云南叉Chi科五新种：Chi目：Chi亚目

本文描述云南省叉Ｃｈｉ科五新种：其中劳Ｃｈｉ属ＬｏｂｏｃａｅｃｉｌｉｕｓＬｅｅｅｔＴｈｏｒｎｔｏｎ１种;四裂劳ＣｈｉＬ．ｑｕａｄｒｉｐａｒｔｉｔｕｓｓｐ．ｎｏｖ．蛇Ｃｈｉ属ＯｐｈｉｄｏｄｐｅｏｎａＥｎｄｅｒｌｅｉｎ１种;波纹蛇ＣｈｉＯ．ｆｕｃｔｏｓａｓｐ．ｎｏｖ．,异Ｃｈｉ属ＨｅｔｅｒｏｃａｅｃｉｌｉｕｓＬｅｅａｎｄＴｈｏｒｎｔｏｎ３种;八斑异ＣｈｉＨ．ｏｃｔｏｍａｃｕｌａｔｕｓｓｐ．ｎｏｖ．,景     

云南省虱Chi科三新种（虫Chi目：粉虫Chi亚目）

本文记述了云南省虱Ｃｈｉ科虱Ｃｈｉ属３新种,Ｌｉｐｏｓｃｅｌｉｓ ｅｌｅｇａｎｔｉｓ ｓｐ．ｎ．,Ｌｉｐｏｓｃｅｌｉｓ ｎｉｇｒｉｔｉｂｉａ ｓｐ．ｎ．和Ｌｉｐｏｓｃｅｌｉｓ ｙｕｎｎａｎｉｅｓｉｓ ｓｐ．ｎ．。     

Does Chi Give or Take?

In lytic cycle crosses with Red-Gam-lambda phage, particles were examined that had undergone an Int-mediated exchange. It was assumed that this exchange dimerized the circular lambda, making it packageable. Among these Int-mediated recombinants, particles were identified that had, in addition, enjoyed a close double exchange mediated by the RecBC pathway. Such close double exchanges indicate localized negative interference and are analogous to eukaryotic conversions that have retained parental configuration of flanking markers. These events are stimulated by Chi, a recombinator specific to the RecBC pathway. When Chi is present in only one parent in the cross, the complementary double exchange recombinants are Chi stimulated to the same degree. This behavior of Chi contrasts with that of characterized eukaryotic recombinators.     

Flavonoid 3′-hydroxylase of Camellia nitidissima Chi. promotes the synthesis of polyphenols better than flavonoids

Molecular Biology Reports - Camellia nitidissima Chi. is an ornamental plant of the genus Camellia L. Its flowers contain a lot of flavonoids and polyphenols. Flavonoid 3′-hydroxylase...     

南山茶Camellia semiserrata Chi染色体核型的分析

<正> 引言 南山茶(Camellia semiserrata Chi)又名广宁红花油茶,属山茶属(Camellia L.)山茶亚属(Subg.Camellia)红山茶组(Sect.Camellia),分布于我国广东和广西。南山茶的种子油可供食用,为我国南方主要油料经济树种之一,花红色,形大而艳丽,可供观赏。 山茶属植物约共二百种,但已做过染色体计数者仅47种,做过核型分析者则不超过10种。本文提供的南山茶染色体核型的资料将有助于山茶属植物的遗传育种工作和属内系     

天蓝色链霉菌Streptomyces coelicolor中几丁质酶C(Chi C)的生物信息学分析

利用生物信息学的方法,分析天蓝色链霉菌Streptomyces coelicolor中几丁质酶C（Chi C）的一些基本性质,并针对链霉菌属菌种的几个几丁质酶基因做了进化树,进而验证了天蓝色链霉菌中至少8种几丁质酶的分类;同时对天蓝色链霉菌Streptomyces coelicolor中几丁质酶C（Chi C）蛋白的高级结构作出了预测,得到其编码的属于18家族的蛋白质高级结构图谱。     

Chi竹属和牡竹属（竹亚科）叶表皮微形态特征

利用光学显微镜和扫描电镜,对Chi竹属21个种（包括Chi竹亚属5个种、孝顺竹亚属2种、单竹亚属4种绿竹亚属9种和亚属未定1种）以及牡竹属5种叶表皮微形态特征进行了观察和研究。所得结果表明气孔保卫细胞上乳突的数目和分布存在一定的规律,并具有一定的分类价值。绿竹亚属的叶表皮微形态特征界于Chi竹属和牡竹属之间,但更接近于Chi竹属。因此认为在分类处理上,将绿竹亚属置于Chi竹属比单独成立绿竹属更为合理。     

不同细胞质的普通小麦“中国春”（Triticum aestiuum var.Chi …

１５个同细胞质“中国春”小麦主倍体小偃麦杂交,杂种Ｆ１减数分裂的染色体行为表明：普通小麦与天葛偃麦草的Ｆ或Ｅ组染色体之间存在着部分同源关系;Ｄ＾２型细胞质促进部分同源染色体配对、但却抑制同源染色体配对;Ｓ＾Ｖ型细胞质对同源染色体或部分同源染色体的配对均有抑制作用;Ｇ型细胞质促进同源染色体配对。１５个不同细胞质“中国春”小麦与六倍体小偃麦杂交,Ｆ１结实率很三数体配对。１５个不同细胞质“中国春”泪科与     

TNFα-Mediated Liver Destruction by Kupffer Cells and Ly6Chi Monocytes during Entamoeba histolytica Infection

Amebic liver abscess (ALA) is a focal destruction of liver tissue due to infection by the protozoan parasite Entamoeba histolytica (E. histolytica). Host tissue damage is attributed mainly to parasite pathogenicity factors, but massive early accumulation of mononuclear cells, including neutrophils, inflammatory monocytes and macrophages, at the site of infection raises the question of whether these cells also contribute to tissue damage. Using highly selective depletion strategies and cell-specific knockout mice, the relative contribution of innate immune cell populations to liver destruction during amebic infection was investigated. Neutrophils were not required for amebic infection nor did they appear to be substantially involved in tissue damage. In contrast, Kupffer cells and inflammatory monocytes contributed substantially to liver destruction during ALA, and tissue damage was mediated primarily by TNFα. These data indicate that besides direct antiparasitic drugs, modulating innate immune responses may potentially be beneficial in limiting ALA pathogenesis.     

