Abstract
Efforts to characterize the mechanisms underlying early lung development have been confounded by the absence of a model that permits study of lung development prior to the onset of endodermal differentiation. Since Xenopus laevis development occurs in an extrauterine environment, we sought to determine whether the classical molecular markers of lung development and function, surfactant protein genes, are expressed in X. laevis. Surfactant protein C (SP-C) is a specific marker for lung development, expressed early in development and exclusively in the lung. Surfactant protein B (SP-B) expression is essential for life, as its absence results in neonatal death in mice and gene mutations have been associated with neonatal respiratory failure in humans. Here, we report the cloning of the first non-mammalian SP-C and SP-B genes (termed xSP-C and xSP-B) using the Xenopus model. The processed mature translated regions of both xSP-C and xSP-B have high homology with both human and mouse genes. xSP-C and xSP-B are both expressed throughout the lung of the X. laevis swimming tadpoles soon after the initiation of lung development as assessed by RT-PCR and whole mount in situ hybridization. The temporal expression patterns of xSP-C and xSP-B are consistent with the expression patterns in mammalian models of lung development. In both the tadpole and the adult X. laevis, xSP-C and xSP-B are expressed only in lung. Knowledge of the sequence and expression pattern of these two surfactant proteins in Xenopus might allow for use of this organism to study early lung development.
Original language | English (US) |
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Pages (from-to) | 8-14 |
Number of pages | 7 |
Journal | Gene Expression Patterns |
Volume | 7 |
Issue number | 1-2 |
DOIs | |
State | Published - Jan 2007 |
Bibliographical note
Funding Information:Dr. Cornfield is an Established-Investigator of the American Heart Association. This work was supported by National Institutes of Health Grants RO1 HL60784 (DNC) and RO1 HL70628 (DNC), American Heart Association Established Investigator Award (DNC); Viking Children’s Fund (ER). The authors are thankful for the technical assistance of Ann Neumann and Allison Frasier.
Keywords
- Lung development
- Surfactant proteins
- Xenopus laevis