Retention of duplicated long-wavelength opsins in mosquito lineages by positive selection and differential expression

BMC Evolutionary Biology

Research Article

Michael J. Zanis¹  Gloria I. Giraldo-Calderón²  Catherine A. Hill³ 

[1] Department of Botany and Plant Pathology, Purdue University, 47907-2089, West Lafayette, IN, USA;Present Address: Department of Biology, Seattle University, 98122, Seattle, WA, USA;Department of Entomology, Purdue University, 47907-2089, West Lafayette, IN, USA;Present Address: Department of Biological Sciences, University of Notre Dame, 46556, Notre Dame, IN, USA;Department of Entomology, Purdue University, 47907-2089, West Lafayette, IN, USA;Purdue Institute of Inflammation, Immunology and Infectious Disease, Purdue University, 47907-2089, West Lafayette, IN, USA;

关键词: Mosquito;    Opsin;    Long-wavelength;    Gene duplication;    Positive selection;    Differential expression;    Conserved non-coding sequences;    Vision;   

DOI  :  10.1186/s12862-017-0910-6

 received in 2016-08-13, accepted in 2017-02-09,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundOpsins are light sensitive receptors associated with visual processes. Insects typically possess opsins that are stimulated by ultraviolet, short and long wavelength (LW) radiation. Six putative LW-sensitive opsins predicted in the yellow fever mosquito, Aedes aegypti and malaria mosquito, Anopheles gambiae, and eight in the southern house mosquito, Culex quinquefasciatus, suggest gene expansion in the Family Culicidae (mosquitoes) relative to other insects. Here we report the first detailed molecular and evolutionary analyses of LW opsins in three mosquito vectors, with a goal to understanding the molecular basis of opsin-mediated visual processes that could be exploited for mosquito control.ResultsTime of divergence estimates suggest that the mosquito LW opsins originated from 18 or 19 duplication events between 166.9/197.5 to 1.07/0.94 million years ago (MY) and that these likely occurred following the predicted divergence of the lineages Anophelinae and Culicinae 145–226 MY. Fitmodel analyses identified nine amino acid residues in the LW opsins that may be under positive selection. Of these, eight amino acids occur in the N and C termini and are shared among all three species, and one residue in TMIII was unique to culicine species. Alignment of 5′ non-coding regions revealed potential Conserved Non-coding Sequences (CNS) and transcription factor binding sites (TFBS) in seven pairs of LW opsin paralogs.ConclusionsOur analyses suggest opsin gene duplication and residues possibly associated with spectral tuning of LW-sensitive photoreceptors. We explore two mechanisms - positive selection and differential expression mediated by regulatory units in CNS – that may have contributed to the retention of LW opsin genes in Culicinae and Anophelinae. We discuss the evolution of mosquito LW opsins in the context of major Earth events and possible adaptation of mosquitoes to LW-dominated photo environments, and implications for mosquito control strategies based on disrupting vision-mediated behaviors.

【 授权许可】

CC BY   
© The Author(s). 2017