Strain-specific modifier genes of Cecr2-associated exencephaly in mice: genetic analysis and identification of differentially expressed candidate genes.
The loss of Cecr2, which encodes a chromatin remodeling protein, has been associated with the neural tube defect (NTD) exencephaly and open eyelids in mice.
We previously reported that a homozygous Cecr2 mutation on a BALB/c background causes exencephaly at a frequency of 74% compared with 0% on an FVB/N background.
Mice homozygous for the Cecr2 genetrap-induced mutation show a high penetrance of the neural tube defect exencephaly, the human equivalent of anencephaly, in a strain-dependent fashion.
Grainyhead-like genes represent candidates for involvement in NTDs based on the presence of SB and exencephaly in mice carrying loss-of-function alleles of Grhl2 or Grhl3.
Crosses of white-spotted mice showed that homozygosity for the mutation caused tail and limb abnormalities and embryonic lethality as a result of exencephaly; these phenotypes were analogous to those found in other Pax3 mutants.
If arsenite produces exencephaly by inactivating the Pax3 protein, then the fact that the exencephaly rate was increased in Sp/Sp embryos with no functional Pax3 indicates that arsenite may either induce this defect through additional pathways, or may alter the response via modifier genes.
If arsenite produces exencephaly by inactivating the Pax3 protein, then the fact that the exencephaly rate was increased in Sp/Sp embryos with no functional Pax3 indicates that arsenite may either induce this defect through additional pathways, or may alter the response via modifier genes.