小麦杂种及其亲本苗期叶片家族基因差异表达及其与杂种优势关系的初步研究

为探讨小麦杂种优势形成的分子机理,以一套双列杂交组合的苗期叶片为材料,利用mRNA差异显示技术分析了杂种及其亲本间MADS－box、G－ box、Ser/Thr蛋白激酶、EIF－4A、ARF1基因家族共5类家族基因在杂交种和亲本之间的表达差异。并与杂种性状表现和杂种优势进行了相关分析。结果发现,除ARF1家族基因外,其余家族基因在杂种和亲本间存在显著的表达差异,差异表达类型可概括为4种：（1）双亲共沉默;（20单亲表达沉默;（3）杂种特异表达;（4）单亲表达一致。分析发现,MADS－box、G－box和EIF－4A家族基因在杂种和亲本间的差异表达模式相似,均以单亲特异表达和种特异表达类型所占比例最高。相关分析结果表明,以上所有家族基因的总体差异表达程度与所有性状的杂种表现均不相关,MADS－box家族基因中杂种特异表达类型与小穗数、单株产量和单穗产量杂种优势呈显著正相关,双亲共沉默类型与小穗数、千粒重和单穗产量杂种优势呈显著负相关,另外,EIF－4A家族基因中单亲表达一致型与单穗产量杂种优势呈显著正相,但双亲共沉默类型与小穗数和单穗产量杂种优势呈显著负相关,对于G－box基因家族而言,仅小穗数杂种优势和双亲共沉默类型成显著负相关,而蛋白激酶家族基因的各种差异类型与性状杂种优势的相关分析均不显著。这些研究表明,调控基因的差异表达与杂种优势形成有密切关系。     

Hybrid Ia antigens: Genetic,serologic, and biochemical analyses

Ia specificities 22 and 23 were found to be determinants on hybrid Ia molecules, formed by the noncovalent binding of a 26,000–28,000 dalton beta polypeptide chain (A_e) coded by the I-A subregion and a 32,000–35,000 dalton alpha chain (E_α) coded by the I-E subregion. For expression of Ia. 23 the A_e chain, coded by the I-A subregion, must be derived from the H-2^d haplotype, while A^b, A^s, or A^k can provide the complementing beta chain for the expression of Ia. 22. For expression of Ia. 22 and Ia. 23, most Ia. 7 positive strains can provide the complementing alpha chain (E_α), with the one exception of B 10. PL (E^u), which is Ia. 7 positive but will not complement with A^d to express Ia. 23. Antisera were also produced against hybrid Ia antigens by immunizing with F₁ cells expressing Ia. 22 or Ia. 23 generated by transcomplementation. These antisera detect the same specificities as conventional anti-Ia. 22 and anti-Ia. 23 sera produced against cis-complementing Ia antigens. It is postulated that hybrid Ia determinants are involved in recognition and generation of immune response to antigens under dual Ir gene control. It is also suggested that there are 2 types of Ia specificities: (1) allotypic Ia specificities expressed on the alpha or beta chains (for example, Ia. 7 on the E_α chain) and (2) hybrid Ia specificities, which are unique interaction determinants formed by the association of alpha and beta chains (for example, Ia. 22 and Ia. 23). These interaction gene products may be involved in antigen recognition and presentation.     

四倍体大燕麦×六倍体裸燕麦的杂种F1的产生及鉴定

本研究以四倍体大燕麦 (AvenamagnaL .)做母本 ,六倍体裸燕麦 (AvenanudaL .)做父本进行杂交 ,利用幼胚拯救技术获得了杂种F1,并对其后代形态特征进行了观察 ;对杂种F1同工酶图谱和DNA指纹图谱进行了分析。杂种F1形态特征偏亲本或介于双亲之间 ;同工酶研究表明多数F1具有双亲互补酶带 ;RAPD分析不同引物扩增产物F1呈共显性或偏父、偏母。这些结果表明F1为真杂种     

四倍体大燕麦×六倍体裸燕麦的杂种F1的产生及鉴定

本研究以四倍体大燕麦（Avena magna L.）做母本,六倍体裸燕麦（Avena nuda L.）做父本进行杂交,利用幼胚拯救技术获得了杂种F1,并对其后代形态特征进行了观察;对杂种F1同工酶图谱和DNA指纹图谱进行了分析。杂种F1形态特征偏亲本或介于双亲之间;同工酶研究表明多数F1具有双亲互补酶带;RAPD分析不同引物扩增产物F1呈共显性或偏父、偏母。这些结果表明F1为真杂种。     

