水稻半矮秆基因sd－g的染色体定位研究

以标志基因系和ＩＲ３６三体为工具材料,通过杂交,研究了籼稻矮秆材料双矮所携半矮秆基因ｓｄ－ｇ在染色体上的位置。结果表明：半矮秆基因ｓｄ－ｇ与标志基因系Ｍ４所携隐性主基因ｇｈ－１和Ｍ２７所携隐性主基因ｎ１表现连锁。ｓｄ－ｇ与ｇｈ－１之间的交换值为２４．３３％±３．９６％,ｓｄ－ｇ与ｎ１之间的交换值为２９．４４％±４．８１％。由于ｇｈ－１和ｎ１均位于第５染色体,因而推定ｓｄ－ｇ位于第５染色体上。     

孤啡肽对大鼠顶叶皮层神经元瞬时外向钾电流的抑制作用

目的：研究孤啡肽（N／OFQ）对大鼠顶叶皮层神经元瞬时外向钾电流（IA）的影响,初步探讨其作用的通道动力学机制。方法：采用全细胞膜片钳技术,观察N／OFQ对急性分离的大鼠顶叶皮层神经元IA的作用。结果：①0．1μmol／L N／OFQ使IA幅值由给药前的（5356．1±361．6）pA下降为（4113．3±312．7）pA,抑制率为23．20％±2．17％（P〈0．01,n=10）。②0．1μmol／L N／OFQ使IA的电流-电压（I-V）曲线降低（P〈0．01,n=10）。③0．1μmol／L N／OFQ使,IA激活曲线的半数激活电压（V1／2）和斜率因子（κ）分别由给药前的（-9．2±2．5）mV和（20．4±2．3）mV变为给药后的（30．6±3．7）mV（P〈0．01,n=8）和（22．6±2．1）mV（P〉0．05,n=8）。④0．1μmol／L N／OFQ使IA失活曲线的半数失活电压（V1／2）和斜率因子（κ）分别由给药前的（-64．1±3．2）mV和（21．5±2．1）mV变为给药后的（-55．9±1．9）mV（P〈0．05,n=5）和（19．6±2．2）mV（P〉0．05,n=5）。结论：N／OFQ可抑制大鼠顶叶皮层神经元IA,使其激活曲线、失活曲线均右移。     

家畜多个显性性状半同胞家系选择的育种进展分析

本文提出了固定家畜多个不相连锁显性性状的半同胞家系选择体制,并从群体基因型频率、配子频率及表型频率等方面分析了该体制的育种进展．研究证明,半同胞家系选择效果取决于每头公畜交配母畜数K、母畜产仔数N及群体育种水平;K、N越大,群体育种水平越低,选择效果越好．当K=1时,半同胞家系选择就退化成全同胞家系选择;当K=1且N=1时,退化成“理想型横交固定”;当K较大且群体育种水平较低时半同胞家系选择效果与“多元测交”相当．最后讨论了半同胞家系选择在家畜育种实践中的应用问题.     

棉铃虫对三氟氯氰菊酯的抗性狭义遗传力及其与体重的相关性

利用数量遗传学方法和半同胞交配设计,测定了棉铃虫Helicoverpa armigera对三氟氯氰菊酯抗性和体重的狭义遗传力,并分析了棉铃虫抗药性与其体重之间的相关性。结果表明,棉铃虫对三氟氯氰菊酯的抗性狭义遗传力为0.2476±0.0248,体重遗传力为0.3613 ± 0.1299;抗性与其母体效应无关;抗性与体重之间存在显著的遗传负相关。     

