Mice homozygous for situs inversus (reversal of left-right polarity/left-right reversal of abdominal visceral organs) exhibit polycystic kidney disease (PKD), severe jaundice, and die by seven days of age. Specifically, the stomach and spleen are located on anatomical right instead of left, and the heart, lungs, and liver are mirror-image left-right inversions. These mice may be useful for studying polycystic kidney disease (PKD) and the specification of left-right polarity during vertebrate development.
Paul A Overbeek, Baylor College of Medicine
Mice heterozygous for this mutation are viable and fertile with no gross phenotypic abnormalities. Homozygous mice exhibit severe jaundice, do not increase in size or weight after birth, and die by seven days of age. Homozygous mice display a common pattern of situs inversus (reversal of left-right polarity/left-right reversal of abdominal visceral organs). Specifically, the stomach and spleen are located on anatomical right instead of left, and the heart, lungs, and liver are mirror-image left-right inversions. Homozygous mice have polycystic kidney disease (PKD) characterized by significant kidney pathology with dilated tubules and abnormal glomeruli. Lower incidence of other abnormalities are also reported for homozygous mice; including polysplenia and heterotaxia (normal cardiovascular orientation but inverted abdominal viscera). No defects of the dynein arms in trachea cilia are reported. These mice may be useful for studying polycystic kidney disease (PKD) and the specification of left-right polarity during vertebrate development.
The Ty811C transgene was designed with a tyrosinase minigene containing the tyrosinase upstream regulatory sequences (2.25 kb from the BALB/c tyrosinase promoter and the first 65 bp of exon 1) and a chimeric cDNA made with (from 5' to 3') the upstream part of the C57BL/6-derived Tyrs-J (cysteine at amino acid 103) sequence ligated at a central ScaI site to the downstream part of the DBA/2-derived tyrosinase (valine at amino acid 346). This Ty811C transgene was microinjected into one-cell-stage embryos from albino FVB/N mice. Transgenic mice can be identified by the rescue of albino phenotype (coat color and eye pigmentation). One line of mice with light brown fur pigmentation were assigned as OVE210. Homozygous OVE210 mice die within one week of birth with left-right reversal of abdominal visceral organs. The OVE210 mice were found to have a two transgene copies at a single integration site, and the recessive mutant allele was called inversion of embryonic turning (inv). The transgene integration created a small duplication and 47 kb deletion in the proximal region of chromosome 4; this deleted exons 3-11 (causing a frameshift in the remaining coding segment) of the inversin (Invs) gene. These mice were then backcrossed to FVB/NJ mice for several generations prior to arrival at The Jackson Laboratory Repository. Upon arrival, mice were bred with FVB/NJ inbred mice for at least one generation to establish the colony.
|Allele Name||inversion of embryonic turning|
|Allele Synonym(s)||inv; inv-|
|Gene Symbol and Name||Invs, inversin|
|Strain of Origin||FVB/N|
|General Note||This is the only situs inversus mutation in which the asymmetries occur 100% of the time. Transgenic complementation studies demonstrated that the Invs gene alone corrects the inv mutation, and should be considered the gene responsible for the inv phenotype (J:49759, J:50117).|
|Molecular Note||The inv mutation was caused by a transgene insertion mutagenic event that resulted in a small duplication and a 47-kb deletion. This deletion eliminated exons 3-11, causing a frameshift in the remaining coding segment.|
|Mutations Made By|| |
Paul Overbeek, Baylor College of Medicine
Homozygous mice die in the first week after birth. When maintaining a live colony, heterozygous mice may be bred to wildtype siblings or to FVB/NJ inbred mice.
When using the inversion of embryonic turning mouse strain in a publication, please cite the originating article(s) and include MMRRC stock #36523 in your Materials and Methods section.