TY  - JOUR
TI  - Altered Hox expression and increased cell death distinguish Hypodactyly from Hoxa13 null mice.
AU  - Post, L C
AU  - Innis, J W
T2  - The International Journal of Developmental Biology
AB  - Hypodactyly (Hoxa13Hd) mice have a small deletion within the coding sequence of Hoxa13 and a limb phenotype that is more severe than that of mice with an engineered null allele of Hoxa13. We used whole-mount in situ hybridization, Nile blue sulfate staining and genetic crosses to determine the basis for the phenotypic differences between these two mutants. Expression of Hoxd13 was unaffected in Hoxa13-/- mice, but its domain was reduced at the anterior and posterior margins of the autopod in Hoxa13Hd/Hd limb buds. The maturation of Hoxd11 expression was delayed and expression of Hoxa11 failed to become restricted to the autopod/zeugopod junction in both Hoxa13Hd/Hd and Hoxa13-/- limb buds compared to wild-type mice. Fgf8 expression was normal in both Hoxa13Hd/Hd and Hoxa13-/- mice throughout limb development. A dramatic increase in cell death was observed in limb bud mesenchyme of Hoxa13Hd/Hd mice as early as E11.5 but not in mice homozygous for the null allele. Genetic background was excluded as the basisforthe phenotypic differences. Compound heterozygotes (Hoxa13-/Hd) displayed an intermediate phenotype relative to both homozygotes suggesting that Hoxa13Hd has an effect on the development of the autopod beyond that which may result from a loss of HOXA13 protein. These results showthat Hoxa13Hd has a negative effect on the survival of the mesenchyme in the autopod, unlike the Hoxa13 null mutation, that cannot be explained by a failure of the AER to express Fgfs. In addition, at least one target of HOXA13 may be Hoxa11.
PY  - 1999
VL  - 43
IS  - 4
SP  - 287
EP  - 294
J2  - Int. J. Dev. Biol.
LA  - en
SN  - 0214-6282
SN  - 1696-3547
UR  - https://ijdb.ehu.eus/article/10470645
Y2  - 2024/11/05/17:19:40
ER  -