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PubMed1977

Carotenoids in fish. XVIII--carotenoids in the brain of some fishes.

Using column and thin-layer chromatography the occurrence of various carotenoids was studied in the brain of some (11) fishes. In result of the analyses the presence of the following carotenoids has been established: beta-zeacarotene, canthaxanthin, cryptoxanthin, alpha-cryptoxanthin, isocryptoxanthin, lutein, lutein-5,6-epoxide, zeaxanthin, isozeaxanthin, tunaxanthin, flavoxanthin, astaxanthin ester, 4-hydroxy-alpha-carotene, 4-keto-alpha-carotene and unknown xanthophylls.

Animals↗

PubMed1976

Gene action in fish of tetraploid origin. III. Ribosomal DNA amount in cyprinid fish.

Phylogenetically diploid and tetraploid cyprinid fish species have cells of very similar volumes and protein contents. This finding has prompted us to postulate a regulatory system established during the evolution of the tetraploids leading to a diploid state of genic expression. It was proposed that this might be accounted for by a selective loss of ribosomal genes. RNA-DNA hybridization experiments, however, reveal a clear-cut 1:2 relationship of ribosomal DNA amounts between the diploid and the tetraploid species.

Animals↗

PubMed1975

Gene action in fish of tetraploid origin. II. Cellular and biochemical parameters in clupeoid and salmonoid fish.

By use of cell size, protein and hemoglobin content, and enzyme activities as markers, it becomes apparent that in the course of evolution the gene expression of anciently tetraploid fish of the order Ostariophysi was diploidized, but no such regulatory mechanism has evolved in the phylogenetically tetraploid species of the order Isospondyli. This finding is discussed in terms of possible selective neutrality of tetraploid expression and the phylogenetic age of Isospondyli.

Animals↗

PubMed1975

Gene action in fish of tetraploid origin. I. Cellular and biochemical parameters in cyprinid fish.

In phylogenetically diploid and tetraploid Cyprinid fish species, erythrocyte volumes, protein contents, and mean activities of the enzymes LDH, 6PGD, and PGI per cell per active gene locus decline with increasing DNA contents. These findings are assumed to reflect an evolutionary tendency of polyploids to regulate their genic activity down to the level of the diploids.

Animals↗

PubMed1976