Familial imprinting determines H-2 selective mating preferences

Inbred male mice typically prefer to mate with females of a different, non-self H-2 haplotype. To determine whether this natural preference is irrevocable or results from familial imprinting, a test system was used which relied on previous observations that B6 males (H-2b) mate preferentially with congenic B6-H-2k rather than B6 females, and B6-H-2k males with B6 females. This preference was reversed in B6 males fostered by B6-H-2k parents and in B6-H-2k males fostered by B6 parents, preference in these cases favoring the same H-2 type. Thus, H-2 selective mating preference is acquired by imprinting on familial H-2 types.     

Genetic control of the antibody response: relationship between immune response and histocompatibility (H-2) type

The immune responses of inbred mice to a related series of three synthetic polypeptide antigens are genetically controlled traits which are closely correlated with the genotype for the major histocompatibility (H-2) locus. All strains of the same H-2 type exhibit the same pattern of immune response, independent of the remainder of a given strain's genetic background. There is marked antigen-specific polymorphism between strains of different H-2 types with respect to their patterns of response.     

Autoimmune murine thyroiditis relation to histocompatibility (H-2) type

Immunization of 33 inbred strains of mice with thyroid extract emulsified in complete Freund's adjuvant showed differences in both thyroid autoantibody response and autoimmune thyroid damage, related to the histocompatibility (H-2) type of the strain. Congenic mice of the same H-2 type exhibited the same pattern of antibody response and thyroiditis, regardless of the strain's genetic background, thus showing a close relation between histocompatibility determinants and autoimmunity.     

Prevention of allogeneic bone marrow graft rejection by H-2 transgene in donor mice

Rejection of bone marrow grafts in irradiated mice is mediated by natural killer (NK) cells and is controlled by genes linked to the major histocompatibility complex (MHC). It has, however, not been possible to identify the genes or their products. An MHC class I (Dd) transgene introduced in C57BL donors prevented the rejection of their bone marrow by NK cells in irradiated allogeneic and F1 hybrid mice expressing the Dd gene. Conversely, H-2Dd transgenic C57BL recipients acquired the ability to reject bone marrow from C57BL donors but not from H-2Dd transgenic C57BL donors. These results provide formal evidence that NK cells are part of a system capable of rejecting cells because they lack normal genes of the host type, in contrast to T cells, which recognize cells that contain abnormal or novel sequences of non-host type.     

Homograft tolerance in mice: use of urethan and sublethal irradiation

Adult mice [CBA/J (H-2(k))], which received either a single sublethal dose of x-radiation (500 rad) or urethan plus 500 rad, were given intravenous injections of C3H/HeJ (H-2(k)) spleen or bone marrow cells (18 to 42 x 10(6) cells per mouse) or both, for 3 days. C3H/HeJ tail-skin homografts were retained (over 130 days) by these mice, whereas BALB/cJ (H-2(d)) homografts all were rejected within 33 days. Similarly irradiated or urethan-treated controls (or controls treated with a combination of both), which did not receive C3H cells, rejected both homografts. Specific homograft tolerance is induced in adult mice by this procedure.     

Male-specific antigen: modification of potency by the H-2 locus in mice

Skin grafts from C57BL/10 (B10) male mice survive significantly longer than do B10.BR male skin grafts on (B10 x X B10.BR)F(1) females. This indicates that the H-2 locus influences the potency of the male-specific antigen in mice.     

H-2-linked resistance to mastocytoma in male mice: immune response to a histocompatibility antigen on the X chromosome

Male hybrids from a cross between female mice of strain C57BL/6Kh and males of strain DBA/2J lived longer after injection of P815 mastocytoma cells of DBA/2 origin than did their female siblings. Responses to the histocompatibility antigen on the X chromosome of the DBA/2 strain may be involved in resistance to the tumor. When the female parent was replaced with a C57BL/6Kh carrying one of several mutations in the H-2 region, this sex effect disappeared in some of the hybrid combinations. Thus, the H-2 complex appears to be involved in the regulation of the immune response to the X-linked histocompatibility antigen in this tumor model.     

H-2 antigen class: effect on mouse islet allograft rejection

Rejection of mouse pancreatic islet allografts occurred in a high percentage of donor recipient combinations identical for H-21-region antigens and differing at H-2K and H-2K + H-2D without I-region disparities. The results suggest that disparities in major histocompatibility complex antigens of class I (H-2K and H-2D) alone are capable of eliciting islet allograft rejection, and that lack of a stimulus from class II (I-region) alloantigens does not ensure permanent islet allograft survival.     

