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Excess amino acid polymorphism in mitochondrial DNA: contrasts among genes from Drosophila, mice, and humans 总被引:13,自引:3,他引:10
Recent studies of mitochondrial DNA (mtDNA) variation in mammals and
Drosophila have shown an excess of amino acid variation within species
(replacement polymorphism) relative to the number of silent and replacement
differences fixed between species. To examine further this pattern of
nonneutral mtDNA evolution, we present sequence data for the ND3 and ND5
genes from 59 lines of Drosophila melanogaster and 29 lines of D. simulans.
Of interest are the frequency spectra of silent and replacement
polymorphisms, and potential variation among genes and taxa in the
departures from neutral expectations. The Drosophila ND3 and ND5 data show
no significant excess of replacement polymorphism using the
McDonald-Kreitman test. These data are in contrast to significant
departures from neutrality for the ND3 gene in mammals and other genes in
Drosophila mtDNA (cytochrome b and ATPase 6). Pooled across genes, however,
both Drosophila and human mtDNA show very significant excesses of amino
acid polymorphism. Silent polymorphisms at ND5 show a significantly higher
variance in frequency than replacement polymorphisms, and the latter show a
significant skew toward low frequencies (Tajima's D = -1.954). These
patterns are interpreted in light of the nearly neutral theory where mildly
deleterious amino acid haplotypes are observed as ephemeral variants within
species but do not contribute to divergence. The patterns of polymorphism
and divergence at charge-altering amino acid sites are presented for the
Drosophila ND5 gene to examine the evolution of functionally distinct
mutations. Excess charge-altering polymorphism is observed at the carboxyl
terminal and excess charge-altering divergence is detected at the amino
terminal. While the mildly deleterious model fits as a net effect in the
evolution of nonrecombining mitochondrial genomes, these data suggest that
opposing evolutionary pressures may act on different regions of
mitochondrial genes and genomes.
相似文献
3.
Maternal origin of nucleated erythrocytes in peripheral venous blood of pregnant women 总被引:3,自引:0,他引:3
Anna Slunga-Tallberg Wa'el El-Rifai Mauri Keinänen Kari Ylinen Tapio Kurki Katherine Klinger Olavi Ylikorkala Sakari Knuutila 《Human genetics》1995,96(1):53-57
We studied the origin of nucleated red blood cells (NRBC) in peripheral venous blood samples from 40 pregnant women carrying a male fetus, using a technique that allows direct chromosomal analysis by in situ hybridisation on immunologically and morphologically classified cells. Samples from ten nulligravid women were studied as controls. NRBC were enriched by negative magnetic activated cell sorting (miniMACS) using anti-CD45 monoclonal antibody. NRBC were detected by alkaline phosphatase anti-alkaline phosphatase immunostaining using a monoclonal anti-glycophorin A antibody. The origin of the NRBC was determined by fluorescence in situ hybridisation using X and Y specific probes. NRBC were found in 37 of the 40 pregnant women at a range of 1 to 230 per 20 ml of venous blood and in 6 of the 10 controls at a range of 1 to 3 per 20 ml of venous blood. All NRBC detected in the pregnant women were evidently of maternal origin, and in the pregnant women the number of NRBC was significantly higher (P < 0.05) than in the controls. Pregnancy per se seems to induce the appearance of maternal NRBC in the circulation, and it cannot therefore be assumed that NRBC isolated from the maternal blood are of fetal origin on the basis of morphology alone. Discrimination of fetal NRBC must occur for prenatal diagnosis of fetal genetic disorders. 相似文献
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Ylinen JJ Julin M Rezasoltani A Virtapohja H Kautiainen H Karila T Mälkiä E 《Journal of strength and conditioning research / National Strength & Conditioning Association》2003,17(4):755-759
