Fen zi xi bao sheng wu xue bao = Journal of molecular cell biology最新文献

Cymbidium is one of the Orchidaceae genera. There are 70 Cymbidium species in the world, mainly distributed over the tropical and the subtropical area of Asia and northern Australia. In China, approximately 49 species and some variations are distributed over the provinces to the south of Qinling. The orchid market of China is quite wide, not only because of their view and admiration value, but also their officinal value as well. Some species of Cymbidium are morphologically similar, so the identification of Cymbidium species and the understanding of the relationships between them are very important for new varieties breeding of Cymbidium. This study attempts to apply RMAPD to detect the relationships between the Cymbidium species. 456 pairs of RMAPD combinations were screened, but only 12 pairs of them were used to analyze the genetic polymorphism of 16 Cymbidium. 362 bands were produced by 12 pairs of RMAPD primers in total, including 90 polymorphic bands (24.8%). The polymorphic bands of each primer combination ranged from 3 to 11 with the average of 8. Among all species, genetic similarity coefficient ranged from 0.63 to 0.87. The result showed that the genetic distance was closest between C. floribundum and C. aestivum, C. ensifolium and C. sinense, C. maguanense and C. hookerianum, which is almost the same as the traditional classification. It was the first time that species of Cymbidium were detected by RMAPD technique. This study shows RMAPD is an appropriate and effective molecular marker technique to identify the relationships of Cymbidium.

A germplasm line Shannong05078 was developed from the progenies of Am3 x Triticum aestivum-Dasypyrum villosum amphidiploid, the purpose of this study is to ascertain the genome composition of Shannong05078 and then supply wheat breeding with reference. The results showed that Shannong05078 was stable in morphology characters and presenting favorable agronomic traits, it was resistant to powdery mildew and rust. Its protein content was higher, and the HWM-GS of it was 7+8, 5+10. The chromosome number of Shannong05078 was 2n=28, and the chromosome configuration was 2n=14 II at the PMC MI. SSR analysis showed that Shannong05078 contained the whole A and B genomes, and had little genetic materials from D genome. A specific primer of Dasypyrum villosum (phv29) was used to identify the genetic materials form Dasypyrum villosum in Shannong05078, and specific band of Dasypyrum villosum appeared in it. It can be deduced that the genomic composition of Shannong05078 is 2n=AABB=28, and genetic materials of D genome and Dasypyrum villosum were translated into Shannong05078.

Spermatogonial stem cells (SSCs), the only stem cells that are capable of transmitting genetic information to subsequent generations in adult animals,have abilities to self-renew and differentiate into spermatozoa. Therefore, SSCs are not only the study object of stem cell biology, but also the valuable resource of in vitro spermatogenesis, gene analysis and functional genomics. In the present study, we selected the mouse SSCs from mice on STO (SIM mouse embryo-derived thioguanine and ouabain resistant) feeders by differential adherence selection in DMEM/F12 containing 5% FBS, and used a serum-free defined medium prepared with Knockout SR basal medium to culture SSCs. Our results showed that enriched SSCs could be maintained for a short of time and form colonies, but the proliferation of SSCs was unconspicuous, suggesting that some factors that are detrimental to the self-renewal of SSCs possibly existed in the Knockout SR basal medium. However, the use of KSR medium, which was widely used in the culture of embryonic stem cells (ESCs), in the SSC maintenance was the first time, and our results indicated that the Knockout SR basal medium don't appropriate for the long-time culture of SSCs.