Genomic instability in mice lacking histone H2AX

Higher order chromatin structure presents a barrier to the recognition and repair of DNA damage. Double-strand breaks (DSBs) induce histone H2AX phosphorylation, which is associated with the recruitment of repair factors to damaged DNA. To help clarify the physiological role of H2AX, we targeted H2AX in mice. Although H2AX is not essential for irradiation-induced cell-cycle checkpoints, H2AX-/- mice were radiation sensitive, growth retarded, and immune deficient, and mutant males were infertile. These pleiotropic phenotypes were associated with chromosomal instability, repair defects, and impaired recruitment of Nbs1, 53bp1, and Brca1, but not Rad51, to irradiation-induced foci. Thus, H2AX is critical for facilitating the assembly of specific DNA-repair complexes on damaged DNA.     

Recognition of H-2 types in relation to the blocking of pregnancy in mice

Inbred BALB/c females were mated and subsequently exposed in a divided cage to "stimulus" males or females whose H-2 type was similar or dissimilar to the stud male's. The incidence of pregnancy blocking was considerably higher when stud and stimulus males differed in H-2 type than when they did not. Similar results were obtained with urine samples of H-2 identical and nonidentical males. Females exposed after mating to other females whose H-2 type differed from the stud male, under the same experimental conditions, also showed an appreciable incidence of pregnancy block. It is therefore concluded that chemosensory recognition of H-2 types affects the reproductive hormonal status of the pregnant female.     

Immune responses of inbred mice to repeated low doses of antigen: relationship to histocompatibility (H-2) type

Immunization of inbred strains of mice with repeated minute doses (0.1 to 1.0 microgram) of hapten-protein conjugates demonstrated wide differences in the magnitude of their antibody responses, which were related to the histocompatibility (H-2) type of the strains. Immunization with a single high dose (100 micrograms) of antigen failed to demonstrate these differences.     

薰衣草新品种新薰二号的选育及应用

[目的]为薰衣草（LavandulaattgustifoliaMill．）新品种新薰二号的推广应用提供科学依据。[方法]新薰二号是由薰衣草品系H-701种子经太空辐射诱变单株选育而成的薰衣草新品种,介绍其选育经过、生物学特征、品质、产量及栽培要点。[结果]2011—2013年生产示范,新薰二号精油平均产量达102．2kg／hm2较对照H-701（97．0kg／hm2）增产5．7％,达到显著水平。2013年该品种通过新疆维吾尔自治区非主要农作物品种审定委员会审定命名。[结论]新薰二号是一个综合性状优良的薰衣草品种,具有很好的推广应用前景。     

Influence of the major histocompatibility complex on positive thymic selection of V beta 17a+ T cells

A monoclonal antibody was used to show directly positive thymic selection of the T cell repertoire in mouse strains expressing the 17a beta-chain variable domain (V beta 17a) of the T cell receptor. In the absence of the potent tolerizing class II major histocompatibility complex (MHC) molecule, I-E, peripheral expression of V beta 17a+ T cell receptors varied with the MHC haplotype of the mouse strain. In the most extreme case, H-2q mice expressed high peripheral levels of CD4+ V beta 17a+ T cells (14 to 19 percent), whereas H-2b mice expressed low levels (3 to 4 percent). Analysis of (b x q)F1 mice and chimeric mice showed that these differences were determined by positive thymic selection and implicated the thymic epithelium as the controlling cell type.     

Drug-induced tolerance for skin allografts across the H-2 barrier in adult mice

Mice treated with methylhydrazine derivatives for 3 to 4 weeks before the transplantation showed markedly prolonged survival times for allogeneic skin grafts differing at the H-2 histocompatibility locus. Presumably permanent tolerance was induced in about 20 to 30 percent of the mice when the drug treatment was combined with a single injection of additional donor antigen. The tolerance persists without further drug treatment and is specific for donor tissue.     

2-(4-氯苯基)-1-(1H-1,2,4-三唑-1-基)-2-丁醇的合成研究

唑醇类杀菌剂对植物的常见致病菌如鞭毛菌、担子菌、半知菌等均有很好的预防和治疗作用,在农药领域应用十分广泛。以对氯苯丙酮为原料,经Corey-Chaykovsky环氧化,再与1H-1,2,4-三氮唑缩合,合成了唑醇化合物2-(4-氯苯基)-1-(1H-1,2,4-三唑-1-基)-2-丁醇。探讨了环氧化反应的关键因素,收率可达97.9%。对缩合反应条件进行了正交优化：以碳酸氢钠为碱催化剂,环氧化物、1H-1,2,4-三氮唑、碳酸氢钠的摩尔比为1.0∶1.5∶2.1,反应温度130℃,反应5 h,缩合收率可稳定在82.0%以上。     

