西瓜种皮颜色遗传分析

种皮颜色是西瓜(Citrullus lanatus)重要的外观性状之一.为了揭示西瓜种皮颜色的遗传分析,本研究以种皮颜色差异较大的2个小型西瓜为亲本材料,K1为亲本P1(种皮颜色黄色),L1为亲本P2(种皮颜色黑色)进行正反交得到子一代F1,并构建六世代群体(P1,P2,F1,F2,BC1K1,BC1L1)和重组自交系...     

绿翅鸭繁殖生态初报

2007～2009年在黑龙江中南部地区对绿翅鸭(Anas crecca)繁殖生态习性进行了观察。绿翅鸭在黑龙江属夏候鸟,每年3月末4月初迁来,10月上旬迁离,所观察的4对绿翅鸭居留期约6个月。迁来时成群停留在湖泊及江的冰面上,开江以后散去,繁殖期间,绿翅鸭的配偶关系为一雄一雌,巢址多选择离水域较近的草丛或灌木丛中,所观察的4巢,巢都比较简单,筑巢时间为(5.5±1.0)d(n=4)。巢筑成后的(3.25±0.50)d开始产卵。每窝70～12枚不等,平均(9.80±2.21)枚(n=4)。卵重平均(28.70±0.72)g(n=39),最后一枚卵产出后(2.50±0.577)d(n=4),开始孵卵,孵卵期约为22～26 d不等,平均孵卵期为(24.25±1.17)d(n=4),平均孵化率为79.5%±29.98%。幼鸟为早成鸟,育雏期为(29.75±1.70)d。     

鸭蛋蛋壳颜色的遗传分析

木文应用交配实验的遗传学方法,分析了蛋用鸭各种交配方式（正、反交,自交,测交）子代壳色的变异状况。试验表明,鸭蛋壳色是受一对等位基因所控制,白色蛋壳对绿色蛋壳而言,白色为隐性,绿色为显性。     

稻鸭共育生态效应及经济效益

稻鸭共育是一项无须使用除草剂和施用较少农药的低成本生态农业技术。通常,20d左右大的鸭子按225只.hm-2放入移栽不久的稻田。由于取食和活动,它们能够帮助控制田间杂草、虫害、甚至病害,并且对水稻生长发育、土壤理化性状、水体溶氧量和微生物等产生一定的影响。本文概述了稻鸭共育的生态效应和经济效益的研究进展,并指出应加强在精确施肥和水稻后期病虫害防治等方面的深入研究。     

稻鸭共作对稻田营养生态及稻米品质的影响

通过稻、鸭之间的共生互作,共生期不施用任何农药和化肥,进行优质无公害水稻生产。结果表明,稻鸭共作的除草效果达到99．4％以上,病虫害基数明显降低;水体营养物质和溶解氧增大;土壤速效养分有一定提高,但成熟后土壤速效P、速效K较基础肥力有一定降低;植株N、P、K吸收量增加;产量明显提高,构成因素中成穗率、实粒数和结实率增加;稻米的加工品质、外观品质、营养品质及蒸煮品质得到改善,尤以降低垩白率效果最为明显;稻田生态系统综合效益明显提高。     

印度南瓜果皮和果肉颜色遗传分析及基因定位

以印度南瓜‘98-2-351’与‘06820-1’杂交构建F2群体,对亲本及各世代群体成熟果实果皮和果肉颜色进行调查、统计分析。结果表明:F2群体中果皮桔红色和灰色的分离比呈3∶1,说明果皮灰色是由单隐性基因控制;F2群体中果肉黄色和白色的分离比呈3∶1,说明果肉白色也是由单隐性基因控制。利用群体分离分析法结合隐性群体分析法,采用SSR分子标记,找到了2个与控制灰色果皮基因位点CmRc紧密连锁的SSR标记(PU078072和PU013839),其连锁遗传距离分别为5.9cM和14.5cM;同时找到了1个与控制白色果肉基因位点CmFc紧密连锁的SSR标记PU132712,其连锁遗传距离为6.7cM。本研究为进一步筛选与控制印度南瓜果皮和果肉颜色基因更加紧密连锁的分子标记及相关基因的精确定位奠定了基础。     

