ISSN:
1432-1432
Keywords:
Restriction mapping
;
Southern blotting
;
Cloning and sequencing
;
Australian geckos
;
Control region
;
16S rRNA
;
NADH dehydrogenase 1
;
Nucleocytoplasmic interactions
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary Analysis of mitochondrial DNAs (mtDNAs) from parthenogenetic lizards of theHeteronotia binoei complex with restriction enzymes revealed an ∼5-kb addition present in all 77 individuals. Cleavage site mapping suggested the presence of a direct tandem duplication spanning the 16S and 12S rRNA genes, the control region and most, if not all, of the gene for the subunit 1 of NADH dehydrogenase (ND1). The location of the duplication was confirmed by Southern hybridization. A restriction enzyme survey provided evidence for modifications to each copy of the duplicated sequence, including four large deletions. Each gene affected by a deletion was complemented by an intact version in the other copy of the sequence, although for one gene the functional copy was heteroplasmic for another deletion. Sequencing of a fragment from one copy of the duplication which encompassed the tRNAleu(UUR) and parts of the 16S rRNA and ND1 genes, revealed mutations expected to disrupt function. Thus, evolution subsequent to the duplication event has resulted in mitochondrial pseudogenes. The presence of duplications in all of these parthenogens, but not among representatives of their maternal sexual ancestors, suggests that the duplications arose in the parthenogenetic form. This provides the second instance inH. binoei of mtDNA duplication associated with the transition from sexual to parthenogenetic reproduction. The increased incidence of duplications in parthenogenetic lizards may be caused by errors in mtDNA replication due to either polyploidy or hybridity of their nuclear genomes.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02103135
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