A high density SNP array for the domestic horse and extant Perissodactyla: utility for association mapping, genetic diversity, and phylogeny studies

An equine SNP genotyping array was developed and evaluated on a panel of samples representing 14 domestic horse breeds and 18 evolutionarily related species. More than 54,000 polymorphic SNPs provided an average inter-SNP spacing of ～43 kb. The mean minor allele frequency across domestic horse breeds was 0.23, and the number of polymorphic SNPs within breeds ranged from 43,287 to 52,085. Genome-wide linkage disequilibrium (LD) in most breeds declined rapidly over the first 50-100 kb and reached background levels within 1-2 Mb. The extent of LD and the level of inbreeding were highest in the Thoroughbred and lowest in the Mongolian and Quarter Horse. Multidimensional scaling (MDS) analyses demonstrated the tight grouping of individuals within most breeds, close proximity of related breeds, and less tight grouping in admixed breeds. The close relationship between the Przewalski's Horse and the domestic horse was demonstrated by pair-wise genetic distance and MDS. Genotyping of other Perissodactyla (zebras, asses, tapirs, and rhinoceros) was variably successful, with call rates and the number of polymorphic loci varying across taxa. Parsimony analysis placed the modern horse as sister taxa to Equus przewalski. The utility of the SNP array in genome-wide association was confirmed by mapping the known recessive chestnut coat color locus (MC1R) and defining a conserved haplotype of ～750 kb across all breeds. These results demonstrate the high quality of this SNP genotyping resource, its usefulness in diverse genome analyses of the horse, and potential use in related species.     

Assembly of the eukaryotic PLP-synthase complex from Plasmodium and activation of the Pdx1 enzyme

Biosynthesis of vitamins is fundamental to malaria parasites. Plasmodia synthesize the active form of vitamin B(6) (pyridoxal 5'-phosphate, PLP) using a PLP synthase complex. The EM analysis shown here reveals a random association pattern of up to 12 Pdx2 glutaminase subunits to the dodecameric Pdx1 core complex. Interestingly, Plasmodium falciparum PLP synthase organizes in fibers. The crystal structure shows differences in complex formation to bacterial orthologs as interface variations. Alternative positioning of an α helix distinguishes an open conformation from a closed state when the enzyme binds substrate. The pentose substrate is covalently attached through its C1 and forms a Schiff base with Lys84. Ammonia transfer between Pdx2 glutaminase and Pdx1 active sites is regulated by a transient tunnel. The mutagenesis analysis allows defining the requirement for conservation of critical methionines, whereas there is also plasticity in ammonia tunnel construction as seen from comparison across different species.     

浅谈免疫组化标记结果的解读与淋巴瘤的诊断

目的 提高对正确解读免疫组化结果的重要性的认识.方法 对3例淋巴瘤误诊病例进行复习,并增加相关抗体标记予以鉴别诊断.结果 例1,滤泡性淋巴瘤(FL)误诊为淋巴结淋巴组织反应性增生,与形态学观察忽略肿瘤性滤泡及对免疫表型Bc12表达的认识不足有关.例2,经典型富于淋巴细胞型霍奇金淋巴瘤(LRCHL).①误诊为FL,与形态学观察遗漏R-S细胞,以及误判免疫组化标记Bcl2、CD20有关,即将Bcl2、CD20阳性的非肿瘤细胞,误判为肿瘤细胞.②误诊为结节性淋巴细胞为主型霍奇金淋巴瘤(NLPHL)与免疫组化标记的错误解读有关,把围绕瘤细胞的背景小淋巴细胞CD20阳性,误判为R-S细胞CD20阳性;将CD30阳性的R-S细胞,误判为活化性B淋巴细胞.例3,AML误诊为T-LBL.主要是对瘤细胞表达非特异性抗体TDT、CD7、CD43的意义认识不足有关.结论 淋巴瘤的诊断是建立在形态学、免疫组化标记、临床资料和遗传学之上的,而且,免疫组化标记结果的正确解读对淋巴瘤的诊断至关重要.     

Molecular characteristics and expression of calmodulin cDNA from the freshwater pearl mussel, Hyriopsis schlegelii

Calmodulin (CaM) is a multifunctional intracellular calcium ion receptor protein that participates in a range of cellular processes, including calcium metabolism in mussels. To investigate the role of CaM in freshwater mollusk shell calcium metabolism, the full-length CaM cDNA was isolated from the freshwater pearl mussel, Hyriopsis schlegelii (referred to as hsCaM) using SMART RACE technology. The full-length hsCaM was 855 bp in size, containing a 70-bp 5'-untranslated sequence, a 447-bp open reading frame, a 309-bp 3'-untranslated sequence, and a 26-nucleotide long poly(A) tail. The hsCaM mRNA expression in different mussel tissues was examined using real-time PCR. The hsCaM mRNA was found to be ubiquitously expressed, but far more abundant in the gill, foot, and mantle than in the posterior adductor muscle. Real-time PCR was also used to determine hsCaM mRNA expression levels in mantle tissues of H. schlegelii at different ages. No significant differences between one-, two-, and three-year-old mussels were detected, but expression increased in four-year-old mussels and then decreased in five-year-old mussels. CaM appears to be involved in calcium regulation of the mantle in four-year-old mussels, which may secrete more mother of pearl during pearl culture.     

