P2 receptors in the thymus: expression of P2X and P2Y receptors in adult rats, an immunohistochemical and in situ hybridisation study

The expression of the seven P2X receptor subtypes and of two P2Y receptors was examined immunohistochemically and by in situ hybridisation in thymi of adult male rats. P2X4, P2Y2 and 4 receptor mRNA colocalisation studies combining in situ hybridisation and immunohistochemistry were also carried out. P2X and P2Y receptors were found on thymocytes. P2X receptors were also abundant in cells of the thymic microenvironment, involved in control of T-cell maturation in vivo. We are the first to describe the expression of P2X4 receptors on thymocytes and confirm the finding of P2X1 and P2Y2 receptors on subpopulations of lymphocytes. P2X1,2,3,4 and 5 receptors were present in blood vessels of the thymus. P2X1,2 and 4 receptors were detected in vascular smooth muscle, while P2X3 receptors appeared to be associated with endothelial cells; some small arteries were positive for P2X5, possibly labelling vascular smooth muscle or fibroblasts in the adventitia. P2X2,3,6 and 7 receptors were found on thymic epithelial cells. P2X2 and 3 receptors were abundant on medullary epithelial cells, whilst P2X6 receptors were prominent in Hassall's corpuscles. P2X2 receptors were found on subcapsular and perivascular epithelial cells. P2X2,6 and 7 receptors were detected in epithelial cells along the thymic septa. Expression of P2X receptors was also investigated by Western blotting of crude thymic tissue extracts under reducing conditions. All seven P2X receptor subtypes were found to be dimers of approximately 70 kDa and 140 kDa molecular weight. ATP-mediated apoptosis and cell proliferation of thymocytes are discussed.     

铜、铅、镉、锌、汞和银离子复合污染对水螅的急性毒性效应

以水螅(Hydrasp)为例,通过单因子静态急性毒性试验方法和等毒性溶液法,分别研究Hg2 、Cu2 、Cd2 、Ag 、Zn2 和Pb2 对其单一和复合毒性效应。单一实验结果表明,它们对水螅毒性大小顺序为Hg2 >Cu2 >Cd2 >Ag >Zn2 >Pb2 。复合毒性实验表明,Zn2 与Cu2 、Hg2 、Pb2 、Ag ;Pb2 与Cu2 ;Hg2 与Ag ;Pb2 与Ag 这些组合对水螅联合急性毒性总体上表现出拮抗作用,Cd2 与Cu2 、Hg2 、Pb2 、Ag 组合总体上则是协同作用,Zn2 与Cd2 、Pb2与Hg2 、Cu2 与Hg2 ,Ag 在不同的浓度水平组合下明显表现出不同的毒性效应。     

P16降低二倍体成纤维细胞的凋亡敏感性

脂质体介导法分别介导正、反义p16逆转录病毒表达载体转染人胚肺二倍体成纤维细胞 ,经鉴定后 ,分别用Hoechst33342 PI双染、TUNEL、DNAladder分析检测各转染细胞对H2 O2 的敏感性 .结果显示 ,反义p16重组体转染细胞较易凋亡 ,而正义p16重组体转染细胞不易凋亡 .Western印迹检测显示 ,正义p16重组体转染细胞中P2 1表达增强 ,caspase 3的表达减弱 .H2 O2 作用后 ,正义p16重组体转染细胞Bcl 2蛋白水平显著高于反义p16重组体转染细胞 .     

