褪黑素受体Mel1b在皖西白鹅不同组织中的分布与表达

褪黑素是动物体内一种重要的神经激素,其通过与褪黑素受体结合发挥多种生物学作用。旨在探究褪黑素受体Mel1b在皖西白鹅不同组织中的分布特点与表达水平。采集皖西白鹅的心脏、肝脏、脾脏、肺脏、肾脏、大脑、小脑、胰腺、胸肌、卵巢和分级卵泡,利用免疫组化和Real-time PCR技术检测各组织中Mel1b的分布特点及表达水平。结果表明：Mel1b在皖西白鹅的心、肝、脾、肺、肾、脑、胰腺、胸肌、卵巢及分级卵泡中广泛分布,且各组织间Mel1b基因和蛋白表达水平存在一定差异,卵巢中表达量最高,且随卵泡发育分级卵泡内表达量逐渐增加,其次是胰腺、脾、肾、肺,在脑、心、肝和胸肌中的表达量最少。可见,皖西白鹅各组织中均存在褪黑素受体Mel1b,且各组织间的表达量不同,结果为进一步探究褪黑素及其受体参与调控皖西白鹅机体内广泛的生物学作用奠定了理论基础。     

白血病抑制因子在雌性哺乳动物生殖过程中的作用

白血病抑制因子是一种多功能的细胞因子,与哺乳动物的生殖过程密切相关,在排卵、胚胎发育及胚胎着床等过程中起重要的调节作用。母体激素和细胞因子可通过调控白血病抑制因子的表达而影响生殖过程。在此,对LIF在雌性哺乳动物生殖过程中的作用进行了综述。     

荆豆凝集素-1受体在兔子宫内的分布与激素调节

采用组织化学方法对荆豆凝集素-1(ulex europaeus agglutinin-1,UEA-1)受体在兔发情周期及早期妊娠子宫内的分布以及激素调节进行了研究.结果显示,UEA-1受体主要存在于兔子宫内膜腔上皮,其表达量随妊娠阶段的不同而发生动态性变化.UEA-1受体在休情期兔子宫内未见表达,而在发情期兔子宫内的表达量较高.在早期妊娠兔子宫内,在妊娠第1天子宫内膜腔上皮表面UEA-1受体的表达量较高,妊娠第2天和第3天时在子宫内膜腔上皮表面仅见有少量UEA-1受体的表达,妊娠第4天时,子宫内膜腔上皮表面UEA-1受体的表达量很高,此后其表达量又迅速下降,在妊娠第5至第7天时未见表达.在假孕兔子宫内UEA-1受体的表达方式与正常妊娠时相似.注射雌激素可明显促进卵巢切除后兔子宫内膜UEA-1受体的表达,而注射孕酮对其表达有明显抑制作用.结果表明,兔子宫内UEA-1受体的分布与着床前胚胎与子宫内膜之间的黏附和植入有关,UEA-1受体在兔子宫内的表达受母体分泌的激素所调控.     

小尾寒羊BMF基因在发情不同阶段卵巢及卵泡发育过程中的表达分析

旨在初探BMF基因在小尾寒羊卵泡发育过程中的生物学功能，为将来深入探索其调控机理提供理论依据。对小尾寒羊实施同期发情，采用实时荧光定量PCR(Quantitative real-time PCR,RT-qPCR)、蛋白免疫印迹(Western Blot, WB)及免疫荧光染色(IF)方法检测BMF基因及其编码蛋白在不同生理阶段卵巢中的表达量；随后分离不同直径的卵泡，分析目的基因在大、中、小卵泡中的表达差异。结果显示，BMF mRNA在撤栓后42 h卵巢中的表达量显著高于撤栓后18 h(P<0.05),其编码蛋白表达结果与mRNA基本一致；BMF蛋白主要表达于卵泡颗粒细胞和卵泡膜细胞中；进一步分离卵泡，发现BMF基因及其编码蛋白表达量均在中卵泡中显著高于大卵泡和小卵泡(P<0.05)。以上结果表明，BMF基因可能参与卵巢周期性活动，在卵泡发育过程中发挥重要作用。     