香菇杂交子农艺性状与差异基因表达类型的相关性研究

以香菇(Lentinula edodes)4个菌株为亲本组成3个杂交组合,采用单孢菌株配对获得杂交子,观察锁状联合鉴别出真正的杂交子,测定杂交子及其亲本的农艺性状。在每个杂交组合中分别各选取3个杂交子,研究杂交子和亲本在子实体发育阶段差异基因表达情况。结果表明:杂交子共有4种基因表达类型:双亲沉默型(W1型),单亲沉默型(W2型),杂交子特异表达型(W3型),单亲表达型(W4型)。香菇杂交子农艺性状与基因差异表达类型的相关性分析表明:菌盖厚与双亲沉默型(W1型)呈极显著负相关,而菌柄长与单亲沉默型(W2型)呈显著负相关。     

草木樨状黄芪和木本霸王的科间体细胞杂交

在成功培养原生质体的基础上,用改进的PEG-高pH高钙法诱导草木樨状黄（Astragalus melilotoides）和木本霸王（Zygophyllum xanthoxylum）原生质体融合,得到了科间体细胞杂种融合细胞。采用罗丹明-6G预处理草木樨状黄芪原生质体以及UV-B辐照霸王原生质体,使双亲原生质体及其同源融合产物均不能持续分裂而死亡,融合后的杂种细胞由于生理互补可恢复持续分裂能力而被筛选出来。融合产物经培养分裂获得了2个杂种细胞系,其中1个分化出芽。染色体计数和分子鉴定证明了杂种的真实性。初步比较了杂种细胞系及亲本对盐分和水分胁迫的耐受性,结果表明杂种细胞系对盐分和水分胁迫的耐受性介于两个亲本之间。     

以杜鹃红山茶为母本的优良种间杂交父本筛选

以杜鹃红山茶(Camellia azalea)为母本,‘绿带可娜’、‘红芙蓉’、‘迪朱丽亚’等13个观赏性较强的山茶花品种为父本,采用常规杂交育种方法,共配置13个杂交组合进行杂交试验。以坐果率、结实率、出苗率、单花成苗率作为评价亲和性的指标对杂交父本进行筛选,利用因子分析法对杂交组合亲和力进行综合评价,并采用形态鉴定法比较杂交子代与父母本主要性状差异。结果表明,‘绿带可娜’、‘玛丽费丝’、‘尼丽夫人’、‘花露珍’、‘娃丽娜深’为亲和性高的父本,杜鹃红山茶ב绿带可娜’、杜鹃红山茶ב玛丽费丝’为杂交亲和性较高的组合。杜鹃红山茶种间杂交后代花色、花型表现趋于父本,叶片更接近于母本杜鹃红山茶,杂交后代均遗传母本全年开花的特性。     

甘蓝型油菜Ogura 雄性不育×白菜的回交杂种后代与亲本之间蕾期基因表达差异比较研究*

以甘蓝型油菜（Brassica napus L, AACC,2n＝38）Ogura细胞质雄性不育材料为母本,以不同白菜（B campestris ssp. chinensis Makino, AA, 2n＝20） 自交系‘新选一号’和‘矮脚黄’为父本进行杂交,获得了杂种F1、BC1、BC2代。利用cDNA-AFLP技术对两种材料的不同回交世代BC1、BC2代与其亲本在蕾期的基因表达进行分析。结果表明,两种白菜回交世代与其亲本的基因表达有明显差异,在质和量上都存在差异。基因表达模式有5类共7种：（1）单亲沉默型（2种）,（2）单亲一致型（2种）,（3）双亲共沉默型,（4）杂种特异型,（5）表达一致型。随着回交世代的增加,回交杂种和亲本的基因表达在单亲沉默型、双亲共沉默型呈增加趋势。而在母本一致型、父本一致型、杂交种特异型、表达一致型呈下降的趋势。两种白菜在F1、BC1、BC2 3个世代与回交亲本花蕾间的基因差异表达有15种类型,其中以在轮回亲本、F1、BC1、BC2中共同出现表达的带的比例最高。Abstract: Crosses between female parent of Ogura male sterility Brassica napus L. and male parents of B. campestris ssp. chinensis Makino were made and F1, BC1 and BC2 generations produced. Gene expression of two Chinese cabbage backcross hybrid BC1, BC2 and their parents at bud stage was analyzed by means of cDNA-AFLP technique. The results indicated that the patterns of gene expression differ significantly between BC1 and BC2 generations and their parents. There were many patterns of gene expression, including gene overexpression and gene silencing. Five patterns (seven kinds) of gene expression were observed, which include: (1) bands occurring in only one parent (two kinds); (2) bands observed in hybrids and one parent (two kinds); (3) bands occurring in only parents (one kind); (4) bands visualized in only hybrids (one kind); (5) bands observed in parents and hybrids (one kind). In accompany with the addition of backcross, the increase trend in backcross hybrids and their parents were described in the aspects of differential gene expression, bands expressed only in one parent and bands expressed only in both parents. The declined trend in backcross hybrids and their parents were observed in the aspects of bands expressed in both hybrids and one parent (two kinds), bands visualized in only hybrids and bands observed in parents and hybrid. Fifteen patterns of gene expression were observed in F1、BC1、BC2 and backcross parents. The percent of bands expressed in F1、BC1、BC2 and backcross was highest.     