Quantitative variations of the isoforms in haptoglobin 1-2 and 2-2 individual phenotypes

Haptoglobin is a hemoglobin-binding protein presenting in humans three distinct phenotypes (Hpt 1-1, Hpt 1-2, or Hpt 2-2). The Hpt 1-2 and Hpt 2-2 phenotypes are in turn represented by populations of isoforms. The relative amounts of the major isoforms of Hpt 1-2 and Hpt 2-2 were found to differ not only in different individuals, but also in the same individual before and after a physical effort. Exercise-dependent changes in the plasma concentrations of ascorbate, urate, alpha-tocopherol, retinol, and glutathione were also observed, but correlations between such changes and those of the amount for any isoform were not found. Samples of Hpt 1-2 or Hpt 2-2 were challenged with oxidants (H(2)O(2) with ferrous ions, spermine-NO, KO(2), and 3-morpholinosydnonimine), but the isoform levels were not altered. Hpt 2-2 isoforms were present in Hpt 1-2, as minor species. Furthermore, different isoforms exhibited different hemoglobin binding abilities. Thus, these parameters should also be taken into consideration in studies correlating Hpt phenotypes prevalence with pathologies or functional differences.     

杭州地区发酵乳制品中乳酸菌发生耐药传播的安全性研究

目的对杭州地区市售发酵乳制品中分离鉴定的乳酸菌进行耐药传播的安全性分析,旨在揭示发酵乳制品中是否存在可传递耐药基因的超级耐药菌。方法自行分离鉴定的耐药乳酸菌,提取质粒并电泳分析是否存在质粒;以耐受叠氮化钠的大肠埃希菌J53作为受体菌进行质粒接合试验;若乳酸菌存在耐药现象,发现存在耐药质粒,且耐药性可通过质粒传播,评定为3级。乳酸菌存在耐药现象,发现存在耐药质粒,但接合试验未能证明耐药性可通过质粒传播,评定为2级。乳酸菌存在耐药现象,但未检测出耐药质粒,评定为1级。结果美丽健产品中分离的双歧杆菌（MLJ-G-2）和乳杆菌（MLJ-G-1）检测出含有质粒,但不会发生耐药转移,三种菌耐药危害等级分别为2、2、1。伊利产品中分离的双歧杆菌（YL-G-3）、乳杆菌（YL-G-1）、嗜热链球菌（YL-Q）检测出含有质粒,但不会发生耐药转移,四种菌耐药危害等级分别为2、2、1、2。味全产品中分离的双歧杆菌（WQ-G-3）、乳杆菌（WQ-G-1）、乳杆菌（WQ-G-2）、嗜热链球菌（WQ-Q）均检测出含有质粒,其中乳杆菌（WQ-G-1）、乳杆菌（WQ-G-2）会发生耐药转移,四种菌耐药危害等级分别为2、3、3、2。光明产品中分离的乳杆菌（GM-G-2）、乳杆菌（GM-G-3）、嗜热链球菌（GMQ）检测出含有质粒,乳杆菌（GM-G-2）会发生耐药转移,四种菌耐药危害等级分别为2、1、3、2。蒙牛产品中只分离的嗜热链球菌（MN-Q）检测出含有质粒,不会发生耐药转移,耐药危害等级为2。结论发酵乳制品中分离所得的乳酸菌81.2%的菌能检测出质粒,耐药性可能与质粒相关,存在潜在的生物安全威胁;18.8%的菌的耐药性可通过质粒接合发生传播,存在直接的生物安全威胁。     

TGM2 interference regulates the angiogenesis and apoptosis of colorectal cancer via Wnt/β-catenin pathway

Angiogenesis and apoptosis are critical for the growth of colorectal cancer (CRC). The study aimed to investigate the effects of TGM2 in CRC. Forty-two patients were recruited and their TGM2 levels were detected by performing Realtime-qPCR (RT-qPCR), Western blot and immunohistochemistry , respectively. Levels of TGM2, MMP-2 and MMP-9 in four CRC cell lines and in normal cells were determined using RT-qPCR and Western blot. TGM2-siRNA was transfected into LoVo and HCT116 cells, respectively. TGM2 levels, cell viability, cell apoptosis, angiogenesis and related factors were determined. the tumorigenesis rates of mice were detected after TGM2-siRNA transfection. TGM2 were upregulated in patients with CRC. High TGM2 level of CRC patients had a lower survival rate. The levels of TGM2, MMP-2 and MMP-9 were upregulated in all detected CRC cell lines. Silencing TGM2 could inhibit cell viabilities, angiogenesis and suppress the expressions of MMP-2, MMP-9, Wnt3a, β-catenin and Cyclin D1 , whereas cell apoptosis and the expressions of Caspase-3 and TIMP-1 were promoted. Tumor weights and volumes were reduced by TGM2-siRNA interference. The effects of TGM2-siRNA interference might be related to Wnt/β-catenin Pathway. This might prove that TGM2 could be used as a molecular target in the treatment of CRC.     