GDF9与BMP15在绵羊腔前卵泡及卵母细胞体外成熟过程中的差异表达

为了探讨GDF9与BMP15在绵羊腔前卵泡发育及卵母细胞体外成熟过程中的作用,运用腔前卵泡的显微分离方法和RT-PCR技术,检测了GDF9、BMP15 mRNA在绵羊腔前卵泡及卵母细胞体外成熟过程中(0、8、16、24 h)的相对表达丰度。结果表明：绵羊COCs在体外培养的不同时期,卵丘细胞扩展呈现不同的形态学变化;腔前卵泡中GDF9、BMP15 mRNA表达量均低于体外成熟不同时期卵母细胞,且腔前卵泡中GDF9 mRNA表达量显著低于体外成熟不同时期卵母细胞。揭示GDF9和BMP15对卵巢卵泡发育和卵母细胞体外成熟发挥重要作用,在绵羊卵母细胞体外成熟过程中,这2个因子可能是独立或协同地影响卵丘细胞增殖扩散。     

荆豆凝集素-1受体在犬子宫内的分布与激素调节

采用组织化学方法对荆豆凝集素-1(ulex europaeus agglutinin-1,UEA-1)受体在发情周期和早期妊娠犬子宫内的分布以及激素调节进行了研究。结果显示,UEA-1受体主要存在于犬子宫内膜腔上皮和腺上皮,其表达量随妊娠阶段的不同而发生动态性变化。UEA-1受体在休情期犬子宫内未见表达,而在发情期犬子宫内膜腔上皮和腺上皮内的表达量很高。在早期妊娠犬子宫内,在妊娠第6天和12天犬子宫内的表达量较低,此后其表达量逐渐增加,在妊娠第17天时,UEA-1受体在子宫内膜腔上皮和腺上皮内的表达量达到峰值,此后其表达量又逐渐下降,在妊娠第23天时未见表达。注射雌激素可明显促进卵巢切除后犬子宫内膜UEA-1受体的表达。结果表明,犬子宫内UEA-1受体的分布与胚胎着床前胚胎与子宫内膜之间的黏附和植入有关,UEA-1受体在犬子宫内的表达受母体分泌的激素所调控。     

花生凝集素受体在兔子宫内的分布与激素调节

采用组织化学方法对花生凝集素(peanut aggutinin,PNA)受体在兔发情周期和早期妊娠子宫内的分布以及雌、孕激素对其表达的影响进行了研究.结果显示,PNA受体主要存在于兔子宫内膜腔上皮和腺上皮,其表达量随妊娠阶段的不同而发生变化,PNA受体在休情期、发情期及妊娠第1天的兔子宫内未见表达,在妊娠第2至第4天时表达量逐渐增加,且在妊娠第3至4天时表达量最高,此后,在妊娠第5至7天时表达量逐渐减少,妊娠第7天时,着床区子宫内PNA受体的表达量略高于非着床区.假孕兔子宫内PNA受体的表达与正常妊娠时相似.注射孕酮可促进卵巢切除后兔子宫内膜PNA受体的表达,而注射雌激素对其表达有明显抑制作用.结果表明,PNA受体在兔子宫内的分布与着床前胚胎与子宫内膜之间的黏附有关,PNA受体在兔子宫内的表达受母体分泌的孕酮和雌激素所调节.     

TGF-βRⅠ及Smad2表达情况对绵羊腔前卵泡发育的影响

为探索适于哺乳动物腔前卵泡的培养方式以及观察颗粒细胞与卵母细胞的信号表达,为阐明早期卵泡生长的复杂机理和揭示卵泡发生发育的内在规律提供参考,通过使用免疫组织化学染色、荧光免疫组织化学染色以及RT-PCR的方法,观察TGF-βRⅠ与Smad2的蛋白和mRNA在绵羊卵巢卵泡的表达情况。结果表明:TGF-βRⅠ在绵羊腔前卵泡及小腔卵泡的颗粒细胞及卵母细胞有表达,随着卵泡的生长发育,到成熟卵泡时期时,信号消失;Smad2蛋白在绵羊卵泡各个发育时期的颗粒细胞中均有表达,在绵羊腔前卵泡的卵母细胞中无表达,随着卵泡的生长发育,信号逐渐出现,到成熟卵泡时期时,Smad2蛋白在卵母细胞表达较强;TGF-βRⅠmRNA只在成熟卵泡和培养前腔前卵泡颗粒细胞中检测到表达,在成熟卵泡和培养前腔前卵泡颗粒细胞中均有Smad2 mRNA表达,但在培养后腔前卵泡颗粒细胞中Smad2 mRNA表达量较低。TGF-βRⅠ与Smad2的蛋白和mRNA表达与绵羊卵泡发育情况密切相关。     