草木樨状黄芪和木本霸王的科间体细胞杂交

在成功培养原生质体的基础上, 用改进的PEG-高pH高钙法诱导草木樨状黄芪(Astragalus melilotoides)和木本霸王(Zygophyllum xanthoxylum)原生质体融合, 得到了科间体细胞杂种融合细胞。采用罗丹明-6G预处理草木樨状黄芪原生质体以及UV-B辐照霸王原生质体, 使双亲原生质体及其同源融合产物均不能持续分裂而死亡, 融合后的杂种细胞由于生理互补可恢复持续分裂能力而被筛选出来。融合产物经培养分裂获得了2个杂种细胞系, 其中1个分化出芽。染色体计数和分子鉴定证明了杂种的真实性。初步比较了杂种细胞系及亲本对盐分和水分胁迫的耐受性, 结果表明杂种细胞系对盐分和水分胁迫的耐受性介于两个亲本之间。     

The effects of rat selection and reproduction on learning ability in the offspring

We studied the effect of selective reproduction on rats purchased from a breeder, so as to detect learning impairments in their offspring. The parent rats selected for mating were categorized as bright or dull in terms of learning ability on the basis of a learning test in a water maze or passive avoidance response (PAR). Offspring were tested in the same way as the selected rats, with their responses being compared for each generation. 1. The matings, consisting of bright X bright, bright X dull, dull X bright, dull X dull, resulted in a significant increase in the number of dull offspring of dull X dull from parents selected by water maze or PAR learning test. 2. Bright or dull mothers selected by PAR learning were treated with chlorpromazine 6 mg/kg (2 times/day/s.c.) on the 13th day of gestation. Afterwards, a slight increase in dull offspring of dull parents was seen. 3. These results indicate that in order to evaluate the learning ability of F1 in a reproductive test, it is first necessary to check the reaction of the parents, purchased F0, and to classify them as bright or dull.     

Expression and properties of acetylcholine receptors in several clones of mouse neuroblastoma X L cell somatic hybrids

Three clones of somatic cell hybrids between neuroblastoma and L cells, NL-1F, NL-308 and NL-309 (3), have been studied for their electrical excitability and chemosensitivity to acetylcholine (Ach) applied by iontophoresis. Parental and hybrid lines were all treated and tested in media containing mM db-cAMP. The percentage of excitable N X L hybrid cells was as high or higher than that of their neuroblastoma parents. The percentage of cells sensitive to Ach was several-fold higher for the three N X L clones than for the neuroblastoma or L cell parents. While the neuroblastoma parents gave only depolarizing cholinergic responses, the N X L hybrid cells displayed slow hyperpolarizing (H) responses which resembled the H-cholinergic response obtained from L cells. The H-response of the N X L hybrids has properties which indicate the involvement of a muscarinic receptor. A correlation between expression of muscarinic receptors and excitability to electrical current (i.e., action potential ionophores), not found in the neuroblastoma parents, was present in the hybrids. However, a few N X L hybrid cells expressed muscarinic receptors independently from electrical excitability, as is the case for the L cell parent. The three N X L clones are discussed as potentially useful models to study interaction of Ach with muscarinic receptors.     

