Bread matters: a national initiative to profile the genetic diversity of Australian wheat

The large and complex genome of wheat makes genetic and genomic analysis in this important species both expensive and resource intensive. The application of next-generation sequencing technologies is particularly resource intensive, with at least 17?Gbp of sequence data required to obtain minimal (1×) coverage of the genome. A similar volume of data would represent almost 40× coverage of the rice genome. Progress can be made through the establishment of consortia to produce shared genomic resources. Australian wheat genome researchers, working with Bioplatforms Australia, have collaborated in a national initiative to establish a genetic diversity dataset representing Australian wheat germplasm based on whole genome next-generation sequencing data. Here, we describe the establishment and validation of this resource which can provide a model for broader international initiatives for the analysis of large and complex genomes.     

Dynamic change and derivation process of FC and DFC through G1, S and G2 phases in HeLa cells

In order to get a deeper understanding of the relationship between nucleolus structure and its function, the dynamic change and derivation of FC (fibrillar center) and DFC (dense fibrillar component) through interphase were investigated in HeLa cells synchronized at the ultrastructural level. The results showed that there was a process of FC and DFC derivation in the nucleolus of HeLa cells during interphase. In G1 phase there were a few big FCs in the nucleolus of the HeLa cell. In S phase DFC around the FC got thickened and the configuration of the DFC changed. A lot of tiny FCs were derived from parts of the thickened DFC. We called the FC and DFC formed in G1 phase as primary FC (pri-FC) and primary DFC (pri-DFC) and the FC and DFC derived from the thickened pri-DFC as secondary FC (sec-FC) and secondary DFC (sec-DFC). In G2 phase sec-FC and sec-DFC were gradually separated from pri-DFC and scattered evenly in the nucleolus. Few large pri-FCs coexisted with numerous tiny sec-FCs in the nucleolus of HeLa cells in G2 phase. Based on the results of our observation, we suggest here a model of the dynamic change and the process of derivation of FC and DFC through interphase.     

四川平须舞虻属Platypalpus三新种（双翅目：舞虻科）

平须舞虻属Platypalpus Macquart是舞虻科中最大的属之一,已知550余种分布世界各地.四川以前已知8种.本文记述四川平须舞虻属3新种:短芒平须舞虻Platypalpus breviarista sp.nov.,微距平须舞虻Platypalpus minor sp.nov.和亚丁平须舞虻Platypalpus yadinganus sp.nov,均属于长角平须舞虻种团Platypalpus longicornis species group,并编制了四川平须舞虻属分种检索表.     

Concentration‐ and flux‐based dose–responses of isoprene emission from poplar leaves and plants exposed to an ozone concentration gradient

Concentration‐ and flux‐based O₃ dose–responses of isoprene emission from single leaves and whole plants were developed. Two poplar clones differing in O₃ sensitivity were exposed to five O₃ levels in open‐top chambers for 97 d: charcoal‐filtered ambient air (CF), non‐filtered ambient air (NF) and NF plus 20 ppb (NF + 20), 40 ppb (NF + 40) and 60 ppb (NF + 60). At both leaf and plant level, isoprene emission was significantly decreased by NF + 40 and NF + 60 for both clones. Although intra‐specific variability was found when the emissions were up‐scaled to the whole plant, both leaf‐ and plant‐level emissions decreased linearly with increasing concentration‐based (AOT40, cumulative exposure to hourly O₃ concentrations >40 ppb) and flux‐based indices (POD_Y, cumulative stomatal uptake of O₃ > Y nmol O₃ m^?2 PLA s^?1). AOT40‐ and POD₇‐based dose–responses performed equally well. The two clones responded differently to AOT40 and similarly to POD_Y (with a slightly higher R² for POD₇) when the emission was expressed as change relative to clean air. We thus recommend POD₇ as a large‐scale risk assessment metric to estimate isoprene emission responses to O₃ in poplar.     

CaM BP－10对NAD激酶的抑制效应

ＮＡＤ激酶在光合作用等植物生理过程中起重要作用。ＮＡＤ激酶的激活依赖于钙离子和钙调素（ＣａｌｍＯｄｕｌｉｎ,ＣａＭ）．从植物中分离得到的一种新的ＣａＭ结合蛋白ＣａＭＢＰ－１０（ＢＰ－１０）明显抑制ＮＡＤ激酶的激活活性,抑制作用可被ＣａＭ所克服．动力学研究表明,抑制效应是ＢＰ－１０与ＣａＭ之间特异性相互作用的结果。实验证实ＢＰ－１０对ＮＡＤ激酶活性起着重要调节作用．     

Host-Parasite Interactions and Purifying Selection in a Microsporidian Parasite of Honey Bees

To clarify the mechanisms of Nosema ceranae parasitism, we deep-sequenced both honey bee host and parasite mRNAs throughout a complete 6-day infection cycle. By time-series analysis, 1122 parasite genes were significantly differently expressed during the reproduction cycle, clustering into 4 expression patterns. We found reactive mitochondrial oxygen species modulator 1 of the host to be significantly down regulated during the entire infection period. Our data support the hypothesis that apoptosis of honey bee cells was suppressed during infection. We further analyzed genome-wide genetic diversity of this parasite by comparing samples collected from the same site in 2007 and 2013. The number of SNP positions per gene and the proportion of non-synonymous substitutions per gene were significantly reduced over this time period, suggesting purifying selection on the parasite genome and supporting the hypothesis that a subset of N. ceranae strains might be dominating infection.     

