Transcription factor Dmrt1 triggers the SPRY1-NF-κB pathway to maintain testicular immune homeostasis and male fertility.

Bacterial or viral infections, such as Brucella, mumps virus, herpes simplex virus, and Zika virus, destroy immune homeostasis of the testes, leading to spermatogenesis disorder and infertility. Of note, recent research shows that SARS-CoV-2 can infect male gonads and destroy Sertoli and Leydig cells, leading to male reproductive dysfunction. Due to the many side effects associated with antibiotic therapy, finding alternative treatments for inflammatory injury remains critical. Here, we found that Dmrt1 plays an important role in regulating testicular immune homeostasis. Knockdown of Dmrt1 in male mice inhibited spermatogenesis with a broad inflammatory response in seminiferous tubules and led to the loss of spermatogenic epithelial cells. Chromatin immunoprecipitation sequencing (ChIP-seq) and RNA sequencing (RNA-seq) revealed that Dmrt1 positively regulated the expression of Spry1, an inhibitory protein of the receptor tyrosine kinase (RTK) signaling pathway. Furthermore, immunoprecipitation-mass spectrometry (IP-MS) and co-immunoprecipitation (Co-IP) analysis indicated that SPRY1 binds to nuclear factor kappa B1 (NF-κB1) to prevent nuclear translocation of p65, inhibit activation of NF-κB signaling, prevent excessive inflammatory reaction in the testis, and protect the integrity of the blood-testis barrier. In view of this newly identified Dmrt1- Spry1-NF-κB axis mechanism in the regulation of testicular immune homeostasis, our study opens new avenues for the prevention and treatment of male reproductive diseases in humans and livestock.

OCT6 inhibits differentiation of porcine-induced pluripotent stem cells through MAPK and PI3K signaling regulation.

As a transcription factor of the Pit-Oct-Unc (POU) domain family, octamer-binding transcription factor 6 ( OCT6) participates in various aspects of stem cell development and differentiation. At present, however, its role in porcine-induced pluripotent stem cells (piPSCs) remains unclear. Here, we explored the function of OCT6 in piPSCs. We found that piPSCs overexpressing OCT6 maintained colony morphology and pluripotency under differentiation conditions, with a similar gene expression pattern to that of non-differentiated piPSCs. Functional analysis revealed that OCT6 attenuated the adverse effects of extracellular signal-regulated kinase (ERK) signaling pathway inhibition on piPSC pluripotency by activating phosphatidylinositol 3-kinase-protein kinase B (PI3K-AKT) signaling activity. Our research sheds new light on the mechanism by which OCT6 promotes PSC maintenance.

Four-lncRNA immune prognostic signature for triple-negative breast cancer Running title: Immune lncRNAs predict prognosis of TNBC.

OBJECTIVE: We aimed to explore key immune-related long non-coding RNAs (lncRNAs) and their effect in predicting of prognosis of triple-negative breast cancer (TNBC). METHODS: Four datasets of TNBC were downloaded from TCGA and GEO databases. ImmPort database was utilized to acquire immune-related mRNAs. Single sample gene set enrichment analysis (ssGSEA) and correlation analysis were utilized to screen immune-related lncRNAs. Univariate and multivariate Cox regression analyses were utilized to screen independent prognostic lncRNAs to establish prognostic risk model, and the model was evaluated by survival analysis and nomogram. Differential functions and immune cells infiltration in high and low risk group were analyzed by Gene set variation analysis and ssGSEA. Finally, competitive endogenous RNAs was constructed. RESULTS: We revealed 62 immune-related lncRNAs, of which four lncRNAs (RP11-890B15.3, RP11-1024P17.1, MFI2-AS1 and RP11-180N14.1) had independent prognostic value. These four lncRNAs-based prognostic risk model could stratify the TNBC patients into high and low risk groups, and patients with high risk displayed unfavorable outcomes. Nomogram indicated that the prognostic model could indicate TNBC patients survival very well. We further found that high risk group showed significantly enriched immune response to tumor cell, humoral immune response and high infiltrating abundance of regulatory T cell, Type 2 T helper cell, eosinophil, etc. LncRNAs RP11-180N14.1, RP11-1024P17.1 and RP11-890B15.3 regulated more mRNAs by targeting various miRNAs. While MFI2-AS1 regulated three mRNAs by sponging miR-3150a-3p. CONCLUSION: These four lncRNAs were prognostic biomarkers and could be possible therapeutic targets in TNBC.

[Long-term Variation Characteristics of Zooplankton Community Structure in Meiliang Bay, Lake Taihu].

