云南姬鼠的蛋白多态性及其遗传分化关系

本文采用蛋白电泳技术对来源于云南省若干地区的姬鼠属（Ａｐｏｄｅｍｕｓ）的３种姬鼠──高山姬鼠（Ａ．ｃｈｅｖｒｉｅｒｉ）８只,中华姬鼠（Ａ．ｄｒａｃｏ）３只和大耳姬鼠（Ａ．ｌａｔｒｏｎｕｍ）１只,以及作为外群的同科的绒鼠属的大绒鼠（Ｈａｐａｌｏｍｙｓｄｅｌａｌｏｒｉ）３只进行了分析。共检测遗传座位２７个,发现２１个座位存在多态性。根据蛋白多态的数据对研究对象进行遗传分化关系的探讨,用系统分析软件ＰＨＹＬＩＰ计算它们之间的分化关系,得到了一棵无根系统树。结果表明,作为外群的大绒鼠明显不同于其它３种姬鼠而聚在最外面。８只高山姬鼠个体汇聚成独立的一支,中华姬鼠的３个个体也聚成一支,但大耳姬鼠却聚在中华姬鼠一支中,因此我们认为大耳姬鼠同中华姬鼠的分化时间可能比较晚近。     

Social Motility of African Trypanosomes Is a Property of a Distinct Life-Cycle Stage That Occurs Early in Tsetse Fly Transmission

The protozoan pathogen Trypanosoma brucei is transmitted between mammals by tsetse flies. The first compartment colonised by trypanosomes after a blood meal is the fly midgut lumen. Trypanosomes present in the lumen—designated as early procyclic forms—express the stage-specific surface glycoproteins EP and GPEET procyclin. When the trypanosomes establish a mature infection and colonise the ectoperitrophic space, GPEET is down-regulated, and EP becomes the major surface protein of late procyclic forms. A few years ago, it was discovered that procyclic form trypanosomes exhibit social motility (SoMo) when inoculated on a semi-solid surface. We demonstrate that SoMo is a feature of early procyclic forms, and that late procyclic forms are invariably SoMo-negative. In addition, we show that, apart from GPEET, other markers are differentially expressed in these two life-cycle stages, both in culture and in tsetse flies, indicating that they have different biological properties and should be considered distinct stages of the life cycle. Differentially expressed genes include two closely related adenylate cyclases, both hexokinases and calflagins. These findings link the phenomenon of SoMo in vitro to the parasite forms found during the first 4–7 days of a midgut infection. We postulate that ordered group movement on plates reflects the migration of parasites from the midgut lumen into the ectoperitrophic space within the tsetse fly. Moreover, the process can be uncoupled from colonisation of the salivary glands. Although they are the major surface proteins of procyclic forms, EP and GPEET are not essential for SoMo, nor, as shown previously, are they required for near normal colonisation of the fly midgut.     

ARK2 stabilizes the plus-end of microtubules and promotes microtubule bundling in Arabidopsis

Microtubule dynamics and organization are important for plant cell morphogenesis and development. The microtubule-based motor protein kinesins are mainly responsible for the transport of some organelles and vesicles, although several have also been shown to regulate microtubule organization. The ARMADILLO REPEAT KINESIN (ARK) family is a plant-specific motor protein subfamily that consists of three members (ARK1, ARK2, and ARK3) in Arabidopsis thaliana. ARK2 has been shown to participate in root epidermal cell morphogenesis. However, whether and how ARK2 associates with microtubules needs further elucidation. Here, we demonstrated that ARK2 co-localizes with microtubules and facilitates microtubule bundling in vitro and in vivo. Pharmacological assays and microtubule dynamics analyses indicated that ARK2 stabilizes cortical microtubules. Live-cell imaging revealed that ARK2 moves along cortical microtubules in a processive mode and localizes both at the plus-end and the sidewall of microtubules. ARK2 therefore tracks and stabilizes the growing plus-ends of microtubules, which facilitates the formation of parallel microtubule bundles.     

Exogenous Melatonin Improves the Growth of Rice Seedlings by Regulating Redox Balance and Ion Homeostasis Under Salt Stress

This study evaluated the effects of foliar spraying melatonin (MT) on the growth of salt-stressed rice. Seedlings were treated with 50 and 100 mM of NaCl and different concentrations of MT (25, 50, 100, 200, 300, and 400 μM) for 14 days. Different concentrations of MT could promote plant growth significantly under salt stress, particularly at concentrations of 200, 300, and 400 μM. A concentration of 200 μM MT was considered as optimal and used in a subsequent experiment on biomass, water content, antioxidation, mineral nutrition, salt absorption, and distribution of salt-stressed rice seedlings. Results showed that MT’s promoting effect on plant growth under salt stress was evident with time, particularly under high salt stress. MT improved the activities of antioxidant enzymes, reduced membrane lipid peroxidation, alleviated cell injury in plant leaves, and increased N content and Si accumulation in the leaves and roots under salt stress, particularly under high salinity. This compound also inhibited Na uptake and upward transport, but it promoted or maintained the uptake and upward transport of K and Ca in salt-stressed rice. Thus, MT improved the ion homeostasis of K/Na and Ca/Na in plants, particularly in the leaves. Foliar spraying of MT alleviated salt stress on rice by promoting nutrient accumulation or translocation, improving ion homeostasis, which is evident in the leaves, and consequently enhancing its salt resistance. The antioxidative improvement caused by MT might also be related to the improved ion homeostasis.

