TY  - JOUR
A1  - Ottilie, S.
A1  - Raulf, F.
A1  - Barnekow, A.
A1  - Hannig, G.
A1  - Schartl, Manfred
T1  - Multiple src-related kinase genes, srk1-4, in the fresh water sponge Spongilla lacustris
N2  - In one of the simplest metazoan organisms, the sponge Spongilla lacustris, at least four different src-related kin ase genes (srkl-4) are expressed, aD of which show a high degree of similarity to the c-src genes of vertebrates. Whereas srk2 and srk3 are c1early unrelated at the nucleic acid level, srkl and srk4 share identical sequences in the 5' parts of their cDNAs. The cloning of several primer extension clones and genomic polymerase chain re action experiments confirmed the hypo thesis of an alternative splicing of tandemly arranged carboxyterminal parts of srkl and srk4. The genomic sequence encoding both proteins was found to be interrupted at the splice point by an intron which is located in the same position as one of the introns in the chicken src gene, which is the only gene conserved in invertebrates and vertebrates. All four srk genes are expressed in adult sponges as mRNA transcripts of about 2.2 kb. Tyrosine kin ase activity of a src-related kin ase could be detected in adult sponges but not in their resting form (gemmulae), and may reflect the activity of the srk protein products. Spongilla lacustris is the simplest organism from which a pro tein tyrosine kinase gene has been isolated. The presence of at least four such genes in the evolutionary ancient and primitive phylum Porifera suggests that tyrosine kinase genes arose concomitantly with or shortly after the appearance of multicellular organisms and that their activity may be involved in aggregation and cell-cell recognition.
KW  - Spongilla lacustris
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-80282
ER  - 
TY  - JOUR
A1  - Schartl, Manfred
A1  - Wittbrodt, J.
A1  - Mäueler, W.
A1  - Raulf, F.
A1  - Adam, D.
A1  - Hannig, G.
A1  - Telling, A.
A1  - Storch, F.
A1  - Andexinger, S.
A1  - Robertson, S. M.
T1  - Oncogenes and melanoma formation in Xiphoporus (Teleostei: Poeciliidae)
N2  - In Xiphophorus melanoma formation has been attributed by classical genetic findings to the overexpression of a cellular oncogene (Tu) due to elimination of the corresponding regulatory gene locus in hybrids. We have attempted to elucidate this phenomenon on the molecular biological level. Studies on the structure and expression of known proto-oncogenes revealed that several of these genes, especially the c-src gene of Xiphophorus, may act as effectors in establishing the neoplastic phenotype of the melanoma cells . However, these genes appear more to participate in secondary steps of tumorigenesis. Another gene, being termed Xmrk, which represents obviously a so far unknown proto-oncogene but with a cons iderably high similarity to the epidermal growth-factorreceptor gene, was mapped to the Tu-containing region of the chromosome. This gene shows features with respect to its structure and expression that seem to justify it to be regarded as a candidate for a gene involved in the primary processes leading to neoplastic transformation of pigment cells in Xiphophorus.
KW  - Schwertkärpfling
KW  - Onkogen
KW  - Melanom
Y1  - 1993
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-87149
ER  -