Basonuclin 2 has a function in the multiplication of embryonic craniofacial mesenchymal cells and is orthologous to disco proteins

Proc Natl Acad Sci U S A. 2009 Aug 25;106(34):14432-7. doi: 10.1073/pnas.0905840106. Epub 2009 Aug 12.


Basonuclin 2 is a recently discovered zinc finger protein of unknown function. Its paralog, basonuclin 1, is associated with the ability of keratinocytes to multiply. The basonuclin zinc fingers are closely related to those of the Drosophila proteins disco and discorelated, but the relation between disco proteins and basonuclins has remained elusive because the function of the disco proteins in larval head development seems to have no relation to that of basonuclin 1 and because the amino acid sequence of disco, apart from the zinc fingers, also has no similarity to that of the basonuclins. We have generated mice lacking basonuclin 2. These mice die within 24 h of birth with a cleft palate and abnormalities of craniofacial bones and tongue. In the embryonic head, expression of the basonuclin 2 gene is restricted to mesenchymal cells in the palate, at the periphery of the tongue, and in the mesenchymal sheaths that surround the brain and the osteocartilagineous structures. In late embryos, the rate of multiplication of these mesenchymal cells is greatly diminished. Therefore, basonuclin 2 is essential for the multiplication of craniofacial mesenchymal cells during embryogenesis. Non-Drosophila insect databases available since 2008 reveal that the basonuclins and the disco proteins share much more extensive sequence and gene structure similarity than noted when only Drosophila sequences were examined. We conclude that basonuclin 2 is both structurally and functionally the vertebrate ortholog of the disco proteins. We also note the possibility that some human craniofacial abnormalities are due to a lack of basonuclin 2.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Newborn
  • Blotting, Northern
  • Cell Line
  • Cell Proliferation*
  • Cleft Palate / embryology
  • Cleft Palate / genetics
  • Craniofacial Abnormalities / genetics
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism
  • DNA-Binding Proteins / physiology*
  • Drosophila Proteins / genetics
  • Drosophila Proteins / metabolism
  • Embryo, Mammalian / cytology
  • Embryo, Mammalian / embryology
  • Embryo, Mammalian / metabolism
  • Female
  • Fluorescent Antibody Technique, Indirect
  • Gene Expression Regulation, Developmental
  • Male
  • Mesenchymal Stem Cells / cytology*
  • Mesenchymal Stem Cells / metabolism
  • Mice
  • Mice, Knockout
  • Oligonucleotide Array Sequence Analysis
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Skull / cytology
  • Skull / embryology
  • Skull / metabolism
  • Tongue / abnormalities
  • Tongue / metabolism
  • Transcription Factors / genetics
  • Transcription Factors / metabolism
  • Zinc Fingers


  • DNA-Binding Proteins
  • Drosophila Proteins
  • RNA, Messenger
  • Transcription Factors
  • basonuclin 2, mouse
  • disco protein, Drosophila