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41.
A recent insertion of an alu element on the Y chromosome is a useful marker for human population studies 总被引:23,自引:2,他引:21
A member of the Alu family of repeated DNA elements has been identified on
the long arm of the human Y chromosome, Yq11. This element, referred to as
the Y Alu polymorphic (YAP) element, is present at a specific site on the Y
chromosome in some humans and is absent in others. Phylogenetic comparisons
with other Alu sequences reveal that the YAP element is a member of the
polymorphic subfamily-3 (PSF-3), a previously undefined subfamily of Alu
elements. The evolutionary relationships of PSF-3 to other Alu subfamilies
support the hypothesis that recently inserted elements result from multiple
source genes. The frequency of the YAP element is described in 340
individuals from 14 populations, and the data are combined with those from
other populations. There is both significant heterogeneity among
populations and a clear pattern in the frequencies of the insertion:
sub-Saharan Africans have the highest frequencies, followed by northern
Africans, Europeans, Oceanians, and Asians. An interesting exception is the
relatively high frequency of the YAP element in Japanese. The greatest
genetic distance is observed between the African and non-African
populations. The YAP is especially useful for studying human population
history from the perspective of male lineages.
相似文献
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Rajesh Kumar Kar Ashleigh S. Hanner Matthew F. Starost Danielle Springer Teresa L. Mastracci Raghavendra G. Mirmira Myung Hee Park 《The Journal of biological chemistry》2021,297(5)
Eukaryotic initiation factor 5A (eIF5A)†, ‡ is an essential protein that requires a unique amino acid, hypusine, for its activity. Hypusine is formed exclusively in eIF5A post-translationally via two enzymes, deoxyhypusine synthase (DHPS) and deoxyhypusine hydroxylase. Each of the genes encoding these proteins, Eif5a, Dhps, and Dohh, is required for mouse embryonic development. Variants in EIF5A or DHPS were recently identified as the genetic basis underlying certain rare neurodevelopmental disorders in humans. To investigate the roles of eIF5A and DHPS in brain development, we generated four conditional KO mouse strains using the Emx1-Cre or Camk2a-Cre strains and examined the effects of temporal- and region-specific deletion of Eif5a or Dhps. The conditional deletion of Dhps or Eif5a by Emx1 promotor–driven Cre expression (E9.5, in the cortex and hippocampus) led to gross defects in forebrain development, reduced growth, and premature death. On the other hand, the conditional deletion of Dhps or Eif5a by Camk2a promoter–driven Cre expression (postnatal, mainly in the CA1 region of the hippocampus) did not lead to global developmental defects; rather, these KO animals exhibited severe impairment in spatial learning, contextual learning, and memory when subjected to the Morris water maze and a contextual learning test. In both models, the Dhps-KO mice displayed more severe impairment than their Eif5a-KO counterparts. The observed defects in the brain, global development, or cognitive functions most likely result from translation errors due to a deficiency in active, hypusinated eIF5A. Our study underscores the important roles of eIF5A and DHPS in neurodevelopment. 相似文献
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Kristina A Tendl Stefan MF Schulz Thomas P Mechtler Adele Bohn Thomas Metz Susanne Greber-Platzer David C Kasper Kurt R Herkner Chike B Item 《Epigenetics》2013,8(12):1261-1267
Diagnosis of bacterial sepsis in preterm neonates can be difficult when using serum markers that rely on physiological changes because these changes may not necessarily be the result of bacterial infections alone. This retrospective investigation explores the potential use of the DNA methylation pattern of CpG sites in the promoter region of the calcitonin-related polypeptide α (CALCA) gene as an epigenetic biomarker for bacterial sepsis in preterm newborns. Four novel changes in the DNA methylation of eight CpG sites were detected in this gene and are present only in neonates with bacterial sepsis: (1) partial methylation at -769 CpG in gram-negative or gram-positive early onset sepsis (EOS) and late onset sepsis (LOS) episodes; (2) demethylation of 8 CpGs in gram-negative EOS followed by LOS (ELS) and in gram-negative EOS; (3) demethylation of 7 CpGs in gram-positive ELS and gram-positive EOS; (4) -771 C:G > T:A; 5′ de novo -778 CpG mutation on both alleles in EOS. These changes were not detected in birth weight and gestational age matched controls or in newborns with isolated infections. Our results indicate that the DNA methylation pattern of the promoter region of the CALCA gene varies in different types of bacterial preterm sepsis, thus suggesting a potential use as an epigenetic biomarker. A prospective confirmation of these results is essential. 相似文献
46.
