Preferential expression of the maternal allele for alcohol dehydrogenase (ADH) in the amphibian hybrid Ambystoma mexicanum (axolotl) × Ambystoma texanum
1977; Elsevier BV; Volume: 60; Issue: 1 Linguagem: Inglês
10.1016/0012-1606(77)90112-9
ISSN1095-564X
Autores Tópico(s)Lipid metabolism and biosynthesis
ResumoAlcohol dehydrogenase (ADH) is found primarily in larval and adult liver of both Ambystoma mexicanum (axolotl) and Ambystoma texanum. It is undetectable in the developing organism until early larval stages (4 weeks; 2.5 cm in length). Upon starch gel electrophoresis the ADHs of A. mexicanum and A. texanum appear as single bands. A. texanum ADH migrates cathodally, while A. mexicanum ADH migrates anodally. Several ADH variants are described in A. texanum. It is possible to produce hybrid offspring by means of artificial insemination. The offspring are viable regardless of which species is the maternal or paternal parent. Both hybrid combinations (A. mexicanum ♀ × A. texanum ♂; A. mexicanum ♂ × A. texanum ♀) are used to detect the time of expression of ADH genes during development. Starch gel analysis of livers from offspring of both crosses reveals that the maternal form of the enzyme appears at the normal time during development (4 weeks), while the paternal allele is not expressed until 3–5 weeks later. In a cross between A. texanum with the wild-type allele of ADH and an individual of the same species with the variant ADH, both maternal and paternal ADH alleles are expressed simultaneously. These observations suggest that there may be a regulatory incompatibility either at the transcriptional or post-transcriptional level between the two species.
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