Three anti-tumor saponins from Albizia julibrissin

Three new triterpenoid saponins, julibroside J(29) (1), julibroside J(30) (2), and julibroside J(31) (3), were isolated from the stem bark of Albizia julibrissin Durazz. (Leguminosae) by using chromatographic method. Their structures were established by spectroscopic methods. Compounds 1, 2, and 3 displayed significant anti-tumor activities in vitro against PC-3M-1E8, HeLa, and MDA-MB-435 cancer cell lines at 10microM assayed by SRB and MTT methods.     

Molecular cloning, characterization and localization of chicken type II procollagen gene

Chicken type II procollagen (ccol2a1) has become as an important oral tolerance protein for effective treatment of rheumatoid arthritis. However, its molecular identity remains unclear. Here, we reported the full-length cDNA and nearly complete genomic DNA encoding ccol2a1. We have determined the structural organization, evolutional characters, developmental expression and chromosomal mapping of the gene. The full-length cDNA sequence spans 4837 bp containing all the coding region of the ccol2a1 including 3' and 5' untranslation region. The deduced peptide of ccol2a1, composed of 1420 amino acids, can be divided into signal peptide, N-propeptide, N-telopeptide, triple helix, C-telopeptide and C-propeptide. The ccol2a1 genomic DNA sequence was determined to be 12,523 bp long containing 54 exons interrupted by 53 introns. Comparison of the ccol2a1 with its counterparts in human, mouse, canine, horse, rat, frog and newt revealed highly conserved sequence in the triple helix domain. Chromosomal mapping of ccol2a1 locates it on 4P2. While the ccol2a1 mRNA was expressed in multiple tissues, the protein was only detected in chondrogenic cartilage, vitreous body and cornea. The ccol2a1 was found to contain two isoforms detected by RT-PCR. The distribution of the ccol2a1 lacking exon 2wasfrequently detected in chondrogenic tissues, whereas the exon 2-containing isoform was more abundant in non-chondrogenic tissues. These results provide useful information for preparing recombinant chicken type II collagen and for a better understanding of normal cartilage development.     

Biomass dynamics of Quercus aliena var. acutesrata community on Mountain Xiaolong in Gansu Province, China

The dynamics of tree layer biomass was studied by combining 35 sample plots of field census with biomass model estimation in a natural Quercus aliena var.acutesrata community on Mountain Xiaolong in Gansu Province,China.The tree layer biomass of Quercus aliena var.acutesrata community was 183 660 kg/ha,in which the slow growth group accounted for 64.89% of the total biomass.The fast-medium growth group accounted for 33.40% and the coniferous group accounted for 1.38%.The organs biomass was found to be in the following order:trunk＞root＞branch＞leaf.The total biomass accumulated with the development of the community.The total biomass and the biomass of the organs were highest in the mature community and became stable as the community developed.The relative growth rate of organs was in the following order:trunk＞branch＞root＞leaf.The biomass ratio of the slow growth group trees tended to increase and the fast-medium group trees tended to decrease as the community developed,which was reveresed in the decline development stage.The biomass of the coniferous group was very small throughout the development process.     

Genetic mapping and developmental timing of transmission ratio distortion in a mouse interspecific backcross

Background

Sheep carcasses with yellow fat are sporadically observed at Norwegian slaughter houses. This phenomenon is known to be inherited as a recessive trait, and is caused by accumulation of carotenoids in adipose tissue. Two enzymes are known to be important in carotenoid degradation in mammals, and are therefore potential candidate genes for this trait. These are beta-carotene 15,15'-monooxygenase 1 (BCMO1) and the beta-carotene oxygenase 2 (BCO2).

Results

In the present study the coding region of the BCMO1 and the BCO2 gene were sequenced in yellow fat individuals and compared to the corresponding sequences from control animals with white fat. In the yellow fat individuals a nonsense mutation was found in BCO2 nucleotide position 196 (c.196C>T), introducing a stop codon in amino acid position 66. The full length protein consists of 575 amino acids. In spite of a very low frequency of this mutation in the Norwegian AI-ram population, 16 out of 18 yellow fat lambs were found to be homozygous for this mutation.