Survivin regulates the expression of VEGF-C in lymphatic metastasis of breast cancer

ABSTRACT: BACKGROUND: As a known regulator of apoptosis, survivin has positive relationship with lymphatic metastasis in breast cancer. This study aims to detect the difference in expression between survivin and vascular endothelial growth factor-C (VEGF-C) in treated breast cancer cells and tissues, and to analyze the correlation among survivin, VEGF-C and lymphatic metastasis. METHODS: Plasmid with survivin and VEGF-C shRNA and lentivirus with survivin gene were constructed and transfected into breast cancer cell ZR-75-30. Then the expressions of the two genes were examined using western blot analysis and real-time PCR. The change of invasiveness of breast cancer cells was assessed using matrigel invasion assay. Using immunohistochemistry, the expression of survivin and VEGF-C were analyzed in 108 clinical breast cancer cases with breast cancer tissue and lymph node. RESULTS: Survivin regulated the expression of VEGF-C at both protein and mRNA levels in breast cancer cells. Immunohistochemical analysis showed that the level of VEGF-C expression was significantly related with that of survivin in breast cancer tissues (p<0.05). VEGF-C was found to participate in the process of breast cancer cells invasion mediated by survivin. The co-expression of the two and the single expression of any one took significant difference in positive lymph node (p<0.05). CONCLUSIONS: Survivin takes an important part in regulating the expression of VEGF-C. VEGF-C could influence the invasive ability mediated by survivin. The co-expression of survivin and VEGF-C is more statistically significant to assess lymphatic metastasis in breast cancer. Virtual slides The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/9193530897100952.     

Inhibition of MMP-9 by a selective gelatinase inhibitor protects neurovasculature from embolic focal cerebral ischemia

ABSTRACT: BACKGROUND: Cerebral ischemia has been shown to induce activation of matrix metalloproteinases (MMPs), particularly MMP-9, which is associated with impairment of the neurovasculature, resulting in blood-brain barrier breakdown, hemorrhage and neurodegeneration. We previously reported that the thiirane inhibitor SB-3CT, which is selective for gelatinases (MMP-2 and 9), could antagonize neuronal apoptosis after transient focal cerebral ischemia. RESULTS: Here, we used a fibrin-rich clot to occlude the middle cerebral artery (MCA) and assessed the effects of SB-3CT on the neurovasculature. Results show that neurobehavioral deficits and infarct volumes induced by embolic ischemia are comparable to those induced by the filament-occluded transient MCA model. Confocal microscopy indicated embolus-blocked brain microvasculature and neuronal cell death. Post-ischemic SB-3CT treatment attenuated infarct volume, ameliorated neurobehavioral outcomes, and antagonized the increases in levels of proform and activated MMP-9. Embolic ischemia caused degradation of the neurovascular matrix component laminin and tight-junction protein ZO-1, contraction of pericytes, and loss of lectin-positive brain microvessels. Despite the presence of the embolus, SB-3CT mitigated these outcomes and reduced hemorrhagic volumes. Interestingly, SB-3CT treatment for seven days protected against neuronal laminin degradation and protected neurons from ischemic cell death. CONCLUSION: These results demonstrate considerable promise for the thiirane class of selective gelatinase inhibitors as potential therapeutic agents in stroke therapy.     

Senegenin Attenuates Hepatic Ischemia-Reperfusion Induced Cognitive Dysfunction by Increasing Hippocampal NR2B Expression in Rats

Background

The root of Polygala tenuifolia, a traditional Chinese medicine, has been used to improve memory and intelligence, while the underlying mechanisms remain largely unknown. In this study, we investigated the protective effects of senegenin, an component of Polygala tenuifolia root extracts, on cognitive dysfunction induced by hepatic ischemia-reperfusion.

Methodology/Principal Findings

Initially, we constructed a rat model of hepatic ischemia-reperfusion (HIR) and found that the memory retention ability of rats in the step-down and Y maze test was impaired after HIR, paralleled by a decrease of N-methyl-D-aspartate (NMDA) receptor NR2B subunit mRNA and protein expressions in hippocampus. Furthermore, we found that administration of senegenin by gavage attenuated HIR-induced cognitive impairment in a dose and time dependent manner, and its mechanisms might partly due to the increasing expression of NR2B in rat hippocampus.

Conclusions/Significance

Cognitive dysfunction induced by HIR is associated with reduction of NR2B expression. Senegenin plays a neuroprotective role in HIR via increasing NR2B expression in rat hippocampus. These findings suggest that senegenin might be a potential agent for prevention and treatment of postoperative cognitive dysfunction (POCD) or other neurodegenerative diseases.