Structural organization of the mitochondrial DNA control region in Aedes aegypti

Abstract

The complete A+T - rich region of Aedes aegypti mitochondrial DNA has been cloned and sequenced. In Argentinean populations of the species, a polymorphism in the length of the amplified fragment was observed. Nucleotide sequence comparison of the shortest and longest A+T - rich amplified fragments detected revealed the presence of 2 types of tandemly repeated blocks. The size variation observed in natural populations is mainly due to the presence of a variable number of a 181 bp tandem repeat unit, located toward the 12S rRNA gene end. The size of the longest A+T - rich region was of 2070 bp, representing the largest control sequence reported for any mosquito species. Few relevant short blocks of primary-sequence similarity conserved in the control region of mosquitoes and other insects were detected scattered throughout the whole region. Five putative stem-loop secondary structures were found, one of them flanked by conserved sequences described in other insects. Our results suggest that there are no universal models of structure-function relations in the control region of insect mtDNA. In addition, we identified a short A+T - rich variable segment in the Ae. aegyti control region that would be suitable for population genetic studies.

The Worldwide Spread of the Tiger Mosquito as Revealed by Mitogenome Haplogroup Diversity

“…This mitogenome sequence confirmed that the A. albopictus control region belongs to group 2 of insect control regions (Zhang and Hewitt, 1997), like that of A. aegypti (Dueñas et al, 2006). Three conserved blocks are positioned along the region, which contains two different types (I and II) of tandem repeats ( Figure 2 ).…”

“…Black diamonds represent in the order from left to right: a poly-T stretch motif, a poly-T stretch motif followed by a GC-rich block, and a short poly-A stretch motif. All of these are conserved in different mosquito species (Dueñas et al, 2006). …”

Gene flow networks among American Aedes aegypti populations

“…The MLEs for the F84 nucleotide substitution model parameters suggested unequal base frequencies in line with observations from mtDNA of insects and Ae. aegypti (Dueñas et al. 2006; Table S3).…”

“…The MLEs for the F84 nucleotide substitution model parameters suggested unequal base frequencies in line with observations from mtDNA of insects and Ae. aegypti (Dueñas et al 2006; Table S3). Across sampling scales, differences in base frequency MLEs were on the order of 10 )3 and were considered too small to be reported.…”

The mitochondrial genome of Ruspolia dubia (Orthoptera: Conocephalidae) contains a short A+T-rich region of 70 bp in length

“…The length of the A+T-rich region ranges from tens to several thousands of base pairs (Lewis et al 1995;Shao et al 2001). It is one of the most variable regions of mtDNA, not only because of its high rates of nucleotide substitution and insertions/ deletions, but also because of the presence of varying copy numbers of tandemly repeated elements (Zhang and Hewitt 1997;Duenas et al 2006). The structural organization of the insect mtDNA A+T-rich region (also known as the control region) has been studied extensively (Zhang et al 1995;Zhang and Hewitt 1997;Duenas et al 2006;Cha et al 2007).…”