Larger Image Fig. 1. osr1 and osr2 are dynamically expressed in the developing Xenopus foregut and are required for lung development. (A-G′′) In situ hybridization of osr1 (A-D) and osr2 (E-H) expression in Xenopus tropicalis embryos and isolated gut tubes (D,H) at the indicated stages (st), anterior leftwards, dorsal upwards. Stage 15 embryos (A,E) are bisected and stage 33 embryos (C′-C[H11630],G′-G[H11630]) are sectioned to show the endoderm (outlined in yellow in A,E). fg, foregut; hg, hindgut; de, dorsal endoderm; pe, posterior endoderm; e, esophagus; l/t, presumptive lung and trachea; lv, liver; lpm, lateral plate mesoderm; k, kidney; s, stomach. (I-N′) surfactant protein c (sftpc) (I-L) and nkx2.1 (M,N′) expression in embryos injected on one side with Osr1/Osr2-MOs (10 ng each) or negative control mutated oligos MM-MO (20 ng) shows lung agenesis on the Osr1/Osr2-depleted side. (M’-N′) Sections. Numbers of embryos with the shown phenotype are indicated. Dorsal view of an isolated gut tube (K,L) shows the lung bud absent on the injected side (red arrow). Image published in: Rankin SA et al. (2012) Copyright © 2012. Image reproduced with permission of the publisher and the copyright holder. This is an Open Access article distributed under the terms of the Creative Commons Attribution License. Gene Synonyms Species Stage(s) Tissue osr1 odd1 X. tropicalis Throughout NF stage 15 endoderm central endoderm osr1 odd1 X. tropicalis Throughout NF stage 28 endoderm foregut lateral plate mesoderm alimentary system stomodeal-hypophyseal primordium hindgut intermediate mesoderm pronephric mesenchyme lung primordium osr1 odd1 X. tropicalis Throughout NF stage 33 and 34 lung endoderm foregut lateral plate mesoderm alimentary system anterior dorsal lateral plate region otic vesicle eye mouth primordium brain midbrain hindbrain spinal cord osr1 odd1 X. tropicalis Throughout NF stage 42 lung esophagus foregut stomach alimentary system osr2 osr2-a, osr2-b, xosr2 X. tropicalis Throughout NF stage 15 dorsal endoderm central endoderm osr2 osr2-a, osr2-b, xosr2 X. tropicalis Throughout NF stage 28 endoderm lateral plate mesoderm anterior dorsal lateral plate region eye foregut intermediate mesoderm lung primordium dorsal lateral plate mesoderm hindgut osr2 osr2-a, osr2-b, xosr2 X. tropicalis Throughout NF stage 42 lung esophagus alimentary system foregut osr2 osr2-a, osr2-b, xosr2 X. tropicalis Throughout NF stage 33 and 34 endoderm esophagus lateral plate mesoderm alimentary system pronephric kidney pronephric duct eye foregut intermediate mesoderm lung primordium otic vesicle spinal cord pharyngeal region head brain sftpc SP-C, SPC, surfc, xSP-C X. tropicalis Sometime during NF stage 37 and 38 to NF stage 42 lung endoderm foregut nkx2-1.L nkx2.1, titf1, ttf1, Xnkx-2.1, xnkx2-1 X. laevis Throughout NF stage 42 lung trachea endoderm foregut Image source: Published Experiment + Assay Source Phenotypes and Disease Xtr Wt + osr1 MO + osr2 MO + NF37/38 (in situ hybridization) fig.1.j Anatomical Phenotype absent lung bud Expression Phenotype decreased amount sftpc expression in lung bud Xtr Wt + osr1 MO + osr2 MO + NF42 (in situ hybridization) fig.1.l Anatomical Phenotype absent lung bud Expression Phenotype decreased amount sftpc expression in lung bud Xtr Wt + osr1 MO + osr2 MO + NF37/38 (in situ hybridization) fig.1.n, n' Anatomical Phenotype absent lung bud Expression Phenotype decreased amount nkx2-1 expression in lung bud Permanent Image Page Printer Friendly View XB-IMG-77878