哺乳动物原始生殖细胞与EG细胞研究进展

本文综述了哺乳动物原始生殖细胞的来源、增殖、迁移及生物学特点及近年来国内外用原始生殖细胞分离EG细胞的研究进展，探讨了EG细胞作为另一种多能性干细胞的优越性。     

干细胞与肿瘤研究进展

肿瘤是危害人类健康的恶性疾病,近年来越来越多证据显示肿瘤与干细胞有着密切的关系。肿瘤可能是干细胞在异常微环境中差异分化的结果。它与正常干细胞有相似的表面标志和生化特点。在此,综述了干细胞与肿瘤发生的关系及干细胞工程在肿瘤治疗中的应用前景,旨在为肿瘤发生发育的研究及干细胞在肿瘤治疗方面的应用提供理论依据。     

In vitro Plant Regeneration from the Mature Tissue of Navel Orange (Citrus sinensis L. Osbeck) by Direct Organogenesis

An efficient in vitro regeneration system by direct organogenesis from mature nodal and internodal stem segments of Newhall navel orange (Citrus sinensis L. Osbeck) was developed. Illuminating conditions together with plant growth regulators affected the adventitious bud regeneration frequency and efficiency. The initial 15 d darkness inoculation is beneficial for the adventitious bud regeneration. The highest regeneration frequency (85.2%) and bud formation efficiency (3.7 per responsive internodal stem segment) were obtained in the media supplemented with 1.0 mg L-1 BAP and 0.5 mg L-1 NAA. ABA at 0.2 mg L-1 positively affected the bud formation efficiency, which amounted to 8.5 buds per internodal segment in the presence of BAP at 1.0 mg L-1. The adventitious shoots successfully rooted and were transferred to the soil.     

小麦矮秆育种中性状间关系的多元分析

以7个株高梯度系列的35个系统及5个亲本品种为材料,采用典范分析和逐步回归分析研究了株高及其构成因子与产量因子、产量生理性状间的关系。结果表明:①株高因子通过产量生理性状影响产量因子,一定的生物学产量是获得高产的基础。②矮秆品种的高化对提高产量、千粒重和收获指数有利,对蛋白质含量的影响不明显;高秆品种矮化能显著提高收获指数,对籽粒的蛋白质含量影响不大。③在主要性状符合育种目标的前提下,选择倒二节间较长、第一和第二叶间距略长、穗颈和穗部较长的类型可能对提高产量有利。     

Resistance to yellow rust in Triticum dicoccoides. II. Crosses with resistant Triticum dicoccoides sel. G-25

A comparison was made between the genes in 29 new selections of wild emmer wheat resistant to yellow rust over wide geographic areas and the previously extensively studied selectionTriticum dicoccoides G-25. In 23 selections the resistance may be conferred by 1 dominant gene; these include 11 selections in which the gene is different from the dominant gene in sel. G-25 and two others in which the genes were closely linked or allelic to the gene in G-25, differing from sel. G-25 by race-specificity. Two dominant genes different from the gene in sel. G-25, seem to be present in one selection. In five selections the resistance may be conferred by one or two recessive genes, including three instances in which the recessive gene was associated with a dominat gene. Our findings show that at least 19 out of the 29 selections studied possess genes which are different from the gene inT. dicoccoides sel. G-25.Samenvatting In dit onderzoek werden 29 nieuwe resistente wilde-emmer selecties (Triticum dicoccoides) gekruist met de reeds uitvoerig bestudeerde resistente selectie G-25, om na te gaan of de resistentie van de nieuwe selecties wordt veroorzaakt door genen op dezelfde locus als het dominante gen in sel. G-25 of dat er andere loci bij zijn betrokken. De ouders, de F₁-en F₂-populaties van een bepaalade selectie werden in het kiemplantstadium getoetst met één Israëlisch gele-roest isolaat van fysio 2E0 of van fysio 2E18. In de uitsplitsende F₂-populaties werden de niet-sporulerende planten als resistent beschouwd en de sporulerende als vatbaar.In de F₂-populaties van 12 herkomsten werden geen vatbare planten gevonden, hetgeen er op duidt dat de resistentie wordt veroorzaakt door een gen op dezelfde locus als het gen in G-25 of door een gen dat neuw gekoppeld is aan het gen in G-25. Voor twee van deze herkomsten kan op basis van een fysio-specifieke interactie worden vastgesteld dat de resistentie berust op allelen die verschillen van het allel in sel. G-25. In 11 herkomsten werd een uitsplitsing voor twee dominante gene gevonden (RS=151), waarbij het tweede dominante gen uit de getoetste nieuwe selectie afkomstig is. De aanwezigheid van twee dominante genen verschillend van het gen in sel. G-25 werd gevonden in één herkomst (631). In de overige vijf selecties bleek de resistentie te worden veroorzaakt door één of twee recessieve genen waarnaast in drie gevallen ook nog een dominant gen werd gevonden.De resultaten tonen aan dat tenminste 19 van de 29 bestudeerde selecties resistentiegenen bezitten die verschillen van het gen inT. dicoccoides sel. G-25. Slechts in twee van deze selecties kan het gen allel zijn met het gen in sel. G-25.     

