灰葡萄孢侵染垫缺失突变体的筛选及其相关生物学特性的研究

【目的】从农杆菌介导获得的灰葡萄孢RoseBC-3的突变体库中筛选侵染垫缺失突变体菌株,并明确其相关生物学特性。【方法】将菌株接种于洋葱表皮,利用棉兰染色观察侵染垫形成情况,筛选得到一个侵染垫缺失突变体(AT19)。采用形态学方法、离体叶片接种法、钌红染色法、小麦种子幼芽生长抑制法分别对该菌株的菌落培养性状、侵染垫产生情况、致病力、产果胶酶能力以及产植物毒性代谢产物能力进行测定。【结果】筛选灰葡萄孢突变体168株,根据侵染垫形成可分为三类：快速形成侵染垫型(158株)、缓慢形成侵染垫型(9株)和侵染垫形成缺陷型(1株,AT19)。AT19在接种洋葱120 h后依然无法形成成熟侵染垫。该菌株生长较为缓慢,菌落扩展均匀,可以产生分生孢子,对烟草、草莓、蚕豆和豌豆叶片均不能致病,可以产生果胶酶和植物代谢毒性物质。【结论】突变体菌株AT19可以产生果胶酶和植物代谢毒性物质,其致病力缺失与侵染垫产生缺陷相关。研究结果为了解灰葡萄孢侵染垫形成分子机制提供基础材料。     

Oxidative stress induces meiotic defects of oocytes in a mouse psoriasis model

Psoriasis, an immune-mediated inflammatory disease, is associated with poor pregnancy outcomes. Emerging evidence indicates that these defects are likely attributed to compromised oocyte competence. Nevertheless, little is known about the underlying associated mechanisms between psoriasis and poor oocyte quality. In this study, we construct an imiquimod-induced chronic psoriasis-like mouse model to review the effects of psoriasis on oocyte quality. We discover that oocytes from psoriasis-like mice display spindle/chromosome disorganization, kinetochore-microtubule mis-attachment, and aneuploidy. Importantly, our results show that melatonin supplement in vitro and in vivo not only increases the rate of matured oocytes but also significantly attenuates oxidative stress and meiotic defects by restoring mitochondrial function in oocytes from psoriasis-like mice. Altogether, our data uncover the adverse effects of psoriasis symptoms on oocytes, and melatonin supplement ameliorates oxidative stress and meiotic defects of oocytes from psoriatic mice.Subject terms: Meiosis, Immunology     

Mitogenomes provide new insights of evolutionary history of Boreheptagyiini and Diamesini (Diptera: Chironomidae: Diamesinae)

Mitogenomes have been widely used for phylogenetic reconstruction of various Dipteran groups, but specifically for chironomid, they have not been carried out to resolve the relationships. Diamesinae (Diptera: Chironomidae) are important bioindicators for freshwater ecosystem monitoring, but its evolutionary history remains uncertain for lack of information. Here, coupled with one previously published and 30 new mitogenomes of Diamesinae, we carried out comparative mitogenomic analysis and phylogenetic analysis. Mitogenomes of Diamesinae were conserved in structure, and all genes arranged in the same order as the ancestral insect mitogenome. All protein‐coding genes in Diamesinae were under stronger purifying selection than those of other nonbiting midge species, which may exhibit signs of adaptation to life at cold living conditions. Phylogenetic analyses strongly supported the monophyly of Diamesinae, with Boreheptagyiini deeply nested within Diamesini. In addition, phylogenetic relationship of selected six genera was resolved, except Sympotthastia remained unstable. Our study revealed that the mitogenomes of Diamesinae are highly conserved, and they are practically useful for phylogenetic inference.     

Time-Series Clustering of lncRNA-mRNA Expression during the Adipogenic Transdifferentiation of Porcine Skeletal Muscle Satellite Cells

Skeletal muscle satellite cells (SMSCs), which are multifunctional muscle-derived stem cells, can differentiate into adipocytes. Long-chain non-coding RNA (lncRNA) has diverse biological functions, including the regulation of gene expression, chromosome silencing, and nuclear transport. However, the regulatory roles and mechanism of lncRNA during adipogenic transdifferentiation in muscle cells have not been thoroughly investigated. Here, porcine SMSCs were isolated, cultured, and induced for adipogenic differentiation. The expressions of lncRNA and mRNA at different time points during transdifferentiation were analysed using RNA-seq analysis. In total, 1005 lncRNAs and 7671 mRNAs showed significant changes in expression at differential differentiation stages. Time-series expression analysis showed that the differentially expressed (DE) lncRNAs and mRNAs were clustered into 5 and 11 different profiles with different changes, respectively. GO, KEGG, and REACTOME enrichment analyses revealed that DE mRNAs with increased expressions during the trans-differentiation were mainly enriched in the pathways for lipid metabolism and fat cell differentiation. The genes with decreased expressions were mainly enriched in the regulation of cell cycle and genetic information processing. In addition, 1883 DE mRNAs were regulated by 193 DE lncRNAs, and these genes were related to the controlling in cell cycle mainly. Notably, three genes in the fatty acid binding protein (FABP) family significantly and continuously increased during trans-differentiation, and 15, 13, and 11 lncRNAs may target FABP3, FABP4, and FABP5 genes by cis- or trans-regulation, respectively. In conclusion, these studies identify a set of new potential regulator for adipogenesis and cell fate and help us in better understanding the molecular mechanisms of trans-differentiation.     

