Molecular aspects of mammalian fertilization

Mammalian fertilization is a highly regulated process, much of which are not clearly understood. Here we presentsome information in order to elaborate a working hypothesis for this process, beginning with the sperm modifications inthe epidydimis up to sperm and egg plasmalemma interaction and fusion. We also discuss the still poorly understood ca-pacitation process, the phenomenon of sperm chemo-attraction that brings the capacitated sperm to interact with theoocyte vestments and certain aspects of the acrosome reaction. (Asian J Androl 2001 Dec; 3 : 243 - 249)

An Optimization Study of α-Amylase Production by Aspergillus niger ATCC 16404 Grown on Orange Waste Powder

In this work, sequential optimization strategy, based on statistical designs, was employed to enhance the production of α-amylase by Aspergillus niger ATCC 16404. This statistical study consists of optimizing the factors that influence the production of α-amylase of A. niger ATCC 16404. Indeed, another statistical study has allowed the selection of 5 factors (pH, starch, yeast extract, “corn steep liquor”, CaCl2 and salts) affecting both the development of mould (biomass) and that of the enzyme production. The central composite design allows the determination of the optimum of these selected factors and a quadratic model explains the factor reaction. Thus, the “ridge analysis” method, has led to maximizing the experimental reaction. The results indicate that the production rate of α-amylase is maximized in the presence of starch at 8.97 g/l, yeast extract at 2.86 g/l, CaCl2 at 1.224 g/l, salts (composed of 25% FeSO4, 7H2O, 25% MnSO4 and 50% MgCl2, 6H2O): FeSO4, 7H2O, MnSO4 0.1518 g/l and MgCl2, 6H2O at 0.3036 g/l. As for the pH, it is maintained at the rate of 5.68.

A fusion at the root of prostate cancer

Many hematopoietic malignancies have oncogenic gene fusions, like BCR-ABL, in their tumor-initiating cells. This implicates the product of the fusion as a powerful cancer-initiating event. In human prostate cancers, despite the detection of numerous similar fusions,

草原围栏对普氏原羚行为和栖息地面积的影响

在欧亚草原区,建设草原围栏将草原围成家畜放牧场的趋势越来越明显,然而草原围栏对野生动物的影响却鲜为人知.仅分布在青藏高原东部青海湖流域草原上的普氏原羚被国际自然保护联盟物种生存委员会列为濒危级物种.为了探索草原围栏对其行为和栖息地面积的影响,笔者开展了相关研究.结果表明:(1)在建有围栏的区域内,普氏原羚昼间活动距离平均值为5081±1187m(湖东-克图分布区)和4110±912m(元者分布区),远远低于无围栏分布区中普氏原羚的昼间活动距离7223±546m(快尔玛分布区);(2)在建有围栏区域内的普氏原羚采食周期比无围栏生境中的短;(3)普氏原羚沿围栏行走的频次比例达81%;跳越围栏的行为频次比例为1.2%,从围栏底部钻过围栏的频次为17.8%;(4)建立围栏后,湖东-克图和元者分布区内普氏原羚的活动范围分别缩小为建立围栏前的20%和6%;(5)围栏降低了普氏原羚逃离天敌的能力.在元者和湖东-克图,直接被围栏挂住死亡的比例为5%,或因围栏限制了逃避天敌的能力而导致普氏原羚被狼捕食的比例为15%～20%.由此可见,草原围栏不利于普氏原羚生存,建议加强草原生物多样性保护,对家畜牧场进行综合管理.

Impacts of grassland fence on the behavior and habitat area of the critically endangered Przewalski's gazelle around the Qinghai Lake

