Remodeling of the intestine during metamorphosis of Xenopus laevis.
Thyroid hormone controls remodeling of the tadpole intestine during the climax of amphibian metamorphosis. In 8 days, the Xenopus laevis tadpole intestine shortens in length by 75%. Simultaneously, the longitudinal muscle fibers contract by about the same extent. The radial muscle fibers also shorten as the diameter narrows. Many radial fibers undergo programmed cell death. We conclude that muscle remodeling and contraction play key roles in the shortening process. Shortening is accompanied by a temporary "heaping" of the epithelial cells into many layers at climax. Cells that face the lumen undergo apoptosis. By the end of metamorphosis, when the epithelium is folded into crypts and villi, the epithelium is a single-cell layer once again. Throughout this remodeling, DNA replication occurs uniformly throughout the epithelium, as do changes in gene expression. The larval epithelial cells as a whole, rather than a subpopulation of stem cells, are the progenitors of the adult epithelial cells.
Schreiber
Alex M
AM
Department of Embryology, Carnegie Institution of Washington, Baltimore, MD 21210, USA.
Cai
Liquan
L
Brown
Donald D
DD
D000818:Animals; D017209:Apoptosis; D049109:Cell Proliferation; D004847:Epithelial Cells / Q000166:cytology; D020869:Gene Expression Profiling; D007422:Intestines / Q000166:cytology / Q000254:growth & development*; D007814:Larva / Q000166:cytology / Q000254:growth & development; D008675:Metamorphosis, Biological; D013963:Thyroid Hormones / Q000502:physiology; D014982:Xenopus laevis / Q000254:growth & development* / Q000378:metabolism
D013963:Thyroid Hormones
Dev Biol. 1999 Nov 15;215(2):243-52
10545234
Proc Natl Acad Sci U S A. 2001 Sep 11;98(19):10739-44
11517345
Proc Natl Acad Sci U S A. 2002 Sep 17;99(19):12230-5
12213960
Proc Natl Acad Sci U S A. 2003 Feb 18;100(4):1769-74
12560472
J Cell Sci. 2003 Aug 1;116(Pt 15):3157-64
12799417
Proc Natl Acad Sci U S A. 2004 Jan 6;101(1):165-70
14691251
J Cell Biol. 1970 Jan;44(1):151-71
4187705
J Biol Chem. 1993 Sep 25;268(27):20312-7
7690754
Dev Biol. 1994 Jan;161(1):48-58
8293885
Neuron. 1994 Jul;13(1):67-81
8043282
Anat Rec. 1995 Jul;242(3):417-23
7573988
Cell Tissue Res. 1996 Dec;286(3):467-76
8929349
Dev Genet. 1997;20(4):329-37
9254907
Dev Biol. 1997 Dec 1;192(1):149-61
9405104
Dev Growth Differ. 1998 Apr;40(2):177-88
9572360
Dev Biol. 1998 Nov 1;203(1):12-23
9806769
Dev Biol. 1998 Nov 1;203(1):24-35
9806770
J Cell Biol. 1963 Sep;18:579-97
14064111
J Exp Zool A Comp Exp Biol. 2004 Dec 1;301(12):992-1002
15562447
J Anat. 1978 May;126(Pt 1):133-44
649494