中国科学家在植物细胞骨架研究领域取得突破性进展

微管是细胞骨架的重要组成部分,为真核细胞生命活动所必需。与其它生物体类似,微管不仅在植物生长发育中起重要作用,而且参与响应外界环境信号。近期,中国科学家在解析植物微管精准切割及微管骨架动态重构调控机制的研究中取得突破性进展。     

Distinct impacts of reductive soil disinfestation and chemical soil disinfestation on soil fungal communities and memberships

Applied Microbiology and Biotechnology - Soil disinfestation is an important agricultural practice to conquer soil-borne diseases and thereby ensure crop productivity. Reductive soil disinfestation...     

Response of host–bacterial colonization in shrimp to developmental stage,environment and disease

The host‐associated microbiota is increasingly recognized to facilitate host fitness, but the understanding of the underlying ecological processes that govern the host–bacterial colonization over development and, particularly, under disease remains scarce. Here, we tracked the gut microbiota of shrimp over developmental stages and in response to disease. The stage‐specific gut microbiotas contributed parallel changes to the predicted functions, while shrimp disease decoupled this intimate association. After ruling out the age‐discriminatory taxa, we identified key features indicative of shrimp health status. Structural equation modelling revealed that variations in rearing water led to significant changes in bacterioplankton communities, which subsequently affected the shrimp gut microbiota. However, shrimp gut microbiotas are not directly mirrored by the changes in rearing bacterioplankton communities. A neutral model analysis showed that the stochastic processes that govern gut microbiota tended to become more important as healthy shrimp aged, with 37.5% stochasticity in larvae linearly increasing to 60.4% in adults. However, this defined trend was skewed when disease occurred. This departure was attributed to the uncontrolled growth of two candidate pathogens (over‐represented taxa). The co‐occurrence patterns provided novel clues on how the gut commensals interact with candidate pathogens in sustaining shrimp health. Collectively, these findings offer updated insight into the ecological processes that govern the host–bacterial colonization in shrimp and provide a pathological understanding of polymicrobial infections.     

胸腺肽的合成及抗衰老作用研究

我们采用Ｍｅｒｒｉｆｉｌｄ固相法合成了胸腺生成素Ⅱ的活性片段ＴｈｙｍｏｐｏｉｅｔｉｎⅡ３２～３６（Ｔｐ－５）和胸腺素α１的活性片段Ｔｈｙｍｏｓｉｎ２３～２７（（Ｌｙｓ２３）α１－５）,用０．１,１,１０,１００,１０００ｕｇ／ｋｇ体重的Ｔｐ－５和（Ｌｙｓ２３）α１－５分别腹腔注射小鼠,连续１０天,能使小鼠肝、脑、脾和胸腺组织中丙二醛含量显著降低,可以促进免疫活性和抑制体内脂质过氧化物的生成,最适剂量集中在１～１００μｇ／ｋｇ体重,Ｐ＜０．０１。     

Possible role of histone H1 in the regulation of furin-dependent proprotein processing

Histone H1 and its C-terminal lysine rich fragments were recently found to be potent inhibitorsof furin,a mammalian proprotein convertase.However,its role in the regulation of furin-dependent proproteinprocessing remains unclear.Here we report that histone H1 efficiently blocks furin-dependent pro-yonWillebrand factor(pro-vWF)processing in a dose-dependent manner.Coimmunoprecipitation and immunof-luorescence studies confirmed that histone H1 could interact with furin,and the interaction mainly took placeon the cell surface.We noted that histone H1 was released from cells undergoing necrosis and apoptosisinduced by H_2O_2.Our findings suggested that histone H1 might be involved in extracellular and/or intracellu-lar furin regulation.     

