C57BL/6-Esr1^em1Ksk/J

Stock number: 035739
Product name: Esr1-Q
Research areas: Mouse/Human Gene Homologs, Reproductive Biology Research

Description

Esr1-Q mice carry a CRISPR/Cas9 generated missense mutation resulting in a glutamine to histidine change at amino acid 379 (Q379H) of the estrogen receptor 1 (alpha) (Esr1) gene, making this strain useful when studying estrogen insensitivity syndrome (EIS).

Detailed description

Esr1-Q mice carry a CRISPR/Cas9 generated missense mutation resulting in a glutamine to histidine change at amino acid 379 (Q379H) of the estrogen receptor 1 (alpha) (Esr1) gene. This mutation is analogous to the human ESR1 Q375H mutation associated with estrogen insensitivity syndrome (EIS) and is characterized by the inability of estrogen to exert its biological effects. Estrogens are key regulators of cell growth, cell differentiation, and a variety of physiological functions in both males and females. There have only been three cases of this rare disorder and those afflicted exhibit delayed puberty, delayed bone maturation, and enlarged multicystic ovaries among other phenotypes. The causative mutation in these mice was identified in one patient with EIS who displayed estrogen insensitivity, resulting in delayed puberty, primary amenorrhea, continued linear growth, incomplete epiphyseal closure into adulthood, low bone mineral density, lack of breast development, enlarged bilateral multicystic ovaries, and hypoplastic uterus with no endometrial stripe.

The donating investigator reports that heterozygous mice are viable and fertile. Homozygous female Esr1-Q mice are infertile and have similar phenotypes as the αERKO mice (Stock No. 004774), including hypoplastic uteri, reduced uterine weight, hemorrhagic cystic ovaries, increased body weight, rudimentary mammary ducts, and elevated levels of luteinizing hormone (LH) and estradiol.

Homozygous males are also infertile and exhibit increased body weight. They also show induction of seminal vesicle weight and disruption of seminiferous tubule formation.

Mice treated with norethindrone (NET, a synthetic progestogen) or the gonadotropin-releasing hormone [GnRH] inhibitor, FMG, show some significant reduction in the total number of cysts and partial restoration of uterine weight, but not to WT levels.

Development

A guide RNA (CGAGAAGGTGGACCTGATCANGG) was designed to insert a missense mutation resulting in a glutamine to histidine change at amino acid 379 (Q379H) of the estrogen receptor 1 (alpha) (Esr1) gene. This mutation is analogous to the human ESR1 Q375H mutation associated with estrogen insensitivity syndrome (EIS). Four other silent bp changes were also introduced in order to prevent re-targeting and mis-targeting. sgRNA, single-stranded 200 bp oligo, and the cas9 nuclease were introduced into the cytoplasm of C57BL/6J-derived zygotes with well recognized pronuclei. Correctly targeted embryos were transferred to pseudopregnant females. Esr1-Q pups were identified by PCR and sequencing and founder mice were further bred to C57BL/6J mice (Stock No. 000664) by the donating laboratory (see SNP note below). Cryopreserved embryos were sent to The Jackson Laboratory. Upon arrival, embryos were recovered to establish our colony.

In 2021, a 48 SNP (single nucleotide polymorphism) panel analysis, with 43 markers covering all 19 chromosomes and the X chromosome, as well as 5 markers that distinguish between the C57BL/6J and C57BL/6N substrains, was performed on the rederived living colony at The Jackson Laboratory Repository. Four of the 5 markers that determine C57BL/6J from C57BL/6N were found to be segregating, including the rd8 recessive mutation associated with retinal degeneration on Chromosome 1 within the Crb1 locus. These data suggest the mice sent to The Jackson Laboratory Repository were on a mixed C57BL/6N;C57BL/6J genetic background.

Allele

Symbol: Esr1^em1Ksk
Name: endonuclease-mediated mutation 1, Kenneth S Korach
MGI accession ID: MGI:6470475
Generation method: Endonuclease-mediated
Attributes: Humanized sequence
Synonyms: Esr1-Q
Marker symbol: Esr1
Marker name: estrogen receptor 1 (alpha)
Marker synonyms: ER; ER[a]; Era; ERalpha; ER-alpha; Esr; ESRA; Estr; Estra; ESTRR; NR3A1; RNESTROR
Chromosome: 10
Strain of origin: C57BL/6J
Molecular note: A guide RNA (CGAGAAGGTGGACCTGATCANGG) was designed to insert a missense mutation resulting in a glutamine to histidine change at amino acid 379 (Q379H). This mutation is analogous to the human ESR1 Q375H mutation associated with estrogen insensitivity syndrome (EIS). Four other silent bp changes were also introduced in order to prevent re-targeting and mis-targeting.