The experimental foundation for investigating the pharmacological action of hydroxycamptothecin at subcellular quantitative proteomic level can be obtained depending on the information of differentially expressed nuclear proteins in hydroxycamptothecin-treated cells and control cells. The apoptosis was induced by hydroxycamptothecin in hepatoma cells, the nucleus of cells were isolated and verified with western blot. Nuclear proteins labelled with cleavable isotope-coded affinity tag (c-ICAT) reagent were digested and purified. The expression ratio of the identical nuclear protein derived from apoptosis cell and control cell can be gained using shotgun proteomic method based on multiple dimensional liquid chromatography-linear ion trap/orbitrap mass spectrometer combined with c-ICAT strategy. A total of 42 nuclear proteins were significantly (P<0.05) altered in hydroxycamptothecin-treated cells, among them, 12 proteins showed significantly down-regulation, and 30 proteins showed up-regulation compared with control cells. The function of these proteins were likely involved in life processes of cells such as proliferation, apoptosis, differentiation, energy metabolism, nucleic acid synthesis and metabolism, structure of cell skeleton.

Nuclear mitochondrial pseudogenes (Numts), widely existing in nuclear genomes of many organisms, are those nuclear DNA sequences which have high similarity with mtDNAs. In this study, we identified 14 different multiple nuclear pseudogenes of mitochondrial cytochrome oxidase I gene from an individual Scylla paramamosain (Decapoda: Portunidae). Of these sequences, ninety-six variable sites were detected, accounting for 15.7%. Nucleotide diversity (Pi) index and Haplo-type diversity (Hd) index were 0.05682 and 0.8800, respectively. Among the 14 pseudogenes, the copies of sequence one were the most, occupying 30.8% of total copies, and sequence two run the second one (occupying 19.2%). These sequences were divided into two groups compared with their homologues. In Group 1, there were no insertion or deletion sites, while 8 deletion and 5 insertion sites were detected in Group 2, resulting in frame-shift mutations. It was proved that these two groups of pseudogenes were evolved from at least two independent mtDNA integrations into S. paramamosain nuclear genomes through Chi-square and homogeneity tests.

To explore the existence,distribution of prohibitin in nuclear matrix and the co-localization relationship between prohibitin and the products of some interrelated genes in the human osteosarcoma MG-63 cells before and after HMBA treatment, the nuclear matrix of MG-63 cells and the cells induced by HMBA were selectively extracted. It was confirmed by Western blot that prohibitin existed in the component of nuclear matrix protein of MG-63 cells and its expression was decreased by HMBA treatment. The immunofluorescence observation revealed that prohibitin located in the nuclear matrix, and its distribution regions and expression level had altered after HMBA treatment. The co-localization and its alternation of distributive area in the cells treated by HMBA were observed between prohibitin and the products of oncogenes or tumor repression genes including c-fos, c-myc, p53 and Rb by using laser scanning confocal microscopy. The results of this study demonstrated that prohibitin was a kind of nuclear matrix protein, and locacted in the nuclear matrix,and the distribution and expression of prohibitin and its relationship with associated genes play an important role during the differentiation of MG-63 cell.

Analysis of ISSR (Inter-Simple Sequence Repeat) and DDRT-PCR (Differential Display Reverse Transcriptase Polymerase Chain Reaction) was performed between cytoplasmic male sterility cauliflower ogura-A and its corresponding maintainer line ogura-B. Totally, 306 detectable bands were obtained by ISSR using thirty oligonucleotide primers. Commonly, six to twelve bands were produced per primer. Among all these primers only the amplification of primer ISSR3 was polymorphic, an 1100 bp specific band was only detected in maintainer line, named ISSR3(1100). Analysis of this sequence indicated that ISSR3(1100) was high homologous with the corresponding sequences of mitochondrial genome in Brassica napus and Arabidopsis thaliana,which suggested that ISSR3(1100) may derive from mitochondrial genome in cauliflower. To carry out DDRT-PCR analysis, three anchor primers and fifteen random primers were selected to combine. Totally, 1122 bands from 1 000 bp to 50 bp were detected. However, only four bands, named ogura-A 205, ogura-A383, ogura-B307 and ogura-B352, were confirmed to be different display in both lines. This result was further identified by reverse Northern dot blotting analysis. Among these four bands, ogura-A205 and ogura-A383 only express in cytoplasmic male sterility line, while ogura-B307 and ogura-B352 were only detected in maintainer line. Analysis of these sequences indicated that it was the first time that these four sequences were reported in cauliflower. Interestingly, ogura-A205 and ogura-B307 did not exhibit any similarities to other reported sequences in other species, more investigations were required to obtain further information. ogura-A383 and ogura-B352 were also two new sequences, they showed high similarities to corresponding chloroplast sequences of Arabidopsis thaliana and Brassica rapa subsp. pekinensis. So we speculated that these two sequences may derive from chloroplast genome. All these results obtained in this study offer new and significant information to investigate the molecular mechanism of cytoplasmic male sterility and fertile maintenance in cauliflower.

