Shain D H, Zuber M X
Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins 80523, USA.
Gene. 1995 Nov 20;165(2):319-20. doi: 10.1016/0378-1119(95)00544-g.
We have isolated four non-tissue-specific helix-loop-helix (HLH) transcription factors from Xenopus laevis (Xl). While some are clearly orthologous to known mammalian HLH proteins, others have dramatic amino-acid differences in otherwise highly conserved protein domains. We propose that these changes arose following the tetraploidization of Xl approx. 30 Myr ago.
