B6.Cg-Sh2b1^em3Ccsu/J

Stock number: 036415
Product name: Sh2b1^DELα/δ
Strain synonyms: Sh2b1 ∆alpha/delta
Research areas: Diabetes and Obesity Research, Metabolism Research, Neurobiology Research, Research Tools

Description

Sh2b1^DELα/δ mice exhibit decreased food intake, protection from weight gain on standard and high-fat diets, and improved glucose homeostasis. These mice may be useful in the study of obesity and metabolism.

Detailed description

The Sh2b1 gene encodes an adapter protein which is recruited to the receptors of multiple hormones and neurotrophic factors and is associated with obesity, feeding behavior, and insulin regulation.

The Sh2b1^DELα/δ knock-out allele lack the brain-specific alpha and delta Sh2b1 isoforms, but retain the widely expressed beta and gamma isoforms. Absence of protein expression of the alpha and delta isoforms of SH2B1 from the knock-out allele was confirmed by western blot analysis of whole brain lysates from homozygous mice. Male and female homozygotes maintain lower body weights on both standard and high-fat diets, though metabolic cages reveal no differences in VO₂, respiratory exchange ratio, or locomotor activity. When fed high-fat diet, Sh2b1^DELα/δ homozygotes gain significantly less weight than wildtype mice, with increased lean mass and reduced adiposity, as well as significantly lower plasma insulin levels under both fed and fasting conditions (Cote et al., 2021). Otherwise, homozygous mice are viable and fertile with no reported reproductive deficiency.

Development

The Sh2b1^DELα/δ allele was generated in the laboratory of Dr. Christin Carter-Su (University of Michigan Medical School) using CRISPR/Cas9 endonuclease-mediated genome editing. A 4kb donor template was designed to juxtapose exon 9 of the Sh2b1 locus, the sequence in exon 10 that contains the β/γ stop codons, and the region of exon 10 downstream of the α stop codon. These sequences and an hSpCas9 expression cassette containing the sgRNAs were introduced into single cell C57BL/6J X SJL F2 oocytes and transferred to pseudopregnant females. Progeny were screened by DNA sequencing to identify correctly targeted pups, which were then bred to C57BL/6J mice for germline transmission. The Sh2b1^DELα/δ colony was subsequently backcrossed to C57BL/6J for a total of at least 10 generations before males were sent to The Jackson Laboratory in 2021. Upon arrival, sperm was cryopreserved. To establish our live colony, an aliquot of frozen sperm was used to fertilize C57BL/6J oocytes (Stock No. 000664).

Of note, the donating investigator reports that, at least once during backcrossing, a Sh2b1^DELα/δ female was bred to a C57BL/6J inbred male (thus the Y chromosome of the congenic strain is of C57BL/6J origin). Also, a neomycin resistance cassette from an unknown source was found in this strain associated with the mutation of interest.

Allele

Symbol: Sh2b1^em3Ccsu
Name: endonuclease-mediated mutation 3, Christin Carter-Su
MGI accession ID: MGI:6718275
Generation method: Endonuclease-mediated
Attributes: Modified isoform(s)
Synonyms: alphadeltaKO; Sh2b1^{DELalphadelta}
Marker symbol: Sh2b1
Marker name: SH2B adaptor protein 1
Marker synonyms: Irip; PSM; SH2B; SH2-B; SH2-Bb; Sh2bpsm1
Chromosome: 7
Strain of origin: (C57BL/6J x SJL)F2
Molecular note: CRISPR/cas9 genome editing is used to delete exon 9, intron 9, the sequence in exon 10 that contains the beta/gamma; stop codons, and the region of exon 10 downstream of the alpha/stop codon. Immunoblot analysis confirms the absence of alpha and delta splice variants and the presence of the beta/gamma proteins in brain lysates.