Phenotypes associated with this allele

• Allele Symbol: Tmem258^{tm1.1(KOMP)Vlcg}
• Allele Name: targeted mutation 1.1, Velocigene
• Allele ID: MGI:5892142
• Summary: 3 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Tmem258^tm1.1(KOMP)Vlcg/Tmem258^tm1.1(KOMP)Vlcg	involves: C57BL/6NTac	MGI:5897843
ht2	Tmem258^tm1.1(KOMP)Vlcg/Tmem258^+	involves: C57BL/6NTac	MGI:5897844
cn3	Gt(ROSA)26Sor^tm1(CAG-cas9*,-EGFP)Fezh/? Tmem258^tm1.1(KOMP)Vlcg/Tmem258^+	involves: C57BL/6NTac	MGI:5897845

Genotype
MGI:5897843

hm1

• Allelic Composition: Tmem258^{tm1.1(KOMP)Vlcg}/Tmem258^{tm1.1(KOMP)Vlcg}
• Genetic Background: involves: C57BL/6NTac

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

mortality/aging

embryonic lethality, complete penetrance ( J:240635 )

• no homozygotes are recovered from multiple breeding pairs; no signs of fetal resorption are detected in timed matings, suggesting early embryonic lethality

Genotype
MGI:5897844

ht2

• Allelic Composition: Tmem258^{tm1.1(KOMP)Vlcg}/Tmem258⁺
• Genetic Background: involves: C57BL/6NTac

digestive/alimentary system

increased enterocyte apoptosis ( J:240635 )

• DSS-treated heterozygotes exhibit a higher frequency of apoptotic colonic epithelial cells than DSS-treated wild-type controls, as shown by active caspase 3 staining

abnormal enterocyte proliferation ( J:240635 )

• DSS-treated heterozygotes exhibit decreased proliferation and disorganized dispersion of colonic epithelial cells relative to DSS-treated wild-type controls, as shown by Ki67 staining

abnormal large intestine crypts of Lieberkuhn morphology ( J:240635 )

• DSS-treated heterozygotes show more severe colonic crypt destruction than DSS-treated wild-type controls

decreased colon length ( J:240635 )

• DSS-treated heterozygotes show reduced colon length relative to DSS-treated wild-type controls

increased susceptibility to induced colitis ( J:240635 )

• at day 8 after oral administration of 2.5% dextran sulfate sodium (DSS), heterozygotes show accelerated weight loss, increased histopathological severity scores (based on severity of inflammation, depth of inflammation and crypt damage), decreased colon length, reduced epithelial proliferation in response to injury, and a marked inflammatory gene expression signature in colonic tissue relative to wild-type controls

• however, untreated heterozygotes exhibit normal intestinal barrier function

increased susceptibility to colitis induced morbidity/mortality ( J:240635 )

• following oral administration of 2.5% DSS for 7 days, heterozygotes show accelerated mortality with a >75% decline in survival at 10 and 15 days post-treatment, unlike in wild-type controls where a ~40% decline in survival does not occur until 15 days post-treatment

growth/size/body

increased susceptibility to weight loss ( J:240635 )

• DSS-treated heterozygotes show accelerated weight loss relative to DSS-treated wild-type controls

immune system

increased susceptibility to induced colitis ( J:240635 )

• at day 8 after oral administration of 2.5% dextran sulfate sodium (DSS), heterozygotes show accelerated weight loss, increased histopathological severity scores (based on severity of inflammation, depth of inflammation and crypt damage), decreased colon length, reduced epithelial proliferation in response to injury, and a marked inflammatory gene expression signature in colonic tissue relative to wild-type controls

• however, untreated heterozygotes exhibit normal intestinal barrier function

increased susceptibility to colitis induced morbidity/mortality ( J:240635 )

• following oral administration of 2.5% DSS for 7 days, heterozygotes show accelerated mortality with a >75% decline in survival at 10 and 15 days post-treatment, unlike in wild-type controls where a ~40% decline in survival does not occur until 15 days post-treatment

endocrine/exocrine glands

abnormal large intestine crypts of Lieberkuhn morphology ( J:240635 )

• DSS-treated heterozygotes show more severe colonic crypt destruction than DSS-treated wild-type controls

cellular

increased enterocyte apoptosis ( J:240635 )

• DSS-treated heterozygotes exhibit a higher frequency of apoptotic colonic epithelial cells than DSS-treated wild-type controls, as shown by active caspase 3 staining

abnormal enterocyte proliferation ( J:240635 )

• DSS-treated heterozygotes exhibit decreased proliferation and disorganized dispersion of colonic epithelial cells relative to DSS-treated wild-type controls, as shown by Ki67 staining

increased endoplasmic reticulum stress ( J:240635 )

• after induction of colitis with DSS, heterozygotes show clear evidence of ER stress in the colonic epithelium, with an increased frequency of HSPA5 (BiP/GRP78)-positive epithelial cells relative to wild-type controls

• however, untreated heterozygotes do not exhibit significant ER stress in colonic epithelium

mortality/aging

increased susceptibility to colitis induced morbidity/mortality ( J:240635 )

• following oral administration of 2.5% DSS for 7 days, heterozygotes show accelerated mortality with a >75% decline in survival at 10 and 15 days post-treatment, unlike in wild-type controls where a ~40% decline in survival does not occur until 15 days post-treatment

Genotype
MGI:5897845

cn3

• Allelic Composition: Gt(ROSA)26Sor^{tm1(CAG-cas9*,-EGFP)Fezh}/?; Tmem258^{tm1.1(KOMP)Vlcg}/Tmem258⁺
• Genetic Background: involves: C57BL/6NTac

cellular

increased cell death ( J:240635 )

• after introduction of single guide RNAs (sgRNAs) targeting exonic Tmem258 sequences (Tmem258 CRISPR) by transduction with lentiviral particles co-encoding Cre recombinase, spheroid cultures derived from colonic crypts exhibit fewer viable Cas9-GFP-positive cells than colonic organoid cultures that have received control sgRNAs targeting noncoding intronic Tmem258 regions

• morphologically, Tmem258 CRISPR organoids contain scattered Cas9-GFP-positive cells within small spheroids that encapsulate numerous dead cells within the lumen, whereas control CRISPR organoids appear healthier and larger with contiguous Cas9-GFP-positive cells suggestive of active proliferation

increased endoplasmic reticulum stress ( J:240635 )

• after simultaneous delivery of Cre recombinase and sgRNA targeting of Tmem258 sequences by lentiviral transduction, Tmem258 CRISPR organoid cultures contain more in-frame mutations in Cas9-GFP-positive cells than control CRISPR organoids, suggesting that out-of-frame alleles are negatively selected, consistent with increased ER stress