Length heteroplasmy of sturgeon mitochondrial DNA: an illegitimate elongation model

• Published in: Genetics (Austin) 1990, Vol.124 (1), p.157-163
• Main Authors: Buroker, N. E, Brown, J. R, Gilbert, T. A, O'Hara, P. J, Beckenbach, A. T, Thomas, W. K, Smith, M. J
• Format: Article
• Language: English
• Subjects: acipenser; Acipenser transmontanus; adn; Animals; Base Sequence; Biological and medical sciences; british columbia; california; californie; colombie britannique; columbia britanica; dna; DNA Replication; DNA, Mitochondrial - genetics; DNA, Mitochondrial - metabolism; Fishes - genetics; Fundamental and applied biological sciences. Psychology; Genes. Genome; genetic polymorphism; genetica; genetics; genetique; Investigations; mitochondria; mitochondrie; mitocondria; Models, Genetic; Molecular and cellular biology; Molecular genetics; Molecular Sequence Data; Nucleic Acid Conformation; nucleotide; nucleotides; nucleotidos; polimorfismo genetico; Polymorphism, Restriction Fragment Length; polymorphisme genetique; Repetitive Sequences, Nucleic Acid; washington
• ISSN: 0016-6731; 1943-2631; 1943-2631
• DOI: 10.1093/genetics/124.1.157

Extensive length polymorphism and heteroplasmy (multiple forms within an individual) of the D-loop region are observed in mitochondrial DNA of the white sturgeon (Acipenser transmontanus). The nucleotide sequence of this region, for both a short and a long form, shows that the differences are due to variable numbers of a perfect 82-bp direct repeat. We propose a model for the replicative origin of length differences, involving a competitive equilibrium between the heavy strand and the D-loop strand. This model suggests that frequent misalignment in the repeat region prior to elongation, facilitated by a stable secondary structure in the displaced strand, can explain both the polymorphism and heteroplasmy in this species.