不同激素处理对白桦幼树萌条及三萜合成的影响

探索一种可持续、稳定的获得白桦（Betula platyphylla Suk.）枝条的方法,拟通过促萌处理建立多枝条类型白桦材料。以一年生白桦幼苗为试材,采用3个截干高度：10、20、30 cm处理后,每个截干高度使用4种激素或化学药剂处理（20 mg·L^-1 2,4-D、20 mg·L^-1 KT、20 mg·L^-1 6-BA和20 mg·L^-1 KMnO₄）进行促发萌条试验。结果表明,白桦幼苗初次截干（30 d后）采条,截干高度10 cm进行激素KT、6-BA处理的白桦苗萌芽率最高,达65.0%以上;锯末保湿处理下3种截干高度萌条率、萌条产量均较高,萌条率达75.0%以上。枝条中总三萜含量以截干高度20 cm处理下最高,达76.43 mg·g^-1,其次为截干高度10 cm处理下,其他处理均不利于总三萜积累。叶中总三萜含量以截干高度30 cm下激素6-BA处理最高,达91.16 mg·g^-1,是锯末处理（30 cm）的2.68倍。在锯末处理、KT和KMnO₄处理下的枝条和叶片中总三萜含量显著低于其他处理。6-BA对枝条、叶片中齐墩果酸的积累有利,其他处理均不利于齐墩果酸积累。锯末处理有利于二次萌条及产量的提高,截干高度为10 cm处理下萌条产量达126.96 g。枝条总三萜含量以截干高度20 cm进行激素6-BA处理效果较好,达97.99 mg·g^-1。叶中总三萜含量以截干高度30 cm进行激素KT处理最佳,达99.22 mg·g^-1,其次为锯末处理组和6-BA处理组。该研究结果为可持续、高效的利用白桦资源及获得三萜产物提供了技术支持。     

骨顶鸡等游禽对不同人为干扰的行为响应

分别于2008年4月至6月和2009年4月至6月,采用目标动物取样法在黑龙江省安邦河湿地和大庆龙凤湿地研究了骨顶鸡等水鸟对人为干扰的行为响应.结果表明:骨顶鸡对行人和机动车辆两种干扰的反应距离类似,但耐受程度有所不同,骨顶鸡对机动车辆干扰的耐受性要好于行人干扰.在以游客等行人干扰为主的安邦河湿地,骨顶鸡以及其他游禽对干扰产生行为反应的比例要高于以机动车辆干扰为主的龙凤湿地,说明相对于行人干扰骨顶鸡对机动车辆更容易耐受;在安邦河湿地,骨顶鸡对划船的反应距离以及反应程度要大于人行走,说明骨顶鸡对于侵入性的干扰更为敏感.此外,对凤头鹛鹏(Podicepscristatus)、黑颈鹏鹧(Podiceps nigricollis)、小鹏鹏(Tachybaptus ruficoUis)、黑水鸡(Gallinula chloropus)、红头潜鸭(Aythya ferina)、赤膀鸭(Anas strepera)、绿头鸭(Anas platyrhynchos)、斑嘴鸭(Anas poecilorhyneha)、绿翅鸭(Arias crecca)、白眉鸭(Anasquerquedula)、赤颈鸭(Ariaspenelope)、琵嘴鸭(Anas clypeata)等游禽对人为干扰的反应距离、耐受距离以及遭受干扰时的反应比例进行了研究,结果显示3种鹛鹧对干扰的耐受距离差异不显著,12种鸭类中红头潜鸭对人为干扰的敏感性要小于其他鸭类,斑嘴鸭和绿头鸭则相对敏感.     

Involvement of over-expressed BMP4 in pentylenetetrazol kindling-induced cell proliferation in the dentate gyrus of adult rats

The dentate gyrus (DG) of the hippocampus is one of a few regions in the adult mammalian brain characterized by ongoing neurogenesis. Proliferation of neural precursors in the granule cell layer of the DG has been identified in pentylenetetrazol (PTZ) kindling epilepsy model, however, little is known about the molecular mechanism. We previously reported that the expression pattern of bone morphogenetic proteins-4 (BMP4) mRNA in the hippocampus was developmentally regulated and mainly localized in the DG of the adult. To explore the role of BMP4 in epileptic activity, we detected BMP4 expression in the DG during PTZ kindling process and explore its correlation with cell proliferation combined with bromodeoxyuridine (BrdU) labeling technique. We found that dynamic changes in BMP4 level and BrdU labeled cells dependent on the kindling stage of PTZ induced seizure-prone state. The number of BMP4 mRNA-positive cells and BrdU labeled cells reached the top level 1 day after PTZ kindled, then declined to base level 2 months later. Furthermore, there was a significant correlation between increased BMP4 mRNA expression and increased number of BrdU labeled cells. After effectively blocked expression of BMP4 with antisense oligodeoxynucleotides(ASODN), the BrdU labeled cells in the dentate gyrus subgranular zone(DG-SGZ) and hilus were significantly decreased 16d after the first PTZ injection and 1, 3, 7, 14d after kindled respectively. These findings suggest that increased proliferation in the DG of the hippocampus resulted from kindling epilepsy elicited by PTZ maybe be modulated by BMP4 over-expression.