以水稻雄性不育系为母本不经幼胚培养获得Oryza sativa×O.officinalis杂种的研究

利用亚洲栽培稻(Oryza sativa L.)的核质互作型和光敏感型雄性不育系为母本,药用野生稻(O.officinalis Wall)为父本进行杂交,首次在未经幼胚培养的条件下得到了杂种种子。杂种F_1生长优势强,分蘖力和发根力等超过双亲,并具有父本的植株散生、高位分蘖、小穗具芒、穗分枝散生、落粒性和感光性强等特性。其酯酶同工酶谱中含有双亲的全部酶带。花粉母细胞中染色体数为2n=24,在减数分裂中期Ⅰ。基本上全部为单价体。杂种自交不孕。本研究结果表明,利用雄性不育系进行异源种间的远缘杂交具有简化杂交过程以便大量配组、增加异源遗传物质导入机会和杂种可靠、便于鉴定等优点。本研究不但对探讨水稻远缘杂交的新途径有一定意义,而且为雄性不育系的利用展开了新的视野。     

辣椒种间杂种的表型鉴定及SRAP分析

运用有性杂交方法,以微辣一年生辣椒自交系B9431为母本(P1)、强辣野生灌木辣椒H108为父本(P2)进行种间杂交,获得了其种间杂种.对种间杂种F125个表型性状进行了观察比较,以期从形态学及分子生物学方面验证种间杂种的真实性.结果表明,F1兼具双亲的形态特征,大多数表型性状介于P1与P2之间.SRAP分析显示,F1与P1、P2共有带550条,占总位点数的68.4%,与P1或P2共有带159条,占19.8%;F1与P1遗传相似系数为0.856,与P2的遗传相似系数为0.786,表明杂种在DNA水平上更趋向于母本.     

马铃薯杂种F1的SSR鉴定

为选育抗黑痣病、高产优质的马铃薯新品种,选用引进品种‘大西洋’分别与‘陇薯6号’、‘陇薯7号’杂交,获得了杂种F1代,利用SSR标记技术对‘大西洋’与‘陇薯6号’的42个杂种F1、‘大西洋’与‘陇薯7号’的9个杂种F1单株进行了鉴定。从59对SSR引物中筛选出2对在亲本间存在差异、扩增稳定、条带清晰的引物S184和STM1049,用于‘大西洋’ב陇薯6号’杂种F1、‘大西洋’ב陇薯7号’杂种F1及其亲本的基因组DNA扩增。SSR带型分析显示,杂种F1的SSR带型呈双亲互补型、缺失型、父本型和母本型4类,依据带型特征鉴定出供试的51个马铃薯杂种F1单株均为真杂种,表明SSR分子标记技术用于马铃薯杂种真实性鉴定是可行的。该研究可为进一步开展马铃薯杂交后代目标性状优异株系选育提供依据。     

Specific inhibition of hybrid resistance in F1 hybrid mice pretreated with parent-strain spleen cells. II. Evidence for an Hh-1 antigen-specific tolerization

Lethally irradiated F1 mice reject bone marrow graft from H-2b parents. In a previous paper we showed that pretreatment of F1 hybrid with H-2b parental spleen cells abrogates this hybrid resistance (HR) to parental bone marrow growth by inducing a Thy-1+Lyt-1+2- nylon-adherent suppressor cell. We studied the mechanism of induction of this suppressor cell. Two hypotheses were tested; both were based on the observation that parental spleen cells when injected into a F1 hybrid, recognize the alloantigens of the opposite parent and proliferate; the proliferation of these Hh-1+ cells may result in an overload of the pretreated F1 hybrids with Hh-1 Ag, and in the development of a graft-vs-host reaction that is followed by a non-specific immunodeficiency (GVHID). Thus abrogation of HR could be due to either a tolerization with high doses of Hh-1 Ag or the GVHID. Our results show that abrogation of HR does not correlate with the GVHID because 1) it is induced after pre-treatment with H-2b parental cells only, whereas GVHID is observed after injection with cells from either of the two parents; and 2) it is induced in several conditions where GVHID does not occur; after pre-treatment with 1000-rad-irradiated or T-cell depleted or only class I incompatible spleen cells or with spleen cells from nude parents as well as after pre-treatment with H-2b bone marrow cells. HR is overcome by the injection of H-2Db homozygous or of cross-reactive H-2Ds homozygous cells only. However, although pretreatment with H-2Db homozygous spleen cells is necessary, it is not sufficient for an efficient overcoming of HR. Indeed enhancement of H-2b bone marrow growth after pre-treatment with 1000-rad-irradiated, T-cell depleted or nude parent spleen cells is very short-lasting and never reaches the level observed after pre-treatment with normal spleen cells. We conclude that inhibition of HR in F1 hybrids pretreated with parental spleen cells is not a consequence of a GVHID but of a specific tolerization with Hh-1 Ag; however, the HR is inhibited more consistently when inoculum used for the pretreatment contains fully immunocompetent T cells. The role of the immunocompetent parental T cells in abrogation of HR is discussed.     