Special training methods in wrestling have been assumed to improve the stability and tolerance of the neck. The aim of this study was to measure the neck strength levels reached in an extremely physically demanding sport. A neck strength measurement system was used to measure various parameters of maximal isometric neck strength in Finnish senior wrestlers competing at the international level. The results were compared with those achieved by junior wrestlers and a control group. The means (SD) of the maximal isometric neck strength for cervical rotation were 0.4 (0.1) Nm.kg(-1) for the senior wrestlers, 0.3 (0.1) Nm.kg(-1) for the junior wrestlers, and 0.2 (0.1) Nm.kg(-1) for the nonsportsmen. The respective results for cervical flexion were 4.4 (1.4), 3.8 (0.7), and 2.3 (0.8) Nm.kg(-1); for extension, 6.0 (1.1), 5.9 (0.7), and 4.0 (0.9) Nm.kg(-1). Neck strength in flexion seems to improve more than in extension as the result of wrestling. The greatest difference was found in rotation, which in the senior wrestlers was almost 3 times that in the nonsportsmen. There was great individual variation within all groups, and the results revealed weaknesses in all directions. Maximal neck strength measurements provide information useful in planning training programs to correct possible muscle deficiency and imbalance. 相似文献
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The ImmunoDeficiency Resource (IDR), freely available at http://www.uta.fi/imt/bioinfo/idr/, is a comprehensive knowledge base on immunodeficiencies. It is designed for different user groups such as researchers, physicians and nurses as well as patients and their families and the general public. Information on immunodeficiencies is stored as fact files, which are disease- and gene-based information resources. We have developed an inherited disease markup language (IDML) data model, which is designed for storing disease- and gene-specific data in extensible markup language (XML) format. The fact files written by the IDML can be used to present data in different contexts and platforms. All the information in the IDR is validated by expert curators. 相似文献
9.
S Iu Kliushnik L M Selimova LM V M Za?des 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》1990,(6):23-30
The optimum conditions for using the method of radioimmunoprecipitation (RIP) for the detection of human immunodeficiency virus (HIV) in serum samples have been established. Out of several available cell lines persistently infected with HIV, specially selected line 17 has been chosen. The characteristic feature of this is the high and stable (under the conditions of prolonged cultivation) accumulation of virus-specific proteins in infected cells. The optimum conditions for making the test and its evaluation have also been established. The data of literature on the advantages of the method of RIP over such traditional methods as the enzyme immunoassay and immunoblotting have been confirmed. Thus, the presence of specific antibodies in several serum samples registered as false negative has been established. The intertypical reactivity of two serotypes of the virus, HIV-1 and HIV-2, has been studied. Cross reactivity of antibodies with respect to the HIV gene gag, but not with respect to viral glycoproteids, has been established. Ideas on the expediency and prospects of using RIP for the serological control of HIV infection are presented. 相似文献
10.
Recruitment of TBK1 to cytosol‐invading Salmonella induces WIPI2‐dependent antibacterial autophagy 下载免费PDF全文
Teresa LM Thurston Keith B Boyle Mark Allen Benjamin J Ravenhill Maryia Karpiyevich Stuart Bloor Annie Kaul Jessica Noad Agnes Foeglein Sophie A Matthews David Komander Mark Bycroft Felix Randow 《The EMBO journal》2016,35(16):1779-1792
Mammalian cells deploy autophagy to defend their cytosol against bacterial invaders. Anti‐bacterial autophagy relies on the core autophagy machinery, cargo receptors, and “eat‐me” signals such as galectin‐8 and ubiquitin that label bacteria as autophagy cargo. Anti‐bacterial autophagy also requires the kinase TBK1, whose role in autophagy has remained enigmatic. Here we show that recruitment of WIPI2, itself essential for anti‐bacterial autophagy, is dependent on the localization of catalytically active TBK1 to the vicinity of cytosolic bacteria. Experimental manipulation of TBK1 recruitment revealed that engagement of TBK1 with any of a variety of Salmonella‐associated “eat‐me” signals, including host‐derived glycans and K48‐ and K63‐linked ubiquitin chains, suffices to restrict bacterial proliferation. Promiscuity in recruiting TBK1 via independent signals may buffer TBK1 functionality from potential bacterial antagonism and thus be of evolutionary advantage to the host. 相似文献