Zooplankton, as an important part of the water food chain, plays an important role in lake ecosystems. It is an important monitoring indicator for water bodies. However, due to the lack of long-term monitoring data of zooplankton community structure, there is a lack of understanding about its long-term characteristics. Based on monthly monitoring data from 1997 to 2017 of Meiliang Bay in Lake Taihu, the long-term trends of zooplankton community structure and its relation to the environment were examined. The results showed that the abundance and biomass of zooplankton in Meiliang Bay significantly decreased from 1997 to 2017 (P<0.05). In particular, the abundance and biomass of rotifer and copepod slowly declined, and the abundance of cladocerans fluctuated but its biomass presented a significant decreasing trend (P<0.05). The cladocerous biomass contributed the most to the zooplankton biomass in Meiliang Bay. The dominance of smaller cladocerans and copepods increased with decreasing rotifer density, significantly decreasing the average body size of zooplankton (P<0.05). This study indicated that zooplankton were becoming smaller, potentially weakening the top-down control on phytoplankton. In addition, zooplankton abundance and biomass showed an upward trend in spring and decreased in autumn and winter, and reached maximum values of 1406.70 ind.·L-1 and 25.64 mg·L-1, respectively, in September. In the summer, their changes were the opposite. Pearson correlation analysis showed that zooplankton community structure was significantly related to water physical characteristics (alkalinity, electrical conductivity, water depth, suspended substance, and water temperature), chlorophyll a, and nitrogen (P<0.05). This indicated that the eutrophication of Meiliang Bay in Lake Taihu had a significant impact on the community structure of zooplankton.

[High-Frequency Dynamics of Water Quality and Phytoplankton Community in Inflowing River Mouth of Xin'anjiang Reservoir, China].

The tail of the reservoir is the unstable zone regarding water quality and phytoplankton community. Therefore, it is the crucial zone in aquatic ecosystem transitions. To understand the transition characteristics and driving mechanisms of water environment dynamics, high-frequency monitoring of the water environment and phytoplankton community in the tail of a deep and large reservoir, the Xin'anjiang Reservoir in southeast of China, was conducted using a water quality monitoring buoy and three-day interval water sampling during 18 months. Results show clear seasonal thermal and oxygen stratification in the river mouth of the reservoir. The nutrient and chlorophyll-a concentrations also show stratifying phenomena during the thermal stratification period. Heavy rain and inflow quickly consume the stratification. Nutrient concentrations were highly dynamic in the river mouth. The total phosphorus ranges from 0.011 mg·L-1 to 0.188 mg·L-1, and total nitrogen ranges from 0.75 mg·L-1 to 2.76 mg·L-1. Dissolved phosphorus comprised 56% of total phosphorus, and dissolved nitrogen occupied 88% of total nitrogen, respectively. Nutrient concentrations were influenced strongly by rainfall intensity and inflow rate. Total phosphorus and nitrogen concentrations were significantly related to the three-day accumulated rainfall. Nutrient concentrations in the flood season (March to June) were significantly higher than in the non-flood season (P<0.001). Seasonal phytoplankton proliferation also significantly influenced by total phosphorus concentration. The phytoplankton community changes significantly with seasons and flood events. Bacillariophytea was generally dominant throughout the year, with the predominant genus of Fragilaria spp., Cyclotella spp., Synedra spp., and Melosira spp. Cyanophyta biomass peaked in July, August, and September, with the dominant genus of Aphanizomenon spp., Microcystis spp., and Oscillatoria spp. Apart from the high temperature, storm inflow events also triggered Cyanophyta proliferation. The proliferation of Chlorophyta was similar to Cyanophyta, with the predominant genus of Pediastrum spp. and Closterium spp.. While the Cryptophyta biomass peaked during March to May, with the predominant genus of Cryptomonas spp.. Redundancy analysis shows that the influence factors of phytoplankton community dynamics include the inflow rate, temperature, water level, water transparency, total nitrogen, total phosphorus, and nitrogen to phosphorus ratio. The meteorological and hydrological factors were major factors for phytoplankton dynamics during later autumn and winter, while the nutrient will be the co-driving factors of phytoplankton community dynamics during summer and early autumn. The research confirmed the huge influence of the intensity rainfall event on the water environment in reservoirs and described the key environmental conditions for phytoplankton community dynamics. The research is useful for the design of the monitoring and forecasting system for water safety in drinking water source reservoirs.

Effect of Regulatory Network of Exosomes and microRNAs on Neurodegenerative Diseases.

