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Abstract : |
The identification of a number of cDNA sequences at the splice sites ofأƒâ€ڑأ‚آ Waxy (Wx) geneأƒâ€ڑأ‚آ inأƒâ€ڑأ‚آ rice endospermأƒâ€ڑأ‚آ point to the variation of gene expression associated with the G to T mutation at the 5` splice site ofأƒâ€ڑأ‚آ intron 1 and the alternative splicing produces variants transcripts by shortening. As consequence, variationأƒâ€ڑأ‚آ ofأƒâ€ڑأ‚آ amylose content in this tissue. Toأƒâ€ڑأ‚آ determine whether the splicing type of Wx genes are also foundأƒâ€ڑأ‚آ in rice endosperm of Thai rice cultivars, cDNA of the gene have been isolated by using RT-PCR and sequenced.أƒâ€ڑأ‚آ Analysis of theأƒâ€ڑأ‚آ twenty-five cDNA clones led to the identification of the splicing pattern ofأƒâ€ڑأ‚آ the gene, four cryptic splice sites was found inأƒâ€ڑأ‚آ cDNA sequences of low-amylose cultivars (<20%),أƒâ€ڑأ‚آ while two cryptic splice sites of intermediate (20-25%) and high (>25%)أƒâ€ڑأ‚آ amylose cultivars were characterized. The alternatively spliced transcripts were observed in much higher proportion in low amylose cultivars than that in intermediate and high amylose cultivars. These findings raise a possibility explanation that the degree of amylose content in non-glutinous rice cultivars may reflect to the amount of efficiently spliced transcripts., |
