Head blebs (Frem1heb) produces abnormal or missing eyes due to prenatal blebs, usually on the head, some fetal death, open eyelids, and folded retinas at birth. Extra toes or ectopic brains are occasionally observed. Affected adults usually have closed eyelids and atrophic eyes. These mice, along with other mouse blebbing mutants, have been considered as models for Fraser syndrome, a rare recessive disorder in humans characterized by cryptophthalmos, syndactyly, renal defects, and a range of other developmental abnormalities.
The Frem1heb (head blebs) mutation arose spontaneously on AKR/J. To produce embryos for cryopreservation, C57BL/6J (B6) female mice were bred to (B6xAKR-Frem1heb)F1 males, e.g., male F1 offspring from a cross of a female C57BL/6J mouse with an AKR/J-Frem1heb/+ male of generation F140N1F22.
|Allele Name||head blebs|
|Gene Symbol and Name||Frem1, Fras1 related extracellular matrix protein 1|
|Strain of Origin||AKR/J|
|Molecular Note||Inverse PCR of C57BL/6J identified a LINE1 insertion 41 bp from the 3' end of the exon that was not present in the AKR/J background, thereby rearranging exon 17.|