Chen CY Chi YH Mutalif RA Starost MF Myers TG Anderson SA Stewart CL Jeang KT 《Cell》2012,149(3):565-577
Human LMNA gene mutations result in laminopathies that include Emery-Dreifuss muscular dystrophy (AD-EDMD) and Hutchinson-Gilford progeria, the premature aging syndrome (HGPS). The Lmna null (Lmna(-/-)) and progeroid LmnaΔ9 mutant mice are models for AD-EDMD and HGPS, respectively. Both animals develop severe tissue pathologies with abbreviated life spans. Like HGPS cells, Lmna(-/-) and LmnaΔ9 fibroblasts have typically misshapen nuclei. Unexpectedly, Lmna(-/-) or LmnaΔ9 mice that are also deficient for the inner nuclear membrane protein Sun1 show markedly reduced tissue pathologies and enhanced longevity. Concordantly, reduction of SUN1 overaccumulation in LMNA mutant fibroblasts and in cells derived from HGPS patients corrected nuclear defects and cellular senescence. Collectively, these findings implicate Sun1 protein accumulation as a common pathogenic event in Lmna(-/-), LmnaΔ9, and HGPS disorders. 相似文献
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Julie M. Schultz Zubair M. Ahmed Saima Riazuddin Ali M. Waryah Matthew F. Starost Stephanie Buckley Madhulika Kabra Muhammad J. Hassan Muhammad Ansar Edward R. Wilcox Wasim Ahmad Suzanne M. Leal Thomas B. Friedman 《American journal of human genetics》2009,85(1):25-137
A gene causing autosomal-recessive, nonsyndromic hearing loss, DFNB39, was previously mapped to an 18 Mb interval on chromosome 7q11.22-q21.12. We mapped an additional 40 consanguineous families segregating nonsyndromic hearing loss to the DFNB39 locus and refined the obligate interval to 1.2 Mb. The coding regions of all genes in this interval were sequenced, and no missense, nonsense, or frameshift mutations were found. We sequenced the noncoding sequences of genes, as well as noncoding genes, and found three mutations clustered in intron 4 and exon 5 in the hepatocyte growth factor gene (HGF). Two intron 4 deletions occur in a highly conserved sequence that is part of the 3′ untranslated region of a previously undescribed short isoform of HGF. The third mutation is a silent substitution, and we demonstrate that it affects splicing in vitro. HGF is involved in a wide variety of signaling pathways in many different tissues, yet these putative regulatory mutations cause a surprisingly specific phenotype, which is nonsydromic hearing loss. Two mouse models of Hgf dysregulation, one in which an Hgf transgene is ubiquitously overexpressed and the other a conditional knockout that deletes Hgf from a limited number of tissues, including the cochlea, result in deafness. Overexpression of HGF is associated with progressive degeneration of outer hair cells in the cochlea, whereas cochlear deletion of Hgf is associated with more general dysplasia. 相似文献
49.
Status of complete proteome analysis by mass spectrometry: SILAC labeled yeast as a model system 总被引:5,自引:1,他引:4
Background
Mass spectrometry has become a powerful tool for the analysis of large numbers of proteins in complex samples, enabling much of proteomics. Due to various analytical challenges, so far no proteome has been sequenced completely. O'Shea, Weissman and co-workers have recently determined the copy number of yeast proteins, making this proteome an excellent model system to study factors affecting coverage. 相似文献50.