Identification and Mapping of Two New Genes Conferring Resistance to Powdery Mildew from Aegilops tauschii （Coss,） Schmal

Two powdery mildew resistance genes were Identified from Aegilops tauschll accessions Y201 and Y212 and mapped using two different F2 populations derived from the crosses between susceptible accession Y2272 and Y201, and susceptible accession Y2263 and Y212. Genetic analysis of resistance to powdery mildew Indicated that the resistance of Y201 was controlled by a single dominant gene, whereas the resistance of Y212 was controlled by a single recessive gene. We have temporarily designated these genes as PmY201 and PmY212, respectively. By bulk segregation analysis, six mlcrosatelllte markers Including Xgwm174, cfd26, cfd57, cfdl02, Xgwm583 and Xgwm639 were found to be linked to PraY201 with genetic distances of 5.2, 7.7, 9.6, 12.5, 20.2 and 22.1 cM, respectively. Five SSR markers, including cfd57, Xgwm182, cfd7, cfd102, and cfd12, were found to be linked to PmY212 with distances of 5.6, 7.2, 11.5, 14.7, and 18.5 cM, respectively. According to the locations of the linked markers, the two resistance genes were located In the 5DL region. Based on the chromosomal locations and the resistance patterns of the two genes, we propose that PmY201 and PmY212 are two novel powdery mildew resistance genes, and are suitable for marker-assisted selection.     

花馔及其氨基酸营养

应用日立835 50型高效氨基酸自动分析仪,对十五种常见食用花卉干样进行了水解蛋白氢基酸成分测定,结果发现:①花馔中酸水解蛋白氨的基酸种类齐全,总氨基酸含量较高,占食用干物质的6.00—29.45％。②花馔中人体必需氨基酸含量丰富,占总氨基酸含量的29.50—42.60％。尤以亮氨酸、苯丙氨酸、赖氨酸和苏氨酸含量为高。③花馔中甜、鲜类氨基酸含量也较高,分别占总氨基酸的25.94—39.89％,23.35—33.38％,花馔是兼有营养、颜色、美味的天然食物,值得人类利用。     

Social organization of black-and-white snub-nosed monkeys (Rhinopithecus bieti) at Deqin, China

Data on social organization of two bands of black-and-white snub-nosed monkeys (Rhinopithecus bieti) were collected when the monkeys were crossing an open spot at Nanren and Bamei (northwest of Yunnan, China) using a sampling rule where individuals within one social unit are spatially closer to each other than individuals between social units. The typical pattern of social organization in this sample was multiple adult females (AFs) and their offspring with one adult male (AM) in a one-male unit (OMU), similar to that of many other colobines. In such units, on average one male is associated with 4.0 AFs and 2.5 of their offspring. Moreover, there are multimale/multifemale units and monogamous units besides OMUs. All bisexual units traveled together with at least one all-male unit as a cohesive band. In two bands of monkeys, 87% of AMs in bisexual units were within OMUs, 7.8% within monogamous units and 5.2% within multimale, multifemale units. In the Bamei band, 6.7% of AMs were in the all-male unit. The size of OMUs in the Nanren band was larger than that of the Bamei band, with more AFs and juveniles, which may be related to better conservation in the Nanren band's habitat. For the Nanren band, the average number of AFs in OMUs varied across time, increasing from 4.3 in 1994 to 5.1 in 2001, and then decreasing to 3.8 in 2005. This article suggests three possible explanations for this variation, but more data are needed for these hypotheses to be tested.     

SUMO Modification Regulates BLM and RAD51 Interaction at Damaged Replication Forks

The gene mutated in Bloom''s syndrome, BLM, is important in the repair of damaged replication forks, and it has both pro- and anti-recombinogenic roles in homologous recombination (HR). At damaged forks, BLM interacts with RAD51 recombinase, the essential enzyme in HR that catalyzes homology-dependent strand invasion. We have previously shown that defects in BLM modification by the small ubiquitin-related modifier (SUMO) cause increased γ-H2AX foci. Because the increased γ-H2AX could result from defective repair of spontaneous DNA damage, we hypothesized that SUMO modification regulates BLM''s function in HR repair at damaged forks. To test this hypothesis, we treated cells that stably expressed a normal BLM (BLM+) or a SUMO-mutant BLM (SM-BLM) with hydroxyurea (HU) and examined the effects of stalled replication forks on RAD51 and its DNA repair functions. HU treatment generated excess γ-H2AX in SM-BLM compared to BLM+ cells, consistent with a defect in replication-fork repair. SM-BLM cells accumulated increased numbers of DNA breaks and were hypersensitive to DNA damage. Importantly, HU treatment failed to induce sister-chromatid exchanges in SM-BLM cells compared to BLM+ cells, indicating a specific defect in HR repair and suggesting that RAD51 function could be compromised. Consistent with this hypothesis, RAD51 localization to HU-induced repair foci was impaired in SM-BLM cells. These data suggested that RAD51 might interact noncovalently with SUMO. We found that in vitro RAD51 interacts noncovalently with SUMO and that it interacts more efficiently with SUMO-modified BLM compared to unmodified BLM. These data suggest that SUMOylation controls the switch between BLM''s pro- and anti-recombinogenic roles in HR. In the absence of BLM SUMOylation, BLM perturbs RAD51 localization at damaged replication forks and inhibits fork repair by HR. Conversely, BLM SUMOylation relieves its inhibitory effects on HR, and it promotes RAD51 function.     

