Life Sciences Commons^™

New Views On Strand Asymmetry In Insect Mitochondrial Genomes, Shu-Jun Wei, Min Shi, Xue-Xin Chen, Michael J. Sharkey, Cornelis Van Achterberg, Gong-Yin Ye, Jun-Hua He

Entomology Faculty Publications

Strand asymmetry in nucleotide composition is a remarkable feature of animal mitochondrial genomes. Understanding the mutation processes that shape strand asymmetry is essential for comprehensive knowledge of genome evolution, demographical population history and accurate phylogenetic inference. Previous studies found that the relative contributions of different substitution types to strand asymmetry are associated with replication alone or both replication and transcription. However, the relative contributions of replication and transcription to strand asymmetry remain unclear. Here we conducted a broad survey of strand asymmetry across 120 insect mitochondrial genomes, with special reference to the correlation between the signs of skew values and …

Comparative Mitogenomics Of Braconidae (Insecta: Hymenoptera) And The Phylogenetic Utility Of Mitochondrial Genomes With Special Reference To Holometabolous Insects, Shu-Jun Wei, Min Shi, Michael J. Sharkey, Cornelis Van Achterberg, Xue-Xin Chen

Entomology Faculty Publications

BACKGROUND: Animal mitochondrial genomes are potential models for molecular evolution and markers for phylogenetic and population studies. Previous research has shown interesting features in hymenopteran mitochondrial genomes. Here, we conducted a comparative study of mitochondrial genomes of the family Braconidae, one of the largest families of Hymenoptera, and assessed the utility of mitochondrial genomic data for phylogenetic inference at three different hierarchical levels, i.e., Braconidae, Hymenoptera, and Holometabola.

RESULTS: Seven mitochondrial genomes from seven subfamilies of Braconidae were sequenced. Three of the four sequenced A+T-rich regions are shown to be inverted. Furthermore, all species showed reversal of strand asymmetry, suggesting …

A Brain-Specific Cytochrome P450 Responsible For The Majority Of Deltamethrin Resistance In The Qtc279 Strain Of Tribolium Castaneum, Fang Zhu, R. Parthasarathy, Hua Bai, Katharina Woithe, Martin Kaussmann, Ralf Nauen, Douglas A. Harrison, Subba R. Palli

Entomology Faculty Publications

Cytochrome P450-mediated detoxification is one of the most important mechanisms involved in insecticide resistance. However, the molecular basis of this mechanism and the physiological functions of P450s associated with insecticide resistance remain largely unknown. Here, we exploited the functional genomics and reverse genetic approaches to identify and characterize a P450 gene responsible for the majority of deltamethrin resistance observed in the QTC279 strain of Tribolium castaneum. We used recently completed whole-genome sequence of T. castaneum to prepare custom microarrays and identified a P450 gene, CYP6BQ9, which showed more than a 200-fold higher expression in the deltamethrin-resistant QTC279 strain when compared …

Molecular Evidence For A Functional Ecdysone Signaling System In Brugia Malayi, George Tzertzinis, Ana L. Egaña, Subba Reddy Palli, Marc Robinson-Rechavi, Chris R. Gissendanner, Canhui Liu, Thomas R. Unnasch, Claude V. Maina

Entomology Faculty Publications

BACKGROUND: Filarial nematodes, including Brugia malayi, the causative agent of lymphatic filariasis, undergo molting in both arthropod and mammalian hosts to complete their life cycles. An understanding of how these parasites cross developmental checkpoints may reveal potential targets for intervention. Pharmacological evidence suggests that ecdysteroids play a role in parasitic nematode molting and fertility although their specific function remains unknown. In insects, ecdysone triggers molting through the activation of the ecdysone receptor: a heterodimer of EcR (ecdysone receptor) and USP (Ultraspiracle).

METHODS AND FINDINGS: We report the cloning and characterization of a B. malayi EcR homologue (Bma-EcR). Bma-EcR dimerizes with …