title: Stage- and tissue-specific expression of two homeo box genes in sea urchin embryos and adults.
abstract: We report the isolation of two different homeo box genes, HB3 and HB4, from the Hawaiian sea urchin Tripneustes gratilla. DNA sequencing revealed a definitive Antennapedia (Antp) class homeo box in each gene. Southern transfer hybridizations showed the genes to be single-copy. A 5.7-kb transcript of the HB3 gene was found in ovary, testis, small intestine and gastrula poly(A)+ RNA. The HB4 gene produces three transcripts. A 3.7-kb and a 4.4-kb transcript are expressed during embryogenesis. A 3.5-kb transcript appears in each of the adult tissues studied. The HB4 gene appears to be the sea urchin cognate of the Drosophila infrabdominal-7 (iab-7) gene, the mouse Hox 1.7 and Hox 3.2 genes and the Xenopus X1Hbox 6 gene. An examination of Antp class homeo box genes in deuterostomes indicates that a chromosomal duplication has taken place in the evolutionary line leading to the vertebrates after the divergence of the echinoderms. Thus, the sea urchin represents the primitive condition.
authors.affiliation: Pacific Biomedical Research Center, University of Hawaii, Honolulu 96813.
authors.forename: G J
authors.initials: GJ
authors.lastname: Dolecki
authors.forename: G
authors.initials: G
authors.lastname: Wang
authors.forename: T
authors.initials: T
authors.lastname: Humphreys
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004331:Drosophila melanogaster; D004625:Embryo, Nonmammalian / Q000032:analysis; D047108:Embryonic Development; D005801:Genes, Homeobox; D051379:Mice; D008969:Molecular Sequence Data; D009928:Organ Specificity; D012150:Polymorphism, Restriction Fragment Length; D011506:Proteins; D012617:Sea Urchins / Q000196:embryology / Q000235:genetics* / Q000254:growth & development; D012689:Sequence Homology, Nucleic Acid; D014158:Transcription, Genetic; D014982:Xenopus laevis
chemical_list: D011506:Proteins