title: The olive flounder (Paralichthys olivaceus) Pax3 homologues are highly conserved, encode multiple isoforms and show unique expression patterns.
abstract: Pax genes encode a highly conserved family of transcription factors that play crucial roles in the formation of tissues and organs during development. Pax3 plays crucial roles in patterning of the dorsal central nervous system (CNS), neural crest and skeletal muscle. Here, we identified two spliced isoforms of Pax3a and three spliced isoforms of Pax3b and characterized their expression patterns. Both of flounder Pax3a-1 and Pax3b-1 contain the conserved paired domain (PD), an octapeptide motif (OP), and a paired type homeodomain (HD). But the PD domain in Pax3a-2 and Pax3b-3 is not intact and there is no HD in Pax3b-2 and Pax3b-3. Pax3a and Pax3b show distinct temporal expression patterns during embryogenesis. Whole-mount in situ hybridization demonstrates that Pax3a and Pax3b are expressed in overlapping patterns in the dorsal central nervous system, with some subtle regional differences between the two genes. In addition, Pax3a is scattered in the somites while Pax3b is specifically expressed in the newly forming somites. RT-PCR results have shown that there were different expression patterns between the different isoforms. These results indicate subfunction partitioning of the duplicated Pax3 genes. The duplicated Pax3 may provide additional flexibility in fine-tuning neurogenesis and somitogenesis.
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao 266071, Shandong, People's Republic of China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Jiao
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao 266071, Shandong, People's Republic of China. Electronic address: tanx@qdio.ac.cn.
authors.forename: Xungang
authors.initials: X
authors.lastname: Tan
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao 266071, Shandong, People's Republic of China; University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao 266071, Shandong, People's Republic of China; University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China.
authors.forename: Meijie
authors.initials: M
authors.lastname: Li
authors.affiliation: Department of Biochemistry and Molecular Biology, School of Medicine, University of Maryland, 701 E. Pratt St, Baltimore, MD 21202, USA.
authors.forename: Shao Jun
authors.initials: SJ
authors.lastname: Du
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D004625:Embryo, Nonmammalian / Q000378:metabolism; D029941:Fish Proteins / Q000235:genetics* / Q000378:metabolism; D005432:Flounder / Q000196:embryology / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D010802:Phylogeny; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D017434:Protein Structure, Tertiary
chemical_list: D029941:Fish Proteins; D020033:Protein Isoforms
keywords: Muscle; Neural crest; Pax3a; Pax3b; Somite; Spliced isoforms