Genetic quality of outbred stock has an important effect for the experimental results by using those animals, but methods and standardization of genetic detection for outbred stock are absent. In the present study, 6 microsatellite markers were screened for Wistar from Beijing and Spague-Darley (SD) from Shanghai outbred rats by fluorescence-based semi-automated genotyping method. Good polymorphisms were detected on all the 6 microsatellite loci, with 36 alleles found in the 2 stocks, 5-8 alleles each locus, and the polymorphic information content (PIC) ranged from 0.5892 (D11Mgh3) to 0.8019 (D6Mit1), with an average of 0.6881. 25 and 26 alleles were detected in the 6 loci, and averages of unbiased expected heterozygosity were 0.6260 and 0.6249 in Wistar and SD outbred rats, respectively. No significant differences of genetic diversity index were tested between populations. The Fst per locus was varied from 0.0461 to 0.4363, and the average Fst of all loci was 0.2069, which implied large genetic differentiation between populations. Nei's (1972) genetic distance and Nei's (1978) unbiased genetic distance measures between the 2 stocks were 1.2862 and 1.2726, respectively, which indicated the distant genetic relationship and low genetic identity between them. All loci in Wistar and 4 of 6 loci in SD outbred rats showed significant deviations from Hardy-Weinberg equilibrium (HWE), and all deviations were caused by deficiency of heterozygous individuals. From the results, there is abundant genetic variation in Wistar and SD outbred rats. Large genetic differentiation existed between these two outbred stocks, and each possessed distinct genetic characteristic. Deviation from HWE seems a frequent problem in the 2 outbred stocks. This genetic research on outbred rats should assist in developing genetic monitoring methods and standardization of the outbred rats.

The techniques of random amplified polymorphic DNA (RAPD) and amplified fragment length polymorphisms (AFLPs) were used to amplify the genomic DNA of 10 species of Ilex, so as to reveal the polymorphism in different species of Ilex. In RAPD analysis, a total of 301 lines were amplified with 11 kinds of primers selected from 100 kinds of 10 bp random primers, and the polymorphism was 98.63%. In AFLPs analysis,a huge diversity was showed by 3 primers combinations carried out on these species. Both RAPD and AFLPs analysis were clustered by UPGMA and the results showed that the genetic distances were the closest between I. purpurea and I. vomitoria Ait, I. Litseaefolia and I. zhejiangensis, I. hylonoma var. glabra and I. triflora var. kanehirai.

Torenia fournieri is a special plant with embryo sac partly protruding through the micropyle of ovule, and the cells of egg apparatus can be clearly observed using light microscope. Zygotes and the cells of bicellular proembryo could be isolated using enzymatic digestion. In the solution containing 0.05% cellulase and 0.05% pectinase, 14-15 zygotes were isolated from 50 ovules in 1h. In the solution containing 0.2% cellulose, 0.4% hemicellulase and 0.2% pectinase, 19 pairs of apical and basal cells of bicellular proembryo could be isolated from 50 ovules in 1 h. The isolated zygotes and epical and basal cells were collected using a micromanipulator up to a number which will prepare for suing molecular methods to probe the mechanism of early embryogenesis of higher plants.