德晋贵宾厅

• Background: ACTA1 encodes α-skeletal muscle actin, a critical component of the contractile apparatus in striated muscles (skeletal, cardiac) and a key player in force generation and cell motility. In muscle, it maintains structural integrity, enables contraction, and regulates cytoskeletal dynamics.
• Gene editing strategy: An icre/ERT2 sequence cassette was placed in the safe harbor sites Hipp11 under the control of the ACTA1 promoter.
• Validation: By crossing B-ACTA1-iCreERT2 mice and B-CAG-tdTomato cKI mice, tamoxifen-induced B-ACTA1-iCreERT2/CAG-tdTomato cKI mice robustly express tdTomato in cardiac, gastrointestinal smooth, vascular smooth, and skeletal muscles (gastrocnemius, soleus), validating the utility as a muscle tissue-specific reporter model driven by the ACTA1 promoter of B-ACTA1-iCreERT2 mice.
• Application: The ACTA1 promoter-driven iCreERT2 mouse, B-ACTA1-iCreERT2 mice, enables tamoxifen-inducible, muscle-specific Cre recombination, and can achieve precise spatiotemporal control via tamoxifen, high muscle tissue specificity (avoiding off-target activity), and utility for lineage tracing, conditional gene manipulation, and studying muscle development disease—validating its value as a targeted muscle research tool

Gene targeting strategy for B-ACTA1-iCreERT2 mice.

An icre/ERT2 sequence cassette was placed in the safe harbor sites Hipp11 under the control of the ACTA1 promoter. When B-ACTA1-iCreERT2 mice were crossed with a strain containing a loxP-site flanked sequence of interest, and induced with tamoxifen, Cre-mediated recombination will result in deletion of the floxed sequence in the muscle tissues of offspring.

Tamoxifen-Induced tdTomato Expression in B-ACTA1-iCreERT2/CAG-tdTomato cKI Mice. B-ACTA1-iCreERT2/CAG-tdTomato cKI mice (female, 14-week-old) were divided into two groups. G1 (n=1) received daily intraperitoneal (i.p.) vehicle injections for 5 days. G2 (n=5) received i.p. tamoxifen (1 mg/mouse) daily for 5 days. After a 7-day washout period, tissues were collected for IHC to detect tdTomato expression (HUABIO, HA500049). TdTomato can be detected in cardiac muscle, gastrointestinal smooth muscle, vascular smooth muscle, and skeletal muscle (gastrocnemius and soleus muscle), confirming tissue-specific expression driven by the ACTA1 promoter in B-ACTA1-iCreERT2/CAG-tdTomato cKI mice. Scale, 40x.