Modulation of cytosolic-free calcium transients by changes in intracellular calcium-buffering capacity: correlation with exocytosis and O2-production in human neutrophils

The intracellularly trapped fluorescent calcium indicator, quin 2, was used not only to monitor changes in cytosolic-free calcium, [Ca2+]i, but also to assess the role of [Ca2+]i in neutrophil function. To increase cytosolic calcium buffering, human neutrophils were loaded with various quin 2 concentrations, and [Ca2+]i transients, granule content release as well as superoxide [O2-] production were measured in response to the chemotactic peptide formyl-methionyl-leucyl- phenylalanine (fMLP) and the calcium ionophore ionomycin. Receptor- mediated cell activation induced by fMLP caused a rapid rise in [Ca2+]i. The extent of [Ca2+]i rise and granule release were inversely correlated with the intracellular concentration of quin 2, [quin 2]i. These effects of [quin 2]i were more pronounced in the absence of extracellular Ca2+. The initial rate and extent of fMLP-induced O2- production were also inhibited by [quin 2]i. The rates of increase of [Ca2+]i and granule release elicited by ionomycin were also inversely correlated with [quin 2]i in Ca2+-containing medium. As the effects of ionomycin, in contrast to those of fMLP, are sustained, the final increase in [Ca2+]i and granule release were not affected by [quin 2]i. A further reduction of fMLP effects was seen when intracellular calcium stores were depleted by incubating the cells in Ca2+-free medium with ionomycin. The specificity of quin 2 effects on cellular calcium were confirmed by loading the cells with Anis/AM, a structural analog of quin 2 with low affinity for calcium which did not inhibit granule release. In addition, functional responses to phorbol myristate acetate (PMA), which stimulates neutrophils without raising [Ca2+]i, were not affected by [quin 2]i. The findings indicate that rises in [Ca2+]i control the rate and extent of granule exocytosis and O2-generation in human neutrophils exposed to the chemotactic peptide fMLP.     

人SPRED2 基因重组腺病毒载体的制备及其对K562 细胞

目的:构建携带SPRED2的质粒载体与重组腺病毒载体,并观察其在K562细胞的表达及对ERK信号通路的作用,为Spred2在造血细胞中的作用的研究奠定基础。方法:以HepG2细胞cDNA为模板,RT-PCR克隆SPRED2全长CDS序列,并亚克隆到pCDNA3.0和pshuttle-CMV质粒载体,构建携带SPRED2的真核表达载体pCDNA3.0-Spred2与穿梭载体pshuttle-CMV-Spred2;将线性化pshuttle-CMV-Spred2与腺病毒骨架质粒Adf11p在感受态细胞BJ5183中进行同源重组,产生重组质粒Adf11p-Spred2;后者经线性化后转染至HEK293细胞进行病毒包装;在HEK293细胞扩增病毒颗粒,以CsCl密度梯度离心法进行纯化,TCID50法测定病毒滴度;将病毒颗粒以100MOI感染K562细胞,Western blot检测Spred2过表达情况及Spred2对细胞ERK的影响。结果:经酶切、DNA测序、Western blot检测等方法鉴定,证明pCDNA3.0-Spred2与Adf11p-Spred2携带Spred2序列正确,能够在HEK293细胞、K562细胞正确表达,Spred2过表达能够显著抑制K562细胞ERK活性。结论:成功构建对K562细胞有高感染效率的SPRED2重组腺病毒载体,且Spred2对K562细胞ERK信号通路有显著抑制作用。     

Structures of deepoxytrichothecene metabolites from 3'-hydroxy HT-2 toxin and T-2 tetraol in rats.