OBJECTIVE: A comprehensive review of the network regulation of exosomes and microRNAs (miRNAs) in neurodegenerative diseases was done, centering on the mechanism of the formation of exosomes and miRNAs and the sorting mechanism of exosomal miRNAs, with the aim to provide a theoretical basis in the search of biomarkers and the treatment of neurodegenerative diseases. DATA SOURCES: The comprehensive search used online literature databases including NCBI PubMed, Web of Science, Google Scholar, and Baidu Scholar. STUDY SELECTION: The study selection was based on the following keywords: exosomes, miRNAs, central nervous system (CNS), and neurodegenerative diseases. The time limit for literature retrieval was from the year 2000 to 2018, with language restriction in English. Relevant articles were carefully reviewed, with no exclusions applied to study design and publication type. RESULTS: Exosomes are the smallest nanoscale membranous microvesicles secreted by cells and contain important miRNAs, among other rich contents. In the CNS, exosomes can transport amyloid ß-protein, α-synuclein, Huntington-associated protein 1, and superoxide dismutase I to other cells. These events relieve the abnormal accumulation of proteins and aggravating neurological diseases. In some neurodegenerative diseases including Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis, miRNAs are pathologically altered as an inexorable course, suggesting that miRNAs may contribute neurodegeneration. Exosomes and miRNAs form a network to regulate the homeostasis of the CNS, both synergistically and individually. CONCLUSION: The network of exosomes and miRNAs that regulates CNS homeostasis is a promising biomarker for the diagnosis and treatment of neurodegenerative diseases.

[Study of Kinase Inhibitor WP1066 on the STAT3/JAK2 of Prostate Stromal Cells].

OBJECTIVE: To study the role of JAK2 signaling pathway in prostate stromal cells and the effect of inhibitor WP1066 on its expression. METHODS: The phosphorylation of JAK2 and STAT3 in prostate tissues of patients with benign prostatic hyperplasia (BHP) (n=4) and severe histological prostatitis (HP) plus BPH (n=4) was tested by using Western blot to verify the activation of their mediated signaling pathway. Kinase inhibitor WP1066 was added to prostate stromal cells to detect inhibition of the JAK2 and STAT3 activation launched by IL-6. RESULTS: JAK2 phosphorylation level (pJAK2) was significantly increased in the patients with severe HP plus BPH,and the expression of JAK2 or STAT3 was not decreased in WP1066 treatment cells. However,neither phosphorylation in JAK2 nor STAT3 was able to be detected in the cells treated with WP1066 or WP1066+IL-6,indicating that the signaling pathway of JAK2-STAT3 was inhibited. CONCLUSION: JAK/STAT signaling pathway is activated in patients with severe HP plus BPH , but could be inhibited by WP1066.

In vitro DNA SCRaMbLE.

The power of synthetic biology has enabled the expression of heterologous pathways in cells, as well as genome-scale synthesis projects. The complexity of biological networks makes rational de novo design a grand challenge. Introducing features that confer genetic flexibility is a powerful strategy for downstream engineering. Here we develop an in vitro method of DNA library construction based on structural variation to accomplish this goal. The "in vitro SCRaMbLE system" uses Cre recombinase mixed in a test tube with purified DNA encoding multiple loxPsym sites. Using a ß-carotene pathway designed for expression in yeast as an example, we demonstrate top-down and bottom-up in vitro SCRaMbLE, enabling optimization of biosynthetic pathway flux via the rearrangement of relevant transcription units. We show that our system provides a straightforward way to correlate phenotype and genotype and is potentially amenable to biochemical optimization in ways that the in vivo system cannot achieve.

Pollen competition between morphs in a pollen-color dimorphic herb and the loss of phenotypic polymorphism within populations.

Flower color polymorphism is relatively uncommon in natural flowering plants, suggesting that maintenance of different color morphs within populations is difficult. To address the selective mechanisms shaping pollen-color dimorphism, pollinator preferences and reproductive performance were studied over three years in Epimedium pubescens in which some populations had plants with either green or yellow pollen (and anthers). Visitation rate and pollen removal and receipt by the bee pollinator (Andrena emeishanica) did not differ between the two color morphs. Compared to the green morph, siring success of the yellow morph's pollen was lower, but that of mixtures of pollen from green and yellow morphs was lowest. This difference, corresponding to in vivo and ex vivo experiments on pollen performance, indicated that pollen germination, rather than tube growth, of the green morph was higher than that of the yellow morph and was seriously constrained in both morphs if a pollen competitor was present. A rare green morph may invade a yellow-morph population, but the coexistence of pollen color variants is complicated by the reduced siring success of mixed pollinations. Potential pollen competition between morphs may have discouraged the maintenance of multiple phenotypes within populations, a cryptic mechanism of competitive exclusion.

