Comparative analysis of the circadian rhythm genes period and timeless in Culex pipiens Linnaeus, 1758 (Diptera, Culicidae)

Abstract

Nucleotide sequences of the circadian rhythm genes, period and timeless, were studied for the first time in mosquitoes Culex pipiens Linnaeus, 1758. In this work we evaluated variations of the studied genome fragments for the two forms of Culex pipiens (forma “pipiens” – mosquitoes common for aboveground habitats, forma “molestus” – underground mosquitoes). We compared Culex pipiens from Russia with transatlantic Culex pipiens and subtropical Culex quinquefasciatus Say, 1823. Our results show that intraspecies variability is higher for the gene period than for the gene timeless. The revealed substitutions in nucleotide sequences and especially in amino acid sequences grouped the individuals of the two forms into distinct clusters with high significance. The detected fixed amino acid substitutions may appear essential for functioning of the circadian rhythm proteins in Culex pipiens, and may be correlated with adaptations of the taxa within the group Culex pipiens. Our results suggest that natural selection favors fixed mutations and the decrease in diversity of the genes period and timeless in mosquitoes of the Culex pipiens f. “molestus” compared with the Culex pipiens f. “pipiens”, is probably correlated with adaptive features of Culex pipiens f. “molestus”. The studied genome regions may be considered as promising molecular-genetic markers for identification, population and phylogenetic analysis of similar species and forms of the Culex pipiens complex.

Model and Non-model Insects in Chronobiology

“…In the fruit fly, CRY1 interacts with TIM1 (insect type TIM1) after it has been activated by light and leads to the degradation of TIM1 in the proteasome (Ceriani et al, 1999;Naidoo, 1999), a feature that makes flies very sensitive to light (see below). TIM1 and CRY1 are also present in for example mosquitoes, aphids, crickets, butter flies and moths (Iwai et al, 2006;Gentile et al, 2009;Cortés et al, 2010;Danbara et al, 2010;Kobelková et al, 2015;Rodriguez-Sanchez et al, 2015;Shaikevich et al, 2016;. However, in these insects they exist in addition to CRY2 (insect CRY2 or mammalian type CRY) and it is not completely clear, whether and how TIM1 interacts with PER.…”

The diagnostic utility of sequence-based assays for the molecular delimitation of the epidemiologically relevantCulex pipiens pipienstaxa (Diptera: Culicidae)

“…To overcome these difficulties, the issue of the molestus / pipiens differentiation has been tackled by a multitude of molecular approaches. Some of the markers include: the 3’ end of mitochondrial cytochrome c oxidase subunit I gene (Shaikevich et al ., 2005; Kent et al ., 2007), microsatellite loci (Fonseca et al ., 2004; Kent et al ., 2007; Gomes et al ., 2009, 2013; Kothera et al ., 2013), the flanking region of CQ11 microsatellite locus ( CQ11FL ) (Bahnck & Fonseca, 2006; Gomes et al ., 2009, 2013; Di Luca et al ., 2016), intergenic spacer (Shaikevich et al ., 2013), 12S rRNA, HS60 , ND4 (Kent et al ., 2007), and most recently, period and timeless , circadian rhythm genes (Shaikevich et al ., 2016), as well as a genome-wide AFLP approach (Gomes et al ., 2015). The issue of molestus / pipiens identification, however, remains a controversial topic since different DNA regions are subject to varying levels of gene flow as a consequence of their mode of inheritance (Petit & Excoffier, 2009), which is reflected in their diagnostic value.…”

Culex pipiens and Culex restuans egg rafts harbor diverse bacterial communities compared to their midgut tissues

“…At each sampling site, two CDC gravid traps baited with 3.8 l each of grass infusion [ 29 ] were deployed beginning on June 18, 2018 and sampling was conducted three times weekly up to July 20, 2018. Traps were placed in the evening just before dusk and the collection bags collected approximately 12 h later the next morning [ 30 ]. Individual gravid female Culex species mosquitoes were transferred separately to individual 270 ml paper cups to facilitate oviposition; each consisted of a 30 ml inner plastic oviposition cup filled to half capacity with distilled water.…”