绵羊PRLH及其受体基因的克隆及在下丘脑-垂体-性腺轴中差异表达的研究

为了探讨PRLH及其受体基因在绵羊性腺轴中的表达,以绵羊下丘脑-垂体-性腺轴系为研究对象,克隆了PRLH及其受体基因PRLHR,构建了系统进化树,并利用qRT-PCR技术对PRLH及其受体基因在绵羊性腺轴中不同组织的表达差异做了研究。结果表明,绵羊PRLH和PRLHR mRNA核苷酸序列分别为113,237 bp,PRLH基因核苷酸序列与山羊、牛、人、小鼠的同源性分别为96.8%,93.3%,80.3%,74.6%,PRLHR基因与藏羚羊、山羊、牛、人和小鼠的同源性分别为100%,99.3%,97.3%,90.4%,84.4%;PRLH及其受体基因在绵羊的下丘脑、垂体、子宫和卵巢中均有一定量的表达,且PRLH基因在下丘脑、垂体和卵巢中的表达要显著低于子宫(P0.05);PRLHR在子宫与垂体中的表达差异显著(P0.05),其他差异不明显。说明下丘脑、垂体、子宫和卵巢是PRLH合成分泌和发挥作用的主要器官。     

四川白鹅Calm1结构特征及其差异表达的研究

为阐明鹅Calm1基因结构特征及其表达规律。克隆四川白鹅Calm1基因编码区序列并进行生物信息学分析,应用实时荧光定量PCR技术检测鹅不同等级卵泡和不同组织中Calm1基因的相对表达量。鹅Calm1基因编码区序列全长为450 bp,编码149个氨基酸,其氨基酸序列与原鸡相似性为99%。鹅大脑中Calm1表达量显著高于其他组织(P0.05)。Calm1在不同等级卵泡组织中均有表达,F2级卵泡中Calm1表达量是小白卵泡(Small white follicles,SWF)的1.76倍(P0.05),且显著高于F5、F4、F3和F1级卵泡(P0.05);在排卵后卵泡(Postovulatory follicle,POF)组织中,POF1级卵泡组织中Calm1表达量显著高于POF2、POF3和POF4级卵泡(P0.05);卵巢组织中Calm1的表达量,是小白卵泡的1.75倍(P0.05)。Calm1是高度保守、广泛表达的蛋白质,Calm1可能通过影响卵泡细胞增殖和类固醇激素合成来参与调控动物繁殖。     

1个新棉花bHLH类基因GhbHLH130的克隆及表达分析

近年来,已发现碱性/螺旋-环-螺旋(basic/Helix-Loop-Helix,bHLH)类转录因子家族在植物的生长发育调控中发挥重要作用。本研究通过电子克隆方法得到1个新的棉花bHLH类转录因子基因的全长序列,利用反转录-PCR技术从陆地棉中分离出1个bHLH类转录因子基因,并命名为GhbHLH130。该基因包含1个552 bp的开放阅读框,编码184个氨基酸残基。序列分析表明GhbHLH130蛋白包含1个螺旋-环-螺旋(Helix-Loop-Helix)保守结构域,属于bHLH转录因子家族。实时荧光定量分析结果表明GhbHLH130基因的表达受干旱、高盐、低温以及外源脱落酸的显著诱导。亚细胞定位结果表明GhbHLH130基因在细胞核内表达。本研究结果表明GhbHLH130基因可能作为调控基因参与棉花的逆境应答响应过程。     

Effects of climate on different potato genotypes 2. Dry matter allocation and duration of the growth cycle

The total growth and tuber dry matter production of a potato crop are determined mainly by the duration of its growth cycle. This in turn depends on climate, cultivar and crop management. The influence of climate factors defining crop growth and its timing were analysed by dividing the growth cycle into three phases and relating the duration of these phases to temperature, daylength and radiation. The variation in the length of all three phases contributed to the variation in the duration of the growth cycle and thus to the variation in tuber dry matter production. The variation in the length of the first phase (between emergence and tuber initiation) was best explained by the meteorological variables observed. Both higher temperatures and shorter daylengths hastened development in this phase. The magnitude of their effects depended on cultivar. In the second phase, from tuber initiation to end of leaf growth, temperature and daylength had similar effects but they were less clear and the variation in duration of phase 2 could not be explained as well as variation in the duration of phase 1. The last phase, from the end of leaf growth to the end of crop growth, was shortened by high temperatures and high radiation. A small part of the variation in the duration of this phase was explained by these variables. At this level of crop analysis, the effect of climate on crop development was explained best for the first phase, which is the most important one in explaining the variation in ground cover duration and tuber dry matter production. Quantitative understanding of the processes involved is required to be able to explain the effect of climate during the various phases of the growth cycle.     

