Growth period QTL-allele constitution of global soybeans and its differential evolution changes in geographic adaptation versus maturity group extension

Soybean (Glycine max (L.) Merr.) has been disseminated globally as a photoperiod/temperature-sensitive crop with extremely diverse days to flowering (DTF) and days to maturity (DTM) values. A population with 371 global varieties covering 13 geographic regions and 13 maturity groups (MGs) was analyzed for its DTF and DTM QTL-allele constitution using restricted two-stage multi-locus genome-wide association study (RTM-GWAS). Genotypes with 20 701 genome-wide SNPLDBs (single-nucleotide polymorphism linkage disequilibrium blocks) containing 55 404 haplotypes were observed, and 52 DTF QTLs and 59 DTM QTLs (including 29 and 21 new ones) with 241 and 246 alleles (two to 13 per locus) were detected, explaining 84.8% and 74.4% of the phenotypic variance, respectively. The QTL-allele matrix characterized with all QTL-allele information of each variety in the global population was established and subsequently separated into geographic and MG set submatrices. Direct comparisons among them revealed that the genetic adaptation from the origin to geographic subpopulations was characterized by new allele/new locus emergence (mutation) but little allele exclusion (selection), while that from the primary MG set to emerged early and late MG sets was characterized by allele exclusion without allele emergence. The evolutionary changes involved mainly 72 DTF and 71 DTM alleles on 28 respective loci, 10–12 loci each with three to six alleles being most active. Further recombination potential for faster maturation (12–21 days) or slower maturation (14–56 days) supported allele convergence (recombination) as a constant genetic factor in addition to migration (inheritance). From the QTLs, 44 DTF and 36 DTM candidate genes were annotated and grouped respectively into nine biological processes, indicating multi-functional DTF/DTM genes are involved in a complex gene network. In summary, we identified QTL-alleles relatively thoroughly using RTM-GWAS for direct matrix comparisons and subsequent analysis.     

2′-MeO-RNA Containing Oligodeoxyribonucleotide Primers Can Prevent Template-independent Base Extension on Microarrays

DNA microarrays require tens of thousands of deoxyoligonucleotides to be registered in an addressable fashion through immobilization, so that they have the high-throughput capability of analyzing a large number of samples simultaneously in a minimal volume of each reagent. However, using immobilized DNA molecules on microarrays can impose certain technical problems for some assays. For example, high background noise has been observed in using immobilized oligonucleotide microarrays (DNA chip) for primer extension reactions. This noise may be associated with the reactions of secondary structures formed by the adjacent primers physically constrained on the surface. Single-base extension (SBE) of arrayed primers on a chip has been extensively used in mini-sequencing to examine single nucleotide polymorphisms (SNP). Some primers appeared to be extendable in the absence of any template and thus competed against the base extension directed by the assay target such as genomic DNA. In this article, a method is reported that is capable of reducing template-independent extension by the substitution of a 2′-methoxyribonucleotide in the otherwise oligodeoxyribonucleotide primer. The surrogate compound placed at the 5′-end of the putative secondary structure sequence of a given primer was able to inhibit template-independent extension and to improve data quality of surface-attached primer extension assays.     

Dictyosome vesicle production and plasma membrane turnover in auxin-stimulated outer epidermal cells of coleoptile segments fromAvena sativa (L.)

Summary Dark grown coleoptile segments were floated on solutions of IAA alone and of IAA and the secretion inhibitors cytochalasin and monensin. The secretion inhibitors prevented normal elongation of the tissue segments, the monensin inhibition being virtually complete while cytochalasin gave a 40% reduction over the first six hours with little further further elongation in the following 18 hours. Vesicle production was assessed in outer epidermal cells after 6 hours of IAA-stimulated elongation using the vesicle accumulation method following a cytochalasin-block of vesicle transport. The results were compared with the area of plasma membrane required to enable cell elongation to proceed at the observed rate. The area of vesicle membrane delivered to the cell surface exceeded this requirement to such an extent that at least 65% of the delivered membrane must be recycled back into the cytoplasm. Expressed in terms of the whole cell, the plasma membrane turnover rate was found to be once every 200 minutes. It is concluded that limitation of elongation by secretion inhibitors is more likely to reflect a requirement for the vesicle contents than the vesicle membrane. These results are compared with those obtained from other secretory systems using a similar approach.Abbreviations IAA indole acetic acid - DMSO dimethyl sulphoxide - D dictyosome - ER endoplasmic reticulum - V vesicle     

Fine structure of a murine mammary carcinoma cell line

Summary A fine structural study was made of cells from the epithelioid MCF-8/5-2A cell line derived from a MuMTV-free, D2 transplantable hyperplastic outgrowth. Electron microscopy shows the cells to be truly epithelial with many cell-to-cell junctions and microvilli. The cells are similar in many respects to normal mouse mammary gland and some of the conventional mammary tumor derived cell lines. This study supports previous observations of the absence of MuMTV in MCF-8 within the limits of morphological detection, and demonstrates the presence of numerous virus particles within, or budding into, cisternae of the endoplasmic reticulum and nuclear envelope. These intracisternal A particles have not been previously described in such abundance in mammary tumor tissue culture cells. This study was supported by Contract NIH-NCI-E-71-2421, with the NIH and by an institutional grant to the Michigan Cancer Foundation from the United Foundation of Detroit, Michigan.     

