Figure 2.

Interspecific pattern of Mb mRNA expression in Antarctic icefishes. (a) Northern blot analysis performed on total RNA extracted from heart ventricle. Mb mRNA (0.9 kb) was detected by hybridization with random-primed (Boehringer Mannheim) ³²P-labeled N. coriiceps Mb cDNA probe. Lanes: 1, C. rastrospinosus; 2, C. gunnari; 3, P. georgianus; 4, C. aceratus; 5, C. antarcticus; 6, P. macropterus; 7, C. wilsoni; 8, N. coriiceps. Analysis of C. hamatus and G. gibberifrons total RNA also indicated the presence of Mb mRNA in heart ventricle, but not in oxidative skeletal muscle tissues (data not shown). Relative abundance of Mb mRNAs depicted in the figure is representative of results obtained from several individuals of each species. (b) Equal loading of gels indicated by ethidium bromide staining of the 28S and 18S ribosomal RNA in total RNA samples used in a above.