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Have gene knockouts caused evolutionary reversals in the mammalian first arch?

Publication ,  Journal Article
Smith, KK; Schneider, RA
Published in: BioEssays : news and reviews in molecular, cellular and developmental biology
March 1998

Many recent gene knockout experiments cause anatomical changes to the jaw region of mice that several investigators claim are evolutionary reversals. Here we evaluate these mutant phenotypes and the assertions of atavism. We argue that following the knockout of Hoxa-2, Dlx-2, MHox, Otx2, and RAR genes, ectopic cartilages arise as secondary consequences of disruptions in normal processes of cell specification, migration, or differentiation. These disruptions cause an excess of mesenchyme to accumulate in a region through which skeletal progenitor cells usually migrate, and at a site of condensation that is normally present in mammals but that is too small to chondrify. We find little evidence that these genes, when disrupted, cause a reversion to any primitive condition and although changes in their expression may have played a role in the evolution of the mammalian jaw, their function during morphogenesis is not sufficiently understood to confirm such hypotheses.

Duke Scholars

Published In

BioEssays : news and reviews in molecular, cellular and developmental biology

DOI

EISSN

1521-1878

ISSN

0265-9247

Publication Date

March 1998

Volume

20

Issue

3

Start / End Page

245 / 255

Related Subject Headings

  • Vertebrates
  • Mice, Knockout
  • Mice
  • Mammals
  • Homeodomain Proteins
  • Genetic Engineering
  • Directed Molecular Evolution
  • Developmental Biology
  • Biological Evolution
  • Animals
 

Citation

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Smith, K. K., & Schneider, R. A. (1998). Have gene knockouts caused evolutionary reversals in the mammalian first arch? BioEssays : News and Reviews in Molecular, Cellular and Developmental Biology, 20(3), 245–255. https://doi.org/10.1002/(sici)1521-1878(199803)20:3<245::aid-bies8>3.0.co;2-q
Smith, K. K., and R. A. Schneider. “Have gene knockouts caused evolutionary reversals in the mammalian first arch?BioEssays : News and Reviews in Molecular, Cellular and Developmental Biology 20, no. 3 (March 1998): 245–55. https://doi.org/10.1002/(sici)1521-1878(199803)20:3<245::aid-bies8>3.0.co;2-q.
Smith KK, Schneider RA. Have gene knockouts caused evolutionary reversals in the mammalian first arch? BioEssays : news and reviews in molecular, cellular and developmental biology. 1998 Mar;20(3):245–55.
Smith, K. K., and R. A. Schneider. “Have gene knockouts caused evolutionary reversals in the mammalian first arch?BioEssays : News and Reviews in Molecular, Cellular and Developmental Biology, vol. 20, no. 3, Mar. 1998, pp. 245–55. Epmc, doi:10.1002/(sici)1521-1878(199803)20:3<245::aid-bies8>3.0.co;2-q.
Smith KK, Schneider RA. Have gene knockouts caused evolutionary reversals in the mammalian first arch? BioEssays : news and reviews in molecular, cellular and developmental biology. 1998 Mar;20(3):245–255.
Journal cover image

Published In

BioEssays : news and reviews in molecular, cellular and developmental biology

DOI

EISSN

1521-1878

ISSN

0265-9247

Publication Date

March 1998

Volume

20

Issue

3

Start / End Page

245 / 255

Related Subject Headings

  • Vertebrates
  • Mice, Knockout
  • Mice
  • Mammals
  • Homeodomain Proteins
  • Genetic Engineering
  • Directed Molecular Evolution
  • Developmental Biology
  • Biological Evolution
  • Animals