Noninvasive ultrasound deep brain stimulation of nucleus accumbens induces behavioral avoidance

Ultrasound stimulation is an emerging noninvasive option in treating neuropsychiatric disorders. The present study investigates the behavioral alterations resulting from ultrasound stimulation on the nucleus accumbens(NAc) in freely moving mice. Our results show that an acute ultrasound stimulation on the NAc, rather than the visual cortex or auditory cortex, led to a pronounced avoidance behavior, while repeated NAc ultrasound stimulation resulted in an obvious conditioned place aversion with changes in synaptic protein(Glu A1/2 subunit) expression. Notably, NAc ultrasound stimulation suppressed the morphine-induced conditioned place preference. The results provide evidence that NAc ultrasound stimulation can be applied as a potential noninvasive therapeutic option in treating psychiatric disorders.     

Phylogenetic relationships and biogeographic history of the unique Saxifraga sect. Irregulares (Saxifragaceae) from eastern Asia

Saxifraga L. is the largest genus in Saxifragaceae and a characteristic component of the herbaceous flora of the temperate and alpine mountains in the Northern Hemisphere. Section Irregulares is a small group of 15–20 species, representing one of the early‐diverged lineages in the genus characterized with unique zygomorphic flowers. We used both nuclear internal transcribed spacer and chloroplast DNA regions (psbA‐trnH, trnL‐F, and matK) to reconstruct its species relationships, estimate divergence times, and infer its historical biogeography. Our phylogenetic results corroborate the monophyly of sect. Irregulares and its sister relationship to sect. Heterisia from North America. The section was well resolved into two lineages corresponding to their morphological features and biogeographic distributions. One represents ser. Stoloniferae including S. stolonifera Curtis and S. nipponica Makino with long‐creeping stolons/rhizomes and small petals with spots and the other comprises the remaining taxa (ser. Rufescentes) which lack long‐creeping rhizomes. Spots on leaves (abaxially spotted vs. abaxially without spots) and spots on petals (without spots vs. with spots) are inferred to be phylogenetically informative within ser. Rufescentes. Divergence time estimates and ancestral area analysis suggested a western North American origin of sect. Irregulares with migration into East Asia by way of the Bering land bridge in the Middle Oligocene. The development of drying and desertification belt in the late Miocene could have played an important role in the subsequent restriction and separation of the north and south lineages within eastern Asia.     

Allotransplantation of adult spinal cord tissues after complete transected spinal cord injury: Long-term survival and functional recovery in canines

Science China Life Sciences - Spinal cord injury (SCI), especially complete transected SCI, leads to loss of cells and extracellular matrix and functional impairments. In a previous study, we...     

发菜磷酸葡糖胺变位酶(glmM)对干旱胁迫的响应及其基因克隆

glmM编码的磷酸葡糖胺变位酶是肽聚糖合成前体的关键酶。为探究发菜glmM响应干旱胁迫的表达调控机制及明确其分子信息,本研究对干旱胁迫条件下发菜glmM在转录水平的差异表达进行了分析,并对glmM的表达水平、磷酸化修饰、乙酰化修饰和琥珀酰化修饰水平进行了检测,克隆了发菜glmM,进行了序列分析和原核表达。结果表明,干旱胁迫条件下,发菜glmM在转录水平上的表达量先增加后减少,glmM上调表达,glmM的磷酸化修饰水平逐渐增加,乙酰化修饰水平相对稳定,琥珀酰化修饰水平有明显变化。设计特异性引物克隆glmM基因,获得全长1416 bp发菜glmM基因,与肺衣(5183)glmM的核苷酸序列同源性为95%,氨基酸同源性为97%。将glmM在大肠杆菌中表达,获得一个51.45 kD的外源蛋白,MALDI-TOF-TOF/MS分析证明该蛋白为磷酸葡糖胺变位酶。研究结果为深入研究发菜glmM的分子信息、生物学功能及其响应干旱胁迫的分子机制提供帮助。     

