[Molecular study on null allolic RFLPs among rice varieties].
Null allele is an allele that produces no functional products. In RFLP analysis, null allele means that one probe can hybridize to plant DNA from one variety readily, but very faintly to DNA from another variety or even has no hybridization signal under experimental stringency and this may be an indication of deletion, insertion or major sequence rearrangement(s) in the corresponding regions. We report here about null alleles of RFLP among 52 rice varieties uncovered with rice random genomic probe RG684. The results show that this kind of null allele is most likely to occur in typical japonica varieties distributed geographically in Northeast China and Japan, and this tendency is consistent with the hypothesis that rice evolved with a trend of from wild type-->Indica-->Japonica. Sequence analysis indicates that the sequence of RG684 has no encoding function. Therefore, changes in this region may not influence the survival of the plant. Comparison of the sequence of RG684 and gypsy transposon bx34e long terminal repeats (LTR) of D. melanogater shows homology of 78.4% of 37 base pair and this leads to the consideration that the occurrence of null alleles in rice is related to transposition or transposition-like events.
Mao
L
L
Laboratory of Plan Biotechnology, Academia Sinica, Beijing.
Zhu
L
L
D000483:Alleles; D001483:Base Sequence; D018076:DNA, Complementary / Q000737:chemistry; D008969:Molecular Sequence Data; D012275:Oryza / Q000235:genetics*; D012150:Polymorphism, Restriction Fragment Length
D018076:DNA, Complementary