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41.
家鸡和原鸡的线粒体DNA多态性比较 总被引:17,自引:0,他引:17
本文运用11种限制性内切酶分析了家鸡(茶花鸡、尼西鸡、大理漾濞黄鸡)和原鸡共10只个体的线粒体DNA限制性片段长度多态性(RFLP),平均每个个检测到的片段为40条左右。但仅发现3种变异的限制性片制性格局,即StuI-B,Eca-I-b和RI-B.其中StuI-B和ScaI-B为首次报道,而且均为原鸡所物有,EcoRI-B则为大理漾濞黄鸡所特有。茶花鸡和尼西鸡拥有完全相同的限制性格局。经过计算,原 相似文献
42.
Wen Wang Ai-hua Liu Shi-ying Lin Hong Lan Bing Su De-wen Xie Li-ming Shi 《Biochemical genetics》1994,32(9-10):371-378
mtDNA genotypes of six domestic horses (three adult short horses whose heights are under 1 m and three common domestic horses) from a small region of 15 km2 in Malipo county of Yunnan province of China were investigated by the technique of restriction fragment length polymorphism (RFLP) with 16 restriction endonucleases which recognize 6-bp sequences. An average of 56 fragments for an individual was obtained. Unlike other domestic animals, this population of horses exhibits high mtDNA genetic diversity. Each of the six horses has a specific mtDNA genotype showing a pattern of multiple maternal origins, as suggested by fossil and literature records. We think the population of horses is an amazing seed-resource pool of horses and hence deserves to be paid more attention from the view of conservation genetics. However, it is also remarkable that we did not find any typical mtDNA genetic markers which would discriminate between short horses and common domestic horses. 相似文献
43.
The red alga Porphyra purpurea (Roth) C. Agardh has a life cycle that alternates between shell-boring, filamentous sporophytes and free-living, foliose gametophytes. The significant morphological differences between these two phases suggest that many genes should be developmentally regulated and expressed in a phase-specific manner. In this study, we prepared and screened subtracted complementary DNA (cDNA) libraries specific for the sporophyte and gametophyte of P. purpurea. This involved the construction of cDNA libraries from each phase, followed by the removal of common clones through subtractive hybridization. Sampling of the subtracted libraries indicated that 8–10% of the recombinant colonies in each library were specific for the appropriate phase. Of 20 putative phase-specific cDNAs selected from each subtracted library, eight unique clones were obtained for the sporophyte and seven for the gametophyte. After confirming their phase-specificities by hybridization to gametophyte and sporophyte messenger RNA, these 15 phase-specific cDNAs were sequenced, and the deduced amino acid sequences were used to search protein databanks. Two proteins encoded by the sporophyte-specific cDNAs and two by the gametophyte-specific cDNAs were identified by their similarity to databank entries. 相似文献
44.
本文新建立盲走螨属agilis群并限定了该群的主要特征,归纳了世界上已描述的8种,其中分布于我国的3种,此外描述了3个新种。 相似文献
45.
5e-tert-Butyl-2e-[4-(substituted-ethynyl)phenyl]-1,3-dithianes with selected functional groups (R) on the ethynyl moiety are potent blockers of the GABA-gated chloride channel measured as inhibitor concentration (IC50) for 4-n-[3H]propyl-1-(4-ethynylphenyl)-2, 6,7-trioxabicyclo[2.2.2]octanebinding to bovine brain membranes. The terminal R substituents were introduced by coupling 5e-tert-butyl-2e-(4-iodophenyl)-1,3-dithiane with HC ≡ CR or 5e-tert-butyl-2e-(4-ethynylphenyl)-1,3-dithiane with XR. The potency of the parent compound (R=H) with an IC50 of 21 μM is equaled or exceeded by up to 7-fold (i.e. IC50 = 3–21 μM) by several carboxylic acids [R = (CH2)nCO2H (n = 0–3), (CH2nOCH2CO2H (n = 1–3) and CH2SCH2 CO2H] and their esters and two phosphonic acids (CH2CH2PO3H2 and CH2OCH2PO3H2) but not their esters. These carboxyl and phosphonic acids (and their salts) include the most potent water-soluble chloride channel blockers known. Conversion to the monosulfones increases activity of the R = H and CH2OH analogs by 1.2- to 3-fold but decreases that of the R = CH2CH2CO2R′ (R′ = H or CH3) derivatives by 3- to 13-fold. Quantitative structure-activity analyses for 44 2-[4-(substituted-ethynyl)phenyl]-dithianes suggests that the principal feature of the R substituent for high activity is its polarizable volume modeled as molecular refractivity, i.e. this substituent is not a well-defined pharmacophore and undergoes a structurally non-specific interaction with the receptor. These observations lay the background for preparing candidate affinity probes. 相似文献
46.
