Response to selection for grain yield and correlated response for grain size and earliness in cowpea based on early generation testing

Large grain size and earliness to flowering are traits critical to cowpea adoption in the West African savannahs. This study reports on the correlated response to selection in these two traits in the two populations in which selections were made primarily for grain yield potential. Further, the present study reports on the effectiveness of early generation selection for grain yield. Each of the two populations, SARC 2 and SARC 3, was derived from a cross between an adapted parent Marfo-Tuya and an exotic breeding line that has large grain size and early flowering. Replicated yield evaluation of F₅ families showed that grain yield of Marfo-Tuya was not different from those of the highest yielding families in each population. Increases in grain size of individual families over Marfo-Tuya were large and, the response to selection averaged 5.3 and 3.9 g/100 seeds in the SARC 2 and SARC 3 populations, respectively. Response to selection in days to flowering averaged 3 days in SARC 3, whereas response to selection was not observed in SARC 2. Retrospective selection in the F₃ at 40% intensity was efficient in identifying a high proportion of elite families in each population.     

Brief communication: evidence bearing on the status of Homo habilis at Olduvai Gorge

Students of the early hominin career have debated the status of Homo habilis since its discovery in 1960. Today discussion centers on which specimens should be included in the species and what constitutes the holotype. Recent reviews of early Homo suggest that the Olduvai Hominid 8 foot may sample Paranthropus while the OH 7 skull bones, mandible, and hand sample H. habilis. Moreover, some suggest that while H. habilis in Middle Bed I at Olduvai is craniodentally Homo-like, the postcranial skeleton of H. habilis is more like that of Australopithecus. Evidence presented here indicates not only that OH 7 and OH 8 represent H. habilis but also that they come from a single individual. The association of OH 35 with OH 7 and OH 8 is less certain. Morphological, pathological, and taphonomic evidence favors the inclusion of OH 35 in the holotype. However, stratigraphic evidence suggests that OH 35 and OH 8 are not coterminous. With or without OH 35, the holotype of H. habilis ranks as one of the most complete early hominin skeletons and the most complete and functionally informative specimen of early Homo.     

Hypertonia-associated protein Trak1 is a novel regulator of endosome-to-lysosome trafficking

Hypertonia, which is characterized by stiff gait, abnormal posture, jerky movements, and tremor, is associated with a number of neurological disorders, including cerebral palsy, dystonia, Parkinson's disease, stroke, and spinal cord injury. Recently, a spontaneous mutation in the gene encoding trafficking protein, kinesin-binding 1 (Trak1), was identified as the genetic defect that causes hypertonia in mice. The subcellular localization and biological function of Trak1 remain unclear. Here we report that Trak1 interacts with hepatocyte-growth-factor-regulated tyrosine kinase substrate (Hrs), an essential component of the endosomal sorting and trafficking machinery. Double-label immunofluorescence confocal studies show that the endogenous Trak1 protein partially colocalizes with Hrs on early endosomes. Like Hrs, both overexpression and small-interfering-RNA-mediated knockdown of Trak1 inhibit degradation of internalized epidermal growth factor receptors through a block in endosome-to-lysosome trafficking. Our findings support a role for Trak1 in the regulation of Hrs-mediated endosomal sorting and have important implications for understanding hypertonia associated with neurological disorders.     

肾综合征出血热早期诊断方法的比较

应用免疫-PCR方法和ELISA法对比检测96份肾综合征出血热(HFRS)患者血清标本中特异性IgM抗体,结果免疫-PCR方法的阳性检出率高于ELISA法,表明免疫-PCR方法是一种可用于HFRS早期诊断的高敏感性的血清学检测方法。     

新疆核桃早实特性及RAPD分析

用RAPD技术进行新疆核桃早实特性的分子标记研究,用180个10-mer随机引物分别扩增早实和晚实近等基因池DNA,筛选出5个多态性引物,结果只有引物OPG15（5’-ACT GGG ACT C-3’）在早实近等基因池及其个体中能重复扩增出一条约710bp的特异片段OPG15 710,而晚实近等基因池及其个体中无此特异片段,将OPG15 710克隆于pUCm-T载体,筛选阳性克隆用限制性内切酶Pst1消化,表明克隆片段大小正确。实步分析认为,OPG15 710可能是与核桃早实特性相关的分子标记,该标记仍在研究之中,该研究将为进一步克隆早实基因,实现早实优质,探索早实机制奠定基础。     

