Alternative titles; symbols
HGNC Approved Gene Symbol: CPHXL
Cytogenetic location: 16q23.1 Genomic coordinates (GRCh38) : 16:75,714,131-75,726,490 (from NCBI)
CPHXL is a member of the paired (PRD)-like homeobox gene family of transcription factors. CPHXL is expressed in early embryos and is thought to play a role in the regulation of embryo genome activation and preimplantation embryo development (Tohonen et al., 2015 and Madissoon et al., 2016).
Using single-cell RNA sequencing of oocytes, zygotes, and blastomeres from 2- to 3-day-old human embryos, Tohonen et al. (2015) identified genes expressed during the transition from oocyte to the 4-cell stage and from the 4- to 8-cell stage in preimplantation development. Among these were the PRD-like homeobox genes CPHX1 (CPHXL), DUXA (611168), DUXB (618698), ARGFX (611164), DPRX (611165), LEUTX (618701), and CPHX2.
Madissoon et al. (2016) cloned splice variants of 9 human PRD-like homeobox domain genes found in early 8-cell stage embryos: ARGFX, CPHX1, CPHX2, DPRX, DUXA, DUXB, NOBOX (610934), TPRX1 (611166), and TPRX2 (620360). The homeodomain in PRD-like homeobox genes consists of approximately 60 amino acids and folds into an N-terminal arm and 3 alpha-helices. FANTOM5 database, suggesting possible silencing of the genes in later stages of development.
Overexpression of 9 PRD-like homeobox genes in embryonic stem cells (ESCs) by Madissoon et al. (2016) confirmed that the genes are mainly transcription activators (CPHX1, CPHX2, ARGFX) or repressors (DPRX, DUXA, TPRX2) and have distinct target genes that are activated during human preimplantation development. Madissoon et al. (2016) found enrichment of a 36-bp motif upstream of the transcription start site for genes regulated by most of the PRD-like homeobox genes.
Leidenroth and Hewitt (2010) noted that the human CPHXL is a main anchor gene on chromosome 16q23.1 used to identify syntenic regions across species.
Madissoon et al. (2016) reported that the CPHX1, CPHX2, and DUXB genes are clustered within a 68-kb region on chromosome 16q23.1.
Leidenroth, A., Hewitt, J. E. A family history of DUX4: phylogenetic analysis of DUXA, B, C and Duxbl reveals the ancestral DUX gene. BMC Evol. Biol. 10: 364, 2010. Note: Electronic Article. [PubMed: 21110847] [Full Text: https://doi.org/10.1186/1471-2148-10-364]
Madissoon, E., Jouhilahti, E.-M., Vesterlund, L., Tohonen, V., Krjutskov, K., Petropoulos, S., Einarsdottir, E., Linnarsson, S., Lanner, F., Mansson, R., Hovatta, O., Burglin, T. R., Katayama, S., Kere, J. Characterization and target genes of nine human PRD-like homeobox domain genes expressed exclusively in early embryos. Sci. Rep. 6: 28995, 2016. Note: Electronic Article. Erratum: Sci. Rep. 6: 32053, 2016. [PubMed: 27412763] [Full Text: https://doi.org/10.1038/srep28995]
Tohonen, V., Katayama, S., Vesterlund, L., Jouhilahti, E. M., Sheikhi, M., Madissoon, E., Filippini-Cattaneo, G., Jaconi, M., Johnsson, A., Burglin, T. R., Linnarsson, S., Hovatta, O., Kere, J. Novel PRD-like homeodomain transcription factors and retrotransposon elements in early human development. Nature Commun. 6: 8207, 2015. Note: Electronic Article. [PubMed: 26360614] [Full Text: https://doi.org/10.1038/ncomms9207]