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排序方式: 共有314条查询结果,搜索用时 0 毫秒
1.
Mohammadreza Ebrahimi Laura Mara Bernardo Chessa Fabrizio Chessa Abbas Parham Maria Dattena 《Reproduction in domestic animals》2021,56(3):467-475
Microinjection of exogenous DNA into the cytoplasm of matured oocytes or zygotes is a promising technique to generate transgenic animals. However, the data about the microinjection time and procedure in sheep are limited and have not treated in detail. To obtain more in-depth information, the Sarda sheep oocytes from abattoir-derived ovaries were subjected to IVM and IVF. Then, the GFP plasmid as a reporter gene was injected into the cytoplasm of MII oocytes (n: 95) and zygotes at different post-insemination intervals (6–8 hpi, n: 120; 8–10 hpi, n: 122; 10–12 hpi, n: 110 and 12–14 hpi, n: 96). There were no significant differences in the cleavage rates between the groups. However, blastocyst rate of injected zygotes at all-time intervals was significantly lower than injected MII oocytes and control group (p < 0.05). Interestingly, the proportion of GFP-positive embryos was higher at 8–10 hpi compared with other injected groups (4 % versus 0 %, p < 0.01). Among these, the proportion of mosaic embryos was high and two of those embryos developed to the blastocyst stage. In conclusion, we settled on the cytoplasmic microinjection of GFP plasmid at 8–10 hpi as an optimized time point for the production of transgenic sheep and subsequent experiments. 相似文献
2.
黄瓜游离小孢子培养诱导成胚和植株再生 总被引:4,自引:0,他引:4
以10个不同基因型黄瓜为试材进行游离小孢子培养,通过对成胚条件的系统研究,从‘7447’和‘Poinsett97’中获得了子叶形胚和再生植株。研究结果表明:基因型和小孢子发育时期是限制黄瓜游离小孢子成胚的关键因子。不同品种间胚状体产量差异显著,每皿产胚1.5~33.4个。单核靠边期是进行黄瓜游离小孢子培养的最佳时期。低温预处理有利于胚状体的诱导,4 ℃预处理2~4 d为宜,以处理2 d时胚状体产量最高。外源激素在诱导胚状体时并非必需,但低浓度的外源激素(0.5 mg·L-1 2,4-D、0.2 mg·L-1 6-BA)更能促进小孢子成胚。NLN和B5两种基础培养基在诱导胚状体上无显著差异。子叶形胚易分化成苗,而其它类型的胚状体不能获得再生植株。 相似文献
3.
为了查明阿尔泰山两河源国家级自然保护区树附生地衣物种组成成分,以及探讨影响该地区树附生地衣群落分布格局与环境因素之间的关系,以附生地衣覆盖度为指标,应用除趋势对应分析(DCA)对样点进行分组,运用典范对应分析(CCA)分析附生地衣分布与环境因素的关系,结果表明:1)阿尔泰山两河源自然保护区树附生地衣共有49种隶属于15科30属。2)根据DCA分析将该地区树附生地衣划分为3个样点组,样点组1共有地衣22种,总盖度为2.639%,物种多样性指数为1.603;样点组2共有地衣27种,地衣总盖度为3.717%,物种多样性最大为1.972;样点组3:共有地衣12种,地衣总覆盖度为1.036%,物种多样性最小量为0.871。3)CCA排序结果表明:低海拔区,人为干扰强度高,地衣多样性较低;中海拔区,森林郁闭度高,湿度适中,干扰较少,地衣多样性较高;高海拔区,森林郁闭度较低,树种较少,光强度较强,干扰较少,主要以壳状地衣为主,多样性较低。 相似文献
4.
Bracon instabilis Marshal is an ectoparasite attacking the larvae ofP. operculella in Egypt. According to available literatures, this is the first study onB. instabilis. The laboratory rearing of this parasite was undertaken on the third and fourth larval instars ofP. operculella and the method was mentioned in details. Certain aspects of the morphology of the immature and adult stages were given. The durations of the immature stages of the parasite were estimated at 15 and 25°C and 60±5% R.H. The total durations of the immature stages (from egg to adult) were 39.62 and 11.19 days at 15 and 25°C, respectively. 相似文献
5.
6.
Gao Zexia Wang Weimin Yang Yi Khalid Abbas Li Dapeng Zou Guiwei James S. Diana 《Fish physiology and biochemistry》2007,33(3):213-222
The peripheral blood cells of one-year-old Chinese sturgeon (Acipenser sinensis) have been studied by light microscopy and transmission electron microscopy. The erythrocyte count was 84.86 × 104 cell mm−3 in the peripheral blood of the fish and that of leukocytes was 2.24 × 104 cell mm−3. The erythrocytes and four main types of leucocyte—thrombocytes, lymphocytes, granulocytes (including neutrophils and eosinophils),
and monocytes, were identified in the peripheral blood. In addition to normal erythrocytes, reticulocytes and division of
erythrocytes were observed. Thrombocytes were the most numerous among the leukocytes, and the number of neutrophils with lobated
nuclei was larger than for other fish. The structures of the erythrocytes, lymphocytes, monocytes, granulocytes, and thrombocytes
of the fish were studied. The erythrocytes were almost completely devoid of organelles, except for some mitochondria and granules.
