Genetic variability of the sws1 cone opsin gene among New World monkeys

Abstract

Vision is a major sense for Primates and the ability to perceive colors has great importance for the species ecology and behavior. Visual processing begins with the activation of the visual opsins in the retina, and the spectral absorption peaks are highly variable among species. In most Primates, LWS/MWS opsins are responsible for sensitivity to long/middle wavelengths within the visible light spectrum, and SWS1 opsins provide sensitivity to short wavelengths, in the violet region of the spectrum. In this study, we aimed to investigate the genetic variation on the sws1 opsin gene of New World monkeys (NWM) and search for amino acid substitutions that might be associated with the different color vision phenotypes described for a few species. We sequenced the exon 1 of the sws1 opsin gene of seven species from the families Callitrichidae, Cebidae, and Atelidae, and searched for variation at the spectral tuning sites 46, 49, 52, 86, 90, 93, 114, 116, and 118. Among the known spectral tuning sites, only residue 114 was variable. To investigate whether other residues have a functional role in the SWS1 absorption peak, we performed computational modeling of wild-type SWS1 and mutants A50I and A50V, found naturally among the species investigated. Although in silico analysis did not show any visible effect caused by these substitutions, it is possible that interactions of residue 50 with other sites might have some effect in the spectral shifts in the order of~14 nm, found among the NWM. We also performed phylogenetic reconstruction of the sws1 gene, which partially recovered the species phylogeny. Further studies will be important to uncover the mutations responsible for the phenotypic variability of the SWS1 of NWM, and how spectral tuning may be associated with specific ecological features such as preferred food items and habitat use.

Uniform trichromacy in Alouatta caraya and Alouatta seniculus: behavioural and genetic colour vision evaluation

“…Polymerase chain reactions (PCRs) were carried out to amplify exons 3 and 5 of the lws and mws opsin genes, and the exon 1 of the sws1 opsin gene, to identify the specific amino acid residues responsible for the opsins spectral tuning. The primers used to amplify the lws/mws and the sws1 exons were described elsewhere [18,37]; (Supplementary Table S1). PCRs were performed using High Fidelity Platinum Taq Polymerase, and PCR conditions are described in the Supplementary Table S2.…”

Detection of conspicuous and cryptic food by common marmosets (Callithrix jacchus): An evaluation of the importance of color and shape cues

“…The copyright holder for this preprint this version posted April 12, 2021. ; https://doi.org/10.1101/2021.04.11.439391 doi: bioRxiv preprint molecular approaches (Travis et al 1988;Tovée et al 1992;Hunt et al 1993;Wilder et al 1996;Shyue et al 1998;Kawamura et al 2001;Surridge and Mundy 2002;Pessoa et al 2005a;Freitag and Pessoa 2012;Pessoa et al 2014;Moreira et al 2015;Abreu et al 2019;Pessoa and Freitag 2019;Mantovani et al 2020), showing that C. jacchus expresses a tri-allelic visual polymorphism, that encodes M/L pigments with maximum absorption at 543 nm, 556 nm and 562 nm, and allows the existence of six visual phenotypes (three dichromats and three trichromats) in natural populations (Jacobs 2007).…”

Detection of conspicuous and cryptic food by marmosets (Callithrix jacchus): An evaluation of the importance of color and shape cues

“…The copyright holder for this preprint this version posted April 12, 2021. ; https://doi.org/10.1101/2021.04.11.439391 doi: bioRxiv preprint 6 molecular approaches (Travis et al 1988;Tovée et al 1992;Hunt et al 1993;Wilder et al 1996;Shyue et al 1998;Kawamura et al 2001;Surridge and Mundy 2002;Pessoa et al 2005a;Freitag and Pessoa 2012;Pessoa et al 2014;Moreira et al 2015;Abreu et al 2019;Pessoa and Freitag 2019;Mantovani et al 2020), showing that C. jacchus expresses a tri-allelic visual polymorphism, that encodes M/L pigments with maximum absorption at 543 nm, 556 nm and 562 nm, and allows the existence of six visual phenotypes (three dichromats and three trichromats) in natural populations (Jacobs 2007).…”