Effects of clonal integration on the proximal and distal ramets of Cynodon dactylon under shade stress

ABSTRACT In a pot experiment, clonal ramets of Cynodon dactylon, a stolon herbaceous plant, were treated with heterogeneous lighting. Proximal ramets (elder ramets) were subjected to shade stress at three different degrees, and stolons between proximal and distal ramets of each pair were treated in a connected or severed manner. Results showed that in moderate shade stress, the number of ramets and leaves, biomass, net photosynthetic rate (Pn), maximum quantum yield (Fv/Fm), effective quantum yield of PSII (ФPSII), and soil and plant analysis development values (SPAD) of proximal ramets were significantly reduced, regardless of whether stolons were kept intact or severed. However, the growth of distal ramets was not significantly influenced, and keeping the stolons intact also did not bring apparent benefits for the whole clonal fragments. These results show that clonal integration does not help alleviate the shade stress suffered by proximal ramets and the costs of distal ramets and does not significantly influence the whole clonal fragments. The possible reasons are that distal ramets may be at the cost of metabolism for resource transportation when the proximal ramets suffer from shade stress; thus, clonal integration is not favorable.

Development of 15 polymorphic microsatellite markers for Ficus virens (Moraceae).

PREMISE OF THE STUDY: Ficus virens (Moraceae) is distributed widely in South and Southeast Asia, Melanesia, and northern Australia, and it is also cultivated outside its original northern range limit in southwestern China. Therefore, the species is well suited to explore the mechanism of range limits of Ficus species. However, little is known about its genetic background. METHODS AND RESULTS: Fifteen polymorphic microsatellite markers were developed using the biotin-streptavidin capture method. Polymorphism was tested in 85 F. virens individuals sampled from three populations. The number of alleles ranged from three to 17. The observed and expected heterozygosity of each population varied from 0.0667 to 0.9286 and 0.0650 to 0.8890, respectively. Cross-species amplification was also carried out in eight other Ficus species. CONCLUSIONS: These 15 markers will be valuable for studying the genetic variation and population structure of F. virens and related Ficus species.

Perioperative restricted fluid therapy preserves immunological function in patients with colorectal cancer.

AIM: To investigate the effect of perioperative restricted fluid therapy on circulating CD4(+)/CD8(+) T lymphocyte ratio, percentage of regulatory T cells (Treg) and postoperative complications in patients with colorectal cancer. METHODS: A total of 185 patients met the inclusion criteria and were included in the randomized clinical trial. These patients were divided into two groups according to receipt of either perioperative standard (S, n = 89) or restricted (R, n = 96) fluid therapy. Clinical data of these patients were collected in this prospective study. Perioperative complications and cellular immunity changes (CD4(+)/CD8(+) and Treg) were analyzed comparatively between the two groups. RESULTS: Both during surgery and on postoperative days, the total volumes of fluids administered in the R group were significantly lower than those in the S group (1620 ± 430 mL vs 3110 ± 840 mL; 2090 ± 360 mL vs 2750 ± 570 mL; 1750 ± 260 mL vs 2740 ± 490 mL; 1620 ± 310 mL vs 2520 ± 300 mL; P < 0.05). Decreased ratios of circulating CD4(+)/CD8(+) T lymphocytes (1.47 ± 0.28 vs 2.13 ± 0.26; 1.39 ± 0.32 vs 2.21 ± 0.24; P < 0.05) and Treg percentage values (2.79 ± 1.24 vs 4.26 ± 1.04; 2.46 ± 0.98 vs 4.30 ± 1.12; P < 0.05) were observed after surgery in both groups. However, in the R group, these values restored more quickly starting from postoperative day 2 (1.44 ± 0.24 vs 1.34 ± 0.27; 2.93 ± 1.08 vs 2.52 ± 0.96; P < 0.05). The proportion of patients with complications was significantly lower in the restricted group (36 of 89 vs 59 of 96, P < 0.01). CONCLUSION: Perioperative restricted intravenous fluid regimen leads to a low postoperative complication rate and better cellular immunity preservation in patients with colorectal cancer.

[Histological effects of unilateral spermatic cord torsion without removal of the ipsilateral necrotic testis on the contralateral testis in rats].