3'-Hydroxy HT-2 toxin and T-2 tetraol, in vivo metabolites of T-2 toxin, were orally administered to Wistar rats, and four metabolites having a trichothec-9,12-diene nucleus, which were termed deepoxytrichothecenes, were newly found in the excreta. Their structures were confirmed as 3'-hydroxy-deepoxy HT-2, 3'-hydroxy-deepoxy T-2 triol, 15-acetyl-deepoxy T-2 tetraol, and deepoxy T-2 tetraol on the basis of mass and nuclear magnetic resonance spectroscopy. Resolution of T-2 metabolites and corresponding deepoxytrichothecenes by gas-liquid and thin-layer chromatography was also described.     

Pressure overload-induced hypertrophy in transgenic mice selectively overexpressing AT2 receptors in ventricular myocytes

The role of the angiotensin II type 2 (AT2) receptor in cardiac hypertrophy remains controversial. We studied the effects of AT2 receptors on chronic pressure overload-induced cardiac hypertrophy in transgenic mice selectively overexpressing AT2 receptors in ventricular myocytes. Left ventricular (LV) hypertrophy was induced by ascending aorta banding (AS). Transgenic mice overexpressing AT2 (AT2TG-AS) and nontransgenic mice (NTG-AS) were studied after 70 days of aortic banding. Nonbanded NTG mice were used as controls. LV function was determined by catheterization via LV puncture and cardiac magnetic resonance imaging. LV myocyte diameter and interstitial collagen were determined by confocal microscopy. Atrial natriuretic polypeptide (ANP) and brain natriuretic peptide (BNP) were analyzed by Northern blot. Sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA)2, inducible nitric oxide synthase (iNOS), endothelial NOS, ERK1/2, p70S6K, Src-homology 2 domain-containing protein tyrosine phosphatase-1, and protein serine/threonine phosphatase 2A were analyzed by Western blot. LV myocyte diameter and collagen were significantly reduced in AT2TG-AS compared with NTG-AS mice. LV anterior and posterior wall thickness were not different between AT2TG-AS and NTG-AS mice. LV systolic and diastolic dimensions were significantly higher in AT2TG-AS than in NTG-AS mice. LV systolic pressure and end-diastolic pressure were lower in AT2TG-AS than in NTG-AS mice. ANP, BNP, and SERCA2 were not different between AT2TG-AS and NTG-AS mice. Phospholamban (PLB) and the PLB-to-SERCA2 ratio were significantly higher in AT2TG-AS than in NTG-AS mice. iNOS was higher in AT2TG-AS than in NTG-AS mice but not significantly different. Our results indicate that AT2 receptor overexpression modified the pathological hypertrophic response to aortic banding in transgenic mice.     

碱提工艺对茶树菇多糖形貌特征和构象及其生物活性的影响

利用传统水提及碱提的方法得到茶树菇粗多糖S-ACP和J-ACP,经CTAB法和Sephadex G-150凝胶层析法对其分离纯化,分别得到S-ACP2-1和S-ACP2-2以及J-ACP2-1和J-ACP2-2两组主要组分,用扫描电子显微镜（SEM）和原子力显微镜（AFM）对多糖的形貌进行表征并测定其体外抗氧化活性和抗肿瘤活性;对多糖S-ACP2-2、J-ACP2-2进行刚果红实验测定及圆二色谱仪（CD）分析。SEM观测结果：S-ACP2-1为较粗的表面光滑的丝状,J-ACP2-1呈较细的有少量碎屑的丝状;S-ACP2-2为较大的片状,J-ACP2-2在大的片状周围有很多细小的碎屑。AFM观测结果：碱液可以使多糖分子部分断裂成小片段。刚果红实验：S-ACP2-2、J-ACP2-2在水溶液中为自由卷曲构型。CD分析：S-ACP2-2的空间构型中有序结构较少,J-ACP2-2在水溶液中为无序构型。对比4种多糖的活性,碱液作用的多糖J-ACP2-2活性高于S-ACP2-2。     

