The characteristics and expression profiles of the mitochondrial genome for the Mediterranean species of the Bemisia tabaci complex

Abstract

BackgroundThe whiteflies under the name Bemisia tabaci (Gennadius) (Aleyrodidae: Hemiptera) are species complex of at least 31 cryptic species some of which are globally invasive agricultural pests. Previously, the mitochondrial genome (mitogenome) of the indigenous New World B. tabaci species was sequenced and major differences of gene order from the postulated whitefly ancestral gene order were found. However, the sequence and gene order of mitogenomes in other B. tabaci species are unknown. In addition, the sequence divergences and gene expression profiles of mitogenomes in the B. tabaci species complex remain completely unexplored.ResultsIn this study, we obtained the complete mitogenome (15,632 bp) of the invasive Mediterranean (MED), which has been identified as the type species of the B. tabaci complex. It encodes 37 genes, including 13 protein-coding genes (PCGs), 2 ribosomal RNAs and 22 transfer RNAs (tRNA). Comparative analyses of the mitogenomes from MED and New World (previously published) species reveal that there are no gene arrangements. Based on the Illumina sequencing data, the gene expression profile of the MED mitogenome was analyzed. We found that a number of genes were polyadenylated and the partial stop codons in cox1, cox2 and nd5 are completed via polyadenylation that changed T to the TAA stop codon. In addition, combining the transcriptome with the sequence alignment data, the possible termination site of some PCGs were defined. Our analyses also revealed that atp6 and atp8, nd4 and nd4l, nd6 and cytb were found on the same cistronic transcripts, whereas the other mature mitochondrial transcripts were monocistronic. Furthermore, RT-PCR analyses of the mitochondrial PCGs expression in different developmental stages revealed that the expression level of individual mitochondrial genes varied in each developmental stage of nymph, pupa and adult. Interestingly, mRNA levels showed significant differences among genes located in the same transcription unit suggesting that mitochondrial mRNA abundance is heavily modulated by post-transcriptional regulation.ConclusionsThis work provides novel insights into the mitogenome evolution of B. tabaci species and demonstrates that utilizing RNA-seq data to obtain the mitogenome and analyze mitochondrial gene expression characteristics is practical.

The Complete Mitochondrial Genome of Aleurocanthus camelliae: Insights into Gene Arrangement and Genome Organization within the Family Aleyrodidae

“…For the two whiteflies, gene rrnS is immediately followed by rrnL , with no transfer RNA gene but a long non coding sequence (94 and 53 bp) between them. However, the other whiteflies have one or more transfer genes between the two rRNAs [21,22,23,24,27]. …”

“…Family Aleyrodidae, with around 1450 named species, belongs to the order Hemiptera and comprise a single superfamily, Aleyrodoidea, within the suborder Sternorrhyncha [20]. Recent studies showed that mt genome of whiteflies have numerous gene rearrangements and transfer RNA gene absences [21,22,23,24]. Transposition of gene block cox3 - trnG - nad3 and the position of trnY and trnC are typical in whitefly mt genomes.…”

Standardized molecular diagnostic tool for the identification of cryptic species within the Bemisia tabaci complex

“…To date, the complete mtDNA genome (mtGenome) of only one invasive Bemisia species (i.e. the true B. tabaci ) MED are publicly available …”

Survival of Bemisia tabaci and activity of plant defense-related enzymes in genotypes of Capsicum annuum L.

“…This species is particularly harmful in tropical and subtropical areas, where currently B. tabaci is known as a complex composed of cryptic species (Wang et al, 2013;Marubayashi et al, 2013;Boykin, 2014;Barbosa et al, 2014). Bemisia tabaci damages plants by direct feeding and transmission of Begomoviruses and Criniviruses that cause serious problems due to viral epidemics (Morales, 2007;Marubayashi et al, 2013).…”