Isolation of homeodomain-leucine zipper genes from the moss Physcomitrella patens and the evolution of homeodomain-leucine zipper genes in land plants.
Homeobox genes encode transcription factors involved in many aspects of developmental processes. The homeodomain-leucine zipper (HD-Zip) genes, which are characterized by the presence of both a homeodomain and a leucine zipper motif, form a clade within the homeobox superfamily and were previously reported only from vascular plants. Here we report the isolation of 10 HD-Zip genes (named PPHB:1-PPHB:10) from the moss Physcomitrella patens. Based on a phylogenetic analysis of the 10 PPHB: genes and previously reported vascular plant HD-Zip genes, all of the PPHB: genes except Pphb3 belong to three of the four HD-Zip subfamilies (HD-Zip I, II, and III), indicating that these subfamilies originated before the divergence of the vascular plant and moss lineages. Pphb3 is sister to the HD-Zip II subfamily and has some distinctive characteristics, including the difference of the a(1) and d(1) sites of its leucine zipper motif, which are well conserved in each HD-Zip subfamily. Comparison of the genetic divergence of representative HD-Zip I and II genes showed that the evolutionary rate of HD-Zip I genes was faster than that of HD-Zip II genes.
National Institute for Basic Biology, Okazaki, Japan.
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Sakakibara
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Nishiyama
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Kato
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Hasebe
D000595:Amino Acid Sequence; D019068:Bryopsida / Q000235:genetics*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000032:analysis; D019143:Evolution, Molecular; D005801:Genes, Homeobox; D018398:Homeodomain Proteins / Q000235:genetics*; D016350:Leucine Zippers / Q000235:genetics*; D008969:Molecular Sequence Data; D005810:Multigene Family; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics*; D010944:Plants / Q000235:genetics; D016415:Sequence Alignment
D018076:DNA, Complementary; C091850:HD-Zip protein, Helianthus annuus; D018398:Homeodomain Proteins; D010940:Plant Proteins