Somatic cell hybrid between the established human line D98 (presumptive HeLa) and 3T3

Somatic cell hybrids have been made between an established human cell line with a long culture history and established mouse fibroblast line. When first analyzed, the hybrid cells contained nearly twice as many mouse chromosomes as the mouse parent line and a human chromosome complemnent of about half that of the human parent. There was further loss of human chromosomes on continued cultivation. This behavior resembles that of other human mouse hybrids and appears to be characteristic of the human-mouse combination. However, the number of human chromosomes is greater than in hybrids made from human diploid fibroblasts. Some clones contain more than a haptoid quantity of human DNA per cell and should synthesize a much greater number of human gene products.     

Senescence of nickel-transformed cells by an X chromosome: possible epigenetic control

Transfer of a normal Chinese hamster X chromosome (carried in a mouse A9 donor cell line) to a nickel-transformed Chinese hamster cell line with an Xq chromosome deletion resulted in senescense of these previously immortal cells. At early passages of the A9/CX donor cells, the hamster X chromosome was highly active, inducing senescence in 100% of the colonies obtained after its transfer into the nickel-transformed cells. However, senescence was reduced to 50% when Chinese hamster X chromosomes were transferred from later passage A9 cells. Full senescing activity of the intact hamster X chromosome was restored by treatment of the donor mouse cells with 5-azacytidine, which induced demethylation of DNA. These results suggest that a senescence gene or genes, which may be located on the Chinese hamster X chromosome, can be regulated by DNA methylation, and that escape from senescence and possibly loss of tumor suppressor gene activity can occur by epigenetic mechanisms.     

Superinduction of endogenous type C virus by 5-bromodeoxyuridine from transformed mouse clones

Certain transformed subclones of the mouse cell line BALB/3T3 release 5 to 15 times more type C virus per cell than the parent cell line after treatment with 5-bromodeoxyuridine. Virus release begins within 8 hours and exponentially increases for the first 24 to 48 hours. Superinducibility is associated with the transformed phenotype.     

猪─仓鼠杂种细胞中猪染色体鉴定

对猪与仓鼠细胞融合形成的一稳定的杂种细胞系进行染色体分析,Ｇ１１ 染色显示该杂种细胞中具有１ 条猪的染色体和２１ 条仓鼠染色体,经ＰＣＲ 检测确证该杂种细胞中含有猪１２ 号染色体     

早熟优质糯玉米杂交种苏玉糯2号的选育及应用

苏玉糯2号是江苏沿江地区农科所以自选系361为母本,自选系366为父本,于1994年组配成的糯玉米单交种,各级试验示范结果表明:苏玉糯2号比目前东南区和黄准海区生产上大面积种植的苏玉(糯)1号鲜果穗、干子粒产量各增产5%~10%以上,采收期早4~5 d,具有早熟,高产,优质的特点。     

Human chromosome 21 dosage: effect on the expression of the interferon induced antiviral state

Human primary skin fibroblasts trisomic for chromosome 13, 18, or 21 and diploid human skin fibroblasts were induced for an antiviral response with human interferon. The cells that were trisomnic for chromosome 21 were three to seven times more sensitive to protection by human interferon than the normal diploid or trisomic 18 or 13 fibroblasts. The differential response in trisomnic 21 cells is consistent with the known assignment of the human antiviral gene to chromosome 21.     

首创直接利用野生稻杂交选育恢复系与应用

袁隆平先生利用野生稻的败育型细胞质基因育成不育系,而笔者则首创了直接利用野生稻细胞核基因选育恢复系的新途径。笔者介绍了直接利用野生稻杂交选育恢复系的技术路线及方法,该法利用野生稻作为主体亲本,与多个各具有显著特点的恢复材料杂交,充分利用野生稻抗性强、适应性广、米质优等特点。采用“大群体多世代”的育种方法成功育成强优广谱性恢复系测253,并育成一系列高产、优质、多抗的新组合。笔者还介绍了测253及其配组组合的应用和产生的社会效益。     

谷胱甘肽产生菌株航天育种初探

以谷胱甘肽产生菌酿酒酵母(Saccharomyces cerevisiae)Y-15为出发菌株,经"实践八号"育种卫星搭载后,以放线菌素D作筛选标记,获得一株抗性突变体HY-90,经摇瓶发酵,谷胱甘肽产量达到123.04 mg/L,是出发菌株的1.7倍,其胞内含量为14.86 mg/g,是出发菌株的1.5倍。此外,本试验还对谷胱甘肽乙醇抽提法作了优化。结果表明:将酵母干菌体按质量体积比1∶90∶10,用40%的乙醇和25%的偏磷酸进行抽提,可提高提取率。     

Interferon: protection of cells infected with an intracellular protozoan (Toxoplasma gondii)

Chick and mouse cell monolayers treated with interferon were significantly protected from destruction by toxoplasma. The results suggest that fewer numbers of organisms were released from interferon-treated cells. Interferons were uniformly more active in a viral assay than in a toxoplasma assay, and they had the same properties in both assays. The data suggest that interferon activity may be directed against organisms phylogenetically higher than viruses.     

Strain dependence of the antiproliferative action of interferon on murine erythroid precursors

Electrophoretically pure mouse interferon inhibits erythropoietin-dependent proliferation of committed erythroid precursors (CFU-E) obtained either from adult mouse bone marrow or from 14-day fetal mouse livers. The degree of inhibition is significantly influenced by the genotype of the cell donor; about ten times as much interferon is required to inhibit proliferation of CFU-E from C57BL/6 than is needed for comparable inhibition of CFU-E from BALB/c or Swiss mice. These strain-dependent results point to the existence of genes that influence the degree of the inhibitory effect of interferon on cell multiplication.     

