A large number of retrotransposons are expressed when the zygotic genome is first transcribed, including the endogenous retroviruses (ERVs), LINE-1 elements, and the non-autonomous SINE elements. At the 2C stage, MuERV-L/MERVL retrovirus-like elements are transiently de-repressed and produce 3% of the transcribed mRNAs. Following the 2C stage, MERVL-retroelement expression is silenced. The newly study discovered that this regulated pattern of MERVL expression overlapped with greater than one hundred 2C-specific genes that have co-opted regulatory elements from these foreign retroviruses to initiate their transcription.
Western blot analysis of MuERVL-Gag on different lysates with Rabbit anti-MuERVL-Gag antibody (HA724067) at 1/5,000 dilution.
Lane 1: ES-D3 cell lysate Lane 2: ES-W4 cell lysate
Lysates/proteins at 20 µg/Lane.
Predicted band size: 67 kDa Observed band size: 67 kDa
Exposure time: 3 minutes; ECL: K1801;
4-20% SDS-PAGE gel.
Proteins were transferred to a PVDF membrane and blocked with 5% NFDM/TBST for 1 hour at room temperature. The primary antibody (HA724067) at 1/5,000 dilution was used in primary antibody dilution (K1803) at 4℃ overnight. Goat Anti-Rabbit IgG - HRP Secondary Antibody (HA1001) at 1/50,000 dilution was used for 1 hour at room temperature.
MuERVL-Gag was immunoprecipitated from 0.2 mg ES-W4 cell lysate with HA724067 at 2 µg/10 µl beads. Western blot was performed from the immunoprecipitate using HA724067 at 1/5,000 dilution. HRP Conjugated Anti-Rabbit IgG for IP Nano-secondary antibody at 1/5,000 dilution was used for 1 hour at room temperature.
Lane 1: ES-W4 cell lysate (input) Lane 2: HA724067 IP in ES-W4 cell lysate Lane 3: Rabbit IgG instead of HA724067 in ES-W4 cell lysate