[Construction of BAC Library of Fagopyrum tataricum and Analysis of BAC End Sequences].

Objective: To further study Fagopyrum tataricum genome and to screen the functional genes. Methods: The variety JINQIAO No. 2( Fagopyrum tataricum) native to Shanxi, was used for BAC library construction. The high molecular weight DNA( HMWDNA) was isolated from Fagopyrum tataricum leaves used the methods of Peterson. The HMW-DNA was cut by Hind Ⅲ and ligated to BAC vectors; the ligations were transformed into Escherichia coli DH10 B. Then 48 BAC clones were randomly selected and sequenced BAC end sequences. Results: The library consisted of 30 000 clones with an average insert size of about 123 kb and the empty clone ratio was less than 1%. The library represented an equivalent about 6. 9 fold size of Fagopyrum tataricum genome. Which obtained 89 BAC end sequences,among which 7 sequences( 8%) had alignment results when comparing with NCBI Gen Bank database. The blast hits contained some genes with known function,such as rpo Tm2,Trrap and MDR1 genes,etc. Those genes were associated with DNA binding, transmembrane transport and phosphotransferase activity function. And it was also found that the sequence of 40G19-F was probably repetitive sequences in Fagopyrum tataricum genome. Conclusion: The BAC library will be helpful for the gene cloning and whole genome sequencing of Fagopyrum tataricum.

Comparison of ginsenosides Rg1 and Rb1 for their effects on improving scopolamine-induced learning and memory impairment in mice.

Rg1 and Rb1 are two major active compounds of ginseng that facilitate learning and memory. The present study aimed to compare the nootropic effects of Rg1 and Rb1 in a scopolamine induced dementia mice model. After 6 and 12 mg/kg of Rg1 and Rb1 intraperitoneal administration to mice for 7 days, their effects were assessed using the step-down passive avoidance (SD) and the Morris water maze (MWM) tests, the acetylcholinesterase (AChE) activity, acetylcholine (ACh) content and serotonin (5-HT) level in the hippocampus were analysed after SD and MWM tests. The results showed that Rg1 and Rb1 ameliorated cognition-deficiency in mice with dementia. Rg1 showed stronger effects than Rb1 on escape acquisition in MWM. Both Rg1 and Rb1 increased ACh levels in the hippocampus, but Rg1 inhibited AChE activity while Rb1 had no effect on AChE activity. Both Rg1 and Rb1 inhibited the decrease of 5-HT induced by scopolamine, but Rb1 was more active than the same dose of Rg1. These results demonstrate that multiple administrations of Rg1 and Rb1 are effective in improving memory deficiency induced by scopolamine. Rg1 appears to be more potent than Rb1 in improving acquisition impairment, and the two ginsenosides may act through different mechanisms.