甘蓝型油菜含油量的主基因+多基因遗传效应分析

应用多世代联合分析数量性状主基因和多基因混合遗传的统计方法,分析了甘蓝型油菜两个组合的5个世代——亲本P1、P2、F1、F2和F2：3家系材料含油量的遗传效应。结果表明,分离世代F2及F2：3家系含油量次数分布均呈混合的正态分布,符合主基因＋多基因的遗传特征。D-2模型是该项研究两个甘蓝型油菜杂交组合含油量的最适遗传模型,含油量的遗传是由一对加性主基因和加-显性多基因共同控制的。组合1（1141Bx垦C1-1）主基因加性效应值为-1．74,表明亲本1141B中主基因位点上的等位基因降低含油量,而亲本垦C1-1中的等位基因增加含油量。多基因加性效应值和显性效应值分别为1．20和-1．93;F2的主基因遗传力和多基因遗传力分别为68．21％和27．17％;F2：3的主基因遗传力和多基因遗传力分别为81．70％和16．80％。组合2（32Bx垦C1-2）主基因加性效应值为-3．74,表明亲本32B中主基因位点上的等位基因降低含油量,而亲本垦C1-2中的等位基因增加含油量。多基因加性效应值和显性效应值分别为-1．99和0．93;F2的主基因遗传力和多基因遗传力分别为66．20％,和28．10％;F2：3的主基因遗传力和多基因遗传力为81．00％和14．90％。两组合在F2：3家系世代含油量的主基因遗传力均较F2高,因此认为高含油量育种中在F2：3家系进行选择效率较高。     

近交系小鼠过氧化氢酶-2遗传生化标记位点的研究

目的为了进一步完善近交系小鼠遗传生化标记检测方法,对近交系小鼠过氧化氢酶-2生化标记位点进行研究。方法将CBA/Ca与BALB/c交配得到杂交F1代动物,同时将CBA/Ca与C57BL/6交配得到杂交F1代动物,然后通过F1代动物之间的交配,以及F1代动物与母代的回交,得到F2代动物,对F2代动物进行过氧化氢酶-2生化标记检测。结果在杂交F1代不表现的过氧化氢酶-2的b型基因,在F2代出现。结论近交系小鼠过氧化氢酶-2遗传生化标记位点的等位基因a是完全显性的。     

连锁的两个基因间最大重组值不会超过50％的证明

连锁和互换规律是遗传学的重点内容之一,对连锁基因间重组值和交换值的关系,不少人往往难以透彻理解。连锁的两个基因间可以相距很远,例如,玉米第一染色体上的基因Sr(条纹叶)与bm_2(褐色中脉)间为172图距单位(两连锁基因间重组值1％定为1个图距单位),又如豌豆第一染色体上的基因a(花青甙形成)与i(子叶颜色)间为203图距单位,然而,两对相对性状杂交后得到的杂种F_1,在其产生的配子中重组型配子却不会超过50％。为什么两连锁基因间图距超过200图距单位而重组值却不会超过50％呢?《遗传学》仅列举了发生单交换和双交换的结果,并提到了重组值不会超过50％是因为两基因间发生了多次交换的关系,但没有具体说明。本文着重证明两个连锁基因间不论发生几次交换后重组型配子仍然不会超过50％,对单交换和双交换的结果也作简要介绍。     

TNF—α对哮喘模型大鼠气道平滑肌细胞增殖及ERK1／2活性的影响

目的探讨TNF—α对哮喘大鼠气道平滑肌细胞（ASMCs）增殖及对ASMCs上ERK1／2mRNA、p-ERK1／2表达水平的影响。方法通过对哮喘模型大鼠ASMCs培养,分别以0．2μg／L、1．0μg/L、20μg/L TNF-α干预ASMCs生长。采用流式细胞仪、MTT法检测ASMCs增殖情况,观察不同浓度TNF—α对ASMCs增殖的影响。RT-PCR检测ASMCs上ERK1／2mRNA表达,免疫细胞化学染色法检测磷酸化ERK1／2蛋白的表达及定位。结果哮喘组ASMCsS期比例、A值、ERK1／2mRNA、p-ERK1／2蛋白的表达量分别为（34．45±2．08）％、（0．550±0．010）、（0．995±0．118）、（130．77±4．16）,与对照组（11．17±0．96）％、（0．292±0．008）、（0．576±0．098）、（163．82±1．38）比较均显著增高（均P〈0．01）。各TNF—α干预组ASMCs的S期比例、A值、ERK1／2mRNA和p-ERK1／2蛋白表达量与哮喘组比较均显著降低（均P〈0．01）,0．2μg/L和1．0μg／LTN-α组p-ERK1／2蛋白表达量高于对照组（P〈0．01）,20μg／L TNF-α组p-ERK1／2蛋白表达量与对照组比较无差异（P〉0．05）。结论与正常鼠相比,慢性哮喘大鼠气道平滑肌细胞增殖明显,处于S期的细胞比例明显增高。经TNF—α干预后,慢性哮喘大鼠气道平滑肌细胞处于S期的细胞比例减少,增殖减弱,TNF-α可能抑制慢性哮喘大鼠气道平滑肌细胞增殖。TNF—α可下调慢性哮喘大鼠气道平滑肌细胞上ERK1／2mRNA及p-ERK1／2表达,TNF-α可能通过抑制ERK信号转导通道的活性对气道平滑肌细胞的增殖进行调控。     

