Biotransformation of phenylpyruvic acid to phenyllactic acid by growing and resting cells of a <Emphasis Type="Italic">Lactobacillus</Emphasis> sp.

Phenyllactic acid (PLA) is a novel antimicrobial compound derived from phenylalanine (Phe). Lactobacillus sp. SK007, having high PLA-producing ability, was isolated from Chinese traditional pickles. When 6.1 mM phenylpyruvic acid (PPA) was used to replace Phe as substrate at the same concentration, PLA production increased 14-fold and the fermentation time decreased from 72 h to 24 h with growing cells. With resting cells, however, 6.8 mM PLA could be obtained as optimal yield using the following conditions: 12 mM PPA, 55 mM glucose, pH 7.5, 35°C and 4 h.     

Longevity determined by developmental arrest genes in Caenorhabditis elegans

The antagonistic pleiotropy theory of aging proposes that aging takes place because natural selection favors genes that confer benefit early on life at the cost of deterioration later in life. This theory predicts that genes that impact development would play a key role in shaping adult lifespan. To better understand the link between development and adult lifespan, we examined the genes previously known to be essential for development. From a pool of 57 genes that cause developmental arrest after inhibition using RNA interference, we have identified 24 genes that extend lifespan in Caenorhabditis elegans when inactivated during adulthood. Many of these genes are involved in regulation of mRNA translation and mitochondrial functions. Genetic epistasis experiments indicate that the mechanisms of lifespan extension by inactivating the identified genes may be different from those of the insulin/insulin-like growth factor 1 (IGF-1) and dietary restriction pathways. Inhibition of many of these genes also results in increased stress resistance and decreased fecundity, suggesting that they may mediate the trade-offs between somatic maintenance and reproduction. We have isolated novel lifespan-extension genes, which may help understand the intrinsic link between organism development and adult lifespan.     

Strong Genetic Differentiation of Primula sikkimensis in the East Himalaya–Hengduan Mountains

The East Himalaya-Hengduan Mountains region is the center of diversity of the genus Primula, and P. sikkimensis is one of the most common members of the genus in the region. In this study, the genetic diversity and structure of P. sikkimensis populations in China were assessed using inter-simple sequence repeat (ISSR) and chloroplast microsatellite markers. The 254 individuals analyzed represented 13 populations. High levels of genetic diversity were revealed by ISSR markers. At the species level, the expected heterozygosity and Shannon’s index were 0.4032 and 0.5576, respectively. AMOVA analysis showed that 50.3% of the total genetic diversity was partitioned among populations. Three pairs of chloroplast microsatellite primers tested yielded a total of 12 size variants and 15 chloroplast haplotypes. Strong cpDNA genetic differentiation (G _ST = 0.697) and evidence for phylogeographic structure were detected (N _ST = 0.788, significantly higher than G _ST). Estimated rates of pollen-mediated gene flow are approximately 27% greater than estimated rates of seed-mediated gene flow in P. sikkimensis. Both seed and pollen dispersal, however, are limited, and gene flow among populations appears to be hindered by the patchiness of the species’ habitats and their geographic isolation. These features may have played important roles in shaping the genetic structure of P. sikkimensis. A minimum-spanning tree of chloroplast DNA haplotypes was constructed, and possible glacial refugia of P. sikkimensis were identified.     

Mitochondrial DNA analysis of Sporothrix schenckii clinical isolates from China

Mitochondrial DNA (mtDNA) types based on restriction fragment length polymorphism (RFLP)patterns with HaeIII were investigated in clinical isolates of Sporothrix schenckii in China. In addition to 23 mtDNA types (Types 1–23) so far reported, a new mtDNA type (Type 24) was found in this study. Type 24 was divided into two subtypes, Subtype 24A and 24B based on RFLP with EcoRV. Sixty-seven isolates in China consisted of 58 isolates of Type 4, 5 of Type 6, 1 of Type 5, 1 of Type 20 and 2 of Type 24. Based on the phylogeny of the mtDNA types (Types 1–24) constructed by estimating sequence divergences of mtDNA, mtDNA types clustered into two groups: Group A (Types 1–3, Type 11, Types 14–19 and Types 22–23) and Group B (Types 4–10, Types 12–13,Types 20–21 and Type 24). These results suggest that mostS. schenckii isolates in China belong to Group B.This revised version was published online in October 2005 with corrections to the Cover Date.     