杀配子染色体在小麦-黑麦异代换系中的作用研究

利用小麦-黑麦异代换系H-13(1R/1D), H-24(5R/5A),H-33(6R/6A)与中国春-杀配子染色体二体异附加系CS-DA2C(来自山羊草Ae. cylindrica),CS-DA3C(来自山羊草Ae. triuncialis)配置杂交组合,对杀配子染色体的作用进行了研究。结果表明,杀配子染色体3C对H-13和H-24都是致死的,即有着完全的杀配子作用,但对H-33的杀配子作用则是不完全的,有着接近正常的结实率,说明不同的小麦-黑麦异代换系遗传背景对杀配子作用有很大影响,可能在品系H-33中存在对2C染色体杀配子作用的抑制基因。在以品系H-33为母本时,2个杀配子附加系F1的自交结实率差异显著,说明在相同的小麦-黑麦异代换系遗传背景下,染色体2C与3C的杀配子作用是不同的,在这2个杀配子染色体上可能带有不同的杀配子基因?这些研究结果为进一步创制小麦-黑麦易位系奠定了基础。     

Functional insertion of an Alu type 2 (B2 SINE) repetitive sequence in murine class I genes

The regulation of expression of the family of MHC (major histocompatibility complex) class I genes is complex. Sequence analysis has revealed that class I genes from the H-2D subregion of the MHC (which includes the D and L genes) differ from the class I gene from the H-2K subregion (the K gene) by the insertion of a type 2 Alu-like repetitive element (the murine B2 sequence) within the 3' noncoding region of the D and L genes. The consequence of this insertion in the D and L genes is the introduction of a novel polyadenylation signal, which is preferentially used over the more distal signal, the analog of that found in the K gene. The insertion of the type 2 Alu-like sequence results in a change in the preferred site for endonucleolytic cleavage which is necessary for generating a correct 3' terminus for polyadenylation. The data demonstrate that the type 2 Alu-like sequence has a function; the data also suggest a possible regulatory role of this sequence in the expression of class I genes.     

水稻抗稻瘟病基因Pi2的KASP标记开发与应用

【目的】水稻稻瘟病抗性基因Pi2对稻瘟病生理小种具有广谱抗性,开发Pi2的KASP分子标记并对其评价,为抗稻瘟病水稻品种分子育种提供简便、可靠的基因分型检测方法。【方法】利用593份自然群体中筛选出的不同抗性和亲缘关系的2份材料H-74和H-78,针对Pi2基因核心区域的SNP位点开发成KASP标记Pi2-C3。【结果】利用标记Pi2-C3对自然群体中的84份材料进行KASP基因分型,结果表明,该标记可以准确地将不同水稻材料的Pi2位点分为抗病基因型、杂合基因型和感病基因型,是一种高效鉴定抗稻瘟病基因Pi2的方法。利用标记Pi2-C3对阳江市病圃材料进行检测,结合表型调查结果发现,检测到含有Pi2基因的46份材料均表现出不同程度的稻瘟病抗性,表明该标记可以用于检测材料在病圃的发病情况。【结论】本研究采用KASP技术,开发了能准确检测Pi2基因的特异性分子标记Pi2-C3,并建立一套水稻Pi2基因的KASP基因分型体系,对提高抗性育种效率,改良抗稻瘟病水稻品种具有重要应用价值。     

BALB/C小鼠不同组织RNA提取方法的比较

为获得高质量BALB/C小鼠的核酸用于荧光定量RT-PCR分析,用某公司的RNA试剂盒、TRIzol试剂、氯化锂分别提取BALB/C小鼠心脏、肝脏和肾脏组织中的RNA。经紫外分光光度计检测发现,用TRIzol试剂在小鼠肾脏组织中获得的核酸片段具有更高的纯度及浓度,而1%琼脂糖凝胶电泳检测发现三种来源的RNA均具有较好的完整性。RT-PCR方法扩增小鼠主要组织相容性复合体蛋白H-2K编码基因,3个样品均可扩增出104 bp的特异性条带。试验验证了TRIzol试剂从不同组织中提取小鼠总RNA均可作为RT-PCR的模板,为后续试验工作奠定基础。     

晋麦F2籽粒中HMW-GS的遗传规律研究

[目的]为杂种小麦加工品质预测和优质小麦亲本组配提供依据。[方法]以杂交小麦母本晋麦47和父本丰优1号及其F2籽粒为材料,采用SDS—PAGE电泳法对小麦籽粒中的高分子量麦谷蛋白亚基（HMW—GS）的分离及表达进行分析。[结果]F2籽粒中共出现21种HMW—GS带型组合,其中回归母本的带型（N、7＋9、3＋12）占69．10％,回归父本的带型（1、17＋18、5＋10）占1．04％,其余29．86％为双亲杂合带型或缺失带型;HMW—GS在F2籽粒中按一定规律进行分离,Glu-Dlb,Glu-Dld出现基因重组（重组率5．90％）,17＋18和7＋9亚基同时在Glu—B1位点表达,而Glu—Blc在该位点出现表达空位（空位率5．20％）。[结论]明确了HMW—GS在小麦F2籽粒中的表达及分离规律。