Conclusion

In the present study a nonsense mutation (c.196C>T) in the beta-carotene oxygenase 2 (BCO2) gene is found to strongly associate with the yellow fat phenotype in sheep. The existence of individuals lacking this mutation, but still demonstrating yellow fat, suggests that additional mutations may cause a similar phenotype in this population. The results demonstrate a quantitatively important role for BCO2 in carotenoid degradation, which might indicate a broad enzyme specificity for carotenoids. Animals homozygous for the mutation are not reported to suffer from any negative health or development traits, pointing towards a minor role of BCO2 in vitamin A formation. Genotyping AI rams for c.196C>T can now be actively used in selection against the yellow fat trait.     

The soybean root‐specific protein kinase GmWNK1 regulates stress‐responsive ABA signaling on the root system architecture

In humans, members of the WNK protein kinase family are osmosensitive regulators of cell volume homeostasis and epithelial ion transport, and mutation of these proteins causes a rare inherited form of hypertension due to increased renal NaCl re‐absorption. A related class of kinases was recently discovered in plants, but their functions are largely unknown. We have identified a root‐specific WNK kinase homolog, GmWNK1, in soybean (Glycine max). GmWNK1 expression was detected in the root, specifically in root cells associated with lateral root formation, and was down‐regulated by abscisic acid (ABA), as well as by mannitol, sucrose, polyethylene glycol and NaCl. In vitro and in vivo experiments showed that GmWNK1 interacts with another soybean protein, GmCYP707A1, which is a key ABA 8′‐hydroxylase that functions in ABA catabolism. Furthermore, 35S‐GmWNK1 transgenic soybean plants had reduced lateral root number and length compared with wild‐type, suggesting a role of GmWNK1 in the regulation of root system architecture. We propose that GmWNK1 functions to fine‐tune ABA‐dependent ABA homeostasis, thereby mediating the regulation of the root system architecture by ABA and osmotic signals. The study has revealed a new function of a plant WNK1 gene from the important staple crop soybean, and has identified a new component of a regulatory pathway that is involved not only in ABA signaling, but also in the repression of lateral root formation by an ABA‐dependent mechanism distinct from known ABA signaling pathways.     

Discovery of 3-(2-aminoethyl)-5-(3-phenyl-propylidene)-thiazolidine-2,4-dione as a dual inhibitor of the Raf/MEK/ERK and the PI3K/Akt signaling pathways

A thiazolidine-2,4-dione derivative, 3-(2-aminoethyl)-5-(3-phenyl-propylidene)-thiazolidine-2,4-dione (2), was identified as a dual inhibitor of the Raf/MEK/ extracellular signal-regulated kinase (ERK) and the phosphatidylinositol 3-kinase (PI3K)/Akt signaling cascades. The discovered compound inhibited cell proliferation, induced early apoptosis, and arrested cells in G₀/G₁ phase in human leukemia U937 cells. These results indicate its potential as a new lead compound to develop novel dual signaling pathway inhibitors and anticancer agents.     

Nucleotide diversity in Silene latifolia autosomal and sex-linked genes

The plant Silene latifolia has separate sexes and sex chromosomes, and is of interest for studying the early stages of sex chromosome evolution, especially the evolution of non-recombining regions on the Y chromosome. Hitch-hiking processes associated with ongoing genetic degeneration of the non-recombining Y chromosome are predicted to reduce Y-linked genes'' effective population sizes, and S. latifolia Y-linked genes indeed have lower diversity than X-linked ones. We tested whether this represents a true diversity reduction on the Y, versus the alternative possibility, elevated diversity at X-linked genes, by collecting new data on nucleotide diversity for autosomal genes, which had previously been little studied. We find clear evidence that Y-linked genes have reduced diversity. However, another alternative explanation for a low Y effective size is a high variance in male reproductive success. Autosomal genes should then also have lower diversity than expected, relative to the X, but this is not found in our loci. Taking into account the higher mutation rate of Y-linked genes, their low sequence diversity indicates a strong effect of within-population hitch-hiking on the Y chromosome.     