双价外壳蛋白基因植物表达载体的构建及马铃薯转基因植株的鉴定 总被引:10,自引:0,他引:10
在克隆了马铃薯X病毒(PVX)、马铃薯Y 病毒(PVY)和马铃薯卷叶病毒(PLRV)的外壳蛋白基因的基础上,构建同时包含PVX和PVY 与PVY 和PLRV 两个外壳蛋白基因植物表达框架的表达载体,通过农杆菌(Agrobacterium tumefaciens)介导转化烟草(Nicotianatabacum )和生产上常用的几个马铃薯(Solanum tuberosum )优良品种:“Favorita”、“虎头”、“克4”。经PCR检测证明外源基因已整合到植物的染色体上,得到批量转基因植株。在转PVX+PVY 外壳蛋白基因的烟草上接种PVX (5 μg/m L)、PVY(20 μg/m L)病毒,得到有一定抗性的植株 相似文献
47.
在实验条件下,供试的林木、农作物及牧草种子均能在铅锌矿尾矿中萌发,其中萌发率与非污染土壤中的相近,多数种子的萌发速率低于对照组。供试植物幼苗出土30天内没有死苗现象,但与对照相比,株高下降28.4%,复叶数减少34.1%,生物量下降52.6%. 相似文献
48.
Abstract The ecdysteroid levels in hemolymph, ovary, synganglion and whole body of diapausing female Dermacentor niveus were detected by HPLC, and compared with the results of nondiapausing female. It is revealed that the ecdysteroid levels in hemolymph and ovary of diapausing female are similar basically to that of nondiapausing female in the first few days after engorgement. From the 10th day after engorgement, the ecdysteroid levels of diapausing female decreased and even became distinctly lower than that of nondiapausing female. The paucity of ecdysteroids in these individuals would influence the normal development of oocytes. In order to explore the effect of ecdyateroids on the diapausing female, we injected 20-hydroxyecdysone with different dosages at different time into the ticks, and found that after just complete engorgement the injection with large dosages (10000 and 1375 ng/tick) caused death of the ticks. From 10th to 20th day after engorgement the ecdysteroid levels of diapausing female are lower than that of nondiapausing one before oviposition, the injection with certain dosages 50, 70 and 100 ng/tick> of 20E can accelerate vitellogenesis and terminate reproductive diapause, but the amount of eggs produced by them is less than that produced by nondiapausing female. The termination of diapause in female of ixcdid tick by exogenous ecdysteroids is reported for the first time. 相似文献
49.
RGDS肽对大鼠主动脉球囊内膜剥脱后血管壁增殖的影响 总被引:1,自引:0,他引:1
在大鼠主动脉球囊内膜剥脱术后血管壁细胞过度增殖模型上,用合成的血小板膜纤维蛋白原受体(glycoproteinⅡb/Ⅲacomplex,GPⅡb/Ⅲa)拮抗剂RGDS(Arg-Gly-Asp-Ser,50μmol·kg-1·d-1)治疗可有效地抑制损伤血管壁的细胞计数增加和内膜增厚以及血管平滑肌细胞增殖,显著降低其血管组织3H-TdR和3H-Leu的参入增加程度。实验结果提示RGDS肽作为血管成型术的辅佐剂,对于防治血管再狭窄可能具有潜在的临床应用前景。 相似文献
50.