水稻RIL群体芽期耐冷性基因的分子标记定位

水稻芽期冷害是我国长江中下游的早稻种植区和东北、西北稻区及云贵高原的一季稻区水稻生产中的重要限制因子之一。研究中利用纸卷法测定1个水稻重组自交系群体对10℃低温的芽期耐冷性,结合1张高密度分子遗传图谱,进行QTL定位分析。检测到控制水稻芽期耐冷性的4个QTL,分别位于1、3、7和11号染色体上。其中,位于11号染色体上的QTL qSCT-11的效应最大,在10℃低温处理13d时,对性状的贡献率达26％～30％,被检测到的LOD值也高达16～19,其加性效应值为正,增效等位基因存在于亲本Lemont中,RM202为与QTL qSCT-11紧密连锁的SSR标记。该主效QTL的增效基因,可作为分子标记辅助选择的操作对象用于水稻芽期耐冷性的遗传改良。     

赤红壤早稻田甲烷排放通量及其影响因素

用封闭箱法对广东省赤红壤早稻田CH4排放通量进行了观测。结果表明,CH4排放有明显的季节变化规律,3个排放高峰分别出现在水稻分蘖末期、孕穗抽穗期和乳熟期,平均通量为5.7mg.m-2.h-1。在测定期内,CH4排放与5和10cm土壤温度呈显著正相关,与土壤Eh呈显著负相关,与土壤pH值、水层深浅相关不明显。     

皖南震旦纪-早寒武世沉积岩有机碳、氮元素记录

安徽南部晚震旦世蓝田组、皮园村组和早寒武世荷塘组主要由黑色页岩和硅质岩组成。分析结果表明,蓝田组和荷塘组的总有机碳(可达10％--18％)和总有机氮(可达2．0‰--2．6‰)的高含量,应归于富有机质埋藏所致,反映新元古代末次冰期后和早寒武世海洋浮游生物处于大发展时期。由于海洋植物的光合作用产生大量O2,并消耗大量CO2,导致大气中O2／CO2比率明显增加,为震旦纪晚期多细胞真核生物的辐射、后生动物的出现和‘寒武纪生物大爆发’提供了条件。蓝田组黑色页岩中部的有机碳与有机氮含量大体呈现正比例增加,并且分别达到17．74％和2．66‰的最高值,与该剖面发现的蓝田植物群相对应;荷塘组黑色页岩的有机碳和有机氮垂直分布曲线之间呈现相互背离,即有机氮含量与时增加,而有机碳含量与时减少,与扬子地台相应的地层层位产生的澄江动物群相对应,表明TON和TOC分布特征有可能与早期生物演化历程相关。     

Spatial Models of Prebiotic Evolution: Soup Before Pizza?

The problem of information integration andresistance to the invasion of parasitic mutants in prebiotic replicator systemsis a notorious issue of research on the origin of life.Almost all theoretical studies published so far havedemonstrated that some kind of spatial structure is indispensable forthe persistence and/or the parasite resistance of any feasible replicator system.Based on a detailed critical survey of spatial models on prebiotic informationintegration, we suggest a possible scenario for replicator system evolution leadingto the emergence of the first protocells capable of independent life.We show that even the spatial versions of the hypercycle model are vulnerable toselfish parasites in heterogeneous habitats. Contrary, the metabolic system remainspersistent and coexistent with its parasites both on heterogeneous surfaces andin chaotically mixing flowing media. Persistent metabolic parasites can beconverted to metabolic cooperators, or they can gradually obtain replicase activity.Our simulations show that, once replicase activity emerged, a gradual and simultaneousevolutionary improvement of replicase functionality (speed and fidelity) andtemplate efficiency is possible only on a surface that constrains the mobility ofmacromolecule replicators. Based on the results of the models reviewed, we suggestthat open chaotic flows (`soup') and surface dynamics (`pizza') both played keyroles in the sequence of evolutionary events ultimately concluding in theappearance of the first living cell on Earth.     

HSV-1感染细胞中HTRP基因的克隆及表达纯化

在对单纯疱疹病毒1型（HSV－1）感染KMB－17细胞后的早期基因反应的研究中,从HSV－1感染后细胞特异性cDNA文库中筛选出一个1381bp基因一HTRP,基因测序分析表明为与HSV－1感染相关基因（GenBank登录号：AF450482）,含有完整的ORF框架,cds全长924bp,编码308个氨基酸。构建了pGEX-HTRP表达质粒,在大肠杆菌B21加获得了较高的表达,采用Glutathione Sepharose4B进行亲和纯化后获得较高纯度的HTRP蛋白。用该蛋白免疫小鼠后制备的特异抗血清,在蛋白印迹实验中表现出抗体的特异性。