These mice carry a spontaneous deletion that results in polycystic kidney disease and other dysmorphic features with death by 3 weeks after birth. This strain offers a model for human Meckel Syndrome Type 3.Read More +
Mice homozygous for the bpck deletion develop bilateral polycystic kidneys and die by 3 weeks of age. There is an increased incidence of hydrocephalus. Homozygotes can be identified by their smaller size and swollen abdomens. At 2 weeks of age elevated blood urea nitrogen is found. Ovaries and testes are smaller than normal and progression of maturing cells from spermatocytes to spermatids is disorganized at 3 weeks of age. The primary cilia on the kidney proximal tubule epithelial cells are dysmorphic and vary in length at birth and by 14 days of age cilia are significantly longer than normal. Through overlapping BAC rescues the polycystic kidney disease and hydrocephalus has been traced to the absence of the Tmem67 gene. Although lacking some of the ancillary phenotypes associated with Meckel Syndrome Type 3 in humans, this deletion offers a model for that disease.
The bpck spontaneous deletion arose in the B6C3F3 a/a-tip/J strain at The Jackson Laboratory in 1979 and was maintained for many years by backcrossing hemizygotes to B6C3FeF1/J a/a then intercrossing the offspring to identify hemizygous carriers from their phenotypically affected homozygous offspring. Sperm was cryopreserved from hemizygous males in 2008.
|Gene Symbol and Name||a, nonagouti|
|Strain of Origin||old mutant of the mouse fancy|
|General Note||Insertion of the LV30 retrotransposon without the beta4 retrovirus sequence does not cause the nonagouti phenotype. J:278039|
|Molecular Note||Characterization of this allele shows an insertion of DNA comprised of a 5.5kb virus-like element, VL30, into the first intron of the agouti gene. The VL30 element itself contains an additional 5.5 kb sequence, flanked by 526 bp of direct repeats (beta4 retroviral sequence). The host integration site is the same as for at-2Gso and Aw-38J and includes a duplication of four nucleotides of host DNA and a deletion of 2 bp from the end of each repeat. Northern analysis of mRNA from skin of homozygotes shows a smaller agouti message and levels 8 fold lower than found in wild-type.|
|Allele Name||bilateral polycystic kidneys|
|Gene Symbol and Name||bpck, bilateral polycystic kidney deletion region|
|Strain of Origin||B6C3Fe a/a-tip/J|
|Molecular Note||This spontaneous deletion spans approximately 0.6 cM between D4Mit261 and D4Mit19, including the coding region of 6 genes, but the bilateral polycystic kidney phenotype was traced specifically to the absence of Tmem67 via BAC rescue with various length BACs.|