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91.
人胚DA能神经元移植于帕金森氏病猴模型的TH免疫细胞化学的研究 总被引:3,自引:0,他引:3
为了对人胚黑质DA神经元移植治疗PD人的临床应用作出客观评估,将8-12周人胚黑质细胞移植到用MPTP诱发的偏侧PD猴新纹状体内。实验动物分别存活2个月、5个月和1年后,用TH免疫细胞化学方法对被移植的人胚DA细胞的存活和与宿主间的突触联系进行检查。在光镜下可见被移植侧的新纹状体内有TH阳性细胞,它们成小群散在分布,每小群有3-10个细胞。TH阳性细胞的轴突延伸到整个新纹状体,树突呈现出正常发育过 相似文献
92.
N. J. H. CAMPBELL F. C. HARRISS M. S. ELPHINSTONE P. R. BAVERSTOCK 《Molecular ecology》1995,4(4):407-418
The ability of DNA screening techniques such as Temperature Gradient Gel Electrophoresis (TGGE) and Heteroduplex Analysis to provide resolution approaching that provided by DNA sequencing for a fraction of the time, effort and expense point to them as the logical successor to allozyme electrophoresis for population genetics. Here we present a novel alternative to the standard TGGE/Heteroduplex Analysis protocol - Outgroup Heteroduplex Analysis (OHA). We assess this technique's sensitivity in comparison to previous screening approaches using a known hierarchy of sequence differences. Our data show that Outgroup Heteroduplex Analysis has greatly increased sensitivity for screening DNA variants from that of TGGE used alone and is easily applicable to large numbers of samples. Using this technique we can consistently detect differences of as small as one base change in a 433-base-pair fragment of Control Region mitochondrial DNA from Melomys cerbinipes (an Australian rodent). The approach should easily be extendable to nuclear loci and is not necessarily dependent on the use of a denaturing gradient When combined with a targeted sequencing effort, OHA provides a sensitive and simple means of obtaining allele/haplotype frequencies and their phylogenies for population and phylogeographic studies in molecular ecology. 相似文献
93.
Mitochondrial DNA products among RAPD profiles are frequent and strongly differentiated between races of Douglas-fir 总被引:5,自引:0,他引:5
Racial differentiation and genetic variability were studied between and within the coastal, north interior, and south interior races of Douglas-fir using RAPD and allozyme markers. Nearly half of all RAPD bands scored (13:45%) were found to be amplified from mitochondrial DNA. They exhibited maternal inheritance among hybrids and back-crosses between the races, and were much more highly differentiated (GST= 0.62 for haplotype frequencies) than were allozymes (GST= 0.26). No evidence of hybridization or introgression was detected where the coastal and interior races come into proximity in central Oregon. 相似文献
94.
Colonization history of north European field voles (Microtus agrestis) revealed by mitochondrial DNA
The genetic structure of field vole (Microtus agrestis) populations from northern Europe was examined by restriction fragment length polymorphisms of mitochondrial DNA (mtDNA) in 150 individuals from 67 localities. A total of 83 haplotypes was observed, most of which were rare and highly localized geographically. Overall nucleotide diversity was high (134%), but showed a tendency to decrease with higher latitude. Two major mtDNA lineages differing by 2% in nucleotide sequence were identified. A southern mtDNA lineage was observed in field voles from Britain, Denmark and southern and central Sweden, whereas voles from Finland and northern Sweden belonged to a northern lineage. The strict phylogeographic pattern suggests that the present population generic structure in field voles reflects glacial history: the two groups are derived from different glacial refugia, and recolonized Fennoscandia from two directions. A 150–200-km-wide secondary contact zone between the two mtDNA groups was found in northern Sweden. Distinct phylogeographic substructuring was observed within both major mtDNA groups. 相似文献
95.
Jacqueline M. Orian Richard G. Hadikusumo Sangkot Marzuki Anthony W. Linnane 《Journal of bioenergetics and biomembranes》1984,16(5-6):561-581
We have investigated the extent to which the assembly of the cytoplasmically synthesized subunits of the H+-ATPase can proceed in a mtDNA-less (rho°) strain of yeast, which is not capable of mitochondrial protein synthesis. Three of the membrane sector proteins of the yeast H+-ATPase are synthesized in the mitochondria, and it is important to determine whether the presence of these subunits is essential for the assembly of the imported subunits to the inner mitochondrial membrane. A monoclonal antibody against the cytoplasmically synthesized -subunit of the H+-ATPase was used to immunoprecipitate the assembled subunits of the enzyme complex. Our results indicate that the imported subunits of the H+-ATPase can be assembled in this mutant, into a defective complex which could be shown to be associated with the mitochondrial membrane by the analysis of the Arrhenius kinetics of the mutant mitochondrial ATPase activity.This paper is No. 61 in the seriesBiogenesis of Mitochondria. For paper No. 60, see Novitskiet al. (1984). 相似文献
96.
E. coli ribosomal DNA has been used to probe maize mitochondrial DNA. It hybridizes primarily with chloroplast ribosomal DNA sequences and with fungal and bacterial sequences which may contaminate the mtDNA preparations. It also hybridizes to the chloroplast 16S ribosomal RNA gene sequence present in the mitochondrial genome (1) as well as to the mitochondrial 18S ribosomal RNA gene sequence. Weak sequence homology was detected between E. coli rDNA and the mitochondrial 26S ribosomal RNA gene. 相似文献
97.
