Pitx3 is required for motor activity and for survival of a subset of midbrain dopaminergic neurons

Mesencephalic dopaminergic (MesDA) neurons play crucial roles in motor and behavioral processes; their loss in Parkinson's disease (PD) results in striatal dopamine (DA) deficiency and hypokinetic movement disorder. The Pitx3 homeobox gene is expressed in the MesDA system. We now show that only a subset of MesDA neurons express Pitx3 and that in Pitx3-deficient aphakia mice, this subset is progressively lost by apoptosis during fetal (substantia nigra, SN) and postnatal (ventral tegmental area) development, resulting in very low striatal DA and akinesia. Similar to human PD, dorsal SN neurons (which are Pitx3 negative) are spared in mutant mice. Thus, Pitx3 defines a pathway for survival of neurons that are implicated in PD and that are required for spontaneous locomotor activity.     

Assessment of the genetic diversity among Glyptosternum maculatum, an endemic fish of Yarlung Zangbo River, Tibet, China using SSR markers

The genetic diversity of Glyptosternum maculatum populations from Nyang River, Lhasa River, and Shetongmon Reach of Yarlung Zangbo River was assessed using six microsatellite markers. Overall, the genetic diversity across the three populations was low. The Shetongmon population exhibited the highest level of genetic diversity in terms of number of alleles and effective alleles, heterozygosity, and polymorphic information content value, followed by the Nyang population and Lhasa population. The analysis of molecular variance demonstrated that almost the variation (86.64%) occurred within populations. The differentiation among populations was not significant, and population structure was weak. These results revealed that three natural populations of G. maculatum are not genetically differentiated and the large disparity of living altitude did not caused genetic differentiation between different populations. Our observations will help identify the genetic relationship among populations to understand the genetic diversity of G. maculatum.     

新疆博格达山岩面生地衣群落结构特征

根据对新疆博格达山岩面生地衣群落20个样点(20m×20m)调查的数据,以各地衣种的盖度为指标结合双向指示种分析方法(TWINSPAN)和除趋势对应分析法(DCA)对博格达山岩面生地衣群落进行数量分类并分析了群落结构特征及其多样性和相似性。采用典范对应分析法(CCA)对各群落的物种分布格局与环境因子的关系进行研究。结果表明,TWINSPAN分析和DCA排序将分布在博格达山的37种岩面生地衣分为以下5个群丛。群丛1:斑纹网衣(Lecidea tessellate Florke)+粉芽盾衣(Peltula euploca(Ach.)Poelt)+杜瑞氏黄梅(Xanthoparmelia durietzii Hale)群丛,有25个种,总覆盖度为30.145%,多样性为4.025;群丛2:袋衣(Hypogymnia physodes(L.)Nyl.)+白边平茶渍(Aspicilia sublaqueata(H.Magn.)J.C.Wei)+砖孢胶衣(Collema subconveniens Nyl.)群丛,有17个种,地衣总盖度为15.885%,多样性为3.196;群丛3:聚茶渍(Lecanora accumulate H.Magn.)+丽石黄衣(Xanthoria elegans(Link)Th.Fr.)+亚洲平茶渍(Aspicilia asiatica(H.Magn.)Yoshim.)群丛,有30个种,地衣总盖度为37.87%,多样性为4.357;群丛4:中华石果衣(Endocarpon sinense H.Magn.)+伴藓大孢蜈蚣衣(Physconia muscigena(Ach.)Poelt.)+垫脐鳞衣(Rhizoplaca melanophthalma(DC.)LeuckertPoelt)群丛,有24个种,地衣总盖度为30.458%,多样性为3.912;群丛5:石胶衣(Collema flaccidum(Ach.)Ach.)+短绒皮果衣(Dermatocarpon vellereum Zschacke)+绿黑地图衣(Rhizocarpon viridiatrum(Wulfen)Korber.)群丛,有18个种,地衣总盖度为19.331%,多样性为3.515。CCA排序结果反映,该地区岩面生地衣的分布与海拔高度、光照强度、岩石pH和人为干扰有关,其中影响最大的因素是海拔高度,其次为光照强度和干扰。坡向和岩石大小对地衣种类分布的影响不显著。     

Natural versus adaptive regulatory T cells

The regulation of immune responses to self-antigens is a complex process that involves maintaining self-tolerance while retaining the capacity to mount robust immune responses against invading microorganisms. Over the past few years, many new insights into this process have been gained, leading to the re-emergence of the idea that regulatory T (T(Reg)) cells are a central mechanism of immune regulation. These insights have raised fundamental questions concerning what constitutes a T(Reg) cell, where they develop and what signals maintain T(Reg)-cell populations in a functional state. Here, we propose the existence of two subsets of CD4+ T(Reg) cells--natural and adaptive--that differ in terms of their development, specificity, mechanism of action and dependence on T-cell receptor and co-stimulatory signalling.     