A large number of vacuoles and a few organelles were observed in cytoplasm of the monocytes. There were many microvilli on
the membrane and pseudopodia-like cytoplasm bulge in the lymphocytes. The neutrophils were round or oval in shape with bilobed,
trilobed, or multilobed nuclei whereas the eosinophils had big special granules, dark stained. There were many vesicles in
some thrombocytes, which were related to its phagocytosis; some thrombocytes had almost no cytoplasm or organelles. 相似文献
7.
Hafiz Mohkum Hammad Abdul Khaliq Farhat Abbas Wajid Farhad Shah Fahad Muhammad Aslam 《Communications in Soil Science and Plant Analysis》2020,51(10):1406-1422
ABSTRACT Organic amendments in the soil perform better than synthetic fertilizers in regards to soil fertility and sustainable crop productivity. Experiments were conducted to compare the effects of organic and synthetic fertilizers on soil fertility and wheat (Triticum aestivum L.) productivity. Soil fertility and protein contents of wheat grains (13.2% and 13.3% during 2005–06 and 2006–07, respectively) were improved by organic amendments. However, synthetic fertilizer (at the rate of 150, 100, and 60 kg ha?1 N, P2O5, and K2O, respectively) applications resulted in the maximum grain yield (4.05 and 4.46 t ha?1 during 2005–06 and 2006–07, respectively). The observed and simulated soil organic carbon (SOC) reasonably agreed during RothC model validation (R 2 = 0.99). Economic analysis showed the maximum net profit and relative increase in income ($729 US ha?1 and 309%, respectively) from inorganic treatment. Application of synthetic fertilizers increased grain yield and farm profit while organic manure enhanced grain quality. The RothC model had potential for determining the SOC in organic farming under arid environment. 相似文献
8.
Abbas Rezaeizad Benjamin Wittkop Rod Snowdon Maen Hasan Valiollah Mohammadi Abbas Zali Wolfgang Friedt 《Euphytica》2011,177(3):335-342
Association mapping identifies quantitative trait loci (QTLs) by examining the marker-trait associations that can be attributed
to the strength of linkage disequilibrium between markers and functional polymorphisms across a set of diverse germplasm.
In this study, association mapping was performed to detect QTL-linked and genome wide SSR markers linked to phenolic compounds
of extraction meal in a population of 49 genetically diverse oilseed rape cultivars of dark-seeded, winter-type oilseed rape
accessions. Correction for population structure was performed using 559 genome wide SSR markers. Results showed that seed
colour is an important contributor to seed meal quality. Totally, 52 SSR markers linked to phenolic compounds were detected,
five of them being QTL linked markers. Some of these markers were already mapped on Brassica napus chromosomes that contain known QTL controlling oilseed rape meal quality traits. Our results demonstrate that association
mapping is a useful approach to complement and enhance previous QTL information for marker-assisted selection. 相似文献
9.
Flasar FM Achterberg RK Conrath BJ Pearl JC Bjoraker GL Jennings DE Romani PN Simon-Miller AA Kunde VG Nixon CA Bézard B Orton GS Spilker LJ Spencer JR Irwin PG Teanby NA Owen TC Brasunas J Segura ME Carlson RC Mamoutkine A Gierasch PJ Schinder PJ Showalter MR Ferrari C Barucci A Courtin R Coustenis A Fouchet T Gautier D Lellouch E Marten A Prangé R Strobel DF Calcutt SB Read PL Taylor FW Bowles N Samuelson RE Abbas MM Raulin F Ade P Edgington S Pilorz S Wallis B Wishnow EH 《Science (New York, N.Y.)》2005,307(5713):1247-1251
Stratospheric temperatures on Saturn imply a strong decay of the equatorial winds with altitude. If the decrease in winds reported from recent Hubble Space Telescope images is not a temporal change, then the features tracked must have been at least 130 kilometers higher than in earlier studies. Saturn's south polar stratosphere is warmer than predicted from simple radiative models. The C/H ratio on Saturn is seven times solar, twice Jupiter's. Saturn's ring temperatures have radial variations down to the smallest scale resolved (100 kilometers). Diurnal surface temperature variations on Phoebe suggest a more porous regolith than on the jovian satellites. 相似文献
10.
托木尔峰自然保护区地衣的补充研究 总被引:6,自引:0,他引:6
我们根据多年的研究并结合前人的工作进一步地整理了分布在新疆托木尔峰自然保护区的地衣种类。分析该地区的地衣种有120个,分别隶性于49属,其中有11个变种和4个变型。调查中我们还发现该地区地衣随着海拔高度的升高而有所不同,北坡和南坡也有明显的差异。 相似文献