The Sox18Ra-Op allele causes a more severe phenotype than either the Sox18Ra or Sox18Ra-J allele. Green and Mann determined that only approximately 17% of the Sox18Ra-Op/+ heterozygotes are born and survive to wean age. Heterozygotes have a deficiency of vibrissae, a distinguishing feature in utero and usually evident at birth, and can be distinguished at three days of age by their pink skin which, with its delayed coat development, fails to darken like that of wildtype siblings. A paucity of fur is apparent by 9 days of age and persists throughout life. Heterozygotes are smaller in overall size and many of those that die shortly after birth are cyanotic and edematous. Dead pups have glossy skin with red patches that may result from superficial hemorrhages. Homozygotes die by embryonic day 11.5. (Green and Mann, 1961; Mann, 1963.)
|Allele Synonym(s)||Op; RaOp|
|Gene Symbol and Name||Sox18, SRY (sex determining region Y)-box 18|
|Strain of Origin||(C57BL/6J x DBA/2J)F1|
|Molecular Note||The mutation was identified as a deletion of a single cytosine at nucleotide 1048.|
Homozygotes are embryonic lethal. Heterozygous females are poor breeders, and some heterozygotes may die at birth. When maintaining a live colony, wildtype females from the colony may be bred to heterozygous males.
When using the opossum mouse strain in a publication, please cite the originating article(s) and include JAX stock #000508 in your Materials and Methods section.