[Studies of the correlation between fragile sites and giant panda's breeding problem]

An unique culture system has been established which can effectively indicate fragile sites induced by BrdU on giant panda chromosomes. After we cultured the lymphocytes of giant panda for 96 hours and treated it with low concentration of BrdU (10 micrograms/ml) for only a short time (4 hours), the areas of high-frequency-expressed fragile sites were successfully located on the centromeres of No. 2 and No. 12 chromosomes. After statistic analysis, we found that the frequency of fragile sites on No. 2 and No. 12 chromosomes are notably different among pandas. What is more important, the former is relative to giant pandas' breeding conditions and correlation coefficiency (r equals to -0.772). The result indicates that high frequency of fragile sites on No. 2 chromosome is unfavorable to giant panda's breeding and survival of filial generation.