Alternative titles; symbols
HGNC Approved Gene Symbol: MORC1
Cytogenetic location: 3q13.13 Genomic coordinates (GRCh38): 3:108,958,248-109,118,134 (from NCBI)
Using exon trapping, Inoue et al. (1999) identified the mouse testis-specific Morc gene whose disruption by a transgene resulted in arrest of spermatogenesis at meiotic prophase I (see ANIMAL MODEL). Transgene insertion deleted 3 evolutionarily conserved exons and severely truncated the predicted translation product. Similar sequences are present in human, nematode, slime mold, and plant genomes. The Morc gene is expressed in spermatogonia and primary spermatocytes. Epitope-tagged recombinant Morc protein localized to the nucleus in cultured cells.
To identify the human Morc homolog, Inoue et al. (1999) screened a human testis cDNA library with the mouse Morc cDNA. Human MORC encodes a deduced 984-amino acid protein with 66% overall identity to mouse Morc. Sequence analysis detected a bipartite nuclear localization signal, 2 coiled-coil domains, and a leucine zipper motif. The human ortholog, like the mouse gene, showed testis-specific expression. Inoue et al. (1999) concluded that MORC defines a novel gene family whose members may serve important biologic functions in both meiotic and mitotic cells of multicellular organisms.
Inoue et al. (1999) used an interspecific mouse backcross to map the Morc gene to chromosome 16. By fluorescence in situ hybridization, they mapped the human MORC gene to 3q13, further defining an evolutionary breakpoint between human and mouse.
The microrchidia (morc) autosomal recessive mutation in the mouse results in the arrest of spermatogenesis at an early stage, specifically at the primary to secondary spermatocyte transition. The morc mutation arose spontaneously during the development of a mouse strain transgenic for a tyrosinase cDNA construct. Homozygous morc -/- males are infertile and have grossly reduced testicular mass, whereas morc -/- females are normal, indicating that the morc gene product acts specifically during male meiosis. An apoptosis assay revealed massive numbers of cells undergoing apoptosis in testis of morc -/- mice. No other abnormality was observed in mutant animals (Watson et al., 1998).
Inoue, N., Hess, K. D., Moreadith, R. W., Richardson, L. L., Handel, M. A., Watson, M. L., Zinn, A. R. New gene family defined by MORC, a nuclear protein required for mouse spermatogenesis. Hum. Molec. Genet. 8: 1201-1207, 1999. [PubMed: 10369865] [Full Text: https://doi.org/10.1093/hmg/8.7.1201]
Watson, M. L., Zinn, A. R., Inoue, N., Hess, K. D., Cobb, J., Handel, M. A., Halaban, R., Duchene, C. C., Albright, G. M., Moreadith, R. W. Identification of morc (microrchidia), a mutation that results in arrest of spermatogenesis at an early meiotic stage in the mouse. Proc. Nat. Acad. Sci. 95: 14361-14366, 1998. [PubMed: 9826705] [Full Text: https://doi.org/10.1073/pnas.95.24.14361]