福建武夷山黄山松群落的氮、磷累积和循环

本文是福建武夷山森林生态系统研究的一部分,主要讨论黄山松（Pinustaiwanensis）群落的氮磷累积和循环。测定结果表明：（1）群落现存量中氮（N）、磷（P）的库量分别为925．844kghm-2和45．981kghm-2,其中地上部分别为719．438kghm-2（占总库量的77．706%）和35．534kghm-2占77.280％）,地下部分别为206．406kghm-2（占22．294％）和10．447kghm-2（占22.720％）;（2）N、P的生物循环中,年吸收量分别为65．344kghm-2和2627kghm-2,年存留量分别为37．019kghm-2和1．695kghm-2,年归还量分别为28．325kghm-2和0.932kghm-2;（3）氮、磷的富集率分别为1．324和1．083两者均大于1,说明该群落对N、P仍在不断累积。     

Lethal and mutagenic action of hydrogen peroxide on Haemophilus influenzae.

The lethal and mutagenic effects of H2O2 on wild-type Haemophilus influenzae Rd and on uvr1, uvr2, rec1, and rec2 mutant strains were studied. The first two mutants are sensitive to UV, and the second two are defective in recombination. Rd, urv1, and rec1 strains were more sensitive to the killing effect of H2O2 treatment than were uvr2 and rec2 strains. There were peaks of mutagenesis at two H2O2 concentrations over a range of 30 to 275 mM. Our results suggest a specific repair of H2O2 damage that is independent of the Uvr2 and Rec2 gene products. Sensitivity to the killing effect of H2O2 and to the lethal action of near-UV light were similar for Rd and uvr1 strains. This finding suggests that the mechanisms of killing by and repair of H2O2 damage may have some overlap with those of near-UV radiation.     

大戟科野桐属4种6个居群的核型研究

采用常规压片法对大戟科野桐属4种(含变种)6个居群进行了体细胞染色体数目和核型研究。研究结果显示其染色体数目为2n=22或2n=44,核型均为1A。核型公式分别为:绒毛野桐2n=4x=44m;白背叶2n=20m 2sm或2n=2x=22m或2n=20m(2sat) 2sm;广西白背叶2n=2x=22m;毛桐2n=2x=22m。其中白背叶[Mallotus apelta(Lour.)Muell.-Arg.]、广西白背叶[M.apelta(Lour.)Muell.-Arg.var.kwangsiensisMetic.]和毛桐[M.barbatus(Wall.)Muell.-Arg.]的染色体数目和核型均为首次报道。根据野桐属细胞分类学资料推测,多倍化和异基数变异是野桐属属内物种形成的重要方式。     

小鼠Prx2正义和反义真核表达载体的构建与表达

目的：构建小鼠Prx2正义及反义真核表达载体pEGFP-N1-sPrx2、pEGFP-N1-aPrx2并在小鼠卵巢颗粒细胞中表达。方法：应用RT—PCR技术,从小鼠卵巢颗粒细胞提取的总RNA中,获得Prx2基因编码序列的正义及反义片段,克隆至真核表达载体pEGFP—N1中,对重组质粒进行酶切和测序鉴定后,以脂质体介导法转染至体外培养的未成熟小鼠颗粒细胞,通过荧光显微镜观察和Westernblot检测其在颗粒细胞中的表达改变。结果：酶切和测序证明重组真核衰达载体pEGFP—N1一sPrx2、pEGFP—N1-aPrx2构建成功,荧光显微镜观察及Westernblot确认目标蛋白在颗粒细胞中表达增强或减弱。结论：成功构建小鼠Prx2基因正义及反义真核表达载体pEGFP-N1-sPrx2、pEGFP-N1．aPrx2并在小鼠卵巢颗粒细胞中表达。     

