https://scholars.lib.ntu.edu.tw/handle/123456789/143312
Title: | I醣抗原轉化基因的突變與白內障的生成(3/3) | Authors: | 余榮熾 Yu, Lung-Chih |
Issue Date: | 30-Apr-2005 | Publisher: | 臺北市:國立臺灣大學生化科學研究所 | Abstract: | The human i and I antigens are characterized as linear and branched repeats of N-acetyllactosamine, respectively. Conversion of the i to the I structure requires I-branching β-1,6-N-acetylglucosaminyltransferase activity. It has been noted that the null phenotype of I, the adult i phenotype, is associated with congenital cataracts in Asians. Previously, the identification of molecular changes in the IGnT gene, associated with the adult i phenotype, has been reported. In the present study, it has been demonstrated that the human I locus express three IGnT forms, designated IGnTA, IGnTB, and IGnTC, which have different exon 1, but identical exons 2 and 3, coding regions. The molecular genetics proposed for the I locus offers a new perspective of the formation and expression of the I antigen in different cells, and provides an insight into the questions derived from investigation of the adult i phenotype. Molecular genetic analyses of the I loci of the two adult i groups, with and without congenital cataracts, were performed, and enzyme function assays and expression patterns for the three IGnT transcripts in reticulocytes and lens-epithelium cells were analyzed. The results suggest a molecular genetic mechanism which may explain the partial association of the adult i phenotype with congenital cataracts, and indicating that a defect in the I locus may lead directly to the development of congenital cataracts. The results also suggest that the human blood group I gene should be re-assigned to the IGnTC form, not the IGnTB, as has previously been described. |
URI: | http://ntur.lib.ntu.edu.tw//handle/246246/10258 | Other Identifiers: | 933112B002003 | Rights: | 國立臺灣大學生化科學研究所 |
Appears in Collections: | 生化科學研究所 |
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933112B002003.pdf | 27.21 kB | Adobe PDF | View/Open |
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