Identification and characterization of potential NBS-encoding resistance genes and induction kinetics of a putative candidate gene associated with downy mildew resistance in <Emphasis Type="Italic">Cucumis</Emphasis>

Background  

Due to the variation and mutation of the races of Pseudoperonospora cubensis, downy mildew has in recent years become the most devastating leaf disease of cucumber worldwide. Novel resistance to downy mildew has been identified in the wild Cucumis species, C. hystrix Chakr. After the successful hybridization between C. hystrix and cultivated cucumber (C. sativus L.), an introgression line (IL5211S) was identified as highly resistant to downy mildew. Nucleotide-binding site and leucine-rich repeat (NBS-LRR) genes are the largest class of disease resistance genes cloned from plant with highly conserved domains, which can be used to facilitate the isolation of candidate genes associated with downy mildew resistance in IL5211S.     

Novel CaO/polylactic acid nanoscaffold as dental resin nanocomposites and the investigation of physicochemical properties

In this study, for the first time, calcium oxide (CaO)/polylactic acid nanoscaffolds were synthesized by co‐precipitation assistant reverse micelles method. The physical and chemical (physicochemical) properties of the structures as dental resin composites were also studied. Nanocomposite materials as primary and basic dental compounds can be conveniently applied as dental filling materials with a high esthetic quality. In this research nanoscaffolds act as a bed for nanoparticles and improve the mechanical and chemical (mechanochemical) properties, CaO nanoparticles were loading in polylactic acid nanoscaffold as a bioactivity polymer for usage in the dental resin composites. Mechanical properties of the dental resin composite containing CaO/polylactic acid nanoscaffold were calculated: the flexural strength (137.2 MPa), modulus (12.9GPa) and compressive strength (344.2 MPa). Potential of the basic nanoparticle and the products were characterized by X‐ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), dynamic light scattering (DLS), ultraviolet‐visible spectroscopy (UV‐visible) and atomic force microscopy (AFM) showed the size of the optimized nanostructures was about 85 to 120 nm. According to TGA results of polylactic acid nanofibers with thermal stability below 300°C these high thermal stability materials can be used as dental resin composites.     

Role of 677C→T polymorphism a single substitution in methylenetetrahydrofolate reductase (MTHFR) gene in North Indian infertile men

Failure or severe difficulty in conceiving a child is surprisingly common, worldwide problem. Half of these cases are due to male factors with defects in sperm (1 in 15 men) being the single most common cause. Also about 60–75 % of male infertility cases are idiopathic, since the molecular mechanisms underlying the defects remain unknown. DNA methylation is crucial for spermatogenesis and high methylenetetrahydrofolate reductase (MTHFR) activity in adult testis than other organs in mouse, signifies its critical role in spermatogenesis. According to recent findings there is a correlation of epigenetic regulation of several imprinted genes with disturbed spermatogenesis and fertility. Consequently any change in the MTHFR gene sequence can modify the spermatogenesis including transmission of infertility to the carriers. The aim of the study is to analyze the distribution of the single nucleotide polymorphism C677T in the MTHFR gene in 637 North Indian infertile patients and 364 fertile North Indian men as controls by using PCR–RFLP technique and Chi Square test for statistical analysis. The average MTHFR 677CC, 677CT, 677TT genotype frequencies of total infertile men were 70.17, 24.17, 5.65 % in infertile men and 75.27, 21.7, 2.74 % in controls, respectively. The average frequency of the MTHFR 677T allele was 17.73 % in infertile men as compared to 13.59 % in controls. The statistical difference was significant. Disease risk was found 2.27-folds increased in patients who were carrying T allele. We found an association of C677T polymorphism with male infertility and that it may be a genetic risk factor for male infertility in North Indian population.     

Comparative Efficacy of Weed Control Practices for Parthenium Weed and Sunflower Crop under Varying Tillage Systems

Parthenium poses serious threat to modern crop production system and necessitate evaluating control practices for its effective management. Efficacy of different weed control practices for controlling parthenium was explored in conventional and deep tillage systems in the field conditions. Hand hoeing (20 and 35 days after emergence), S-Metolachlor (pre-emergence herbicide), sorghum straw mulch @ 5 tons ha^-1 and combination of hand hoeing and sorghum straw mulch (hand hoeing at 20 and straw mulch at 35 days after emergence) were used as weed control practice. Weedy check where no weed control measure was applied was also included in this experiment for comparison. Results concluded that the all weed management treatments significantly reduced parthenium density, its fresh and dry biomass during both the years of study as compared to weedy check. Maximum sunflower achene yield was recorded in hand hoeing (20 and 35 days after emergence) in combination with deep tillage. So, mold bold plough used for the purpose of deep tillage should be encouraged for better control of parthenium and higher achene yield of sunflower crop (3293.3 kg ha^-1 in 2017 and 3221.3 kg ha^-1 in 2018). Moreover, is also inferred that total dose of herbicide might be reduced by using hoeing and mulching in an integrated way.