title: Endogenous retroviral insertion in Cryge in the mouse No3 cataract mutant.
abstract: No3 (nuclear opacity 3) is a novel congenital nuclear cataract in mice. Microsatellite mapping placed the No3 locus on chromosome 1 between D1Mit480 (32cM) and D1Mit7 (41cM), a region containing seven crystallin genes; Cryba2 and the Cryga-Crygf cluster. Although polymorphic variants were observed, no candidate mutations were found for six of the genes. However, DNA walking identified a murine endogenous retrovirus (IAPLTR1: ERVK) insertion in exon 3 of Cryge, disrupting the coding sequence for gammaE-crystallin. Recombinant protein for the mutant gammaE was completely insoluble. The No3 cataract is mild compared with the effects of similar mutations of gammaE. Quantitative RT-PCR showed that gammaE/F mRNA levels are reduced in No3, suggesting that the relatively mild phenotype results from suppression of gammaE levels due to ERVK insertion. However, the severity of cataract is also strain dependent suggesting that genetic background modifiers also play a role in the development of opacity.
authors.affiliation: Section on Molecular Structure and Functional Genomics, National Eye Institute, National Institutes of Health, Building 7, Room 201 Bethesda, MD 20892, USA.
authors.forename: Nabanita
authors.initials: N
authors.lastname: Nag
authors.forename: Katherine
authors.initials: K
authors.lastname: Peterson
authors.forename: Keith
authors.initials: K
authors.lastname: Wyatt
authors.forename: Sonja
authors.initials: S
authors.lastname: Hess
authors.forename: Sugata
authors.initials: S
authors.lastname: Ray
authors.forename: Jack
authors.initials: J
authors.lastname: Favor
authors.forename: Debora
authors.initials: D
authors.lastname: Bogani
authors.forename: Mary
authors.initials: M
authors.lastname: Lyon
authors.forename: Graeme
authors.initials: G
authors.lastname: Wistow
mesh_terms: D000818:Animals; D001483:Base Sequence; D002386:Cataract / Q000235:genetics*; D051379:Mice; D008817:Mice, Mutant Strains; D016254:Mutagenesis, Insertional; D009154:Mutation; D010641:Phenotype; D012333:RNA, Messenger / Q000032:analysis; D038222:gamma-Crystallins / Q000235:genetics*
chemical_list: D012333:RNA, Messenger; C107256:crystallin gammaE; D038222:gamma-Crystallins