Biomedical subjects

W Parson

Publications and source records attributed to W Parson.

52 records · Page 3Linked to original sources

PubMed1998

Population data for 101 Austrian Caucasian mitochondrial DNA d-loop sequences: application of mtDNA sequence analysis to a forensic case.

The sequence of the two hypervariable segments of the mitochondrial DNA (mtDNA) control region was generated for 101 random Austrian Caucasians. A total of 86 different mtDNA sequences was observed, where 11 sequences were shared by more than 1 individual, 7 sequences were shared by 2 individuals and 4 sequences were shared by 3 individuals. One of the four most common mtDNA sequences in Austrians is also the most common sequence in both U.S. and British Caucasians, found in approximately 3.0% of Austrians, 4.0% of British, and 3.9% of U.S. Caucasians. Of the remaining three common Austrian sequences, one was not observed in either U.S. or British Caucasians. However, three British Caucasians exhibited a similar sequence type. Therefore, this particular cluster of sequence polymorphisms may represent a common "European" mtDNA sequence type. In general, Austrian Caucasians show little deviation from other Caucasian databases of European descent. Finally, mtDNA sequence analysis was applied to a forensic case, where hairs found at a crime scene matched the control hairs from the suspect.

Austria↗

PubMed1998

Molecular characterization of the human protein kinase C theta gene locus (PRKCQ).

Members of the protein kinase C (PKC) family of serine/threonine kinases, in particular PKCtheta, play critical roles in the regulation of differentiation and proliferation of T lymphocytes. In this study the genomic structure of the human PRKCQ gene that encodes PKCtheta was determined. Two genomic P1 clones were isolated from human P1 libraries using the PKCtheta cDNA as a probe and have been used to confirm the assignment of the single PRKCQ locus to chromosome 10p15 by FISH analysis. The PRKCQ locus, the first mammalian PKC gene locus characterized so far, spans approximately 62 kb and is composed of 15 coding exons and 14 introns, varying in size between 98 and 16000 bp. All exon-intron boundaries have been determined by long-range PCR and subsequent DNA sequence analysis. Comparison with other known genomic PKC genes reveals a high degree of homology to the genomic organization of the Drosophila melanogaster dPRKC gene. Alignment of the intron positions in the PRKCQ gene with the intron locations in the dPRKC gene indicates that the sites of seven of the 14 PRKCQ introns are exactly conserved. Exons 5 (32 bp), 11 (174 bp) and 12 (92 bp) share highest similarity in size, organization and primary structure with their counterparts in the Drosophila gene. On the basis of this knowledge of the genomic PRKCQ locus, a directed search for potential genetic polymorphisms and/or genetic abnormalities involved in human genetic disease(s) can now be initiated.

Animals↗

PubMed1997

Evaluation of Y-chromosomal STRs: a multicenter study.

A multicenter study has been carried out to characterize 13 polymorphic short tandem repeat (STR) systems located on the male specific part of the human Y chromosome (DYS19, DYS288, DYS385, DYS388, DYS389I/II, DYS390, DYS391, DYS392, DYS393, YCAI, YCAII, YCAIII, DXYS156Y). Amplification parameters and electrophoresis protocols including multiplex approaches were compiled. The typing of non-recombining Y loci with uniparental inheritance requires special attention to population substructuring due to prevalent male lineages. To assess the extent of these subheterogeneities up to 3825 unrelated males were typed in up to 48 population samples for the respective loci. A consistent repeat based nomenclature for most of the loci has been introduced. Moreover we have estimated the average mutation rate for DYS19 in 626 confirmed fatherson pairs as 3.2 x 10(-3) (95% confidence interval limits of 0.00041-0.00677), a value which can also be expected for other Y-STR loci with similar repeat structure. Recommendations are given for the forensic application of a basic set of 7 STRs (DYS19, DYS3891, DYS389II, DYS390, DYS391, DYS392, DYS393) for standard Y-haplotyping in forensic and paternity casework. We recommend further the inclusion of the highly polymorphic bilocal Y-STRs DYS385, YCAII, YCAIII for a nearly complete individualisation of almost any given unrelated male individual. Together, these results suggest that Y-STR loci are useful markers to identify males and male lineages in forensic practice.

