Phenotypes Associated with This Genotype

Genotype
MGI:8350483

• Allelic Composition: Mbnl1^em1Coop/Mbnl1^em1Coop; Mbnl2^em1Coop/Mbnl2^em1Coop; X/Tg(Myh11-icre/ERT2)1Soff
• Genetic Background: B6.Cg-Mbnl1^em1Coop Mbnl2^em1Coop Tg(Myh11-icre/ERT2)1Soff

• ♀: phenotype observed in females
• ♂: phenotype observed in males
• N: normal phenotype

digestive/alimentary system

abnormal intestinal smooth muscle morphology ( J:386516 )

♂ • mice treated with tamoxifen between 25 and 40 days of age for a total of 8 days and a minimum of 4-week washout period exhibit thickened smooth muscle layers in the intestine

♂ • however, no histopatholgical changes are seen in the intestine, with no infiltration of inflammatory cells or atrophy of villi in TAM treated mice

♂ • Ccnd1, but not Pcna, is upregulated in TAM treated mice, suggesting that smooth muscle cells may enter but not progress through the cell cycle or could indicate cellular senescence

decreased intestine length ( J:386516 )

♂ • whole intestines are shorter in TAM treated mice

decreased small intestine length ( J:386516 )

♂ • small intestine length is shorter while colon length is unaffected in TAM treated mice

increased intestinal transit time ( J:386516 )

♂ • mice treated with tamoxifen exhibit a delay in both small intestine and colonic transit

abnormal intestine physiology ( J:386516 )

♂ • jejunum segments from TAM-treated mice show increased force generation in response to carbachol, indicating a strong response and decreased ability to normalize tone after carbachol stimulation

♂ • colonic segments from TAM-treated mice show increased baseline tone which is concurrent with decreased contractile frequency, increased contractile amplitude, and increased contractile activity

♂ • colonic segments from TAM-treated mice show decreased contractile force after high doses of carbachol stimulation

muscle

abnormal intestinal smooth muscle morphology ( J:386516 )

♂ • mice treated with tamoxifen between 25 and 40 days of age for a total of 8 days and a minimum of 4-week washout period exhibit thickened smooth muscle layers in the intestine

♂ • however, no histopatholgical changes are seen in the intestine, with no infiltration of inflammatory cells or atrophy of villi in TAM treated mice

♂ • Ccnd1, but not Pcna, is upregulated in TAM treated mice, suggesting that smooth muscle cells may enter but not progress through the cell cycle or could indicate cellular senescence

abnormal muscle physiology ( J:386516 )

♂ • TAM treated mice show increased smooth muscle contractile tone of jejunum and colon segments ex vivo

abnormal muscle contractility ( J:386516 )

♂ • smooth muscle contraction dynamics are disrupted to favor a hypercontracted state in both the jejunum and colon

abnormal muscle tone ( J:386516 )

♂ • TAM treated mice exhibit increased jejunum and colon smooth muscle tone

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
myotonic dystrophy type 1		DOID:11722	OMIM:160900	J:386516