长蓝猪QTL定位资源群建立及其遗传分析

利用高度选育的8头瘦肉型长白猪为父本,16头中国优良地方品种蓝塘猪为母本,采用远交系杂交的F2代设计方法,建立包括8头F1公猪、40头F1母猪和232头F2个体的猪资源群体。资源群体的遗传分析表明,所测定的32个性状都有一定的变异,主要经济性状的变异系数都在10％以上。进一步的方差组分估计表明,主要经济性状的加性遗传方差较大。在所测定6号染色体连锁群的22个微卫星DNA标记中,12个表现有多态性,全群平均杂合度为0.53,多态信息含量为0.46,能较好地为QTL检测提供信息。因此,F2代有较好的分离状态,有可能利用该资源群体检测到较多的QTL。     

新疆野生郁金香与栽培品种的杂交性状

为研制具有自主知识产权的郁金香（Tulipa gesneriana）新种质,本实验选择6种栽培郁金香品种为母本,5种野生郁金香为父本进行杂交试验。结果显示,平均受精率为（84．8±3．5）％,母本受精率最高的是克斯奈丽斯,平均为（94．0±2．3）％,受精率最低的是蒙特卡罗,平均为（71．0±3．8）％。果实发育1个月最高坐果率为100．0％,平均为（75．2±4．1）％,2个月最高坐果率为（90．0±3．6）％,平均为（47．0±3．4）％;杂交种子平均结实率为24．3％。研究结果表明,母本与杂交组合对受精率、坐果率和结实率有显著影响,父本则没有显著影响：杂交组合小黑人×伊犁郁金香、小黑人×柔毛郁金香及小黑人X天山郁金香亲合性较好,其杂交种子结实率分别为78．2％、68．4％和57．5％。     

On the origin of the Hirudinea and the demise of the Oligochaeta

The phylogenetic relationships of the Clitellata were investigated with a data set of published and new complete 18S rRNA gene sequences of 51 species representing 41 families. Sequences were aligned on the basis of a secondary structure model and analysed with maximum parsimony and maximum likelihood. In contrast to the latter method, parsimony did not recover the monophyly of Clitellata. However, a close scrutiny of the data suggested a spurious attraction between some polychaetes and clitellates. As a rule, molecular trees are closely aligned with morphology-based phylogenies. Acanthobdellida and Euhirudinea were reconciled in their traditional Hirudinea clade and were included in the Oligochaeta with the Branchiobdellida via the Lumbriculidae as a possible link between the two assemblages. While the 18S gene yielded a meaningful historical signal for determining relationships within clitellates, the exact position of Hirudinea and Branchiobdellida within oligochaetes remained unresolved. The lack of phylogenetic signal is interpreted as evidence for a rapid radiation of these taxa. The placement of Clitellata within the Polychaeta remained unresolved. The biological reality of polytomies within annelids is suggested and supports the hypothesis of an extremely ancient radiation of polychaetes and emergence of clitellates.     

