Towards understanding paternal extragenic contributions to early amphibian pattern specification: the axolotl ts-1 gene as a model system.

As a model system for understanding the role sperm extragenic components might play in early embryogenesis the genetics and phenotype of the ts-1 axolotl (Ambystoma mexicanum) mutant gene are reviewed. That mutant gene displays parental effects. It exhibits both maternal (egg-mediated) as well as paternal (sperm-mediated) phenotypic effects. A variety of possible modes of action of the ts-1 gene are reviewed. Comparisons of various precedents to the ts-1 genetic data are made. In addition, novel models which account for the ts-1 phenotypic data are presented.