植物抗旱性中的补偿效应及其在农业节水中的应用

在论述植物补偿效应存在类型和研究范畴的基础上,详细评述了植物抗旱性中根系形态结构功能及地上部干物质积累、产量和水分利用效率方面的补偿效应及其影响因素,并对植物抗旱作用中补偿生长的可能生理学机制作了探讨。同时,对补偿效应在提高农业水分利用效率中的应用进行了讨论     

人类新型β 3半乳糖基转移酶基因β 3GalT7 的克隆和鉴定

从人肺 cDNA 文库中克隆到人类β 3- 半乳糖基转移酶家族中的一个新成员β 3GalT7 (AY277592 , EC2.4.1.-) ,并对其进行了鉴定 . 该基因定位在人类染色体 19q13.2. 它包含一个 1 191 bp 的开放阅读框 (ORF). 编码的蛋白质包括一个信号肽和一个半乳糖基转移酶结构域,分子质量和等电点分别为 43.3 ku 和 8.37. 从原核表达中获得的融合蛋白的分子质量和预测相符 . RNA 印迹杂交显示β 3GalT7 在肺、喉和回肠组织中高表达,而在舌、乳房、子宫、睾丸等组织中表达较低 . 此外半定量 RT-PCR 显示β 3GalT7 在人类不同的肿瘤细胞中转录水平有明显差异 .     

人骨保护素N端片段在大肠杆菌中的表达及其活性分析

骨保护素 (OPG)成熟肽N端D1～D4结构域仅由 2个外显子编码 .以人基因组DNA作为模板 ,采用重叠延伸PCR得到N端D1～D4域编码序列 ,并在其上游引入 2×His密码子序列 ,然后克隆入载体pQE 30进行表达 ,SDS PAGE表明 8×His融合蛋白主要以包涵体形式存在 ,可被抗OPG抗体识别 .变性条件下通过Ni NTA金属螯合亲和层析对表达产物进行纯化后再经梯度透析进行复性 ,采用破骨细胞样细胞 (osteoclast likecell ,OLC)诱导分化实验来检测重组蛋白的生物活性 ,证实单核 巨噬细胞集落刺激因子 (M CSF)和破骨细胞分化因子 (ODF)可协同促进多核OLC的生成 ,但加入重组OPG片段后 ,OLC生成显著减少 .     

Behavioural responses of juvenile cuttlefish (Sepia officinalis) to local water movements

Physiological studies have shown that the epidermal head and arm lines in cephalopods are a mechanoreceptive system that is similar to the fish and amphibian lateral lines (Budelmann BU, Bleckmann H. 1988. A lateral line analogue in cephalopods: Water waves generate microphonic potentials in the epidermal head lines of Sepia officinalis and Lolliguncula brevis. J. Comp. Physiol. A 164:1-5.); however, the biological significance of the epidermal lines remains unclear. To test whether cuttlefish show behavioural responses to local water movements, juvenile Sepia officinalis were exposed to local sinusoidal water movements of different frequencies (0.01-1000 Hz) produced by a vibrating sphere. Five behavioural responses were recorded: body pattern changing, moving, burrowing, orienting, and swimming. Cuttlefish responded to a wide range of frequencies (20-600 Hz), but not to all of the frequencies tested within that range. No habituation to repeated stimuli was seen. Results indicate that cuttlefish can detect local water movements (most likely with the epidermal head and arm lines) and are able to integrate that information into behavioural responses.     

Refinement of a cell line based artificial diet for rearing the parasitoid wasp, Trichogramma pretiosum

An artificial diet incorporating insect cells originally developed for Trichogramma australicum Girault (Hymenoptera: Trichogrammatidae) was successfully used to rear Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae). To refine the diet, individual components were removed. Chicken egg yolk and the insect cells were identified as the most important components for T. pretiosum development. Their removal resulted in few pupae and no adults. Removal of Grace’s insect medium, a common component of artificial diets, was found to markedly improve the development of T. pretiosum, producing 60% larva to pupa transition and 19% pupa to adult transition. There was no significant difference in T. pretiosum development on diets in which milk powder, malt powder or infant formula were interchanged, despite differences in nutrient composition. The use of yeast extract resulted in significantly higher survival to the adult stage when compared with yeast hydrolysate enzymatic and a combination of yeast extract and yeast hydrolysate enzymatic. Comparison of four antimicrobial agents showed the antibacterial agent Gentamycin and the antifungal agent Nystatin had the least detrimental effect on T. pretiosum development. The use of insect cell line diets has the potential to simplify artificial diet production and significantly reduce T. pretiosum production costs in Australia compared to diets using insect hemolymph or the use of natural or factitious hosts.     

药用植物细胞生物反应器技术的研究进展

利用植物细胞生物反应器技术生产植物有用代谢产物,近些年来取得了很大发展,但植物细胞悬浮培养的工业化应用仍受到来自生物及工程技术上的限制。针对植物细胞生物反应器技术的特点及其研究进展,提出在综合考虑生物学和工艺学两方面的基础上,选育药用植物稳定高产的优良细胞系是提高植物细胞生物反应器技术可行性的关键。