A comparative analysis of karyotypes of three species of Macleaya—producers of a complex of isoquinoline alkaloids

Using a set of methods (C-banding, DAPI-staining, fluorescence hybridization in situ (FISH) with probes of 26S and 5S rDNA, and analysis of meiosis), the first comparative cytogenetic study of three species of Macleaya, producers of complex isoquinoline alkaloids, cordate Macleaya cordata (Willd.) R. Br. (2n = 20), small-fruited Macleaya microcarpa (Maxim.) Fedde (2n = 20) and Macleaya kewensis Turrill (2n = 20), was first carried out. On the basis of morphometric analysis, formulas of karyotypes were made for each species. Species ideograms for M. cordata, M. microcarpa, and M. kewensis were constructed taking into account the polymorphic variants of the C-banding patterns and indicating the location of 26S and 5S rDNA sites. A comparative study revealed that the karyotypes of M. microcarpa and M. kewensis have more in common with each other than with M. cordata. Analysis of meiotic chromosomes suggests of genetic stability of Macleaya genomes. The results of chromosome analysis were used to confirm the close relationship of Macleaya and to clarify their phylogenetic relationships.     

Effect of γ-Irradiation on Development of Lachrymator of Onion

A thermosensitive uracil requiring mutant of Bacillus subtilis Marburg 168 thy trp₂ ts42 was examined as to the colony forming ability at the permissive and nonpermissive temperatures. The viability of the mutant cells decreased rapidly at the restrictive temperature in the modified Woese’s (MW) medium. However, the cells retained viability when sodium succinate or potassium chloride was added to the medium at that temperature although uracil deficiency was unchanged. A little but significant incorporation of adenine-8-¹⁴C into RNA still continued even after the incorporation of N-acetyl-³H-d-glucosamine into acid insoluble fraction of the cells terminated in the MW medium at 48°C. Both incorporations as well as increase of absorbance were slowed down in the presence of sodium succinate at 48°C. This mutant, ts42, was more sensitive to deoxycholate (DOC) than the parent strain. The restoration of colony forming ability after the temperature shift back from 48 to 37°C was suppressed by the addition of DOC to the medium. However, the cell became resistant to DOC when uracil was added to the medium prior to the temperature shift.     

Mechanisms of action of the α-amylase of Micromonospora melanosporea

The -amylase of Micromonospora melanosporea was produced extracellularly during batch fermentation in a 5.0-1 fermentor. The absence of an organic nitrogen source in its growth medium facilitated subsequent purification of the enzyme by ammonium sulphate fractionation and two consecutive Superose-12 gel-filtration steps. The enzyme exhibited maxima for activity at pH 7.0 and 55° C and was 72% stable at pH 6.0–12.0 for 30 min at 40° C. It had a relative molecular mass of 45 000 and an isoelectric point at pH 7.6. The enzyme catalyses the conversion of starch to maltose (53%, w/w) as the predominant final end-product. Initial hydrolysis of this substrate, however, gave rise to the formation of maltooligosaccharides in the range maltotriose to maltohexaose. Maximum yields of these intermediate sugars accumulated to between 31 and 42% (w/w) as the reaction proceeded. The action of the M. melanosporea amylase on high concentrations of saccharides larger than maltotriose resulted in the formation of mainly maltose and maltotriose without concomitant glucose production. A combination of hydrolytic and transfer events is postulated to be responsible for this phenomenon and for the high maltose levels achieved. Correspondence to: C. T. Kelly     

Selection of optimal variants of Gō-like models of proteins through studies of stretching

The Gō-like models of proteins are constructed based on the knowledge of the native conformation. However, there are many possible choices of a Hamiltonian for which the ground state coincides with the native state. Here, we propose to use experimental data on protein stretching to determine what choices are most adequate physically. This criterion is motivated by the fact that stretching processes usually start with the native structure, in the vicinity of which the Gō-like models should work the best. Our selection procedure is applied to 62 different versions of the Gō model and is based on 28 proteins. We consider different potentials, contact maps, local stiffness energies, and energy scales—uniform and nonuniform. In the latter case, the strength of the nonuniformity was governed either by specificity or by properties related to positioning of the side groups. Among them is the simplest variant: uniform couplings with no i, i + 2 contacts. This choice also leads to good folding properties in most cases. We elucidate relationship between the local stiffness described by a potential which involves local chirality and the one which involves dihedral and bond angles. The latter stiffness improves folding but there is little difference between them when it comes to stretching.     

Mechanism of action of α-galactosidase

The effect ofpH on K_m and V_max values of coconut α-galactosidase indicates the involvement of two ionizing groups with pK_a values of 3.5 and 6.5 in catalysis. Chemical modification has indicated the presence of two carboxyl groups, a tryptophan and a tyrosine, at or near the active site of α-galactosidase. Based on these facts a new mechanism of action for α-galactosidase is proposed in which the ionizing group with a pK_a of 3.5 is a carboxyl group involved in stabilizing a carbonium ion intermediate and the ionizing group with a pK_a of 6.5 is a carboxyl group perturbed due to the presence of a hydrophobic residues in its vicinity which donates a H⁺ ion in catalysis.