FERONIA is involved in phototropin 1-mediated blue light phototropic growth in Arabidopsis

Plant shoot phototropism is triggered by the formation of a light-driven auxin gradient leading to bending growth. The blue light receptor phototropin 1(phot1) senses light direction, but how this leads to auxin gradient formation and growth regulation remains poorly understood. Previous studies have suggested phot1’s role for regulated apoplastic acidification, but its relation to phototropin and hypocotyl phototropism is unclear. Herein, we show that blue light can cause phot1 to interact with...     

乳链菌肽高产菌株AL2的发酵条件研究

对乳链菌肽高产菌株ＡＬ２的发酵条件进行了研究,发现３０℃是产乳链菌肽的最适温度;蔗糖和酵母膏是最佳的碳、氮源,浓度分别为０．５％和１％。发酵培养基起始ｐＨ为６．５;锰离子对乳链菌肽的产生有促进作用,而铜离子却有严重的抑制作用。     

磨盘山天然次生林凋落物数量及动态

以磨盘山5.76hm2天然次生林群落固定监测样地为平台,均匀布设144个凋落物收集器,于2006年每月末(4—11月)连续收集其凋落物,用以分析群落尺度上的凋落物产量、组成及时空变化。结果表明,天然次生林年凋落量为3039.6 kg/hm2,以凋落叶(2499.2 kg/hm2)所占的比例最大,占年凋落量的82.22%,而凋落枝仅占年凋落量的9.92%,花果皮等所占比例更小,占总量的5%以下。1a内,凋落物收集器内共收集到42种树木的凋落叶,占样地内树种总数(46种)的91.30%,其中花曲柳(Fraxinus rhynchophylla)、核桃楸(Juglans mandshurica)和蒙古栎(Quercus mongolica)3个树种的凋落叶占落叶总量的82.97%,为叶凋落量的主要来源。不同收集器之间凋落量存在较大差异,99个收集器的年凋落量在200—400 g,2个收集器超过600 g;单个收集器全年最多可收集到19种树种的凋落叶,收集到凋落叶种数12种的收集器最多(29个)。凋落量月动态呈单峰型,69.78%的凋落量产生于9—10月份,叶凋落量月动态与凋落总量变化相同。落叶以秋季为主,但树种间叶凋落节律存在差异,其中核桃楸叶的凋落高峰集中在8—9月,花曲柳和春榆(Ulmus japonica)集中在9—10月,色木槭(Acer mono)为10月,蒙古栎叶为10—11月。     

SINPV基因组酶切图谱及多角体基因的序列分析

用限制性内切酶ＥｃｏＲＩ、ＸａｂＩ、ＸｈｏＩ、ＢａｍＨＩ、ＰｓｔＩ、ＳａｃＩ、ＨｉｄｎⅢ、ＳｍａＩ酶解斜纹夜蛾核多角体病毒广州株基因组ＤＮＡ,分别得到２６、２６、２４、２０、１３、１７、９、１条片段,并算得基因组平均大小为１３６．０ｋｂｐ。以ＡｃＮＰＶ多角体基因的部分读码框为探针,经Ｓｏｕｔｈｅｍ杂交将ＳＩＮＰＶ多角体基因定位于ＸｂａＩＯ片段上。将此片段克隆并序列分析,结果表明ＳＩ     

干扰对生态系统多功能性的影响研究进展

干扰作为生态系统中的一种固有属性,在部分生态系统中已严重影响到了该地区生态系统平衡。生态系统多功能性作为衡量生态系统的一个综合指标,能够同时反映生态系统的整体功能。随着干扰活动的不断变化,干扰对生态系统的影响也受到社会各界广泛关注,针对干扰对生态系统多功能性的研究也在不断增加,但由于对干扰对生态系统多功能性的影响还缺乏系统总结,因此本文从概念进展、量化指标、测度方法、影响因子四个方面论述生态系统多功能性的研究现状,结合干扰对生态系统多功能性的研究,对比分析其研究进展,以期为今后生态系统多功能性的研究提供参考。针对目前森林生态系统多功能性研究存在的问题,今后的相关研究应从以下三点实现突破:(1)生态系统多功能性的应用性研究;(2)评估各生态系统功能之间的相互作用对生态系统多功能性的影响研究;(3)干扰对生态系统多功能性影响的机制性研究。以期为进一步探索干扰对生态系统多功能性的影响机制研究提供借鉴,以推动该领域的发展。