The Lbc gene promotes differentiation of chicken embryo stem cell into spermatogonial stem cells via the regulation of transcriptional factor Hoxa5.

Recently, the surface marker genes of spermatogonial stem cells (SSCs) were increasingly excavated and verified. However, few studies focused on the key genes involved in the regulation of SSCs differentiation. Our laboratory has screened the Lbc gene (GenBank accession number: XM_429585.3), which is specifically expressed on the SSCs. The aim of this study is to investigate the function of Lbc and its regulatory mechanism for SSCs. The indirect immunofluorescence assay (IFA) showed that Lbc was located in both nucleus and cytoplasm. Lbc was also overexpressed and knocked out both in vitro and in vivo to verify its function in SSCs, respectively. As a result, the overexpressed Lbc could promote the formation of spermatogonial stem cells like cells (SSCs-like), while the deficiency of Lbc blocked the formation of SSCs-like. We also identified the core region of Lbc promoter that located into the upstream of the transcription initiation site -247 to -2bp. Moreover, the activity of Lbc promoter could be increased by histone acetylation which is leading to the higher expression of Lbc. When we mutated the transcription factor HOXA5 and SOX10 that bound to the core region of Lbc promoter, HOXA5 could reduce the transcription activity of Lbc whereas the SOX10 was not. Currently, we found Lbc is a new specific marker of SSCs. This gene can be modified by histone acetylated and promote the formation of chicken SSCs via the transcription factor HOXA5. The present research will lay the foundation for further study on the regulatory mechanism of SSCs.