相容性复合体的胸腺白血病抗原（Tla）基因座内。已从TLev1整合位点两侧的序列中分离出低拷贝探针，以研究TLev1在具有基因分型确定的TL抗原表达差异的近交小鼠品系中的分布。发现低拷贝探针以基因型特异性方式与Tla基因座内的区域交叉杂交。虽然在TL小鼠品系和TLev1之间发现了很强的关联，但TLev1基因座的存在与否并不完全与TL抗原的表达或不表达相关。对不同小家鼠亚种的分析表明，TLev1整合到小家鼠物种的一个共同祖先中。有人提出，某些小鼠基因组中TLev1基因座的缺失反映了TL区域的进化重排；由此产生的多样性可能与小鼠品系中TL抗原的差异表达有关。这里描述的探针为研究Tla基因座进化过程中发生的基因组扩增和收缩提供了一个有用的工具。