Tagging of a maize gene involved in kernel development by an activated Uq transposable element

Summary A quiescent Uq transposable element has been activated in a maize plant treated with 5-aza-2-deoxycyti-dine. This activated Uq cosegregates with a heritable dominant miniature (Mn) kernel phenotype, indicating its physical association with a maize miniature locus (Mn:: Uq). The Mn:: Uq mutant is dominant in producing a miniature seed phenotype of variable size and in reducing seedling vigor in the early growth stage. Genetic experiments indicate that the Mn:: Uq mutant also affects the activity of the male gametophyte, whereby pollen germination is inhibited, thus lacking pollen tube growth resulting in the male nontransmissibility of this mutant. Proof for the Uq element in this mutant is derived by its ability to transactivate the standard a-ruq reporter allele to yield spotted aleurone tissue. However, the Mn:: Uq mutant does not transactivate a normally Uq-responsive c-ruq allele, suggesting a structural difference between the two ruq receptors at the A1 and C1 loci. It is anticipated that cloning of the Uq transposable element would facilitate the molecular cloning and characterization of the maize miniature gene.Journal Paper No. J-13425 of the Iowa Agriculture and Home Economics Experiment Station, Ames, Iowa 50011, USA, Project No. 2850     

Phylogeny of Snub-Nosed Monkeys Inferred from Mitochondrial DNA,Cytochrome B,and 12S rRNA Sequences

Snub-nosed monkeys (Rhinopithecus spp.) are confined to isolated mountainous regions in China and North Vietnam. Their systematic classification and phylogenetic relationship has been controversial. The structures of mitochondrial DNA cytochrome b and 12S rRNA show that the 4 species of Rhinopithecus are quite different from other colobines. It is reasonable to regard them as an independent genus, as determined by external features, morphometric characters and behavior. However, whether or not there should be a subdivision between the Vietnamese and Chinese species at the subgeneric level remains to be clarified; more evidence from a large range of Asian colobine species is needed. The Guizhou species, Rhinopithecus brelichi, is a valid species, which is more closely related to Pygathrix than the other species ( R. roxellana, R. bieti and R. avunculus) are. Results also indicate that 3 species—Rhinopithecus roxellana, R. bieti and R. avunculus—might have diverged from R. brelichi, but the phylogenetic relationship of R. avunculus is not clear.     

Genetic diversity within Oryza rufipogon germplasms preserved in Chinese field gene banks of wild rice as revealed by microsatellite markers

Nineteen microsatellite markers were employed to evaluate the genetic diversity of 92 accessions of common wild rice Oryza rufipogon Griff., which represent a significant portion of the distribution range from field gene banks of China. In comparison, a total of 57 varieties from most of the rice growing areas in China were also analyzed. The microsatellite analysis revealed a considerable amount of genetic diversity resided within the preserved wild rice germplasms. In all, the nineteen microsatellites revealed 328 alleles. The number of alleles per locus varied widely among these markers, ranging from 6 at RM242 to 30 at RM206. A comparison of the genetic parameters showed that wild rice strains preserved in the field gene banks (na = 17.27; R _S = 15.66; H _S = 0.86; H _T = 0.852; H _O = 0.307) possess much higher genetic diversity than cultivated rice varieties (na = 8.27; R _S = 8.14; H _S = 0.75; H _T = 0.758; H _O = 0.051). A total of 196 alleles detected in the wild rice could not be found in cultivated rice, suggesting that about 60% of the alleles of wild rice might be lost during the process of rice domestication. This result shows that these ex situ preserved wild rice strains are of great importance for the discovery and utilization of novel genes in the future rice breeding practices. Considerably abundant genetic variability detected within the studied wild rice germplasms could be comparable to that previously found in a wide sampling of 47 natural populations (na = 16.17; H _S = 0.67; H _O = 0.229), demonstrating that developing field gene banks of wild rice is a necessary and efficient way for preserving genetic diversity of wild rice resources. To determine minimum microsatellites that could distinguish these wild rice accessions, the phylogenetic trees constructed by means of the combinations of different microsatellites suggested that the five highly polymorphic microsatellites could clearly identify these samples. High polymorphisms of rice microsatellite loci and their great resolving power will be particularly helpful for germplasm evaluation and evolutionary studies for better strengthening the conservation and utilization of genetic diversity of wild rice in the field gene banks.     