LIF与心肌条件液在小鼠ES细胞分离中的差异比较

通过比较LIF和大鼠心肌条件液在小鼠ES细胞分离培养过程中的差异, 从而选择较为合适的培养液用于小鼠ES细胞的分离培养与深入研究。取怀孕3.5 d小鼠囊胚, 培养于小鼠胎儿成纤维细胞饲养层上, 然后根据ES细胞培养液的不同分成2组,一组添加LIF的ES细胞培养液,另一组添加由大鼠心肌条件液组成的ES细胞培养液。结果显示,小鼠ICM的孵出率在心肌条件液中为76.30 %, LIF条件液中为59.35 %,两者差异极显著(p＜0.01)))))) ; 在LIF条件液中比心肌条件液中能较早地分离出ICM,时间差分别为11、11、12、10和12 h,平均为11.2 h; 对传代的ES细胞集落,培养48 h时周边出现分化现象的ES细胞集落所占的比例在心肌条件液中为51.55%, LIF条件液中为31.69 %,两者差异显著(p＜0.05); 第五代小鼠ES细胞核型正常率在心肌细胞条件液中为78.6 %, 稍高于LIF条件液中的76 %,差异不显著。     

Biochemical Analysis of Developing Wheat Grains

Developing wheat grain was analysed for its fresh and dry weights, water content and some enzymes of the respiratory pathway. Grain dry weight data was fitted to a polynomial equation and biphasic linear regression analysis. Based on biphasic regression analysis and data of water content, the entire wheat grain development is divided into four phases: (i) cell division; (ii) cell elongation; (iii) dry matter accumulation; and (iv) maturation. Various enzymes of glycolysis, Oxidative pentose phosphate pathway and Tricarboxylic acid cycle have been estimated during entire wheat grain development, which recorded higher activities during cell elongation phase and maintained higher levels during dry matter accumulation phase. The role of these enzymes in the generation of NADPH and provision of carbon skeleton for starch and nucleic acid synthesis is discussed.     

Phenological and physiological evaluation of first and second cropping periods of sorghum and maize crops

Environmental conditions influence phenology and physiological processes of plants. It is common for maize and sorghum to be sown at two different periods: the first cropping (spring/summer) and the second cropping (autumn/winter). The phenological cycle of these crops varies greatly according to the planting season, and it is necessary to characterize the growth and development to facilitate the selection of the species best adapted to the environment. The aim of this study was to characterize phenological phases and physiological parameters in sorghum and maize plants as a function of environmental conditions from the first cropping and second cropping periods. Two parallel experiments were conducted with both crops. The phenological characterization was based on growth analyses (plant height, leaf area and photoassimilate partitioning) and gas exchange evaluations (net assimilation rate, stomatal conductance, transpiration and water-use efficiency). It was found that the vegetative stage (VS) for sorghum and maize plants was 7 and 21 days, respectively, longer when cultivated during the second cropping. In the first cropping, the plants were taller than in the second cropping, regardless of the crop. The stomatal conductance of sorghum plants fluctuated in the second cropping during the development period, while maize plants showed decreasing linear behaviour. Water-use efficiency in sorghum plants was higher during the second cropping compared with the first cropping. In maize plants, in the second cropping, the water-use efficiency showed a slight variation in relation to the first cropping. It was concluded that the environmental conditions as degree-days, temperature, photoperiod and pluvial precipitation influence the phenology and physiology of both crops during the first and the second cropping periods, specifically cycle duration, plant height, leaf area, net assimilation rate, stomatal conductance and water-use efficiency, indicating that both crops respond differentially to environmental changes during the growing season.     

Phenological development in spring cereals: response to temperature and photoperiod under northern conditions

Phenological development of spring cereals was investigated using observations from several sites in Finland during the period 1970–1990. Different mathematical models which relate temperature to development rate were examined to predict the duration of phenological phases. A photoperiodic response of plant development before heading was also tested. For all phases the relationship between temperature and development was approximately linear. There was no significant response of plant development to photoperiod. This was explained by consistently long photoperiods in the observational material. Parameters for a linear model were derived from a regression analysis of mean development rate of each phase against mean temperature. However, a different response may occur under higher or lower temperatures or under shorter photoperiods than those experienced here.     