凤尾菇和桃红平菇种间原生质体电融合获杂种菌株

以有自然标记的双核风尾菇(Pleurotus sajor-caju)和桃红平菇(P．Rhodophyllus)为出发菌株,以它们携带营养缺陷型标记的单孢菌株为直接亲本,采用BAEKON 2 000基因转移仪进行侧耳属种间原生质体电融合,成功地获得若干株融合体,其中有一株编号为F57的融台体已培育出子实体。比较了融合体F57与亲本的形态、生理、生化和遗传等性状,结果证实,融合体F57是一株新的种间杂种菌株。     

Genetic Study on the Herbicide (Liberty) Resistibility and Its Application on Utilizing Heterosis in Rice

Three restoring lines (Minghni 63, Ce 64 and Teqing) as female parents were crossed with herbicide-resistant transgenic cultivars (Bengal-Hul0 and Gulfmont) as male parents. Genetic analysis on generations of F1, F2 and BC1 indicated that the resistance to the herbicide (Liberty) was controlled by a single deminant nuclear gene. The resistance to the herbicide will work as a marker for the true hybrid from crossing with the male parent, but not for all other plants from either selfing, or intracrossing in female parent population. After the application of the herbicide, all plants except the true hybrid were eliminated. With the aid of this technology, the strict requirement of complete sterility for male sterile hne in crops can be reduced. It will be beneficial not only for breeding new excellent male sterile lines, but also for commercializing chemically induced male sterile system in crops.     

普通小麦F_1杂种Glu-1基因表达过程中的共显性,基因组互作和剂量效应

普通小麦F_1杂种Glu-1基因表达过程中的共显性,基因组互作和剂量效应@潘幸来$山西农业科学院棉花研究所!运城044000小麦;;基因表达;;基因组     

Heterosis in hybrids within and between yeast species

The performance of hybrids relative to their parents is an important factor in speciation research. We measured the growth of 46 Saccharomyces yeast F1 interspecific and intraspecific hybrids, relative to the growth of each of their parents, in pairwise competition assays. We found that the growth of a hybrid relative to the average of its parents, a measure of mid‐parent heterosis, correlated with the difference in parental growth relative to their hybrid, a measure of phenotypic divergence, which is consistent with simple complementation of low fitness alleles in one parent by high fitness alleles in the other. Interspecific hybrids showed stronger heterosis than intraspecific hybrids. To manipulate parental phenotypic divergence independently of genotype, we also measured the competitive growth of a single interspecific hybrid relative to its parents in 12 different environments. In these assays, we not only identified a strong relationship between parental phenotypic divergence and mid‐parent heterosis as before, but, more tentatively, a weak relationship between phenotypic divergence and best‐parent heterosis, suggesting that complementation of deleterious mutations was not the sole cause of interspecific heterosis. Our results show that mating between different species can be beneficial, and demonstrate that competition assays between parents and offspring are a useful way to study the evolutionary consequences of hybridization.     

A new approach for obtaining rapid uniformity in rice (Oryza sativa L.) via a 3x x 2x cross

A triploid (2n = 3x = 36) rice plant was obtained by screening a twin seedling population in which each seed germinated to two or three sprouts that were then crossed with diploid plants. One diploid plant was chosen among the various F(1) progenies and developed into an F (2) population via self-pollination. Compared with the control variety Shanyou 63, this F (2) population had a stable agronomical performance in field trials, as confirmed by the F-test. The stability of the F (2) population was further substantiated by molecular analysis with simple sequence repeat markers. Specifically, of 160 markers assayed, 37 (covering all 12 chromosomes) were polymorphic between the parental lines. Testing the F (1) hybrid individually with these markers showed that each PCR product had only a single band instead of two bands from each parent. The bands were identical to either maternal (23 markers) or paternal (eight markers) bands or distinct from both parents (six markers). The amplified bands of all 60 randomly selected F (2) plants were uniform and identical to those of the F (1) hybrid. These results suggest that the F (1) plant is a non-segregating hybrid and that a stable F (2) population was obtained. This novel system provides an efficient means for shortening the cycle of hybrid rice seed production.