1,721,303 research outputs found
Viral and cellular deoxyribonucleases are associated with herpes simplex virus replicative intermediates
No full textThe presence of viral and cellular deoxyribonucleases was investigated in partially purified HSV replicative intermediates (nucleoprotein complexes) and nucelocapsids prepared from BHK-21 cell cultures infected with herpes simplex virus type 1. The 85kd virus-coded alkaline nuclease was detected by Western blotting experiments in infected cell extracts 7 h after infection, and was identified in viral DNA containing nucleoprotein complexes at 18 h after infection. With activity gel experiments, three cellular deoxyribonucleases were detected in mock-infected cells. Two of them were present in infected cell extracts, and one of them (50kd) was detected in nucleocapsids at 9 h P.I., and in nucleoprotein complexes at 18 h P.I. These data indicate a possible role of viral nuclease in the biosynthesis of late replicative intermediates, and suggest an active involvement of the nuclear matrix in viral replication
Tracking disease genes by reverse genetics
No full textIncreasingly, human genes are being identified by the "reverse genetics", or "positional cloning" approach. This molecular genetic strategy is particularly useful in mental illness, for which no readily detectable functional alterations are present to indicate candidate genes. The positional cloning procedure is briefly described. Significant examples of successful positional cloning are presented, including the fragile-X mental retardation syndrome gene. The study of gene expression may be complicated by genetic and non-genetic variability. Genomic imprinting may play a role in several mental illnesses, and may provide an explanation for the unusual inheritance pattern in fragile-X syndrome, for the phenotypic differences observed between Angelman and Prader-Willi syndromes, and for the juvenile onset form of Huntington disease. DNA instability may explain disease anticipation in fragile-X syndrome and myotonic dystrophy. Finally, the prospects of improvements in positional cloning methods for tracking genes responsible for mental illness are briefly discussed
Discussion of "Recent application of DNA analysis to issues of paternity" [letter; comment]
No full textA review of asthma genetics: gene expression studies and recent candidates
No full textRecent evidence indicates an important role of inflammation pathways, airways remodeling and epithelium activation in asthma genetics. In particular, transcriptome studies have detected differentially expressed genes involved in eosinophil apoptosis, the arginase pathway, response to allergens or interleukins, and to inhaled corticosteroids. Candidate gene and genome wide studies have localized genetic regions involved in the disease, such as the A1AR and CLCA1 genes (chromosome 1), IL-1RN and DPP10 (2q14), HLA-G and TNF-a (6p21), GPRA (7p14), FceRI and GSTP1 (11q13), NOS1, IFNG, STAT6, VDR, and other genes (12q13-26), PHF11 and flanking genes (13q14), AACT and PTGDR (14q), and ADAM33 (20p13). The role of these and other genetic determinants has to be confirmed in future, preferably longitudinal, studie
Analysis of herpes simplex virus nucleoprotein complexes extracted from infected cells
No full textHEp-2 cells were infected with herpes simplex virus type 1 and labeled with [3H]thymidine and 14C-amino acids. Infected cells or nuclei prepared from them were extracted with Triton X-100 and NaCl, utilizing a method recently described, and the low-speed supernatant (extract) was partially purified by sedimentation on sucrose gradients. A nucleoprotein complex which sedimented as a wide peak around 200S was identified. The nucleoprotein complex contained viral DNA, which banded at the expected density in CsCl isopycnic gradients and was intact after measurements taken on electron microscopic photographic enlargements. The autoradiographic pattern of 14C-labeled proteins after electrophoresis showed that only a few of the virus-specific polypeptides were present in the nucleoprotein complexes, in particular, VP5, VP12, VP15.2, VP19, and VP24. Cellular histones were absent. The extracts and the nucleoprotein complexes were centrifuged to equilibrium in metrizamide density gradients without prefixation. Electron microscopic direct visualization of the nucleoprotein complexes after sucrose or metrizamide purification revealed that the proteins were preferentially associated with one end of the DNA molecule and formed large irregular terminal thickenings or capsid-like transparent shells enclosing polyglobular cores. No nucleosomes were observed on herpes simplex virus nucleoprotein complexes. The same type of complex was detected after phosphonoacetic acid addition, and grossly altered nucleocapsids were formed
- …