Hybrid cell line from a cloned immunoglobulin-producing mouse myeloma and a nonproducing mouse lymphoma

A hybrid cell line was established by cell fusion between a cloned Balbic myeloma that is resistant to 8-azaguanine and produces immunoglobulin (gammaG and free kappa chain) and C57BL/6N lymphoma that is resistant to bromo-deoxyuridine and does not produce immunoglobulins. The hybrid cells contained the membrane antigens of both parents; they synthesized free kappa chain; no synthesis of gammaG (gamma(2a)) heavy chain was detected.     

北方杂交粳稻核心亲本的播始历期及其稳定性的分析

对于亲本播始历期的准确把握是确保杂交稻制种父母本花期相遇的根本。然而由于水稻的光温敏感性,其播始历期受环境影响较大,而且品种间也存在很大差异,很难做一般性的把握。作者从杂交稻的育种实践出发,采用在不同年份和地点进行分期播种和插秧的方法,对北方杂交粳稻核心亲本的播始历期及其稳定性进行研究。结果表明:(1)多数不育系与保持系播始历期差异不明显;(2)核心亲本105A,91A,95A,99A,02A,屉A,C52,C258,C01,C418的基本播始历期分别为104.7,105,104.8,107.7。106.8,106.9,105.7,111,107.1,115.6d;(3)播始历期具有明显的年份、地点、播期和秧龄效应及其间互作效应;(4)总体上105A、C258,C01,91A,C418的播始历期稳定性较差,而C52,99A,TA,02A,95A稳定性较好。     

超级杂交早稻陆两优996亲本感温特性研究

[目的]研究和探讨两系超级杂交早稻(Oryza sativa L.)陆两优996亲本陆18S和R996的生育期感温特性,尤其对双亲播种至始穗历期与积温的关系进行研究,有利于合理安排其父母本播差期和早期花期预测与调控。[方法]陆18S分5期(3月26日、4月14日、5月21日、6月7日、6月21日)播种,R996也分5期(3月26日、4月20日、5月27日、6月12日、6月29日)播种,分别记载父母本早季低温和晚季高温两播期播种至抽穗期的日期,观察生育动态,并对亲本生育期各阶段有效积温的稳定性以及有效积温与播始历期进行相关和回归分析。[结果]R996感温级别为Ⅵ级,属于中等感温类型;陆18S感温级别为Ⅶ级,属于强感温类型,双亲的感温特性略有差异。[结论]该研究可为解决陆18S与R996组合制种父母本花期不遇问题提供指导。     

芦花鸡与安卡红鸡杂交效果的研究

以地方芦花鸡做母本,安卡红鸡为父本进行杂交试验。试验表明,在10周龄时杂交鸡公鸡体重为2 268.5 g。母鸡为1 947.6g。分别高出亲本芦花鸡284.2 g和264.9 g。饲料转化率分别为2.46和2.58,呈现了很好的杂交优势。     

应用花培技术选育水稻光敏核不育系

对粳型光敏核不育系，常规粳稻品种及其Ｆ１杂种进行花药培养，所得花粉植株用于分期播种和进入人工气候箱以鉴定光敏核不育性．结果表明：不同光敏核不育系及其杂种Ｆ１培养力存在明显差异．从组合Ｎ５０４７Ｓ／浙农大４０和Ｎ５０４７Ｓ／０２４２８分别获得８４个和３５个二倍体花培系，构建成了两个ＤＨ群体；在长日下这两个ＤＨ群体育性发生明显分离，其中２８份为光敏核不育系，短日下各花培系都可育；从Ｎ５０４７Ｓ／０２４２８组合中筛选出一个花培系浙农大１３Ｓ（ＨＰ１３Ｓ），经人工气候箱鉴定表现为光敏核不育特性．不育期为８月上旬到９月２日，长达２０多天，制种是安全的，可育期结实率高，繁种也不成问题     

上农香、黑糯等品种及其杂交后代选系的酯酶同工酶分析

本文利用同工酶电泳技术,分析了上农香、黑糯等4个品种及其6个杂交后代选系的酯酶同工酶谱。结果表明,不同品种（品系）酶谱基本相似;但也各有特异带,其中b_1、b_2带酶活性较强,可作为上农特种稻的特异性标志带。除Z_(17-3),其他杂交后代与母本相似度较高。     

Endogenous regulation of macrophage proliferative expansion by colony-stimulating factor-induced interferon

Stimulation of cultures of murine bone-marrow cells with specific macrophage growth factor (colony-stimulating factor I) resulted in the production of type I interferon. Neutralization of this endogenous interferon by antiserum directed against interferons alpha and beta resulted in a significant enhancement of mononuclear phagocyte proliferation from committed marrow precursors. The effect of the antiserum was lost in cultures depleted of adherent cells, an indication that an adherent regulatory cell (or cells) in the marrow limits mononuclear phagocyte proliferation by producing antiproliferative interferon in response to high levels of specific growth factor.     

Interferon-resistant cell line lacks fatty acid cyclooxygenase activity

A clone of L1210 mouse leukemia cells selected for resistance to both the antiviral and anticellular properties of mouse interferon were essentially devoid of fatty acid cyclooxygenase activity. Experiments in which broken cell preparations were mixed or the two cell types were cultivated together failed to indicate the presence of a diffusible enzyme inhibitor. Fatty acid lipoxygenase activity of similar magnitude was detectable in both cell types. A selective impairment of fatty acid cyclooxygenase in interferon-resistant cells is consistent with recently described data suggesting that this enzyme may play a crucial role in mediating the antiviral and anticellular effects of interferon.