title: Molecular developmental mechanism in polypterid fish provides insight into the origin of vertebrate lungs.
abstract: The lung is an important organ for air breathing in tetrapods and originated well before the terrestrialization of vertebrates. Therefore, to better understand lung evolution, we investigated lung development in the extant basal actinopterygian fish Senegal bichir (Polypterus senegalus). First, we histologically confirmed that lung development in this species is very similar to that of tetrapods. We also found that the mesenchymal expression patterns of three genes that are known to play important roles in early lung development in tetrapods (Fgf10, Tbx4, and Tbx5) were quite similar to those of tetrapods. Moreover, we found a Tbx4 core lung mesenchyme-specific enhancer (C-LME) in the genomes of bichir and coelacanth (Latimeria chalumnae) and experimentally confirmed that these were functional in tetrapods. These findings provide the first molecular evidence that the developmental program for lung was already established in the common ancestor of actinopterygians and sarcopterygians.
authors.affiliation: Department of Anatomy, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-ku, Tokyo 105-8461, Japan.
authors.forename: Norifumi
authors.initials: N
authors.lastname: Tatsumi
authors.affiliation: Department of Anatomy, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-ku, Tokyo 105-8461, Japan.
authors.forename: Ritsuko
authors.initials: R
authors.lastname: Kobayashi
authors.affiliation: Department of Anatomy, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-ku, Tokyo 105-8461, Japan.
authors.forename: Tohru
authors.initials: T
authors.lastname: Yano
authors.affiliation: Department of Anatomy, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-ku, Tokyo 105-8461, Japan.
authors.forename: Masatsugu
authors.initials: M
authors.lastname: Noda
authors.affiliation: Department of Anatomy, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-ku, Tokyo 105-8461, Japan.|Department of Environmental Science, Niigata University, 8050 Ikarashi 2-no-cho, Nishi-ku, Niigata, Niigata 950-2181, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Fujimura
authors.affiliation: Department of Life Sciences, National Cheng Kung University, Tainan 701, Taiwan.|Foundation for Advancement of International Science, Tsukuba 305-0821, Japan.
authors.forename: Norihiro
authors.initials: N
authors.lastname: Okada
authors.affiliation: Department of Anatomy, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-ku, Tokyo 105-8461, Japan.
authors.forename: Masataka
authors.initials: M
authors.lastname: Okabe
mesh_terms: D000818:Animals; D005075:Biological Evolution; D002642:Chick Embryo; D002645:Chickens / Q000235:genetics; D004625:Embryo, Nonmammalian; D004742:Enhancer Elements, Genetic; D005260:Female; D029941:Fish Proteins / Q000235:genetics*; D005399:Fishes / Q000196:embryology / Q000235:genetics / Q000254:growth & development* / Q000502:physiology; D018507:Gene Expression Regulation, Developmental; D007814:Larva; D008168:Lung / Q000254:growth & development* / Q000502:physiology; D008297:Male; D008648:Mesoderm
chemical_list: D029941:Fish Proteins