Gametocyte Specific Factor 1 (GTSF1)

Gtsf1/Cue110 is expressed predominantly in male germ cells, and that the GTSF1/CUE110 protein is localized to the cytoplasm of these cells in the adult testis. The Gtsf1/Cue110-null mice grew normally and appeared healthy; however, the males were sterile due to massive apoptotic death of their germ cells after postnatal day 14.Gtsf1/Cue110-null male meiocytes ceased meiotic progression before the zygotene stage. Gtsf1/Cue110 gene is essential for spermatogenesis beyond the early meiotic phase. the loss of the Gtsf1/Cue110 gene caused increased transcription of the long interspersed nucleotide element (Line-1) and the intracisternal A-particle (IAP) retrotransposons, accompanied by demethylation of their promoter regions.Gtsf1/Cue110 is required for spermatogenesis and involved in retrotransposon suppression in male germ cells.