Effect of red mold rice on antifatigue and exercise-related changes in lipid peroxidation in endurance exercise

This study evaluated the effect of red mold rice supplementation on antifatigue and exercise-related changes in lipid peroxidation of male adult Wistar rats through swimming exercise. Thirty 16-week-old rats were studied by dividing them into three groups (ten for each group). Other than the control group (CD), the other two groups were divided into a high-dose (HD) treatment group (5 g red mold rice/kg body weight for the HD group), and a low-dose (LD) group (1 g red mold rice/kg body weight for the LD group). Swimming endurance tests were conducted after 28 days of red mold rice supplementation, and the result showed that the treatment group showed a higher exercise time (CD, 78.0±6.4; LD, 104.2±9.6; and HD, 129.4±10.9 min; p<0.05) and a higher blood glucose concentration (CD, 76.67±8.08; LD, 111.34±8.50; and HD, 117.67±11.06 mg/dl; p<0.05) than the CD. Moreover, the blood lactate (CD, 45.00±0.90; LD, 31.41±1.80; and HD, 28.89±1.62 mg/dl; p<0.05), blood urea nitrogen (CD, 21.87±0.75; LD, 20.33±0.83; and HD, 20.53±1.09 mg/dl; p<0.05), and hemoglobin (CD, 14.20±0.21; LD, 13.70±0.55; and HD, 13.28±0.35 g/dl; p<0.05) were also significantly lower than those of the CD. Besides, the result suggested that the red mold rice supplementation may decrease the contribution of exercise-induced oxidative stress and improve the physiological condition of the rats.     

Antitumor activity of Pulsatilla chinensis (Bunge) Regel saponins in human liver tumor 7402 cells in vitro and in vivo

Pulsatilla chinensis (Bunge) Regel is a Chinese medicinal herb for "blood-cooling" and detoxification. Now it is used for the treatment of malignant tumor, but the antitumor mechanisms and toxic side effects of P. chinensis are unclear. The present study was undertaken to investigate if P. chinensis saponins (PRS) possesses anticancer effects and toxic side effects in human liver tumor 7402 cells in vitro and vivo. 7402 cells were treated with different concentrations of PRS for 24h. Cell viability was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Cell apoptosis was assessed by flow cytometry. The in vivo effect of PRS on 7402 tumor cells transplanted in athymic nude mice was investigated. 15 saponins were isolated and identified from PRS. PRS inhibited the proliferation of human liver tumor 7402 cells in vitro by apoptosis. 19 days after administration of PRS (100, 200mg/kg), the weight of tumor mass was markly decreased in nude mice. The anti-tumor effect of PRS in vivo was associated with a significant increase in the 7402 apoptosis rate. Although PRS inhibited the weight of mice, it showed almost no effect on leukocyte number, liver and spleen weight index. Light microscopic histopathological examination showed that PRS had no specific lesion in organ. These results suggested that P. chinensis saponins exert potential anticancer activity in treating tumors in nude mice and no toxic side effects.