Host genes regulate transcription of sperm-introduced hepatitis B virus genes in embryo

- A variety of methods was used to isolate differentially expressed host genes.
- Twenty-nine isolated genes showed significant identity to five human gene families.
- Five representative genes (one from each family) were selected as target genes.
- Target genes up- or down- regulate sperm-introduced HBV gene expression in embryo.
- It is first confirmed that HBV gene expression in embryos regulated by host genes.

Hepatitis B virus (HBV) can invade the male germline, and sperm-introduced HBV genes could be transcribed in embryo. This study was to explore whether viral gene transcription is regulated by host genes. Embryos were produced by in vitro fertilization of hamster oocytes with human sperm containing the HBV genome. Total RNA extracted from test and control embryos were subjected to SMART-PCR, SSH, microarray hybridization, sequencing and BLAST analysis. Twenty-nine sequences showing significant identity to five human gene families were identified, with CSH2, EIF4G2, PCBD2, PSG4 and TTN selected to represent target genes. Using qRT-PCR, when CSH2 and PCBD2 (or EIF4G2, PSG4 and TTN) were silenced by RNAi, transcriptional levels of HBV s and x genes decreased (or increased). This is the first report that host genes participate in regulation of sperm-introduced HBV gene transcription in embryo, which is critical to prevent negative impact of HBV infection on early embryonic development.