OBJECTIVE: To investigate the protective effect of retarded removal of the unilateral necrotic testis after long-time (> 24 h) spermatic cord torsion on the contralateral testis in rats. METHODS: Thirty-three male SD rats aged 21 -42 days were divided into a sham-operation group (n = 11), a torsion-reservation group (n = 12) and a torsion-orchiectomy group (n = 10). The rats of the sham-operation group received dartos pouch orchidopexy on the left testis, while those of the latter two groups underwent 720 degrees unilateral spermatic cord torsion on the left side. Ninety-six hours later, the rats of the torsion-reservation group received detorsion with the ipsilateral testis preserved, while those of the torsion-orchiectomy group underwent orchiectomy. Three months after operation, blood samples were obtained from the rats for measurement of serum testosterone and antisperm antibodies by ELISA, and meanwhile testes and epididymides were harvested for determination of the volumes of various structures and the diameter of seminiferous tubules with stereological methods. RESULTS: There were no significant differences in the level of serum testosterone among the three groups. Anti-sperm antibody positive was found in only 1 animal in the torsion-reservation group. The Leydig cell nuclei in the contralateral testis appeared larger in the torsion groups than in the sham-operation group. Marked morphological changes were observed in 1, 3 and 0 of the animals in the sham-operation, torsion-reservation and torsion-orchiectomy group, respectively, mainly including atrophy of seminiferous tubules and reduced number of spermatogenic cells. The volume of the contralateral testis was increased by 19% and 21% in the torsion-reservation and torsion-orchiectomy group, respectively, in comparison with that in the sham-operation group (P < 0.05). No significant differences were observed in the volume of seminiferous tubules of the contralateral testis among the sham-operation, torsion-reservation and torsion-orchiectomy groups ([1.15 +/- 0.07], [1.30 +/- 0.04] and [1.35 +/- 0.05] cm3). The volume of the interstitial tissue was significantly increased in the latter two groups ([0.36 +/- 0.02 and 0.34 +/- 0.03] cm3) as compared with the former ([0.25 +/- 0.02] cm3) (P < 0.05). The diameters of the seminiferous tubules exhibited no significant differences among the three groups ([226.00 +/- 7.00], [223.00 +/- 6.00] and [221.00 +/- 3.0] microm). CONCLUSION: Long-time unilateral spermatic cord torsion may result in compensatory hypertrophy of the contralateral testis, and orchiectomy does not significantly affect the histology of the contralateral testis and epididymis.

Biodegradation of butachlor by Rhodococcus sp. strain B1 and purification of its hydrolase (ChlH) responsible for N-dealkylation of chloroacetamide herbicides.

Rhodococcus sp. strain B1 could degrade 100 mg/L butachlor within 5 days. Butachlor was first hydrolyzed by strain B1 through N-dealkylation, which resulted in the production of butoxymethanol and 2-chloro-N-(2,6-dimethylphenyl)acetamide. Butoxymethanol could be further degraded and utilized as the carbon source for the growth of strain B1, whereas 2-chloro-N-(2,6-dimethylphenyl)acetamide could not be degraded further. The hydrolase designated ChlH, responsible for the N-dealkylation of the side chain of butachlor, was purified 185.1-fold to homogeneity with 16.1% recovery. The optimal pH and temperature of ChlH were observed to be 7.0-7.5 and 30 °C, respectively. This enzyme was also able to catalyze the N-dealkylation of other chloroacetamide herbicides; the catalytic efficiency followed the order alachlor > acetochlor >butachlor > pretilachlor, which indicated that the alkyl chain length influenced the N-dealkylation of the chloroacetamide herbicides. This is the first report on the biodegradation of chloroacetamide herbicides at the enzyme level.

[Total flavonoids and icariin contents of Epimedium pubescens in different types of communities and their relationships with soil factors].

Epimedium pubescens and soil samples were collected from the Betula albosinensis community (community I ), Cyclobalanopsis glauca var. gracilis community (community II), and Cinnamomum longepaniculatum community (community III) in Tangjiahe Nature Reserve in August 2009, with the total flavonoids and icariin contents in E. pubescens samples measured by high performance liquid chromatography and UV-spectrophotometer, and the relationships between these contents and soil parameters analyzed. Among the plant organs of E. pubescens, leaf had the highest contents of total flavonoids and icariin, while stem had the lowest one. The total flavonoids and icariin contents of E. pubescens were significantly higher in community I [(5.32 +/- 0.23)%, (0.47 +/- 0.05)%] than in communities II [(4.06 +/- 0.03)%, (0.32 +/- 0.01)%] and III [(4.15 +/- 0.07)%, (0.28 +/- 0.09)%] (P<0.05), and negatively correlated with soil total nitrogen and alkali-hydrolyzable nitrogen (P<0.05) but positively correlated with soil pH (P<0.01), suggesting that the soil with lower level of nitrogen and higher level of acidity in community I could enhance the total flavonoids and icariin contents of E. pubescens.

