Human male recombination maps for individual chromosomes

Meiotic recombination is essential for the segregation of chromosomes and the formation of normal haploid gametes, yet we know very little about the meiotic process in humans. We present the first (to our knowledge) recombination maps for every autosome in the human male obtained by new immunofluorescence techniques followed by centromere-specific multicolor fluorescence in situ hybridization in human spermatocytes. The mean frequency of autosomal recombination foci was 49.8+/-4.3, corresponding to a genetic length of 2,490 cM. All autosomal bivalents had at least one recombination focus. In contrast, the XY bivalent had a recombination focus in 73% of nuclei, suggesting that a relatively large proportion of spermatocytes may be at risk for nondisjunction of the XY bivalent or elimination by meiotic arrest. There was a very strong correlation between mean length of the synaptonemal complex (SC) and the number of recombination foci per SC. Each bivalent presented a distinct distribution of recombination foci, but in general, foci were near the distal parts of the chromosome, with repression of foci near the centromere. The position of recombination foci demonstrated positive interference, but, in rare instances, foci were very close to one another.     

In situ hybridization of corticotropin-releasing factor-encoding messenger RNA in the hypothalamus of the white sucker,Catostomus commersoni

Summary In situ hybridization procedure with a ³²P-labelled synthetic oligonucleotide probe was used to detect corticotropin-releasing factor-encoding messenger RNA (CRF mRNA) in the hypothalamus of the white sucker, Catostomus commersoni. Adjacent sections were immunostained by a sucker CRF-specific antiserum. CRF mRNA-containing neurons were identified by autoradiography in the magnocellular and parvocellular subdivisions of the preoptic nucleus (PON). Many of these neurons were also immunostained by sucker antiserum, showing the same distribution patterns. These results confirm the presence of CRF mRNA and CRF peptide in the white sucker hypothalamus and support the view that the magnocellular and parvocellular neurons of the PON may be involved in the control of adrenocorticotropic hormone secretion from the pituitary in the white sucker.     

Egr-1, a new downstream molecule of Epstein-Barr virus latent membrane protein 1

To investigate the effect of Epstein-Barr virus (EBV) latent membrane protein 1 (LMP1) on human cancer cells, we sought to identify and analyze potential target genes that were differentially expressed in the presence and absence of LMP1. Our cDNA microarray analysis revealed that expression of early growth response gene-1 (Egr-1) was increased by LMP1 expression in MCF7 and Jurkat cells. An NFkappaB inhibitor (SN50) antagonized LMP1-induced enhancement of Egr-1 expression, indicating that LMP1 induced Egr-1 via NFkappaB. Furthermore, three lines of evidence indicated that Egr-1 was required for LMP1-induced cancer cell survival. First, Egr-1 expression enhanced the survival of doxorubicin-treated MCF7 cells. Second, inhibition of Egr-1 expression by siRNA (siEgr-1) effectively suppressed LMP-1-induced survival of MCF7 cells. Third, Egr-1 knockdown decreased LMP1-induced expression of Bfl-1. Similar relationships among EBV infection, Egr-1 and drug resistance were also observed in tissues of peripheral T-cell lymphoma-unspecified (PTCL-u) patients.     

Karyotype analysis of some Minuartia L. (Caryophyllaceae) taxa

Karyotypic characters, mitotic metaphase chromosomes, monoploid idiograms and karyograms of Minuartia anatolica (Boiss.) Woronow var. phrygia (Bornm.) McNeill, Minuartia anatolica (Boiss.) Woronow var. scleranthoides (Boiss. & Noe) McNeill, Minuartia corymbulosa (Boiss. & Balansa) McNeill var. gypsophilloides McNeill and Minuartia aksoyi M.Koç & Hamzao?lu were investigated for the first time. Analysis of somatic metaphases showed that the chromosome numbers and the formulas of these taxa were 2n = 24 = 14m + 6sm + 4st for Minuartia anatolica var. phrygia, 2n = 14 = 6m + 8sm for Minuartia anatolica var. scleranthoides, 2n = 14 = 6m + 4sm + 4st for Minuartia corymbulosa var. gypsophilloides and 2n = 30 = 14m + 10sm + 6st for Minuartia aksoyi. No satellites were observed in the karyotypes of these taxa. Karyotype asymmetry was estimated by many different methods, namely the Stebbins classification, the karyotype asymmetry index (As K %), the total form percent (TF %), the Rec and Syi indices, the intrachromosomal asymmetry index (A1) and interchromosomal asymmetry index (A2), the dispersion index (DI), the degree of asymmetry of karyotype (A index) and the asymmetry index (AI).     

菝葜科种皮微结构特征及其分类学意义

在光学显微镜和扫描电镜下对菝葜科Smilacaceae3个属(菝葜属Smilax、肖菝葜属Heterosmilax和Ripogonum属)共53种5变种植物的种子形态及种皮微形态特征进行了研究。结果表明其种子形状为球形、半球形或钝三角形。在扫描电镜下种子表皮纹饰可分为7种类型,即脑纹型、粗脑纹型、网纹型、细网纹型、孔穴型、密孔穴型和细条纹型。根据种皮微形态的特征,对菝葜科内属间和属内组间的关系进行了探讨。种皮形态分析结果支持将Ripogonum属从菝葜科中分离、独立成科,支持将肖菝葜属与菝葜属合并的观点,这与孢粉学和分子证据的分析结果一致;推测肖菝葜属和菝葜属的土茯苓组sect.Coilanthus及草本组sect.Coprosmanthus的多数种类之间亲缘关系较近,菝葜组sect.China和圆锥组sect.Macranthae的大多数种类之间的亲缘关系较为密切,但种皮形态证据不支持Koyama将菝葜属分为6个组的观点。     

Proteomic analysis of differential protein expression in atherosclerosis

Although recent studies have shown that several pro-inflammatory proteins can be used as biomarkers for atherosclerosis, the mechanism of atherogenesis is unclear and little information is available regarding proteins involved in development of the disease. Atherosclerotic tissue samples were collected from patients in order to identify the proteins involved in atherogenesis. The protein expression profile of atherosclerosis patients was analysed using two-dimensional electrophoresis-based proteomics. Thirty-nine proteins were detected that were differentially expressed in the atherosclerotic aorta compared with the normal aorta. Twenty-seven of these proteins were identified in the MS-FIT database. They are involved in a number of biological processes, including calcium-mediated processes, migration of vascular smooth muscle cells, matrix metalloproteinase activation and regulation of pro-inflammatory cytokines. Confirmation of differential protein expression was performed by Western blot analysis. Potential applications of the results include the identification and characterization of signalling pathways involved in atherogenesis, and further exploration of the role of selected identified proteins in atherosclerosis.