Assessment of a model for intron RNA secondary structure relevant to RNA self-splicing--a review 总被引:36,自引:0,他引:36
A widespread class of introns is characterized by a particular RNA secondary structure, based upon four conserved nucleotide sequences. Among such "class I" introns are found the majority of introns in fungal mitochondrial genes and the self-splicing intron of the large ribosomal RNA of several species of Tetrahymena. A model of the RNA secondary structure, which must underlie the self-splicing activity, is here evaluated in the light of data on 16 further introns. The main body or "core structure" of the intron always consists of the base-paired regions P3 to P9 with the associated single-stranded loops, with P2 present also in most cases. Two minority sub-classes of core structure occur, one of which is typical of introns in fungal ribosomal RNA. Introns in which the core structure is close to the 5' splice site all have an internal guide sequence (IGS) which can pair with exon sequences adjacent to the 5' and 3' splice sites to align them precisely, as proposed by Davies et al. [Nature 300 (1982) 719-724]. In these cases, the internal guide model allows us to predict correctly the exact location of splice sites. All other introns probably use other mechanisms of alignment. This analysis provides strong support for the RNA splicing model which we have developed. 相似文献
98.
- 1. 1. The 31P-NMR characteristics of intact rat liver mitochondria, mitoplasts and isolated inner mitochondrial membranes, as well as mitochondrial phosphatidylethanolamine and phosphatidylcholine, have been examined.
- 2. 2. Rat liver mitochondrial phosphatidylethanolamine hydrated in excess aqueous buffer undergoes a bilayer-to-hexagonal (HII) polymorphic phase transition as the temperature is increased through 10°C, and thus prefers the HII) arrangement at 37°C. Rat liver mitochondrial phosphatidylcholine, on the other hand, adopts the bilayer phase at 37°C.
- 3. 3. Total inner mitochondrial membrane lipids, dispersed in an excess of aqueous buffer, exhibit 31P-NMR spectra consistent with a bilayer arrangement for the majority of the endogeneous phospholipids; the remainder exhibit spectra consistent with structure allowing isotropic motional averaging. Addition of Ca2+ results in hexagonal (HII) phase formation for a portion of the phospholipids, as well as formation of ‘lipidic particles’ as detected by freeze-fracture techniques.
- 4. 4. Preparations of inner mitochondrial membrane at 4 and 37°C exhibit 31P-NMR spectra consistent with a bilayer arrangement of the large majority of the endogenous phospholipids which are detected. Approx. 10% of the signal intensity has characteristics indicating isotropic motional averaging processes. Addition of Ca2+ results in an increase in the size of this component, which can become the dominant spectral feature.
- 5. 5. Intact mitochondria, at 4°C, exhibit 31P-NMR spectra arising from both phospholipid and small water-soluble molecules (ADP, Pi, etc.). The phospholipid spectrum is characteristic of a bilayer arrangement. At 37°C the phospholipids again give spectra consistent with a bilayer; however, the labile nature of these systems is reflected by increased isotropic motion at longer (at least 30 min) incubation times.
- 6. 6. It is suggested that the uncoupling action of high Ca2+ concentrations on intact mitochondria may be related to a Ca2+-induced disruption of the integrity of the inner mitochondrial phospholipid bilayer. Further, the possibility that non-bilayer lipid structures such as inverted micelles occur in the inner mitochondrial membrane cannot be excluded.
Keywords: 31P-NMR; Inner mitochondrial membrane; Phosphatidylethanolamine; Ca2+; Hexagonal (HII) phase; Lipidic particle 相似文献
99.
Quang Khai Huynh Ryuzo Sakakibara Takehiko Watanabe Hiroshi Wada 《Biochemical and biophysical research communications》1980,97(2):474-479
The complete amino acid sequence of the mitochondrial glutamic oxaloacetic transaminase isozyme from rat liver is presented. The sequence contained 401 amino acid residues, 10 of which are methionine. Cyanogen bromide cleavage of mitochondrial glutamic oxaloacetic transaminase produced 12 peptides, one of which contained an internal homoserine residue resulting from incomplete cleavage by cyanogen bromide. The calculated molecular weight was 44,358. The sequence showed 94% homology with that of the corresponding isozyme from pig heart. These findings support the conclusion that the rate of evolution of the mitochondrial isozymes is lower than that of their cytosolic isozymes. 相似文献
100.
Osamu Gotoh Jun-Ichi Hayashi Hiromichi Yonekawa Yusaku Tagashira 《Journal of molecular evolution》1979,14(4):301-310
Summary We have developed a theory to estimate the degree of sequence divergence between related DNAs from the comparison of restriction endonuclease recognition sites. Two major improvements have been made upon a similar method reported by Upholt (1977). First, the most probable value is calculated by the collective use of all available data. This reduces intrinsic statistical error and extends the analyzable range of sequence divergence. Second, all variables are redefined so that they have strict mathematical implications. This corrects a serious error arising from the misinterpretation of the meaning of the fraction of conserved cleavage sites. With this refined method, sequence divergence between rat and mouse mitochondrial DNAs (mtDNAs) was calculated to be about 25% substitutions/nucleotide, which is in good agreement with the DNA-DNA hybridization data obtained by Jakovcic et al. (1975). It was also estimated that the three types of rat mtDNAs differ from one another by 0.3 ~1% of total base pairs. These values are 2 ~5 times smaller than those obtained with the conventional method. 相似文献