Cell proliferation and nestin expression in cortex and SEZ of MCAO rats

AIM:To explore the effect of brain ischemia injury on cell proliferation and nestin expression in cortex and subependymal zone (SEZ).METHODS:Using a local brain ischemia model(MCAO), BrdU positive cells of cortex and subependymal zone (SEZ), also nestin positive cells, were observed by immunohistochemistry.RESULTS:BrdU and nestin positive cells in SEZ of MCAO rats were obviously increased. In cortex, only nestin positive cells were observed.CONCLUSION:Neural stem cells in SEZ and cortex were activated after brain ischemia, it may be related with neural recovery after brain ischemia injury.     

Bone marrow-derived stromal cells and cartilage tissue engineering

Articular cartilage repair is one of the most challenging issues which remains to be resolved in clinic work. Discovering of bone marrow stromal cells (BMSC) and its application in tissue engineering provide new methods for the treatment of cartilage defects. High seeding density, appropriate cytokines and three-dimensional culture play important roles in the process of inducing BMSC differentiating into chondrocytes, suitable scaffold is also essential in reconstructing cartilage in vitro by methods of tissue engineering.     

Selection and amplification of the liver stem cell subset from rat bone marrow cells with a medium containing cholestatic serum in vitro

AIM: To explore the feasibility of direct separat and selective enlargement of the bone marrow-derived liver stem cells (BDLSC) from bone marrow cells with a culture system containing cholestatic serum in vitro. METHODS: Bone marrow cells of rats were cultured with selective media containing 2%, 5%, 7% and 10% cholestatic rat serum, respectively. The BDLSC were then induced to proliferate with the addition of hepatocyte growth factor (HGF) on the firth day. BDLSC were characterized using immunocytochemistry and RT-PCR for lineage markers, glycogen staining and urea synthetic assay for functions 2 weeks later. RESULTS: Bone marrow cells were unble to form colony in the presence of 2% cholestatic serum and apopotosis appeared gradually in 7% or 10% cholestatic serum. The BDLSC survived in the medium containing 5% cholestatic serum while the other types of cells did not. The survival cells proliferated with a high speed during the second week and then formed hepatocyte-like colony-forming units (H-CFU). Cells in the H-CFU expressed the characteristic proteins of fetal hepatocytes. Furthermore, they had glycogen storage and urea synthesis functions, two of the critical features of hepatocytes. CONCLUSION: The selective micro-environment effectively selected BDLSC from the bone marrow cell, and will be a new way to provide an abundant source of donor hepatocytes for clinical cell therapy.     

Genetic analyses of resistance of the wheat differential cultivars Carstens V and Spaldings Prolific to two races of Puccinia striiformis

Genetic analysis of resistance of wheat seedlings to two races of Puccinia striiformis was conducted on F₁, F₂ and F₃ generations from crosses Carstens V (CV) × Lee, Spaldings Prolific (SPA) × Lee and CV × SPA. F₂ generations from crosses of CV and SPA with Strubes Dickkopf (SD) were also studied. The plants were classified into six resistance classes and analysed by factorial correspondence analysis and nonhierarchical classification. The two P. striiformis isolates tested were a French isolate of race 43E138 and a Lebanese isolate of race 2E16, selected for the differences in their virulence spectra for the common differential cultivars Strubes Dickkopf and Nord Desprez. Resistance of CV and SPA was recessive and dominant to races 43E138 and 2E16, respectively. CV possessed three or four resistance genes, one of them being expressed with both races. Two genes of CV had a cumulative effect for resistance to 43E138 and two or three gave dominant resistance to 2E16. SPA had three resistance genes, all of which gave resistance to 2E16 and two of which also gave resistance to 43E138. SPA had one gene in common with CV for resistance to both races. Furthermore, the gene for resistance to race 2E16 in CV and SPA was allelic with a gene in SD, and was probably Yr25 .     

Adult rat and human bone marrow mesenchymal stem cells differentiate into neurons with Musk's polypeptide

AIM: To investigate the differentiation from adult rat and human bone marrow mesenchymal stem cells (BMMSCs) into neuron with musk polypeptide (Mu-P).METHODS: Adult rat and human BMMSCs were induced with Mu-P.Neuron-specific enolase (NSE),neurofilament (NF),Nestin,glial fibrillary acidic protein (GFAP) were detected by immunohistochemistry.RESULTS: Simple methods with Mu-P induced adult rat and human BMMSCs exhibiting a neuronal phenotype,expressing Nestin at 3 hours to 5 hours,and expressing NE and NF at 5 hours to 7 days.But the neuron-like cells didn't express the glial astrocyte marker GFAP.CONCLUSION: Adult rat and human BMMSCs can be induced to differentiate into neurons with Mu-P.