共表达口蹄疫病毒衣壳前体蛋白P1-2A基因和蛋白酶3C基因牛肾细胞株的筛选及稳定性

[目的]筛选稳定表达口蹄疫病毒衣壳蛋白的牛肾细胞(Madin-Darby bovinekidney,MDBK)株.[方法]采用聚合酶链式反应(Polymerase chain reaction,PCR)方法从重组质粒pMD-P1-2A和pMD-3C中分别扩增口蹄疫病毒衣壳前体蛋白P1-2A基因和蛋白酶3C基因,将两基因依次插入逆转录病毒载体pBABE-puro.重组逆转录病毒载体pBABE-puro/P1-2A-3C和pVSV-G质粒载体用脂质体介导共转染GP2-293包装细胞.产生的重组逆转录病毒感染MDBK细胞后使用嘌呤霉素筛选抗性细胞.利用克隆环套取法得到单克隆细胞.经间接免疫荧光和酶联免疫吸附测定(Enzyme-linkedimmunosorbent assay,ELISA)方法检测MDBK细胞中衣壳蛋白的表达,并在电镜下观察口蹄疫病毒空衣壳.[结果]成功筛选到稳定表达口蹄疫病毒衣壳蛋白的MDBK细胞株,衣壳前体蛋白P1-2A在蛋白酶3C裂解作用下正确组装成空衣壳.[结论]该研究为口蹄疫亚单位疫苗的研制提供了实验材料.     

乌牛早茶园蜡蝉类与其8种天敌空间关系的聚块样方方差分析

为了分析在不同聚块大小条件下,天敌对蜡蝉类Fulgoroidea空间上跟随关系的密切程度、聚集原因和聚集范围,为评价蜡蝉类的天敌优势种和确定样方大小提供科学依据,运用聚块样方方差分析法、灰色关联度法、空间聚集强度指数法、种群聚集均数法和ρ指数法对安徽省合肥市乌牛早茶园不同大小聚块条件下的蜡蝉类及其8种天敌进行分析。蜡蝉类与其8种天敌均方差峰值时聚块样方数的关联度分析结果表明:与蜡蝉类空间上跟随关系密切的前三位天敌依次是茶色新圆蛛Neoscona theisi(0.8010)、草间小黑蛛Erigonidium graminicolum(0.7617)和三突花蟹蛛Misumenops tricuspidatus(0.7613)。在聚块内基本样方数K为1、2、4、8时,随着聚块内基本样方数的增多,聚集分布格局时的扩散系数C不断增大,均匀和随机格局时扩散系数不断减小。聚块内基本样方数K为1、2、4、8时其相互之间的蜡蝉类及其天敌的空间分布聚集程度差异均不显著。蜡蝉类及其天敌的种群聚集均数λ多数情况均大于2,其聚集是该虫本身原因引起的,并且λ的绝对值随着聚块内基本样方数的增加而不断增大。用蜡蝉类不同大小聚块的ρ指数判断个体群聚集时的最小范围是聚块中有4个基本样方,即本文的16 m~2。为该虫抽样时确定样方大小提供了科学依据。聚块样方方差分析法是分析害虫与天敌空间关系的一种简便而又实用的方法。     

Interactions between bovine serum albumin and gemini surfactant alkanediyl-alpha, omega-bis(dimethyldodecyl-ammonium bromide)

Interactions between bovine serum albumin (BSA) and cationic gemini surfactant alkanediyl-alpha,omega-bis(dimethyldodecyl-ammonium bromide) (12-n-12, n=3, 4, 6) in aqueous solution have been investigated by measuring fluorescence, UV-vis transmittance, dynamic lighting scattering, and circular dichroism. Compared to a traditional surfactant dodecyltrimethylammonium bromide (DTAB), 12-n-12 interacts with BSA more strongly. With increasing concentration, 12-n-12 first binds specifically onto BSA leading to the unfolding and aggregation of BSA, and the decrease in alpha-helix content; and then forms micelle-like complexes along the unfolded BSA chains. A gemini surfactant with a longer spacer has a larger effect on BSA unfolding due to a stronger hydrophobic interaction.     

Studies on emerging radiation leukemia virus variants in C57BL/Ka mice.

To analyze the emergence of radiation leukemia virus (RadLV) variants in primary X-ray-induced C57BL/Ka thymoma and to identify the virus responsible for the very high leukemogenic potential of passaged Kaplan strain BL/VL3 preparation, we cloned several primary and passaged ecotropic RadLV infectious genomes. By restriction analysis, we found that BL/VL3 cells harbor three related but different ecotropic RadLVs. Their restriction map differs significantly from those of primary RadLVs. Hybridization analysis also indicated that BL/VL3 and primary RadLVs differ in their p15E and long terminal repeat (LTR) regions. As compared with the LTR sequence of the putative parental endogenous ecotropic provirus, the LTR sequence of primary weakly leukemogenic RadLV has only one change, a C-rich sequence, generating a 6-base-pair direct repeat just in front of the promotor. The LTR of the primary nonleukemogenic RadLV only showed few base changes, mainly clustered in R and U5. The LTR from a moderately leukemogenic passaged BL/VL3 RadLV had conserved the C-rich sequence and acquired a 43-base-pair direct repeat in U3 and several other point mutations, small insertions, and deletions scattered in U3, R, and U5. All cloned primary RadLVs were fibrotropic, and some were weakly leukemogenic. All cloned BL/VL3 RadLVs were thymotropic and nonfibrotropic. The block of their replication was found to be after the synthesis of unintegrated linear and supercoiled viral DNA. Most of the BL/VL3 RadLVs were moderately leukemogenic, and one (V-13) was highly leukemogenic, being as virulent as the Moloney strain. We propose a model for the emergence of the RadLV variants and show that the virus responsible for the high leukemogenic potential of BL/VL3 preparation is a nondefective, ecotropic, lymphotropic, nonfibrotropic, unique retrovirus which most likely arose from a parental primary RadLV similar to those studied here.