Chemical phenotypes of P2X2 purinoreceptor immunoreactive cell bodies in the area postrema

Purines such as adenosine 5'-triphosphate (ATP) act as extracellular messengers through specific purinergic receptors. Three different classes of purinergic receptors have been identified and termed P1, P2X, and P2Y. The purinergic receptor subunit P2X2 is a ligand-gated ion channel that is widely expressed by neurons in the CNS. In the brainstem medulla oblongata, the ionotropic P2X2 receptor (P2X2R) is enriched in the area postrema (AP). Two different antisera to P2X2R were used to determine the chemical nature of P2X2R immunoreactive cell bodies in the rat AP, an area lacking a blood-brain barrier. Subcellularly, P2X2R immunoreactivity was located to the periphery of individual cell bodies. The majority of P2X2R-immunoreactive cells were shown to contain tyrosine hydroxylase (TH) (63.5 ± 7.7%) and dopamine β-hydroxylase (61.5 ± 5.1%). Phenylethanolamine N-methyltransferase (PNMT)-containing cells were not detected in the AP, supporting a noradrenergic nature of P2X2R cells in the AP. There were no P2X2R-immunoreactive cells in the AP that contained the GABA-synthesizing enzyme glutamic acid decarboxylase 65. Only single vesicular glutamate transporter 2-immunoreactive cell bodies that were not P2X2R-positive were demonstrated in the AP. Some P2X2R-positive cells in the AP were immunoreactive for the neuropeptides substance P and pituitary adenylate cyclase-activating polypeptide, whereas dynorphin-, enkephalin-, or cholecystokinin-positive cells were not P2X2R-immunoreactive. Presence of P2X2R in a majority of noradrenergic cells of the AP implies that ATP may have a regulatory action on neuronal noradrenaline release from the AP, a circumventricular organ with a strategic position enabling interactions between circulating substances and the central nervous system.     

Her-2 DNA versus cell vaccine: immunogenicity and anti-tumor activity

Direct comparison and ranking of vaccine formulations in pre-clinical studies will expedite the identification of cancer vaccines for clinical trials. Two human ErbB-2 (Her-2) vaccines, naked DNA and whole cell vaccine, were tested side-by-side in wild type and Her-2 transgenic mice. Both vaccines can induce humoral and cellular immunity to the entire repertoire of Her-2 epitopes. Mice were electro-vaccinated i.m. with a mixture of pGM-CSF and pE2TM, the latter encodes Her-2 extracellular and transmembrane domains. Alternatively, mice were injected i.p. with human ovarian cancer SKOV3 cells that have amplified Her-2. In wild type mice, comparable levels of Her-2 antibodies (Ab) were induced by these two vaccines. However, T cell immunity and protection against Her-2⁺ tumors were superior in DNA vaccinated mice. In BALB Her-2 transgenic (Tg) mice, which were tolerant to Her-2, DNA and cell vaccines were administered after regulatory T cells (Treg) were removed by anti-CD25 mAb. Again, comparable levels of Her-2 Ab were induced, but DNA vaccines rendered greater anti-tumor activity. In B6xDR3 Her-2 Tg mice that expressed the autoimmune prone HLA-DR3 allele, higher levels of Her-2 Ab were induced by SKOV3 cell than by Her-2 DNA. But anti-tumor activity was still more profound in DNA vaccinated mice. Therefore, Her-2 DNA vaccine induced greater anti-tumor immunity than cell vaccine, whether mice were tolerant to Her-2 or susceptible to autoimmunity. Through such side-by-side comparisons in appropriate pre-clinical test systems, the more effective vaccine formulations will emerge as candidates for clinical trials. P. J. Whittington, O. Radkevich-Brown and J. B. Jacob have contributed equally to this work.     

