高原鼢鼠土丘对矮嵩草草甸植被演替及土壤营养元素的作用

本文研究了矮蒿草草甸上高原酚鼠土丘的出现率及其对植被的覆盖状况,土丘高度的下降及其直径的变化,土丘植物地上生物量和土丘营养元素含量。高原鼢鼠土丘出现率为242个/只/年,合土壤干重为1023.82公斤/只/年,对植被的覆盖面积高达22.53平方米/只/年。土丘在地表滞留时间约1年,处于不同演替阶段植被区域内出现的土丘,其植物地上生物量间的差异显著。5月前,在原生植被区出现的土丘,经4个月后,土丘边缘形成环状富草区,士丘边缘至中心区形成环状贫草区,而土丘中心仍处于无草状况。在次生植被区上的土丘则无此现象。新土丘除速效钾的含量与对照区无显著差异外,速效氮、磷的含量显著地高于对照区。旧土丘土壤中的速效氮、磷、钾含量均低于新土丘,但氮、磷的含量仍高于对照区。     

高寒草甸地区小哺乳动物群落多样性的初步研究

高寒苹甸地区的人工草场、半人工草场、次生杂类草草场和撩荒地中共有4个小哺乳类群落;根田鼠+高原鼢鼠群落;根田鼠+甘肃鼠兔群落;高原鼠兔+高原鼢鼠群落;长尾仓鼠+高原鼠兔群落。小哺乳类群落种的多样性与植物群落种的多样性无显著相关关系,而与植被的高度、盖度呈显著负相关关系。高原鼢鼠是各生境中的广布种。根田鼠与甘肃鼠兔在植被郁闭度高的环境中为群落的主要组成者;植被郁闭度低的环境中,高原鼠兔和长尾仓鼠是群落的主要成员。它们的空间格局主要反映空间环境条件的差异。     

Phenotypic and genetic dissection of cadmium accumulation in roots,nodes and grains of rice hybrids

Plant and Soil - Rice accumulates higher levels of cadmium (Cd) in grain than other cereals, and hybrid rice varieties cover around half of the total rice area in China. Therefore, understanding...     

Gentiopicroside promotes the osteogenesis of bone mesenchymal stem cells by modulation of β-catenin-BMP2 signalling pathway

Osteoporosis is characterized by increased bone fragility, and the drugs used at present to treat osteoporosis can cause adverse reactions. Gentiopicroside (GEN), a class of natural compounds with numerous biological activities such as anti-resorptive properties and protective effects against bone loss. Therefore, the aim of this work was to explore the effect of GEN on bone mesenchymal stem cells (BMSCs) osteogenesis for a potential osteoporosis therapy. In vitro, BMSCs were exposed to GEN at different doses for 2 weeks, whereas in vivo, ovariectomized osteoporosis was established in mice and the therapeutic effect of GEN was evaluated for 3 months. Our results in vitro showed that GEN promoted the activity of alkaline phosphatase, increased the calcified nodules in BMSCs and up-regulated the osteogenic factors (Runx2, OSX, OCN, OPN and BMP2). In vivo, GEN promoted the expression of Runx2, OCN and BMP2, increased the level of osteogenic parameters, and accelerated the osteogenesis of BMSCs by activating the BMP pathway and Wnt/β-catenin pathway, effect that was inhibited using the BMP inhibitor Noggin and Wnt/β-catenin inhibitor DKK1. Silencing the β-catenin gene and BMP2 gene blocked the osteogenic differentiation induced by GEN in BMSCs. This block was also observed when only β-catenin was silenced, although the knockout of BMP2 did not affect β-catenin expression induced by GEN. Therefore, GEN promotes BMSC osteogenesis by regulating β-catenin-BMP signalling, providing a novel strategy in the treatment of osteoporosis.     

Structural analysis of glycosaminoglycans from Colla corii asini by liquid chromatography-electrospray ion trap mass spectrometry

Glycoconjugate Journal - Colla corii asini (CCA) made from donkey-hide has been widely used as a traditional animal-based Chinese medicine. Chondroitin sulfate (CS), dermatan sulfate (DS) and...     

围栏条件下母体密度应激对根田鼠 F1代性器官指数的影响

为探讨自然条件下母体密度应激对根田鼠F1代性器官指数的影响,通过在围栏内建立不同密度的母体种群获得相应的F1代个体,以此建立了不同密度的子代种群,并测定了母体种群建群者的血浆皮质酮含量,将建立子代种群后剩余的F1代个体带回实验室饲养.实验结束后,测定了全部F1代个体的性器官指数及皮质酮含量.结果表明,高密度母体种群建群者的皮质酮含量显著高于低密度母体种群建群者;出生于高密度母体种群的F1代个体处于高密度子代种群,其性器官指数显著低于出生于低密度母体种群且处于低密度子代种群的F1代个体,而皮质酮含量显著高于后者;出生于高密度母体种群的F1代个体处于低密度子代种群,其性器官指数及皮质酮含量与出生于低密度母体种群且处于低密度子代种群的F1代个体间无显著差异.此外,实验室饲养条件下,出生于高密度和低密度母体种群的F1代个体间的睾丸指数无显著差异.本研究结果说明,在根田鼠种群中,单一的母体密度应激对子代的性器官指数无影响,但生前应激子代在性成熟后,当再次遭遇密度应激时,其性器官指数显著降低,母体密度应激和当前环境对种群的未来繁殖能力具有耦合效应.     

