The Mouse Mid1 Gene: Implications for the Pathogenesis of Opitz Syndrome and the Evolution of the Mammalian Pseudoautosomal Region

• Published in: Human molecular genetics 1998-03, Vol.7 (3), p.489-499
• Main Authors: Dal Zotto, Laura, Quaderi, Nandita A., Elliott, Rosemary, Lingerfelter, Patricia A., Carrel, Laura, Valsecchi, Valentina, Montini, Eugenio, Yen, Chao-Huang, Chapman, Verne, Kalcheva, Iveta, Arrigo, Giulia, Zuffardi, Orsetta, Thomas, Sushma, Willard, Huntington F., Ballabio, Andrea, Disteche, Christine M., Rugarli, Elena I.
• Format: Article
• Language: English
• Subjects: Abnormalities, Multiple - genetics; Animals; Biological and medical sciences; Biological Evolution; Chromosome Mapping; Classical genetics, quantitative genetics, hybrids; Complex syndromes; Crosses, Genetic; Embryonic and Fetal Development; Female; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Developmental; Genetics of eukaryotes. Biological and molecular evolution; Humans; Male; Mammals - genetics; Medical genetics; Medical sciences; Mice - genetics; Mice, Inbred C57BL; Microtubule Proteins; Molecular Sequence Data; Nuclear Proteins; Pseudogenes; Transcription Factors - biosynthesis; Transcription Factors - genetics; Ubiquitin-Protein Ligases; Vertebrata; X Chromosome; Zinc Fingers - genetics
• ISSN: 0964-6906; 1460-2083; 1460-2083
• DOI: 10.1093/hmg/7.3.489

We have recently reported isolation of the gene responsible for X-linked Opitz G/BBB syndrome, a defect of midline development. MID1 is located on the distal short arm of the human X chromosome (Xp22.3) and encodes a novel member of the B box family of zinc finger proteins. We have now cloned the murine homo-log of MID1 and performed preliminary expression studies during development. Mid1 expression in undifferentiated cells in the central nervous, gastrointestinal and urogenital systems suggests that abnormal cell proliferation may underlie the defect in midline development characteristic of Opitz syndrome. We have also found that Mid1 is located within the mouse pseudoautosomal region (PAR) in Mus musculus, while it seems to be X-specific in Mus spretus. Therefore, Mid1 is likely to be a recent acquisition of the M.musculus PAR. Genetic and FISH analyses also demonstrated a high frequency of unequal crossovers in the murine PAR, creating spontaneous deletion/duplication events involving Mid1. These data provide evidence for the first time that genetic instability of the PAR may affect functionally important genes. In addition, we show that MID1 is the first example of a gene subject to X-inactivation in man while escaping it in mouse. These data contribute to a better understanding of the molecular content and evolution of the rodent PAR.