山羊不同组织器官的内参基因筛选

本研究通过比较9个内参基因在山羊不同组织中的表达水平进而确定最适合研究山羊组织表达的内参基因。本试验以简州大耳羊为试验材料,利用实时荧光定量PCR技术分析9个内参基因(GAPDH,PPIA,18S rRNA,PPIB,UXT,RPLP0,ACTB,EIF3K和TBP)在心脏、肝脏、脾脏、肺脏、肾脏、大肠、瘤胃、背最长肌和皮下脂肪等组织中的表达差异情况,并利用geNorm、NormFinder和BestKeeper等程序分析了它们的表达稳定性。geNorm和NormFinder程序一致显示TBP表达最稳定,其次是UXT和RPLP0;BestKeeper分析显示18S rRNA表达最为稳定,其次为TBP和ACTB;3个程序一致认为GAPDH表达稳定性最差。综合3个程序分析得出TBP最适合作为山羊组织中的内参基因,其次为UXT和RPLP0,GAPDH表达稳定性最差,不适合作为山羊组织内参,这为后续研究其他目的基因在山羊组织器官中的表达模式提供数据保障。     

Two Phytophthora parasitica cysteine protease genes,PpCys44 and PpCys45, trigger cell death in various Nicotiana spp. and act as virulence factors

Proteases secreted by pathogens have been shown to be important virulence factors modifying plant immunity, and cysteine proteases have been demonstrated to participate in different pathosystems. However, the virulence functions of the cysteine proteases secreted by Phytophthora parasitica are poorly understood. Using a publicly available genome database, we identified 80 cysteine proteases in P. parasitica, 21 of which were shown to be secreted. Most of the secreted cysteine proteases are conserved among different P. parasitica strains and are induced during infection. The secreted cysteine protease proteins PpCys44/45 (proteases with identical protein sequences) and PpCys69 triggered cell death on the leaves of different Nicotiana spp. A truncated mutant of PpCys44/45 lacking a signal peptide failed to trigger cell death, suggesting that PpCys44/45 functions in the apoplastic space. Analysis of three catalytic site mutants showed that the enzyme activity of PpCys44/45 is required for its ability to trigger cell death. A virus-induced gene silencing assay showed that PpCys44/45 does not induce cell death on NPK1 (Nicotiana Protein Kinase 1)-silenced Nicotiana benthamiana plants, indicating that the cell death phenotype triggered by PpCys44/45 is dependent on NPK1. PpCys44- and PpCys45-deficient double mutants showed decreased virulence, suggesting that PpCys44 and PpCys45 positively promote pathogen virulence during infection. PpCys44 and PpCys45 are important virulence factors of P. parasitica and trigger NPK1-dependent cell death in various Nicotiana spp.     

Setosphaeria turcica ATR turns off appressorium-mediated maize infection and triggers melanin-involved self-protection in response to genotoxic stress

Eukaryotic organisms activate conserved signalling networks to maintain genomic stability in response to DNA genotoxic stresses. However, the coordination of this response pathway in fungal pathogens remains largely unknown. In the present study, we investigated the mechanism by which the northern corn leaf blight pathogen Setosphaeria turcica controls maize infection and activates self-protection pathways in response to DNA genotoxic insults. Appressorium-mediated maize infection by S. turcica was blocked by the S-phase checkpoint. This repression was dependent on the checkpoint central kinase Ataxia Telangiectasia and Rad3 related (ATR), as inhibition of ATR activity or knockdown of the ATR gene recovered appressorium formation in the presence of genotoxic reagents. ATR promoted melanin biosynthesis in S. turcica as a defence response to stress. The melanin biosynthesis genes StPKS and StLac2 were induced by the ATR-mediated S-phase checkpoint. The responses to DNA genotoxic stress were conserved in a wide range of phytopathogenic fungi, including Cochliobolus heterostrophus, Cochliobolus carbonum, Alternaria solani, and Alternaria kikuchiana, which are known causal agents for plant diseases. We propose that in response to genotoxic stress, phytopathogenic fungi including S. turcica activate an ATR-dependent pathway to suppress appressorium-mediated infection and induce melanin-related self-protection in addition to conserved responses in eukaryotes.