| Budget Amount *help |
¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1988: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1987: ¥800,000 (Direct Cost: ¥800,000)
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| Research Abstract |
Chromosome elimination occurs in hybrids between Hordeum vulgare and H. bulbosum. Frequency of chromosome elimination was higher in spike primordium cells than root meristem cells of the hybrids. Physiological condition of cells also affect the rate of chromosome elimination. In cell division, several chromosomes do not congress at metaphase plate, become laggards at anaphase, and are lost in further nuclear division. Cytological observation suggests that failure of centromere-spindle interaction at prophase is involved in the chromosome elimination.
Root meristems of H. vulgare, h. bulbosum, and their hybrids were treated with cordycepin (10^<-5>M), cycloheximide (10^<-5>M), and colchicine (0.1%) for 30 min. And transferred to water. Anormality of mitosis were examined after the treatment. Cycloheximide and cordycepin induced laggards at anaphase in root meristems of the hybrids 60 min after the treatment, while no laggards were observed in H. vulgare and H. bulbosum. Colchicine did not induce laggards in any lines. These results suggested that inhibition of RNA and protein synthesis at prophase were concerned with chromosome elimination. Centromere of chromosomes of H. vulgare, H. bulbosum and their hybrids were stained with hot SSC method and examined (Utsumi 1977). Centromeres were stained in chromosomes of any lines and no structural difference were observed. Probably, chromosome elimination is involved in centromere fnction rather than their structure.
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