牡丹品种鉴定用ISSR引物的筛选与开发

用于牡丹品种鉴定的DNAISSR-PCR反应体系已经建立。利用DNAISSR分子标记分析少量牡丹品种时,容易获得各品种的特有ISSR标记。然而,中国牡丹品种约有1500个,在小批量品种范围内找到的品种特有ISSR标记有可能出现在其它品种中。因此,利用DNAISSR分子标记对数量庞大的中国牡丹品种进行区分和鉴定时,寻找品种特有标记成为突出的技术难题。标记是由引物通过PCR扩增产生的。因此,关键在于找到理想的ISSR引物。对已知的ISSR引物的筛选未获得良好的PCR扩增结果。报道牡丹鉴定用ISSR引物的设计与开发新途径。     

Prenatal Stress Causes Oxidative Damage to Mitochondrial DNA in Hippocampus of Offspring Rats

Mitochondrion, the primary source of reactive oxygen species (ROS), is also the target of ROS. 8-Hydroxy-2′-deoxyguanosine (8-OH-dG) is the major end-product of damaged DNA caused by ROS. In our previous studies, we showed that prenatal stress (PNS) preferentially caused cognitive dysfunction and increased ROS in the hippocampus of female offspring rats. The present study aimed to determine 8-OH-dG level of mitochondria in order to elucidate the mechanism of hippocampal pyramidal neuronal damage and cognitive dysfunction induced by PNS. Pregnant rats were divided into two groups: control group (undisturbed) and PNS group (exposed to a restraint stress for 7 days at the late stage of gestation). Offspring rats were divided into four groups: female-control group, male-control group, female-stress group, male-stress group and used at 30-day-old after their birth. The content of 8-OH-dG was determined by high performance liquid chromatography-electrochemical detection (HPLC-ECD). The results showed that the contents of 8-OH-dG in female and male prenatal stressed offspring were significantly higher than that in their respective controls (P < 0.001). 8-OH-dG level was significantly higher in the female-stress group than in the male-stress group (P < 0.05), whereas there was no any gender-dependent difference in the control groups. These results suggest that accumulation of oxidative mitochondrial DNA damage may play an important role in PNS-induced cognitive dysfunction in female offspring rats. Special issue article in honor of Dr. Akitane Mori.     

Positive effects of Taxol pretreatment on morphology, distribution and ultrastructure of mitochondria and lipid droplets in vitrification of in vitro matured porcine oocytes

This study was designed to determine the effects of Taxol pretreatment on the morphology, distribution and ultrastructure of mitochondria and lipid droplets in vitrified porcine oocytes matured in vitro. The result showed that: (1) the rate of normal mitochondria distribution in fresh group (92.85%) was significantly higher (P < 0.05) than that in other three groups (toxicity, 72.48%; vitrification, 50.83%; Taxol + vitrification, 69.98%) and Taxol pretreatment significantly (P < 0.05) increased the ratio of normal mitochondria distribution in vitrified oocytes; (2) lipid droplets in vitrified oocytes got cracked, resulting in a great number of smaller lipid droplets (diameter <5 μm). The number of lipid droplets (5–10 μm in diameter) in vitrified oocytes pretreated with Taxol was higher (P < 0.05) than that in the oocytes without Taxol pretreatment (81.87 ± 13.63 vs. 64.27 ± 13.72); (3) both toxicity and vitrification cause the difference in the ultrastructure of mitochondria and lipid droplets. Mitochondria were well maintained in the form of typical round and ellipse shape with smooth surface and clear outline and lipid droplets existed in the form of integrity in Taxol pretreatment group.In conclusion, Taxol pretreatment has positive effects on vitrified porcine oocytes matured in vitro in terms of morphology, distribution and ultrastructure of mitochondria and lipid droplets.