Celia R Espinoza

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The regulation of the human Na(+)/I(-) symporter (NIS) gene is of considerable interest for both the diagnosis and therapy of thyroid pathologies. We investigated the influence of the thyroid-specific transcription factors TTF-1 and Pax8 on the NIS promoter and its 5'-flanking sequence. Reporter genes containing the corresponding genomic fragments coupled(More)
Immunoglobulin rearrangement from variable heavy chain (V(H)) to diversity (D)-joining heavy chain (J(H)), which occurs exclusively in B lineage cells, is impaired in mice deficient for the B lineage-specific transcription factor Pax5. Conversely, ectopic Pax5 expression in thymocytes promotes the rearrangement of D(H)-proximal V(H)7183 genes. In exploring(More)
We have cloned and sequenced genomic DNA from a human library extending 1300 bp upstream the 5'-untranslated sequence of the cDNA coding for the sodium/iodide symporter. In transient transfection assays this sequence exhibited promoter activity, which could be confined to nucleotides -443 to -395 relative to the ATG start codon. This minimal promoter,(More)
Microarray data is most useful when it can be compared with other genetic detection technologies. In this report, we designed a microarray assay format that transforms raw data into a defined scientific unit (i.e., moles) by measuring the amount of array feature present and the cDNA sequence hybridized. This study profiles a mouse reference universal RNA(More)
During B lymphocyte development, Ig heavy and L chain genes are assembled by V(D)J recombination. Individual V, D, and J genes rearrange at very different frequencies in vivo, and the natural variation in recombination signal sequence does not account for all of these differences. Because a permissive chromatin structure is necessary for the accessibility(More)
V, D, and J gene segments rearrange at very different frequencies. As with most biological systems, there are multiple levels of control of V gene recombination frequency, and here we review some of the work from our laboratory that addresses these various control mechanisms. One of the important factors that affect non-random V gene rearrangement frequency(More)
Thyroglobulin (Tg) is an essential thyroid-specific protein, which serves as the matrix for thyroid hormone biosynthesis. To obtain new insights in the regulation of Tg gene expression, we investigated the interaction of the human Tg promoter with the thyroid-specific transcription factors TTF-1 and Pax8. A reporter gene, containing a 202 bp fragment from(More)
We describe the cloning and characterization of a human sodium iodide (NIS) upstream enhancer (NUE). This putative enhancer was cloned based on its sequence homology (69% identity) to the rat NUE. A 296 base pair (bp) genomic DNA fragment, which is located 9000 bp upstream from the human hNIS gene, was amplified by polymerase chain reaction (PCR) and(More)
The molecular mechanisms that control the temporal and lineage-specific accessibility, as well as the rearrangement frequency of V(H) genes for V(H)-to-DJ(H) recombination, are not fully understood. We previously found a positive correlation between the extent of histone acetylation and the differential rearrangement frequency of individual V(H) genes.(More)
To investigate the existence of potential enhancer or silencer elements in the 5'-flanking region of the human Na+/I-symporter (NIS) gene, we cloned 2,512 bp of genomic DNA further upstream of the previously defined proximal promoter. When tested in reporter gene assays, this sequence had no transcriptional activity per se, but was able to repress the(More)