注射用高纯度蛋黄卵磷脂制备新工艺的研究

本文探索建立了一条以新鲜蛋黄为原料,以乙醇为唯一提取溶剂,制备高纯度注射用蛋黄卵磷脂的新工艺。首先,用4倍重量的96%(v/v)乙醇作为沉淀剂将新鲜蛋黄中的蛋白质沉淀为滤饼,得到初级提取液;然后,再用4倍重量的96%(v/v)乙醇对滤饼抽提3次,提取残余卵磷脂,得到次级提取液。合并提取液,置9℃下静置分层,除去大部分蛋黄油。所得上清液上硅胶柱,用86%(v/v)的乙醇作为洗脱剂,纯化蛋黄卵磷脂,经高效液相色谱检测纯度达98%。并对提取过程进行了优化,得到最佳工艺条件:35℃的96%乙醇溶液,添加量为1∶4(w/w)提取蛋黄液,180 rpm转速下搅拌10 min。抽滤后,用60℃的96%乙醇提取滤饼3次,料液比为1∶4,静置15 min。最佳工艺条件下,蛋黄卵磷脂的提取率可达93.38%。     

鸭脂联素基因单核苷酸多态性检测及群体遗传分析

以昆山麻鸭、樱桃谷鸭、高邮鸭、荆江麻鸭、金定鸭, 山麻鸭、龙白鸭和白羽番鸭8个鸭品种为实验材料, 根据鸭脂联素基因开放阅读框序列设计5对引物, 用PCR-SSCP方法进行单核苷酸多态性分析,并对不同品种群体进行群体遗传学分析。结果发现引物4扩增片段上共存有7个单碱基突变, 第430、457、523处的G-A 、A-G、T-C单碱基突变导致第144、153、175个氨基酸分别由丙氨酸（A）变为苏氨酸（T）、异亮氨酸（I）变为缬氨酸(V)、酪氨酸(Y)变为组氨酸(H); 而C507T, T540C, C576T和C597T 4个单碱基突变为沉默突变。鸭群中表现出AA、AB、AC、BB、BC、CC、DD、DE 8种基因型。8种基因型在8个鸭品种间分布存在极显著的差异(P<0.01)。除金定鸭外, 其他品种均处于Hardy-Weinberg平衡状态。群体遗传分析表明金定鸭的纯合度最高, 高邮鸭最低, 其他各群体的纯合度较相近; 金定鸭为低度多态, 高邮鸭为高度多态, 其他品种为中度多态。表明鸭脂联素基因不同品种中具有丰富的单核苷酸多态性, 可以进一步作为候选基因来分析其与脂肪性状的相关性。     

稻鸭共作系统中稻飞虱及主要捕食性天敌的空间生态位

对施用化肥(化肥区)、稻鸭共作(稻鸭区)和无化肥农药(空白区)处理区中稻飞虱及其主要捕食性天敌进行了调查,并对其在稻株中的空间分布及其变化规律和生态位特征进行了分析.结果表明,化肥区、稻鸭区和空白区分别以球蛛、管巢蛛和跳蛛的空间生态位宽度为最高,均在0.80以上;稻鸭区中稻飞虱的空间生态位宽度达0.83,比空白区、化肥区分别低5.0%和5.9%;稻鸭共作使得肖蛸、瓢虫、跳蛛、隐翅虫与稻飞虱发生的空间同域性增强,相遇机率提高,一定程度上提高了对稻飞虱的潜在控制作用,但同时也降低了狼蛛、皿蛛和管巢蛛等与稻飞虱的生态位重叠,削弱了这些天敌对稻飞虱种群的控制潜能;稻鸭共作对天敌在稻株中的发生部位和同域性也具有一定的影响.稻鸭共作可能通过改变稻飞虱及其天敌类群的空间分布格局和生态位特征等影响稻飞虱种群的发生和数量消长.     