[Study on propagation technology of Acanthopanax trifoliatus by cuttings].

OBJECTIVE: In order to obtain substantial clonal plants, we studied the cuttings propagation technology. METHODS: The cutting roots and stems of Acanthopanax trifoliatus were used as plant materials, and different materias, seasons and other conditions for cutting propagation were tested. RESULTS: It showed that the survival rate of stem segments was higher than that of root segments. The test of age of plant materials found that high survival rate could be obtained from semi-lignified stem segments and the segments from the base stem could survive successfully. Autumn was more suitable for plants' survival. Moreover, the rooting rate reached 89.4% by inserting segments with leaves into sand soil after dipping into 1500 mg/L IBA for 10 s, and with plastic membrane and shading net covered. CONCLUSION: The rooting rate can increase significantly by collecting semi-lignified basal stems in autumn, cutting them for leaf cuttings, and inserting them into sand soil after dipping into 1500 mg/L IBA for 10 s.

[Studies on purification of total saponins from the leaves of Acanthopanax trifoliatus by macroporous adsorption resin].

OBJECTIVE: To study the enrichment and purification of total saponins from the leaves of A. trifoliatus. METHODS: Using the total saponins from the leaves of A. trifoliantus as the standard index, we examinad the capability of static adsorption and desorption to select the optimum macroporous adsportion resin. Then we studied the purification technological parameters such as pH value, the dynamic adorption speed of flow, the best type quantity, the eluent density and so on. RESULTS: The optimum purification conditions were as follows: the type of macroporous adsorption resin was AB-8, the pH value of absorbing solution was 5-6, the absorbing velocity of flow was 1.0 mL/min, the concentration of ethanol as elutent was 70%, the proportion of the amount of absorbing solution and resins was 4:1, the proportion of the amount of elutent and resins was 4:1, the eluting velocity of flow was 2.0 mL/min.

[The contents changes of polysaccharides and total flavonoids during flower bud differentiation of Epimedium sagittatum].

OBJECTIVE: To study the dynamic changes of the contents of polysaccharides and total flavonoids Daring flower bud differentiation of Epimedium sagittatum. METHODS: The polysaccharides and total flavonoids from Epimedium sagittatum were extracted by Microwave-assisted method. The content of polysaccharides was determined by anthrone sulphuric acid colorimetry and that of total flavonoids was determined at 270 nm by ultraviolet spectrophotometry. RESULTS: The polysaccharides content in leaf decreased during the initial stages of floral bud differentiation and then increased, while the content in stem and fibrous root decreased steadily until floral bud differentiation completed. The content in rhizome kept invariant. In the flower bud physiological differentiation period,the content of total flavonoids in leaf and stem decreased and then kept invariant, while the content in rhizome increased and kept invariant. The content of total flavonoids in fibrous root increased during the initial stages of floral bud differentiation and then decreased. CONCLUSION: The contents of polysaccharide and total flavonoids have relation with the flower bud differentiation of Epimedium sagittatum.

Cloning and characterization of a curcin gene encoding a ribosome inactivating protein from Jatropha curcas.

A curcin gene was isolated by using genomic walker technology and revealed to encode the type-1 ribosome inactivating proteins (RIPs). Analysis of 1802 bp segments revealed the gene including a 694 bp 5' flanking region, a 882 bp open read frame (ORF) and a 226 bp 3' flanking region. There are one putative TATA boxes and two possible CAAT box lie in the 5'-flanking region. The ORF encodes a 32 kDa precursor, which contains a 42 amino acid signal peptide. Two possible polyadenylation signals are found in the 3'-flanking region. No introns were found, which is typical of other RIPs gene that has been sequenced. The deduced amino acid sequence of Curcin gene coding region shares high homology with RIPs, e.g. ricin A-chain, gelonin, abrin A-chain, bryodin, trichosanthin and momorcharin, which were found to be 34% (99/287), 34% (98/287), 37% (89/240), 34% (86/249), 36% (87/241) and 36% (88/241), respectively. The cloning of the gene is important foundation to further study the structure, expression and regulation mechanism.