Display Settings:


Send to:

Choose Destination
See comment in PubMed Commons below
Genome Res. 2001 May;11(5):754-70.

The basic helix-loop-helix protein family: comparative genomics and phylogenetic analysis.

Author information

  • 1Belgian EMBnet Node, Bioinformatics Laboratory, Université Libre de Bruxelles, Department of Molecular Biology, B-6041 Gosselies, Belgium.


The basic Helix-Loop-Helix (bHLH) proteins are transcription factors that play important roles during the development of various metazoans including fly, nematode, and vertebrates. They are also involved in human diseases, particularly in cancerogenesis. We made an extensive search for bHLH sequences in the completely sequenced genomes of Caenorhabditis elegans and of Drosophila melanogaster. We found 35 and 56 different genes, respectively, which may represent the complete set of bHLH of these organisms. A phylogenetic analysis of these genes, together with a large number (>350) of bHLH from other sources, led us to define 44 orthologous families among which 36 include bHLH from animals only, and two have representatives in both yeasts and animals. In addition, we identified two bHLH motifs present only in yeast, and four that are present only in plants; however, the latter number is certainly an underestimate. Most animal families (35/38) comprise fly, nematode, and vertebrate genes, suggesting that their common ancestor, which lived in pre-Cambrian times (600 million years ago) already owned as many as 35 different bHLH genes.

[PubMed - indexed for MEDLINE]
Free PMC Article

Images from this publication.See all images (4)Free text

Figure 1
Figure 2
Figure 3
Figure 4
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk