小型哺乳动物的繁殖投入与繁殖成功率

动物的繁殖活动关系到整个种群的生存与灭绝, 繁殖投入和繁殖成功率是繁殖生态学研究的重要内容。从繁殖投入的划分入手, 综述了小型哺乳动物的繁殖投入和繁殖成功率之间的关系及其影响因素、分子生物学技术在繁殖生态学中的应用等, 阐述了小型哺乳动物能够根据自身的状态调整每次繁殖活动中的时间投入和能量分配, 采取不同的繁殖对策。这些繁殖对策是长期自然选择的结果, 其目的都是为了最大限度地提高自身的适合度。并且指出分子生物学技术在繁殖生态学中的应用将大大加快这一研究领域的快速发展。     

Discovery of novel taspine derivatives as antiangiogenic agents

VEGFR-2 plays a critical role in vasculogenesis and inhibitors of VEGFR-2 could be used in the treatment of cancer. Taspine was one of the active ingredients screened by using an endothelial cell membrane chromatography and showed inhibition against VEGFR-2. In our research, we explored how the lactone ring and biphenyl scaffold in taspine influence its potent in vitro anticancer and antiangiogenesis activities. Accordingly, we report the design, synthesis, and preliminary evaluation of four novel taspine derivatives as VEGFR-2 inhibitors. The preliminary biological test showed that one of the compounds showed much better inhibitory activities against CACO-2 (IC₅₀ = 52.5 nM) and ECV304 (IC₅₀ = 2.67 nM) than taspine. This result enlarges the interest in ring-opened taspine derivative skeleton in the search of new antiangiogenesis agents.     

植酸在银杏组织培养中应用的研究

本文报道以植酸作抗氧化剂,对银杏愈伤组织抗氧化褐变的研究。结果表明:①植酸具有抑制多酚氧化酶活性的作用,从而有效地控制愈伤组织的褐变,促进愈伤组织生长;②不同的抗褐变剂,以0.1％的植酸效果最好;③不同的培养基以MT附加BA1.0 mg/L,NAA 3.0 mg/L的效果最好。     

湖南通道侗族自治县传统聚落的空间构建

湘西传统聚落作为一种为数不多的、保存完好的聚落景观之一,其保护研究是我国文化生态及其生物多样性保护研究的重要组成部分。以怀化市侗族传统聚落为研究对象,从传统风水学理念与现代生态位出发,探索传统聚落空间格局的构建方法和驱动因素,以期为传统聚落合理的生态位扩充和空间结构演变提供理论依据。研究表明:湘西传统聚落形成了东、南、西、北四面山林围护、中间宽敞开阔的独立地理空间结构,构建了符合大众追求的"山-林-屋-水-林"的理想聚落空间模式,而且民居建筑大多都"坐西朝东,背风向阳,靠山面水而建"。这种聚落是在自然、经济和文化三大因素共同影响下构成的复合生态系统,有其独特的运行机制。在传统聚落空间系统不断发展的过程中,应遵从其演变发展的客观规律,根据不同传统聚落的生产力水平条件,合理推进经济社会空间结构的转型,并适度加以调控,以稳步实现传统聚落的空间演变和生态位扩充。     

冻融循环对金川泥炭沼泽土壤微生物量及群落结构的影响

冻融作用显著改变土壤微生物活性及碳氮循环过程。以长白山金川泥炭沼泽0-15 cm和15-30 cm土壤为研究对象,进行室内冻融交替模拟实验。实验设置两个冻融幅度（-10-10℃和-5-5℃）。经过0/1/3/5/7/15次冻融循环后,分别采用氯仿熏蒸法和磷脂脂肪酸法测定泥炭沼泽土壤微生物量及磷脂脂肪酸含量,并与未进行冻融处理的FTC （0）对比。实验结果表明：冻融作用对土壤微生物量碳、氮及微生物磷脂脂肪酸含量有显著影响（P<0.001）。15次冻融交替作用后,土壤微生物碳（MBC）含量均显著增加,土壤微生物量氮（MBN）含量显著降低。两种冻融模式下,各类型微生物磷脂脂肪酸含量均显著降低。冻融作用显著改变了泥炭沼泽土壤微生物群落结构。冻融作用降低了土壤真菌/细菌比值（-5-5℃,0-15 cm土壤除外）,增加了革兰氏阳性菌/革兰氏阴性菌比值。-5-5℃冻融作用下,各土壤微生物磷脂脂肪酸含量变幅大于-10-10℃,土壤MBC的变化则与其相反,在-10-10℃变化幅度更大。两种冻融幅度下MBC与大部分微生物群落在15-30 cm土壤的变幅更大,这说明冻融作用对不同深度土壤微生物量和微生物群落结构的影响存在差异。冻融次数对土壤微生物量和各类型磷脂脂肪酸含量有显著影响（P<0.01）。相关性分析结果表明多种微生物磷脂脂肪酸含量与MBN含量呈正相关关系（P<0.01）,与DOC含量呈负相关关系（P<0.05）。综上,冻结作用促进了微生物的死亡,为融化期微生物生存提供更多碳源与营养物质,改变了土壤微生物群落结构。冻融期间各类型微生物磷脂脂肪酸含量降低,可能会降低泥炭沼泽土壤碳汇能力。     