肾脏免疫区室化与肾小管间质损伤

免疫系统区室化(compartmentalization)是近年提出的一个新观念,为人们从整体和局部两方面进一步了解免疫系统提供了新的视角,且有助于对临床疾病免疫机制的阐释。最近肾脏免疫系统区室化现象也已引起人们重视。肾小管损伤和肾间质纤维化是各类肾脏疾病发展到终末期肾衰竭的重要原因和共同通路,也与肾小管间质免疫区室的局部微环境调控密切相关,并涉及区域内树突状细胞等专职免疫细胞,以及具有免疫特性肾小管上皮细胞的共同作用及相互调节,由此影响着肾脏疾病的发生、发展及预后。因此,从肾脏免疫区室化角度进一步探讨肾小管间质损伤机制,有助于深入分析肾脏疾病的病变过程,并可为相关研究及临床诊治提供新的思路。     

Opioid activity of synthetic deltorphin II analogues and their spin labeled derivatives

Deltorphin II (Tyr-D-Ala-Phe-Glu-Val-Val-Gly-NH₂, Del II), an endogenous linear heptapeptide, is a highly selective agonist of the -opioid receptor. To study the effect of the position 4 residue (Glu) on the opioid activity of Del II, we designed and synthesized three analogues of Del II by solid-phase peptide synthesis. They were [Val⁴,Glu⁵]Del II, [Val⁴,Glu⁶]Del II and [Gly⁴,Glu⁷]Del II. To study the effect of spin labeling on peptide bioactivities, all the peptides were labeled using a free radical. The labeling material was a stable nitrogen–oxygen free radical which was linked to the N-terminal via an amide bond. We investigated the opioid bioactivities of these analogues both in vivo and in vitro, and concluded that the differences in opioid activity of Del II and its analogues were due to structural differences. When the Glu residue is at position 5 or 6, the internal hydrogen bonds in Del II are affected and there is a change in three-dimensional structure and opioid activity. The antinociceptive activity of all the peptides decreased after spin labeling. This indicates that the stable nitrogen–oxygen free radical is a dual-function spin-labeling molecule.     

Abnormal spectra alteration observed in Triton calibration method for measuring [Ca2+]i with fluorescence indicator, fura-2

We compared two commonly used calibration methods for measuring the concentration of intracellular free calcium ([Ca2+]i) by ratiometric fluorescence dye, fura-2 in mouse neuroblastoma-rat glioma hybrid cells (NG108-15). One calibration method, the Triton method, employs detergent Triton X-100, while the other, the Ionomycin method, uses a calcium-specific ionophore, Ionomycin. In the Triton method, we observed that at excitation 380 nm, the fura-2 fluorescence intensity of steady-state cells abnormally situated beyond the limiting intensity for calibration. By excitation scan, we demonstrated that this abnormality was caused by the change of fura-2 isosbestic points, which in turn was due to cell lysis after the addition of Triton X-100. This problem was resolved in the Ionomycin method by avoidance of cell lysis. Our results showed the correlation between inconsistent isosbestic points and cell lysis. As the basis for [Ca2+]i calibration, the proportionality between the fluorescence intensity and the concentration of dye species was impaired because of inconsistent isosbestic points. This inconsistency can be eliminated by a preliminary experiment of excitation scan to test the feasibility of different calibration methods.     

Insulin-like growth factor-1 receptor signaling in 3T3-L1 adipocyte differentiation requires lipid rafts but not caveolae

Previously, we have found that lipid rafts/caveolae were essential for insulin-like growth factor-1 (IGF-1) receptor signaling during 3T3-L1 preadipocytes differentiation induction. However, it was not identified as to which of the membrane lipid-ordered microdomains mediates the receptor signal. Using small double-stranded RNA-mediated interference (RNAi), we successfully suppressed the caveolin-1 protein expression. In cells stably transfected with vector expressing small interfering RNA (siRNA) fragment, no caveolin-1 protein or caveola was detected. On the other hand, removal of caveolin-1 did not affect the caveolinless lipid rafts or the localization of IGF-1 receptor in lipid rafts on plasma membrane. IGF-1 receptor signal transduction and induced cellular differentiation were normal in RNAi cells with only lipid rafts. Furthermore, these IGF-1 receptor signaling events were still sensitive to the cholesterol-binding reagents. Thus, our results suggest that lipid rafts are sufficient for IGF-1 receptor signaling and the recruitment of signal molecules by caveolin-1 is not essential for IGF-1 receptor signaling.