Production and characterization of antibodies against HT-2 toxin and T-2 tetraol tetraacetate.

Three new immunogens which were prepared by conjugation of the carboxymethyl oxime (CMO) derivatives of HT-2 toxin, T-2 tetraol (T-2 4ol), and T-2 tetraol tetraacetate (T-2 4Ac) to bovine serum albumin (BSA) were tested for the production of antibodies against the major metabolites of T-2 toxin. Antibodies against HT-2 toxin and T-2 4Ac were obtained from rabbits 5 to 10 weeks after immunizing the animals with CMO-HT-2-BSA and CMO-T-2 4Ac-BSA conjugates. Immunization with CMO-T-2 4ol-BSA resulted in no antibody against T-2 4ol. The antibody produced against HT-2 toxin had great affinity for HT-2 toxin as well as good cross-reactivity with T-2 toxin. The relative cross-reactivities of anti-HT-2 toxin antibody with HT-2 toxin, T-2 toxin, iso-T-2 toxin, acetyl-T-2 toxin, 3'-OH HT-2, 3'-OH T-2, T-2 triol, and 3'-OH acetyl-T-2, were 100, 25, 10, 3.3, 0.25, 0.15, 0.12 and 0.08%, respectively. Antibody against CMO-T-2 4Ac was very specific for T-2 4Ac and had less than 0.1% cross-reactivity with T-2 toxin, HT-2 toxin, acetyl-T-2 toxin, diacetoxyscirpenol, deoxynivalenol, and deoxynivalenol triacetate as compared with T-2 4Ac. The detection limits for HT-2 toxin and T-2 4ol by radioimmunoassay were approximately 0.1 and 0.5 ng per assay, respectively.     

Secondary Trisomics and Telotrisomics of Rice: Origin, Characterization, and Use in Determining the Orientation of Chromosome Map

Secondary trisomics and telotrisomics representing the 12 chromosomes of rice were isolated from the progenies of primary trisomics. A large population of each primary trisomic was grown. Plants showing variation in gross morphology compared to the primary trisomics and disomic sibs were selected and analyzed cytologically at diakinesis and pachytene. Secondary trisomics for both arms of chromosomes 1, 2, 6, 7 and 11 and for one arm of chromosomes 4, 5, 8, 9 and 12 were identified. Telotrisomics for short arm of chromosomes 1, 8, 9 and 10 and for long arms of chromosomes 2, 3 and 5 were isolated. These secondary and telotrisomics were characterized morphologically and for breeding behavior. Secondary trisomics 2n + 1S.1S, 2n + 1L.1L, 2n + 2S.2S, 2n + 2L.2L, 2n + 6S.6S, 2n + 6L.6L and 2n + 7L.7L are highly sterile, and 2n + 1L.1L, 2n + 2L.2L and 2n + 7L.7L do not set any seed even upon backcrossing. Telotrisomics are fertile and vigorous. Genetic segregation of 43 marker genes was studied in the F(2) or backcross progenies. On the basis of segregation data, these genes were delimited to specific chromosome arms. Correct orientation of 10 linkage groups was determined and centromere positions on nine linkage groups were approximated. A revised linkage map of rice is presented.     

Successive spontaneous abortions including one with whole-arm translocation between chromosomes 2

Summary A family with five induced and seven spontaneous abortions and no live births is described. Four of the seven spontaneous abortuses were available for cytogenetic examination and three were successfully karyotyped. Their karyotypes were 46,XX; 46,XX/46,XX,t(2;2)(2p2p;2q2q); and 46,XY. The karyotypes of the parents were normal. The origin of the 2p/2p and 2p/2p translocation in one of the abortuses was assigned to an interhomologous whole-arm translocation in an early mitotic division in a conceptus with a 46,XX karyotype.