Plant Genome I Conference
Town & Country Conference Center, San Diego, CA, November, 1992.
PG-I: PCR-Amplified Microsatellites AS Markers in Wheat GENOME
MAPPING
PCR-Amplified Microsatellites AS Markers in Wheat GENOME
MAPPING
J.S. Ziegle, W.J. Raupp 2, K.S. Gill 2 and B.S. Gill 2 Applied
Biosystems, Inc. Foster City, CA.; 2 Kansas State University,
Manhattan, KS.
Microsatellite loci have proven to be the markers of choice
for mapping the human genome. Microsatellites are VNTR
(variable number of tandem repeats) markers characterized by
short repeat units of 1 - 5 bp in length. Microsatellite loci
have proven to be informative, abundant and evenly distributed in
the genome. Because of the relative ease with which the loci can
be identified and genotyped, microsatellites offer great
potential for linkage mapping. Hundreds of polymorphic
microsatellite loci have been mapped so far in the human genome.
However, microsatellites have yet to be fully exploited in plant
genomes. A search of GenBank listings for Triticum resulted in
290 entries. These listings were searched for any 2-bp repeat
(>9 repeats long) and any 3-bp repeat (>7 repeats long). These
queries resulted in identification of 33 repeat-positive entries.
There were two for the repeat (AT)g, both of which were for the
same alpha-amylase gene. There were 8 and 23 listings
respectively for the repeats (GCA)7 and (CAA)7, all of these were
associated with gliadin genes. A PCR assay was developed for one
of the (CGA) repeat sequences, GenBank listing WHTGLIABG. PCR
amplification products were compared for various commercial
strains, nullisomic and tetrasomic lines, and the loci was mapped
in an F2 population (60 plants) of T. tauschii (2n = 14, DD).
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