PCR genotyping

The tail samples of the mice were collected using sterilized scissors and forceps into a 1.5 ml Eppendorf containing 500 μl of tail lysis buffer. About 10 μl Proteinase K (Stock 20 mg/ml) was added to each tube, followed by incubation at 55–60 °C O/N. The next day, 300 μl of 5 M NaCl was added to each tube, and the tubes were shaken vigorously for 15–20 times and then placed on ice for 10 min. The tubes were then centrifuged at 7600 rpm for 10 min at 4 °C. The supernatant was collected into a fresh Eppendorf tube, 650 μl of isopropanol was added and mixed gently by inverting the tubes. The tubes were incubated at RT for 15 min followed by centrifugation at 14,000 rpm for 10 min at RT to pellet out the DNA. About 50 μl of sterile water was added to the pellet in each tube and incubated in dry bath at 50 °C for 5 min to dissolve the DNA completely. The DNA concentration and purity (260/280 ratio) was measured by Nanodrop quantification. For 25 μl PCR reaction, 1 to 2 μl of DNA was used. Refer to Supplementary Data 4 for details of the primer sequences used for genotyping.

To determine the dose of tamoxifen required for Cre activation, ROSA-YFP:K14CreER^+/− mice were injected intraperitoneally with tamoxifen (75 mg/kg dissolved in corn oil) for 5 consecutive days. After 48 h of the last injection, mice were sacrificed and checked for YFP expression by IFA in dorsal skin sections. For experimental purposes, both K14CreER^−/−Dab2^fl/fl and K14CreER^+/−Dab2^fl/fl (Dab2-cKO) were injected intraperitoneally with tamoxifen (75 mg/kg dissolved in corn oil) for 5 consecutive days. To check the Dab2 KO efficiency in the epidermis, mice were sacrificed at PD68, and dorsal skin sections were collected. We incubated the skin sections in 10 ml 0.25% trypsin O/N at 4 °C. The next day, 10 ml fresh trypsin was added followed by incubation at 37 °C for 30 min. The epidermis was then peeled off from the dermis using a surgical blade and further processed for single-cell suspension. The cells were lysed in trizol for RNA isolation.