Differential γH2Ax pan-staining and TUNEL assay.

Abstract

Abundant γH2Ax in β cells from IC β Hltf KO mice (A) compared to minimal immunostaining in β cells from ID β Hltf KO mice (B). Two-types of γH2Ax pan-staining are evident. β cells from IC β Hltf KO mice have apoptotic rings and the β cells from ID β Hltf KO mice have limited pan-nuclear staining of the entire nucleus. Results from the terminal deoxynuceotidyl transferase dUTP nick-end labeling (TUNEL) assay (C), which detects β cell death-associated DNA fragmentation (3’-OH termini), indicates the amount of DNA damage is more than the targeted β cells can efficiently repair when the animals are IC. Cell-death in IC Hltf +/+ controls and ID β Hltf KO mice was negligible. A positive mouse testis control (D) was included because apoptosis is an important component of normal spermatogenesis.</p