Ancient antimicrobial peptides kill antibiotic-resistant pathogens: Australian mammals provide new options

Background

To overcome the increasing resistance of pathogens to existing antibiotics the 10×^''20 Initiative declared the urgent need for a global commitment to develop 10 new antimicrobial drugs by the year 2020. Naturally occurring animal antibiotics are an obvious place to start. The recently sequenced genomes of mammals that are divergent from human and mouse, including the tammar wallaby and the platypus, provide an opportunity to discover novel antimicrobials. Marsupials and monotremes are ideal potential sources of new antimicrobials because they give birth to underdeveloped immunologically naïve young that develop outside the sterile confines of a uterus in harsh pathogen-laden environments. While their adaptive immune system develops innate immune factors produced either by the mother or by the young must play a key role in protecting the immune-compromised young. In this study we focus on the cathelicidins, a key family of antimicrobial peptide genes.

Principal Finding

We identified 14 cathelicidin genes in the tammar wallaby genome and 8 in the platypus genome. The tammar genes were expressed in the mammary gland during early lactation before the adaptive immune system of the young develops, as well as in the skin of the pouch young. Both platypus and tammar peptides were effective in killing a broad range of bacterial pathogens. One potent peptide, expressed in the early stages of tammar lactation, effectively killed multidrug-resistant clinical isolates of Pseudomonas aeruginosa, Klebsiella pneumoniae and Acinetobacter baumannii.

Conclusions and Significance

Marsupial and monotreme young are protected by antimicrobial peptides that are potent, broad spectrum and salt resistant. The genomes of our distant relatives may hold the key for the development of novel drugs to combat multidrug-resistant pathogens.     

Chronic hypoxia exposure during pregnancy is associated with a decreased active nursing activity in mother and an abnormal birth weight and postnatal growth in offspring of rats

Stress during pregnancy is known to have a significant impact on animal's behavior and offspring development. The effects of gestational hypoxia on maternal behavior have not been studied. In the present study, we investigated the effects of gestational hypoxia exposure on dam's maternal behavior, offspring's growth and plasma corticosterone levels after parturition in rats. Altitude hypoxia (3 and 5 km) was simulated in the hypobaric chambers during the last week of pregnancy and the effects were compared to those found in controls exposed at sea level. We found that gestational hypoxia significantly decreased dam's arched-back nursing activity across the lactation period. The effect was more profound in 5 km group. Gestational hypoxia also altered other maternal behaviors such as blanket and passive nursing. Hypoxia exposure was associated with abnormal birth weight and postnatal growth in pups, with a significantly higher and lower birth weight than control found in 3 and 5 km groups, respectively, and accelerated growth in both stressed groups. Gestational hypoxia exposure significantly elevated plasma corticosterone levels in dams at the time of weaning and in pups across the measurement days. Taken together, the present results indicate that hypoxia, particularly severe hypoxia during the late phase of pregnancy has a significantly adverse impact on animal's behavior, endocrine function and offspring development. The higher birth weight found in the offspring of 3 km group suggests a compensatory system counteracting with the inhibitory effects of hypoxia on fetus growth at this altitude.     

根田鼠母体捕食应激对其雌性子代雄性化效应的研究

本研究了根田鼠母体捕食应激对其雌性子代雄性化的效应。母体捕食应激使雌性子代在鼻端探究、生殖区探究、试图探究和爬跨及尾随等性行为中花费的时间最多,阴道开口时间显延迟,生殖器与肛门间距离显增大,而母体食物限制和断乳应激子代则未明显呈现上述特征。母体捕食应激使其雌性子代显地降低对雄性个体的性吸引力。因此,母体捕食应激使雌性子代在性行为、形态特征及性吸引力方面呈现雄性化效应,主要归结于捕食应激引起母体内分泌的改变所致;此效应仅产生于胚胎性分化的特定关键时期。全结果检验了田鼠类母体捕食应激对其雌性子代性分化有显影响的假设。     

捕食风险与动物行为及其决策的关系

捕食风险与动物行为及其决策的关系边疆晖樊乃昌（中国科学院西北高原生物研究所,西宁８１０００１）（浙江师范大学,金华３１００００）ＴｈｅＥｆｅｃｔｏｆＰｒｅｄａｔｉｏｎＲｉｓｋｏｎＡｎｉｍａｌｓ’ＢｅｈａｖｉｏｒａｎｄＴｈｅｉｒＤｅｃｉｓｉｏｎ．Ｂｉａ...