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Biomedical subjects

Georg Wieczorek

Publications and source records attributed to Georg Wieczorek.

2 recordsLinked to original sources

Gene expression profile of mouse bone marrow stromal cells determined by cDNA microarray analysis.

Bone marrow stromal cells (BMSC) have gained increased attention because of their multipotency and adult stem cell character. They have been shown to differentiate into other cell types of the mesenchymal lineage and also into non-mesenchymal cells. The exact identity of the original cells, which are isolated from bone marrow by their selective adherence to plastic, remains unknown to date. We have established and characterized mouse BMSC cultures and analyzed three independent samples by cDNA microarrays. The expression profile was compared with two previous expression studies of human BMSC and revealed a high degree of concordance between different techniques and species. To gain clues about the positional context and biology of the isolated cells within the bone marrow stroma, we searched our data for genes that encode proteins of the extracellular matrix, cell adhesion proteins, cytoskeletal proteins and cytokines/cytokine receptors. This analysis revealed a close association of BMSC with vascular cells and indicated that BMSC resemble pericytes.

Animals↗

Phylogenetic analysis of 18S rRNA and the mitochondrial genomes of the wombat, Vombatus ursinus, and the spiny anteater, Tachyglossus aculeatus: increased support for the Marsupionta hypothesis.

The monotremes, the duck-billed platypus and the echidnas, are characterized by a number of unique morphological characteristics, which have led to the common belief that they represent the living survivors of an ancestral stock of mammals. Analysis of new data from the complete mitochondrial (mt) genomes of a second monotreme, the spiny anteater, and another marsupial, the wombat, yielded clear support for the Marsupionta hypothesis. According to this hypothesis marsupials are more closely related to monotremes than to eutherians, consistent with a basal split between eutherians and marsupials/monotremes among extant mammals. This finding was also supported by analysis of new sequences from a nuclear gene--18S rRNA. The mt genome of the wombat shares some unique features with previously described marsupial mtDNAs (tRNA rearrangement, a missing tRNA(Lys), and evidence for RNA editing of the tRNA(Asp)). Molecular estimates of genetic divergence suggest that the divergence between the platypus and the spiny anteater took place approximately 34 million years before present (MYBP), and that between South American and Australian marsupials approximately 72 MYBP.

Animals↗