B6.Cg-Tg(OPTN*E50K,-EGFP)1Mde/J

Stock number: 037205
Product name: BAC-hOPTN^E50K
Research areas: Mouse/Human Gene Homologs, Neurobiology Research, Research Tools, Sensorineural Research

Description

BAC-hOPTN^E50K transgenic mice overexpress low, near-physiological levels of human OPTN carrying the glaucoma-associated, autosomal dominant E50K (GAG to AAG) missense mutation fused to IRES-EGFP. Hemizygotes demonstrate age-related loss of retinal ganglion cells (RGCs) and selective visual impairment in contrast sensitivity by 18 months of age.

Detailed description

Optineurin (encoded by OPTN) has been associated with 3 age-dependent degenerative diseases (glaucoma, amyotrophic lateral sclerosis, and Paget's Disease) and may play a role in Alzheimer's, Parkinson's, and Huntington's diseases. The protein plays a role in protein trafficking, NF-kappaB regulation, autophagy/mitophagy, and defense against bacterial/viral infections.

BAC-hOPTN^E50K transgenic mice express human OPTN carrying the glaucoma-associated, autosomal dominant E50K (GAG to AAG) missense mutation fused to IRES-EGFP. The human transgene is expressed in hemizygotes at near-physiological (low overexpression) levels in a pattern similar that of the endogenous mouse OPTN. GFP requires immunohistochemistry to be observed. Eye anatomy and intraocular pressures (IOPs) in 2- to 3-month-old and 18-month-old mice are similar to wildtype. Features found in the DBA/2J glaucoma mouse model, such as prominent pigment dispersion and iris atrophy, are not observed in hemizygous BAC-hOPTN^E50K mice even after 18 months of age.

Low expression of this transgene does not lead to diffuse loss of retinal layers. Age-related loss of retinal ganglion cells (RGCs) is more pronounced in BAC-hOPTN^E50K mice (~40% decrease) as compared to wildtype animals, and is associated with increased axonal damage. Low overexpression of the E50K mutant of hOPTN results in selective visual impairment in contrast sensitivity, but does not have a quantifiable effect on nerve conduction velocity.

Development

Exon 1 of the 38-kb human OPTN gene carried on BAC clone RP11-1107F3 was modified with an E50K (GAG to AAG) missense mutation. An IRES-EGFP-neomycin cassette was placed at the 3’ end of the gene. The mutation was created in (C57BL/6 x SJL)F1 embryos. Resultant mice were backcrossed to a combination of C57BL/6N and C57BL/6J for more than 20 generations by the donating laboratory. This is founder line 1. No other genes are expressed from the BAC. The integration site is unknown. These mice may carry Pde6b^rd1.

Upon arrival at The Jackson Laboratory, sperm was cryopreserved. Cryorecovery/live colony development will involve C57BL/6J (Stock No. 000664).

Allele

Symbol: Tg(OPTN*E50K,-EGFP)1Mde
Name: transgene insertion 1, Michael D Ehlers
MGI accession ID: MGI:5705748
Generation method: Transgenic
Attributes: Reporter; Inserted expressed sequence; Humanized sequence
Marker symbol: Tg(OPTN*E50K,-EGFP)1Mde
Marker name: transgene insertion 1, Michael D Ehlers
Chromosome: UN
Strain of origin: (C57BL/6 x SJL)F1
Molecular note: The transgene is composed of BAC clone RP11-1107F3 containing the 38 kb-human OPTN locus with about 160 kb of 5 sequence containing the E50K mutation in the middle (GAG to AAG) and a fragment containing the internal ribosome entry site-enhanced green fluorescent protein. Two lines were established, 1 and 2. Line 1 shows overexpression of the gene but line 2 does not. Quantitative rtPCR and immunoblot analysis confirmed mRNA expression and protein expression in the retina.