I醣抗原轉化基因的突變與白內障的生成（3/3）
Date Issued
2005-04-30
Date
2005-04-30
Author(s)
DOI
933112B002003
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.
Publisher
臺北市：國立臺灣大學生化科學研究所
Type
report
File(s)![Thumbnail Image]()
Loading...
Name
933112B002003.pdf
Size
27.21 KB
Format
Adobe PDF
Checksum
(MD5):bc1c97fb24121f75f575035315a24a62