     

基于功能性状的水杉原生母树种群生境适应策略

植物的功能性状变异和表型可塑性是其应对异质生境的主要机制, 对植物的生长和分布有重要贡献。本文以湖北星斗山国家级自然保护区的水杉(Metasequoia glyptostroboides)原生母树为研究对象, 分析了母树种群功能性状对树木形态、地形因子及人为干扰的响应机制。结果表明: 水杉原生母树叶面积、叶干重和比叶面积的变异幅度大, 可塑性较强, 而枝和叶的干物质含量稳定性最高。人为干扰和4个地形因子均对每个功能性状变异方差有5%-20%的解释度, 冠幅对枝、叶干物质含量的变异方差有高达38%和76%的解释度。5个功能性状主要受海拔、坡位和人为干扰影响, 其中, 比叶面积对环境因子和干扰的响应规律不明显, 叶面积和叶干重在强烈人为干扰的环境中普遍增大, 枝和叶的干物质含量对坡向的变化最敏感。总之, 水杉原生母树种群通过功能性状变异对环境能产生一定的可塑性响应, 但人为干扰对母树生长影响较大, 建议人工辅助更新, 并适度减少农业和建筑对现存母树的影响。     

爬沙虫提取液对果蝇繁殖力及寿命的影响

本实验通过研究爬沙虫提取液对果蝇繁殖力及寿命的影响,证实爬沙虫提取液具有增强果蝇的繁殖力和提高雌性果蝇寿命的作用。采用乙醚麻醉法,收集8 h内羽化的成虫,选择个体大小相近的雌雄果蝇,在不同爬沙虫浓度的培养基中培养,统计各组第一子代(first filial generation,F1)果蝇成体的数目及果蝇体重。收集各培养基中果蝇,区分雌雄,在原浓度爬沙虫培养基中培养,每日观察果蝇死亡数,直至全部死亡。结果表明:与对照组比较,各爬沙虫处理组子代果蝇雄体数目均显著增加(P<0.05),2.500%组的子代果蝇雌体数目差异显著(P<0.05)。各爬沙虫处理组刚羽化的果蝇体重极显著高于对照组(P<0.01)。2.500%剂量组果蝇雌体平均寿命极显著增加(P<0.01)。本研究为更好地利用爬沙虫的药用价值提供了参考依据。     

Enhanced resistance to stripe rust disease in transgenic wheat expressing the rice chitinase gene RC24

Stripe rust is a devastating fungal disease of wheat worldwide which is primarily caused by Puccinia striiformis f. sp tritici. Transgenic wheat (Triticum aestivum L.) expressing rice class chitinase gene RC24 were developed by particle bombardment of immature embryos and tested for resistance to Puccinia striiformis f.sp tritici. under greenhouse and field conditions. Putative transformants were selected on kanamycin-containing media. Polymease chain reaction indicated that RC24 was transferred into 17 transformants obtained from bombardment of 1,684 immature embryos. Integration of RC24 was confirmed by Southern blot with a RC24-labeled probe and expression of RC24 was verified by RT-PCR. Nine transgenic T₁ lines exhibited enhanced resistance to stripe rust infection with lines XN8 and BF4 showing the highest level of resistance. Southern blot hybridization confirmed the stable inheritance of RC24 in transgenic T₁ plants. Resistance to stripe rust in transgenic T₂ and T₃ XN8 and BF4 plants was confirmed over two consecutive years in the field. Increased yield (27–36 %) was recorded for transgenic T₂ and T₃ XN8 and BF4 plants compared to controls. These results suggest that rice class I chitinase RC24 can be used to engineer stripe rust resistance in wheat.     

Relationship between leptin receptor and polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders, which is involved in the multi-system disease, and its etiology is still not clearly understood. It is currently considered that not only the genetic factors but also the environment factors play a crucial role in the pathogenesis of PCOS. Obesity plays an important role through the insulin, leptin and endocannabinoid system in the pathological process of PCOS, leading to more severe clinical manifestations. The aim of our present study is to investigate whether there is association between single nucleotide polymorphisms (SNPs) of Gln223Arg and Pro1019Pro in the leptin receptor gene (LEPR) and PCOS in a Korean population. Interestingly, a significant association was found between the Pro1019Pro in LEPR gene and PCOS, and a highly significant association was found between the Gln223Arg in LEPR gene and PCOS (P = 0.033, OR = 1.523, 95% confidence interval and P < 0.0001, OR = 0.446, 95% confidence interval). Moreover, genotype combination and haplotype analyses indicate that Gln223Arg and Pro1019Pro polymorphisms of LEPR are significantly associated with the risk of PCOS.     

甜菜碱醛脱氢酶在菠菜叶细胞中的定位

将菠菜叶片匀浆后．用差速离心和梯度率心分离叶绿体、过氧物酶体、微粒体等细胞器和１０００００×ｇ上清法部分。用酶活测定法测定各部分甜菜碱醛脱氢酶（ＢＡＤＨ）的活性;用免疫扩散法鉴定各组分的ＢＡＤＨ。除叶绿体外,过氧物酶体、微粒体．以及１０００００×ｇ上清液中也存在ＢＡＤＨ。