Abstract
In this paper, we provide evidence for the body temperature effect on the formation of GC-rich isochores, by analysing genomic sequences from two puffer fishes living at different temperatures. The higher body temperature of
Tetraodon nigroviridis compared to
Takifugu rubripes (Δ
T∼15 °C) appears to be the cause of a higher compositional heterogeneity of the former due to the formation of GC-rich regions. Such an effect does not only concern large DNA segments but also coding sequences.