鸭肠炎病毒感染鸭脾脏的转录组分析

为探明鸭肠炎病毒(Duck enteritis virus,DEV)感染鸭脾脏的转录组情况,本研究以DEV GZ株经腿部肌肉接种50d鸭,于接种后66h采集鸭脾组织样本,提取总RNA,采用Illumina HiSeq 2000TM对试验组和对照组样品进行测序,筛选DEV感染鸭脾脏组织的差异表达基因,对其进行生物信息学GO功能分类和KEGG信号通路分析。结果显示,差异表达基因共511个,其中表达上调312个,表达下调199个。GO功能分类结果显示,差异表达基因主要涉及氧运输、整合素活化、补体激活等生物学过程,胞外区、血红蛋白复合物、细胞外间隙等细胞组分,氧转运活动、氧结合、核糖体的结构成分等分子功能。KEGG分析表明这些差异表达基因参与ECM受体相互作用、核糖体、CAMs、JAK-STAT信号通路、细胞因子和细胞因子受体相互作用、PPAR信号通路、神经活性配体/受体相互作用信号通路。本研究为深入探究DEV与鸭脾脏组织互作、宿主抗病机制及相关功能基因的筛选奠定了基础。     

The chicken egg yolk plasma and granule proteomes

Using 1-D SDS-PAGE, LC-MS/MS, and MS(3), we identified 119 proteins from chicken egg yolk, 86 of which were not identified in yolk previously. Proteins were roughly quantitated by calculating their exponentially modified protein abundance index (emPAI) to classify them as major or minor yolk components, and to estimate their distribution between yolk plasma and yolk granular fraction. The proteins with highest abundance were serum albumin, the vitellogenin cleavage products, apovitellenins, IgY, ovalbumin, and 12 kDa serum protein with cross-reactivity to beta2-microglobulin. In addition yolk contained many other serum and egg white proteins, the proteases nothepsin and thrombin, numerous protease inhibitors, and antioxidative enzymes, such as superoxide dismutase and glutathione peroxidase. Among the moderately abundant proteins were two alpha2-macroglobulin-like proteins different from egg white alpha2-macroglobulin, and the major biotin-binding protein of yolk. An unexpected identification was that of the eggshell matrix protein ovocleidin-116, which was previously thought to be eggshell-specific. The list of chicken egg yolk proteins provided in this report is by far the most comprehensive at present and may serve as a starting point for the characterization of less well-known yolk proteins.     

The role of oligosaccharide in transport of egg yolk riboflavin-binding protein to the egg

The carbohydrate portion of chicken egg yolk riboflavin-binding protein was examined to determine its role in the biological activity of the protein. Yolk RBP was found to contain 5–6 mannose, five galactose, 12 N-acetylglucosamine and four sialic acid residues. Specific modifications of the oligosaccharide moiety were performed which included removal of sialic acid by mild acid hydrolysis, oxidation of galactose oxidase, and removal of N-acetylglucosamine and galactose residues by a mixture of glycosidases from Aspergillus niger. All of the modified proteins retained the ability to bind riboflavin although their capacities were lower than that of native yolk RBP. Circular dichroism of the modified yolk RBP samples showed changes in the near ultraviolet, but molar ellipticities in the far ultraviolet displayed only minor variations indicating no gross structural changes. All samples cross-reacted with RBP-specific antiserum. The plasma half-life of ¹²⁵I-labeled yolk RBP was 62 min. Each of the modified samples was cleared more rapidly from the blood than native yolk RBP. Removal of sialic acid decreased the half-life of yolk RBP by 31%, while the other modifications decreased the half-life by as much as 60%. During a 10-day period following injection of ¹²⁵I-labeled yolk RBP, 5.9% of the labeled protein was recovered from egg yolk. Relative to native yolk RBP, the transport of asialo-yolk RBP was decreased by 82%. The other modifications resulted in even less transport to the egg, the lowest being glycosidase-treated asialo-yolk RBP which was decreased by over 99%. By comparison of samples with similar clearance times, a positive correlation was made between sialic acid and ovarian transport.     