On the ontogeny of the haptor and the evolution of the Monogenea

Data on the ontogeny of the posterior haptor of monogeneans were obtained from more than 150 publications and summarised. These data were plotted into diagrams showing evolutionary capacity levels based on the theory of a progressive evolution of marginal hooks, anchors and other attachment components of the posterior haptor in the Monogenea (Malmberg, 1986). 5 + 5 unhinged marginal hooks are assumed to be the most primitive monogenean haptoral condition. Thus the diagrams were founded on a 5 + 5 unhinged marginal hook evolutionary capacity level, and the evolutionary capacity levels of anchors and other haptoral attachement components were arranged according to haptoral ontogenetical sequences. In the final plotting diagram data on hosts, type of spermatozoa, oncomiracidial ciliation, sensilla pattern and protonephridial systems were also included. In this way a number of correlations were revealed. Thus, for example, the number of 5 + 5 marginal hooks correlates with the most primitive monogenean type of spermatozoon and with few sensillae, many ciliated cells and a simple protonephridial system in the oncomiracidium. On the basis of the reviewed data it is concluded that the ancient monogeneans with 5 + 5 unhinged marginal hooks were divided into two main lines, one retaining unhinged marginal hooks and the other evolving hinged marginal hooks. Both main lines have recent representatives at different marginal hook evolutionary capacity levels, i.e. monogeneans retaining a haptor with only marginal hooks. For the main line with hinged marginal hooks the name Articulon-choinea n. subclass is proposed. Members with 8 + 8 hinged marginal hooks only are here called Proanchorea n. superord. Monogeneans with unhinged marginal hooks only are here called Ananchorea n. superord. and three new families are erected for its recent members: Anonchohapteridae n. fam., Acolpentronidae n. fam. and Anacanthoridae n. fam. (with 7 + 7, 8 + 8 and 9 + 9 unhinged marginal hooks, respectively). Except for the families of Articulonchoinea (e.g. Acanthocotylidae, Gyrodactylidae, Tetraonchoididae) Bychowsky's (1957) division of the Monogenea into the Oligonchoinea and Polyonchoinea fits the proposed scheme, i.e. monogeneans with unhinged marginal hooks form one old group, the Oligonchoinea, which have 5 + 5 unhinged marginal hooks, and the other group form the Polyonchoinea, which (with the exception of the Hexabothriidae) has a greater number (7 + 7, 8 + 8 or 9 + 9) of unhinged marginal hooks. It is proposed that both these names, Oligonchoinea (sensu mihi) and Polyonchoinea (sensu mihi), will be retained on one side and Articulonchoinea placed on the other side, which reflects the early monogenean evolution. Except for the members of Ananchorea [Polyonchoinea], all members of the Oligonchoinea and Polyonchoinea have anchors, which imply that they are further evolved, i.e. have passed the 5 + 5 marginal hook evolutionary capacity level (Malmberg, 1986). There are two main types of anchors in the Monogenea: haptoral anchors, with anlages appearing in the haptor, and peduncular anchors, with anlages in the peduncle. There are two types of haptoral anchors: peripheral haptoral anchors, ontogenetically the oldest, and central haptoral anchors. Peduncular anchors, in turn, are ontogenetically younger than peripheral haptoral anchors. There may be two pairs of peduncular anchors: medial peduncular anchors, ontogentically the oldest, and lateral peduncular anchors. Only peduncular (not haptoral) anchors have anchor bars. Monogeneans with haptoral anchors are here called Mediohaptanchorea n. superord. and Laterohaptanchorea n. superord. or haptanchoreans. All oligonchoineans and the oldest polyonchoineans are haptanchoreans. Certain members of Calceostomatidae [Polyonchoinea] are the only monogeneans with both (peripheral) haptoral and peduncular anchors (one pair). These monogeneans are here called Mixanchorea n. superord. Polyonchoineans with peduncular anchors and unhinged marginal hooks are here called the Pedunculanchorea n. superord. The most primitive pedunculanchoreans have only one pair of peduncular anchors with an anchor bar, while the most advanced have both medial and lateral peduncular anchors; each pair having an anchor bar. Certain families of the Articulonchoinea, the Anchorea n. superord., also have peduncular anchors (parallel evolution): only one family, the Sundanonchidae n. fam., has both medial and lateral peduncular anchors, each anchor pair with an anchor bar. Evolutionary lines from different monogenean evolutionary capacity levels are discussed and a new system of classification for the Monogenea is proposed.In agreeing to publish this article, I recognise that its contents are controversial and contrary to generally accepted views on monogenean systematics and evolution. I have anticipated a reaction to the article by inviting senior workers in the field to comment upon it: their views will be reported in a future issue of this journal. EditorIn agreeing to publish this article, I recognise that its contents are controversial and contrary to generally accepted views on monogenean systematics and evolution. I have anticipated a reaction to the article by inviting senior workers in the field to comment upon it: their views will be reported in a future issue of this journal. Editor