Igk^tm4.1Fwa
Targeted Allele Detail

Summary

• Symbol: Igk^tm4.1Fwa
• Name: immunoglobulin kappa chain complex; targeted mutation 4.1, Frederick W Alt
• MGI ID: MGI:8394050
• Gene: Igk Location: Chr6:67532620-70703738 bp, + strand Genetic Position: Chr6, 30.89 cM, cytoband F1-pter

Mutation origin

• Germline Transmission: Earliest citation of germline transmission: J:389722
• Parent Cell Line: EF1 (ES Cell)
• Strain of Origin: 129S/SvEv x C57BL/6

Mutation description

• Allele Type: Targeted (Humanized sequence)
• Mutations: Insertion, Intragenic deletion
• Mutation details:

  The mouse light (Igk) immunoglobulin chain regions were modified to incorporate human sequences to enhance the testing of broadly neutralizing antibody (bnAb) responses to conserved HIV-1 envelope protein immunogens. The mouse Igk region on Chromosome 6: germline human V (hV; IGLV2-14*01) was incorporated in the 3' region of the mouse V (mVk) cluster and J (hJ; IGLJ3*01) replaces all five mouse J (mJk) segments. The hV segment was tagged with a recombination signal sequence incorporating a 23-base pair spacer (23-RSS), and the hJ segment was associated with a 12-RSS in reverse orientation. The mouse V cluster retains its endogenous 3' terminal 12-RSS. Based on the 12-23 rule of V(D)J recombination, the 12-RSS hJ segment can only recombine with the 23-RSS hV, but not the 12-RSS mouse V segments, which lie upstream of the cassette. Consequently, the humanized Igk allele should express exclusively human variable regions, despite the presence of intact mV cluster. Mouse C (mCk) was replaced with human C (IGLC3*04). LoxP-flanked neomycin cassettes in each of the targeting constructs were removed from ES cell clones through the transient expression of Adeno-cre recombinase. (J:389722)

Find Mice (IMSR)

• Mouse strains and cell lines available from the International Mouse Strain Resource (IMSR)
• Carrying this Mutation: Mouse Strains: 1 strain available Cell Lines: 0 lines available
• Carrying any Igk Mutation: 40 strains or lines available

References

• Original: J:389722 Tian M, et al., Mouse models with human antibody repertoires for inducing multiple lineages of HIV-1 broadly neutralizing antibodies. bioRxiv. 2026 June 30
• All: 2 reference(s)