Loss of Hoxa5 gene function in mice perturbs intestinal maturation.
The Hox gene family of transcription factors constitutes candidate regulators in the molecular cascade of events that governs establishment of normal terminal differentiation along the duodenum to colon axis. One member of this family, Hoxa5, displays a dynamic pattern of expression during gut development. Hoxa5 transcripts are present in midgut mesenchyme at the time of remodeling, supporting a role for this gene in digestive tract specification. To study the role of Hoxa5 in proper intestinal development and maturation, we examined whether Hoxa5 mutant mice exhibit any defect in this process. We report here that even though Hoxa5 is not required for midgut morphogenesis, its loss of function perturbs the acquisition of adult mode of digestion, which normally is temporally coordinated with the process of spontaneous weaning. Impaired maturation of the digestive tract might be related to altered specification of intestinal epithelial cells. Our findings provide evidence that Hoxa5 expression in the gut mesoderm is important for the region-specific differentiation of the adjacent endoderm.
Aubin
J
J
Centre de Recherche en Cancérologie de l'Université Laval, Centre Hospitalier Universitaire de Québec, Pavillon de L'Hôtel-Dieu de Québec, Québec G1R 2J6, Canada J1H 5N4.
Chailler
P
P
Ménard
D
D
Jeannotte
L
L
D000818:Animals; D000833:Animals, Suckling; D003345:Corticosterone / Q000097:blood; D004847:Epithelial Cells / Q000201:enzymology; D018507:Gene Expression Regulation, Developmental; D006004:Glycogen Debranching Enzyme System / Q000378:metabolism; D018398:Homeodomain Proteins / Q000235:genetics* / Q000378:metabolism*; D007421:Intestine, Small / Q000196:embryology* / Q000254:growth & development / Q000378:metabolism; D043322:Lactase; D008648:Mesoderm / Q000502:physiology; D051379:Mice; D008817:Mice, Mutant Strains; D010750:Phosphoproteins; D013963:Thyroid Hormones / Q000097:blood; D014157:Transcription Factors; D014886:Weaning; D001616:beta-Galactosidase / Q000378:metabolism
D006004:Glycogen Debranching Enzyme System; D018398:Homeodomain Proteins; C059637:Hoxa5 protein, mouse; D010750:Phosphoproteins; D013963:Thyroid Hormones; D014157:Transcription Factors; C020569:4 alpha-glucanotransferase; D043322:Lactase; D001616:beta-Galactosidase; D003345:Corticosterone