The planarian HOM/HOX homeobox genes (Plox) expressed along the anteroposterior axis.
In the freshwater planarian Dugesia japonica, five cDNAs for HOM/HOX homeobox genes were cloned and sequenced. Together with sequence data on HOM/HOX homeobox genes of platyhelminthes deposited in databases, comparison of the deduced amino acid sequences revealed that planarians have at least seven HOM/HOX homeobox genes, Plox1 to Plox7 (planarian HOM/HOX homeobox genes). Whole-mount in situ hybridization and RT-PCR revealed that Plox4 and Plox5 were increasingly expressed along a spatial gradient in the posterior region of intact animals. During regeneration, Plox5 was expressed only in the posterior region of regenerating body pieces, suggesting that the gene is involved in the anteroposterior patterning in planarians. Plox5 was not found to be expressed in a blastema-specific manner, which contradicts a previous report (J. R. Bayascas, E. Castillo, A. M. Muños-Mármol, and E. Saló. Development 124, 141-148, 1997). X-ray irradiation experiments showed that Plox5 was expressed at least in some cells other than neoblasts, but that the induction of Plox5 expression during regeneration might require neoblasts.
Orii
H
H
Laboratory of Regeneration Biology, Department of Life Science, Faculty of Science, Himeji Institute of Technology, Harima Science Garden City, Akou-gun, Hyogo, 678-1297, Japan. orii@sci.himeji-tech.ac.jp
Kato
K
K
Umesono
Y
Y
Sakurai
T
T
Agata
K
K
Watanabe
K
K
D000595:Amino Acid Sequence; D000818:Animals; D019521:Body Patterning; D003001:Cloning, Molecular; D018076:DNA, Complementary; D004175:Diptera / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D005801:Genes, Homeobox; D018398:Homeodomain Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D007865:Leeches / Q000235:genetics; D051379:Mice; D008969:Molecular Sequence Data; D009348:Nematoda / Q000235:genetics; D010932:Planarians / Q000235:genetics / Q000502:physiology* / Q000528:radiation effects; D016133:Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000096:biosynthesis; D012038:Regeneration; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013997:Time Factors; D014965:X-Rays
D018076:DNA, Complementary; D018398:Homeodomain Proteins; D011994:Recombinant Proteins