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异育银鲫及其人工杂合种外源遗传物质的检测分析 总被引:22,自引:4,他引:18
采用 DNA 杂交的方法,对异育银鲫及其人工杂合种进行了外源 DNA 的检测分析,发现两个雌核发育系的异育银鲫及其人工杂合种的 DNA 与红鲤 DNA 片段间的分子杂交均有阳性斑点出现,这表明,在异育银鲫及其人工杂合种产生过程中,父本(红鲤)的 DNA 片段的确可以随机地掺入到母本细胞的 DNA 中,从而产生了异精效应,使其子代生长加快,并出现父本性状。 相似文献
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Summary Taurine which has antioxidant effects is also known to have effects on cell proliferation, inflammation and collagenogenesis. The aim of this study was to investigate the effect of taurine on incisional skin wounds.The mice incised on the dorsal area were divided into control and experimental groups. Saline was injected intraperitoneally to half of the animals in the control group and locally applied to the other half. Fifty mM taurine solution was given intraperitoneally to the first half of the experimental animals and locally to the second half of the experimental group.After four days of treatment, malondialdehyde (MDA) and histamine levels as well as the tensile strength of the wound tissue were measured. Structural alterations in epidermis and dermis were histologically evaluated.The locally administreated taurine significantly increased wound tensile strength by decreasing the MDA and histamine levels and prevented the degranulation of the mast cells. These observations suggest that taurine may be useful on wound healing. 相似文献
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W. Din R. Anand P. Boursot D. Darviche B. Dod E. Jouvin-Marche A. Orth G.P. Talwar P.-A. Cazenave F. Bonhomme 《Journal of evolutionary biology》1996,9(5):519-539
Although quite a lot is known about the genetic structure of the polytypic species Mus musculus at the periphery of its range, the centre of origin and dispersion of the species remains unknown. To investigate the amount of genetic subdivision that occurs in the central parts of its range, we analysed the genetic variation in four new samples of mice coming from Iran, Pakistan, northern and southern India using 35 autosomal protein loci and restriction fragment length polymorphisms of three genes of the Vβ gene complex of the immune system. The variation was then compared with that found in the subspecies occupying the peripheral regions of the species range. The two samples from the northern part of the Indian subcontinent were shown to be more heterozygous than the samples from any of the other regions. They also contain the majority of the alleles that exist in the differentiated subspecies at the periphery of the species range. A neighbour-joining analysis on Nei's genetic distances and a factorial analysis of correspondences on the allelic composition of each sample both place the Pakistani and Indian populations in a phylogenetically and genetically central position compared to the peripheral subspecies. These results suggest that the populations in this geographically central area have retained most of the ancestral polymorphisms, which in turn indicates that the Indian subcontinent is probably the cradle of the species. The nature of the genetic relationships between the various populations throughout the species range and the possibility that they form an incipient ring species are also discussed. Our results are in agreement with the classical model of geographic differentiation where genetic divergence in allopatry is considered to be the prime cause of subspecies formation that may eventually lead to partial reproductive isolation on secondary contact. 相似文献
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Summary In a low dilution rate study an unexpected pH-related inhibition of yeast fermentation was found. A higher volumetric rate of ethanol production occurred at lower pH values (2.8 to 3.2), suggesting a low optimum pH.Notation Ki
product inhibition constant, L/g
- Ks
substrate saturation constant, g/L
- P
product (ethanol) concentration, g/L
- S
substrate (glucose) concentration, g/L
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specific growth rate, h–1
- 0
maximum specific growth rate, h–1 相似文献
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G. M. Din 《BMJ (Clinical research ed.)》1948,1(4544):274-275