Non-analytical methods for the estimation of total yolk carotenoids in passerine eggs

Carotenoids are essential antioxidant micronutrients. Oviparous species acquire carotenoids from their food and deposit them in the egg yolk, where they support embryonic development. The total carotenoid concentration in the egg yolk is typically measured analytically, which requires time, equipment and expertise, and can limit the sample available for other measurements, at least in species laying small eggs. Here we evaluate whether yolk colour can be used as a reliable alternative measure for total yolk carotenoid concentration. We compare two non-analytical methods, digital photography and visual colour scoring, using eggs from a wild population of Blue Tits Cyanistes caeruleus. Yolk hue estimated from digital photographs correlated more strongly with total yolk carotenoid concentration measured by high-performance liquid chromatography (HPLC) than did the visually assessed colour score based on a Yolk Colour Fan. Previous results based on HPLC measurements of total carotenoid concentration could be reproduced using yolk hue measurements. The results suggest that measuring yolk hue is a suitable proxy for assessing natural variation in total yolk carotenoid concentration in eggs of free-living birds.     

The influence of diet on fatty acids in the egg yolk of green sea turtles, Chelonia mydas

Fatty acid concentrations found in the yolk of green sea turtles reflect differences in the diet of the mothers. All of the 12 fatty acids measured in yolk samples were significantly different between eggs produced from the pellet and wild-type diets. However, the relative pattern of yolk fatty acids in the green turtle mirrored those of other reptiles. Yolk samples contained mostly (63–67%) 14:0. 16:0, 16:1n-7 and 18:1n-9. Yolks from captive animals on pellet diet contained an additional 17.64% of the total yolk lipid as 12:0 and 18:2n-6. Wild yolks contained an extra 11.41% of lipid as 18:0 and 18:1n-7. Selection of fatty acids for the yolk should balance the energetic and anabolic needs of the embryo. Eggs are provisioned based on maternal metabolism of available nutrients and subtle differences between natural foods and those available in captivity could affect the viability of future eggs.     

Sequential deposition of yolk components during oogenesis in an insect,Aedes aegypti (Diptera: Culicidae)

Vitellogenesis in Aedes aegypti of uniform body size was followed at 27 degrees C in narrow time intervals throughout their first reproductive cycle by measuring the length, diameter, and volume of follicles and oocytes, the latter as an expression of the yolk mass (vitellus). Independent of all experimental conditions, a two-step process of elongation was recognized for both follicle length and yolk length, so that growth curves were consistently composed of two linear regressions with different slopes against time. Follicle lengths started to increase immediately after the blood meal, while oocytes took up to 6 h to show a measurable increase in yolk length. The first linear phase continued until 30 h, when yolk length reached 268+/-22 micro m. At this point, a transition occurred where the linearity shifted sharply for the next 6 h to 2-4-times higher slopes for both regressions. This second growth phase represented a 40% elongation of oocytes and follicles. Then, both curves leveled off at their final size, characteristic of mature ovaries: 462+/-10 micro m for oocytes, 489+/-11 micro m for follicles. These values remained constant until oviposition.The first linear growth phase was associated with an equicaloric and synchronous protein and lipid incorporation into the oocytes; levels of these substances reached their maximum by the end of this first phase and remained constant until oviposition. The second linear growth phase was characterized by rapid glycogen incorporation into oocytes from 20 to 100% of the maximum. Subsequently, the surface pattern of the exochorion became visible, marking the end of yolk incorporation. Since eggs are always laid on moist substrates, within 2-3 h of oviposition they double in volume and fresh weight, driven by more than tripling of their water content.When blood-fed females were exposed to five different temperatures between 17 and 37 degrees C, the distinction between the two linear growth phases persisted, but the slopes of the respective regressions, and therefore their durations, were affected. Eggs still matured at 37 degrees C but never hatched and at 12 degrees C only 18% hatched, whereas at all the intermittent temperatures hatching was 80-90%. Oogenesis appears to be limited to the range between 12 and about 32 degrees C.The effects of age, maternal body size and the source of the blood on vitellogenesis were also examined. These parameters affected the onset and/or extent of oogenesis in various ways.     