EDIL3 influenced the αvβ3‐FAK/MEK/ERK axis of endothelial cells in psoriasis

One of the earliest events in the development of psoriatic lesion is a vascular network expansion. The abnormal vascular network is associated with increased endothelial cells (ECs) survival, proliferation, adhesion, migration, angiogenesis and permeability in psoriatic lesion. Our previous study demonstrated that epidermal growth factor‐like repeats and discoidin I‐like domains 3 (EDIL3) derived from psoriatic dermal mesenchymal stem cells (DMSCs) promoted cell–cell adhesion, migration and angiogenesis of ECs, but the molecular mechanism of upstream or downstream has not been explored. So, this study aimed to explore the association between EDIL3 derived from DMSCs (DMSCs‐derived EDIL3) and psoriasis‐associated angiogenesis. We injected recombinant EDIL3 protein to mouse model of psoriasis to confirm the roles of EDIL3 in psoriasis. Besides, we employed both short‐interference RNA (si‐RNA) and lentiviral vectors to explore the molecular mechanism of EDIL3 promoting angiogenesis in psoriasis. In vivo, this research found that after injected recombination EDIL3 protein, the epidermis thickness and microvessel density were both elevated. EDIL3 accelerated the process of psoriasis in the IMQ‐induced psoriasis‐like mouse model. Additionally, we confirmed that in vitro DMSCs‐derived EDIL3 is involved in the tube formation of ECs via αvβ3‐FAK/MEK/ERK signal pathway. This suggested that DMSCs‐derived EDIL3 and αvβ3‐FAK/MEK/ERK signal pathway in ECs play an important role in the pathogenesis of psoriasis. And the modification of DMSCs, EDIL3 and αvβ3‐FAK/MEK/ERK signal pathway will provide a valuable therapeutic target to control the angiogenesis in psoriasis.     

A primary study on relationships between subfossil chironomids and the distribution of aquatic macrophytes in three lowland floodplain lakes,China

Aquatic macrophytes act as an important substrate for zoobenthos-supporting midge communities (chironomids) that can be used for reconstructing past environmental change. This study selected three macrophyte-dominated lakes in the middle reach of the Yangtze floodplain (central China), to identify relationships between macrophyte characteristics (i.e. communities, richness and biomass) and subfossil chironomid assemblages. One-way ANOSIM tests illustrated that there were significant differences in chironomid community compositions between lakes. Most chironomid taxa were not selective of dominant macrophyte species, but Corynoneura species were found to be associated with the development of Vallisneria as revealed by SIMPER analysis. Multivariate analyses indicate that submerged plant biomass, water depth and secchi depth, conductivity and the concentration of HCO₃ ^? were significantly correlated with midge compositions. Overall, this study corroborates the existing opinions that chironomid species show little selectivity to plant type but are significantly influenced by plant density. As an exception to this general trend, we found strong associations between Corynoneura chironomid larvae and Vallisneria macrophytes, prompting the need for future experimental studies to confirm this association.     

NRDR inhibits estradiol synthesis and is associated with changes in reproductive traits in pigs

Cumulus cells secreting steroid hormones have important functions in oocyte development. Several members of the short‐chain dehydrogenase/reductase (SDR) family are critical to the biosynthesis of steroid hormones. NADPH‐dependent retinol dehydrogenase/reductase ( NRDR), a member of the SDR superfamily, is overexpressed in pig breeds that also show high levels of androstenone. However, the potential functions and regulatory mechanisms of NRDR in pig ovaries have not been reported to date. The present study demonstrated that NRDR is highly expressed in pig ovaries and is specifically located in cumulus granulosa cells. Functional studies showed that NRDR inhibition increased estradiol synthesis. Both pregnant mare serum gonadotropin and human chorionic gonadotropin downregulated the expression of NRDR in pig cumulus granulosa cells. When the relationship between reproductive traits and single‐nucleotide polymorphisms (SNPs) of the NRDR gene was examined, we found that two SNPs affected reproductive traits. SNP rs701332503 was significantly associated with a decrease in the total number of piglets born during multiparity, and rs326982309 was significantly associated with an increase in the average birth weight during primiparity. Thus, NRDR has an important role in steroid hormone biosynthesis in cumulus granulosa cells, and NRDR SNPs are associated with changes in porcine reproduction traits.     

Microtubule-associated protein 8 contains two microtubule binding sites

Microtubule-associated proteins (MAPs) are critical regulators of microtubule dynamics and functions, and have long been proposed to be essential for many cellular events including neuronal morphogenesis and functional maintenance. In this study, we report the characterization of a new microtubule-associated protein, we named MAP8. The protein of MAP8 is mainly restricted to the nervous system postnatally in mouse. Its expression could first be detected as early as at embryonic day 10, levels plateau during late embryonic and neonatal periods, and subsequently decrease moderately to remain constant into adulthood. In addition to its carboxyl terminal binding site, the MAP8 polyprotein also contains a functional microtubule-binding domain at its N-terminal segment. The association of the carboxyl terminal of the light chain with actin microfilaments could also be detected. Our findings define MAP8 as a novel microtubule associated protein containing two microtubule binding domains.