The trend of fencing grassland as livestock paddocks is spreading on the Eurasian steppe,however,its impacts on grassland wildlife are little known.In order to explore such impacts,we carried out a field study on how grassland fencing impacts Przewalski's gazelle(Procapra przewalskii),a species listed as EN(Endangered) by SSC/IUCN,on the Qinghai-Tibet Plateau.The results revealed that(1) in the fenced areas,daily movement distance of Przewalski's gazelle was 5081±1187 m(Hudong-Ketu) and 4110±912 m(Yuanzhe),which was much shorter than the 7223±546 m recorded in an unfenced area(Kuaierma);(2) the feeding bout duration of Przewalski's gazelle was much shorter in the fenced habitat;(3) the frequency of walking along both high or low fence lines reached about 81%;while the frequency of jumping across the low fence line was only about 1.2% and frequency of crawling through the bottom of the high fence lines was about 17.8%;(4) the size of post-fencing habitat decreased to about 20% and 6% of the sizes of pre-fencing habitat in Hudong-Ketu and Yuanzhe areas respectively,but no clear change in the size of habitat area was found in the unfenced Kuaierma area;and(5) the fence lines impaired the possibility of gazelles to escape from predators and occasionally trapped the Przewalski's gazelle which failed to jump over the fence lines.Death occurrence of Przewalski's gazelle in the intensively fenced area,including gazelles strangled by fence lines and predated by wolves,reached 5% of the population size in Yuanzhe and up to 15%-20% in Hudong-Ketu.This study highlights the negative impacts of grassland fencing on Przewalski's gazelle and proposes measures for integrating conservation of this gazelle with livestock management practice.

Nucleus-Encoded Light-Harvesting Chlorophyll a/b Proteins are Imported Normally into Chlorophyll b-Free Chloroplasts of Arabidopsis

Chloroplast-located proteins which are encoded by the nuclear genome have to be imported from the cytosol into the organelle in a posttranslational manner. Among these nuclear-encoded chloroplast proteins are the light- harvesting chlorophyll a/b-binding proteins （LHCPs）. After translation in the cytosol, precursor proteins of LHCPs are imported via the TOC/TIC translocase, processed to their mature size to insert into thylakoid membranes where they recruit chlorophylls a and b to form pigment-protein complexes. The translocation of proteins is a highly regulated process which employs several regulators. To analyze whether CAO （chlorophyll a oxigenase） which converts chlorophyll a to chlorophyll b at the inner chloroplast membrane, is one of these regulators, we performed import reactions utilizing a homozygous loss-of-function mutant （cao-1）. We imported in vitro translated and 35S-labeled precursor proteins of light- harvesting proteins of photosystem II LHCB1, LHCB4, and LHCB5 into chloroplasts isolated from cao-1 and show that import of precursor proteins and their processing to mature forms are not impaired in the mutant. Therefore, regulation of the import machinery cannot be responsible for the decreased steady-state levels of light-harvesting complex （LHC） proteins. Regulation does not take place at the transcriptional level either, because Lhcb mRNAs are not down-regulated. Additionally, reduced steady-state levels of LHCPs also do not occur due to posttranslational turnover of non-functional LHCPs in chloroplasts. Taken together, our data show that plants in the absence of CAO and therefore devoid of chlorophyll b are not influenced in their import behavior of LHC proteins.

Association of a genetic variant in AKT1 gene with features of the metabolic syndrome

Metabolic syndrome(MetS)is a clustering of metabolic abnormalities that is associated with increased risk of developing cardiovascular disease and type 2 diabetes.There is growing body of data showing the associations of genetic variants of the genes involved in the PI3K/AKT/mTOR pathway with diabetes and obesity.We aimed to investigate the association between MetS and its components with the genetic polymorphism in AKT1,rs1130233(T>C).Total of 618 participants,recruited from Mashhad stroke and heart atherosclerosis disorder cohort(MASHAD study).Patients with MetS were defined by using international diabetes federation(IDF)criteria(n Z 326)and those without MetS(n Z 261)were recruited.Anthropometric and biochemical parameters were measured in all subjects.Genetic analysis for the rs1130233 polymorphism was performed,using the ABI-StepOne instruments with SDS version-2.0 software.Individuals with MetS had a significantly higher levels of BMI,waistcircumference,total cholesterol,triglyceride,high sensitivity-c reactive protein(hs-CRP)and blood-pressure,and lower concentrations of high density lipoprotein(HDL-C),compared to non-MetS individuals(P<0.05).The association between the rs1130233 and MetS was not significant.Subjects with a CC or CT genotypes had a significantly higher serum hs-CRP-level(OR:1.5;95%CI(1.05e2.1),P Z 0.02).Additionally,subjects who carried the TC genotype had a higher BMI compared to the CC genotype(p value Z 0.045).Our findings demonstrated that AKT1,rs1130233(T>C)polymorphism was associated with major components of MetS such as hs-CRP,and BMI,indicating further investigation in a multi-center setting to explore its value as an emerging biomarker of risk stratification marker.