Formation of primordial yolk granules in the avian oocyte

Summary Electron and light microscopical investigations of early oocytes (between 1.0 mm and 5.0 mm in diameter) from the ovary of 28–30 week-old chickens, suggested the formation of primordial yolk granules from cytoplasmic vesicles. These vesicles formed an aggregation which was observed to be surrounded by membranes, giving the aggregate a multivesicular body-like appearance. At a later stage the vesicles inside the membrane disintegrated and the multivesicular bodies acquired the appearance of primordial yolk granules. The contribution of other structures to the formation of yolk granules is discussed.For constructive criticism I am very grateful to Dr. Hadar Emanuelsson, Institute of Zoophysiology, Lund. The excellent technical assistance of Miss Inger Antonsson and Mrs. Annagreta Petersen is gratefully acknowledgedThis work was supported by Kungliga Fysiografiska Sällskapet, Lund     

Establishment and movement of egg regions revealed by the size class of yolk platelets in Xenopus laevis

Sizes of yolk platelets were measured in sections of oocytes and embryos in Xenopus. It was found that the average size of the largest group of platelets in cells differed between germ layers of neurulae. It was small (3 to 5 m) in the ectoderm, medium-sized (5 to 8 µm) in the mesoderm, and large (over 8 m) in the endoderm. Platelets of these size classes formed layers in egg, the yolk gradient, by the end of oocyte maturation. The yolk gradient contained products of the mitochondrial cloud and a part of the germinal vesicle material at certain positions. The layers of small, medium and large platelets in the egg changed their locations to distribute to the ectoderm, mesoderm and endoderm of neurulae, respectively. The yolk layers in the egg thus represented different prospective fates, and a figure describing the locations of these layers could be regarded as a fate map for the one-cell stage. Most of the marginal blastomeres of embryos at cleavage stages consisted of a few parts with different prospective fates. Results were discussed with reference to available fate maps for cleavage stage embryos.     

Ultrastructure of the pre-implantation shark yolk sac placenta

During ontogeny, the yolk sac of viviparous sharks differentiates into a yolk sac placenta which functions in gas exchange and hematrophic nutrient transport. The pre-implantation yolk sac functions in respiration and yolk absorption. In a 10.0 cm embryo, the yolk sac consists of six layers, viz. (1) somatic ectoderm; (2) somatic mesoderm; (3) extraembryonic coelom; (4) capillaries; (5) endoderm; and (6) yolk syncytium. The epithelial ectoderm is a simple cuboidal epithelium possessing the normal complement of cytoplasmic organelles. The endoplasmic cisternae are dilated and vesicular. The epithelium rests upon a basal lamina below which is a collagenous stroma that contains dense bodies of varying diameter. They have a dense marginal zone, a less dense core, and a dense center. The squamous mesoderm has many pinocytotic caveolae. The capillary endothelium is adjacent to the mesoderm and is delimited by a basal lamina. The endoderm contains yolk degradation vesicles whose contents range from pale to dense. The yolk syncytium contains many morphologically diverse yolk granules in all phases of degradation. Concentric membrane lamellae form around yolk bodies as the main yolk granules begin to be degraded. During degradation, yolk platelets exhibit a vesicular configuration.     

Sequence analysis of a yolk protein secretion mutant of Drosophila melanogaster

Summary The female-sterile mutants fs(1) 1163 of Drosophila melanogaster described by Gans et al. (1975) has been characterised as a yolk protein 1 (YP1) secretion mutant (Bownes and Hames 1978b; Bownes and Hodson 1980). We have cloned and sequenced the YP1 gene from this strain, and the strain in which the mutant was induced. One amino acid substitution was found in the predicted polypeptide sequence, an isoleucine to asparagine change at position 92. The sequence of the leader peptide was identical to previously published YP1 sequences. The possible effects of the amino acid change were investigated by computer analysis, which suggests there is no major alteration of secondary structure, but that a hydrophobic region in YP1 is lost in the mutant. This may affect higher order structure.