Seed number responses to extended photoperiod and shading during reproductive stages in indeterminate soybean

The number of seeds per unit land area, the major yield component in soybean (Glycine max (L.) Merrill) is largely determined after the beginning of flowering, particularly from R3 to R6. Environmental factors increasing crop growth rate (e.g. radiation) or extending the duration of the reproductive phases (e.g. photoperiod) increase the number of seeds. We aimed to compare the mechanisms by which photoperiod and radiation affect the definition of final seed number during the critical period of R3–R6. Two field experiments were conducted with indeterminate soybeans at intermediate maturity group. All plots in each experiment were grown under natural conditions until the beginning-pod stage (R3); and from then onwards different treatments were imposed. Treatments consisted of the factorial combination of two levels of radiation (natural or shading) and two photoperiod regimes (natural or extended). Extended photoperiod increased the duration of reproductive phases, the number of nodes and the number of pods produced on the nodes that flowered during or after the applications of the treatments. Shading had negligible effects on development and node number, but reduced crop growth rate and also reduced the number of pods produced on most nodes of the plants. The number of seeds was positively related to the crop growth rate during R3–R6, but photoperiod increased the number of seeds produced per unit of crop growth rate, due to the lengthening of the phase. The number of seeds was therefore even better related to accumulated growth during R3–R6, irrespective of the factor that increased the accumulated biomass (higher daily radiation or longer duration of the phase) suggesting that long photoperiods increased the number of pods and seeds established per unit land area, mainly through increasing the total resource availability during a phase that is critical for the determination of seed number in soybean. However, photoperiod regulation involved additional changes in the development, evidenced by changes in the pod distribution pattern within the canopy.     

Two powdery mildew resistance mutations induced by ENU in Pisum sativum L. affect the locus er1

The alkylating compounds and strong mutagens methylnitrosourea (MNU) and ethylnitrosourea (ENU) were used to widen the genetic variability of pea (Pisum sativum L.) via experimental mutagenesis. Amongst multiple mutations of agronomical interest, for the first time two mutations conferring broad-range resistance to powdery mildew (Erysiphe pisi Syd.) were induced in pea. Mutagenic treatments were carried out on seedlings using a technique that ensures very high mutagenic efficiency. Two-hour exposure of cv. Solara seedlings to chemical mutagens resulted in almost non noticeable lethality and sterility in the M1 generation and very high mutation rates: ~39% families with visible mutations in the M2 generation. The influence of the cell cycle phase on the process of mutagenesis was studied in cv. Frilene using a previously developed technique for synchronization of shoot apical meristem cells. The cell cycle phase at which cells were treated apparently did not influence the lethality and sterility in the M1 generation, while the visible mutation rate, assessed in the M2 generation, showed a clear cell cycle dependency. Seedlings treated at the G2 and M phases gave rise to progenies exhibiting the highest mutation rate, over 50% of M2 families with visible mutations. The powdery mildew resistant (PMR) mutant S(er1mut1) was induced by treatment of cv. Solara seedlings for 2 h with ENU, while the PMR mutant F(er1mut2) was induced by treatment of cv. Frilene seedlings with the same chemical mutagen for 1 h during the G2 phase of the cell cycle. The genetic analysis of the novel PMR mutant lines showed that both resistances are inherited as monogenic recessive traits. The performed genetic complementation analyses revealed that both mutations affect the same locus—er1, which determines most of the natural sources of PMR in pea. A project aiming at the isolation of the powdery mildew resistance mutated gene via map based cloning is currently under way.     

采收期对‘黄冠’梨果实品质影响的研究

研究采收期对‘黄冠’梨果实品质的影响,旨在揭示‘黄冠’梨果实发育后期果实品质因子的变化规律,为生产中确定‘黄冠’梨的最佳采收期提供理论依据。以‘黄冠’梨为试材,通过测定不同采收期时的单果重、可溶性固形物含量、Vc含量、硬度,并利用液相色谱法测定不同采收期果实的糖酸组成和含量,分析‘黄冠’梨果实发育后期果实品质因子与采收期的关系。结果表明,自果实发育106天开始,随采收期的延后,果实硬度呈显著下降,果实可溶性固形物含量呈上升趋势,并于果实发育137天时达到高峰;Vc含量变化较小,仅在120天时显著较高;在近成熟期采收的果实中糖以果糖为主,占70.09%~84.00%,以果实发育137天时最高;果实中酸以苹果酸为主,苹果酸占酸总量的93.05%~97.28%,苹果酸D占苹果酸的82.92%~91.84%。随采收期的延后,果实发育天数延长,果酸含量下降,采收越晚糖酸比越高。‘黄冠’梨果实发育130~137天时,果实的可溶性固形物、果糖、葡萄糖、蔗糖和Vc含量都较高,糖酸比和果肉硬度适宜,以获得‘黄冠’梨最佳品质为目标的适宜的采收期为8月8—15日。