The Subcellular Localization and Blue-Light- Induced Movement of Phototropin 1-GFP in Etiolated Seedlings of Arabidopsis thalianaw

Phototropin 1 （photl） is a photoreceptor for phototropism, chloroplast movement, stomatal opening, leaf expansion, and solar tracking in response to blue light. Following earlier work with PHOTI：：GFP （Sakamoto and Briggs, 2002）, we investigated the pattern of cellular and subcellular localization of photl in 3-4 d old etiolated seedlings of Arabidopsis thalinana. As expressed from native upstream sequences, the PHOTT：GFP fusion protein is expressed strongly in the abaxial tissues of the cotyledons and in the elongating regions of the hypocotyl. It is moderately expressed in the shoot/root transition zone and in cells near the root apex. A fluorescence signal is undetectable in the root epidermis, root cap, and root apical meristem itself. The plasma membranes of mesophyll cells near the cotyledon margin appear labeled uniformly but cross-walls created by recent cell divisions are more strongly labeled. The pattern of labeling of individual cell types varies with cell type and developmental stage. Blue-light treatment causes PHOTI：：GFP, initially relatively evenly distributed at the plasma membrane, to become reorganized into a distinct mosaic with strongly labeled punctate areas and other areas completely devoid of fluorescenco a phenomenon best observed in cortical cells in the hypocotyl elongation region. Concomitant with or following this reorganization, PHOTT：GFP moves into the cytoplasm in all cell types investigated except for guard cells. It disappears from the cytoplasm by an unidentified mechanism after several hours in darkness. Neither its appearance in the cytoplasm nor its eventual disappearance in darkness is prevented by the translation inhibitor cycloheximide, although the latter process is retarded. We hypothesize that blue-light-induced photl relocalization modulates blue-light-activated signal transduction.

Hsa-circ-000094 in Peripheral blood can be used as a biomarker for the diagnosis of type 2 diabetes

Objective The purpose of this study was to investigate the differential expression of circRNAs in human blood,as a diagnostic marker for pre-diabetes and type 2 diabetes mellitus(T2DM).Methods Microarray analysis was used to select several differentially expressed circRNAs from three normal patients and three T2DM patients.Enlargement of the sample size(normal controls,n=20;subjects with impaired glucose regulation,n=20;and type 2 diabetes mellitus,n=20)determined circRNA to be the most evident differentially expressed by fluorescence quantitative PCR(Q-PCR).Then they were verified with expanded samples(normal controls,n=50;impaired glucose regulations,n=50;type 2 diabetes mellitus,n=50)by Q-PCR.Results A total of 2953 differentially expressed circRNAs were found in microarray analysis,of which 1439 were up-regulated and 1514 were down-regulated.Nine differentially expressed circRNAs were selected from the 1439 circRNAs that were up-regulated(hsacirc-103838,hsa-circ-103965,hsa-circ-104227,hsacirc-002117,hsa-circ-000094,hsa-circ-101226,hsacirc-101720,hsa-circ-400029,and hsa-circ-100633).The Q-PCR results of the expanded sample(n=60)showed that the difference expression of hsa-circ-000094(Alias:has-circ-0000247)in the nine circRNAs was the most obvious one among the 3 groups,the area under the maximum curve was found by ROC curve analysis,SIGR=0.8025[95%confidence interval(0.6655-0.9395),P=0.001];ST2DM=0.77[95%confidence interval(0.624-0.916),P=0.003].In order to verify the clinical diagnostic ability of hsa-circ-000094,the experiment was conducted to further expand the sample(n=150).The results showed that the expression of hsa-circ-000094 in the three groups was different,the difference and ROC curve analysis were statistically significant,SIGR=0.6733[95%confidence interval(0.5757-0.7710),P<0.01];ST2DM=0.7231[95%confidence interval(0.6327-0.8134),P<0.01].Conclusion The higher expression of hsa-circ-000094 in peripheral blood provides a certain diagnostic basis for pre-diabetes as well as type 2 diabetes mellitus.