DNA Mutational Analysis↗

PubMed1997

Chromosome Y microsatellites: population genetic and evolutionary aspects.

By means of a multicenter study, a large number of males have been characterized for Y-chromosome specific short tandem repeats (STRs) or microsatellites. A complete summary of the allele frequency distributions for these Y-STRs is presented in the Appendix. This manuscript describes in more detail some of the population genetic and evolutionary aspects for a restricted set of seven chromosome Y STRs in a selected number of population samples. For all the chromosome Y STRs markedly different region-specific allele frequency distributions were observed, also when closely related populations were compared. Haplotype analyses using AMOVA showed that when four different European male groups (Germans, Dutch, Swiss, Italians) were compared, less than 10% of the total genetic variability was due to differences between these populations. Nevertheless, these pairwise comparisons revealed significant differences between most population pairs. Assuming a step-wise mutation model and a mutation frequency of 0.21%, it was estimated that chromosome Y STR-based evolutionary lines of descent can be reliably inferred over a time-span of only 1950 generations (or about 49,000 years). This reduces the reliability of the inference of population affinities to a historical, rather than evolutionary time scale. This is best illustrated by the construction of a human evolutionary tree based on chromosome Y STRs in which most of the branches connect in a markedly different way compared with trees based on classical protein polymorphisms and/or mtDNA sequence variation. Thus, the chromosome Y STRs seem to be very useful in comparing closely related populations which cannot probably be separated by e.g. autosomal STRs. However, in order to be used in an evolutionary context they need to be combined with more stable Y-polymorphisms e.g. base-substitutions.

Biological Evolution↗

PubMed1997

Expression in insect cells of the functional domain of CD21 (complement receptor type two) as a truncated soluble molecule using a baculovirus vector.

We have made use of the plasmid vector pBSV-8His recently established for baculovirus-mediated expression of His-tagged proteins for the production of a truncated soluble complement regulator protein. The protein comprised the N-terminal part, i.e. short consensus repeats (SCRs) 1-4, of the B-cell membrane protein complement receptor type two (CR2; CD21) and contained the functional epitopes which mediate the binding of the complement component C3 fragments C3dg and iC3b. This recombinant protein, termed rsCR2.1-4, was furnished with a C-terminal histidine-tag for easy purification from insect cell supernatant. The yield of > 90% pure rsCR2.1-4 was 3 micrograms/ml supernatant at day eight p.i. RsCR2.1-4 was expressed as two proteins with a M(r) of 29 and 31 representing differentially glycosylated forms. Both reacted specifically with anti-CR2 mAb HB5 directed against SCRs 3-4, but not with anti-CR2 mAbs recognizing SCRs beyond SCR 4. RsCR2.1-4 was able to bind C3dg and to block binding of C3dg-coated beads to Raji cells. Used as antigen for immunization, it allowed the efficient and well-aimed generation of antisera which specifically blocked attachment of C3dg-coated beads to Raji B cells. Thus, insect cell derived rsCR2.1-4 has proved a valuable tool to study the functional domain of CR2 and its immunoregulatory capacity in B-lymphocytes.

Animals↗

PubMed1997

Austrian Caucasian population data for the quadruplex plus amelogenin: refined mutation rate for HumvWFA31/A.

Human identification of biological specimens has undergone immense change since the development of PCR typing systems for forensic casework. In contrast to RFLP and VNTRs, STRs are the method of choice when the investigated genomic DNA is present in low quantity or in degraded shape. In the current study, the X-Y homologous gene Amelogenin has been added to a widely used multiplex PCR amplification system consisting of four tetrameric STR loci (Quadruplex-HumTH01, HumvWFA31/A, HumFES/FPS, and HumF13A1). The modified Quadruplex was used to type 382 unrelated Caucasians from Western Austria. The population data meet Hardy-Weinberg and linkage equilibrium expectations, and do not show significant deviations from either US, German, and Turkish Caucasian databases. In an investigation of 382 meioses, two mutations were revealed at the HumvWFA31/A locus. Consequently, the data in this paper provide the conditions for adding Amelogenin to the Quadruplex, and suggest that when doing paternity testing, the mutation rate for the HumvWFA31/A locus must be considered.

Alleles↗

PubMed1995