Lycium barbarum glycopeptide(wolfberry extract)slows N-methyl-N-nitrosourea-induced degradation of photoreceptors

Photoreceptor cell degeneration leads to blindness, for which there is currently no effective treatment. Our previous studies have shown that Lycium barbarum(L. barbarum) polysaccharide(LBP) protects degenerated photoreceptors in rd1, a transgenic mouse model of retinitis pigmentosa. L. barbarum glycopeptide(Lb GP) is an immunoreactive glycoprotein extracted from LBP. In this study, we investigated the potential protective effect of Lb GP on a chemically induced photoreceptor-degenerative mouse model. Wild-type mice received the following: oral administration of Lb GP as a protective pre-treatment on days 1–7;intraperitoneal administration of 40 mg/kg N-methylN-nitrosourea to induce photoreceptor injury on day 7;and continuation of orally administered Lb GP on days 8–14. Treatment with Lb GP increased photoreceptor survival and improved the structure of photoreceptors, retinal photoresponse, and visual behaviors of mice with photoreceptor degeneration. Lb GP was also found to partially inhibit the activation of microglia in N-methyl-N-nitrosourea-injured retinas and significantly decreased the expression of two pro-inflammatory cytokines. In conclusion, Lb GP effectively slowed the rate of photoreceptor degeneration in N-methyl-N-nitrosourea-injured mice, possibly through an anti-inflammatory mechanism, and has potential as a candidate drug for the clinical treatment of photoreceptor degeneration.

白蜡窄吉丁嗅觉和视觉研究概述

白蜡窄吉丁Agrilus planipennis Fairmaire是一种国际性检疫害虫,其自然分布于东北亚国家,20世纪初相继在美国和加拿大被发现并造成严重危害。20世纪60年代在我国东北和华北地区发生最为严重,而后在天津、北京、辽宁、吉林等地危害加重。其在我国主要危害的是引进的北美白蜡树种,如美国红梣(洋白蜡)Fraxinus pennsylvanica Marsh.、毡毛梣(绒毛白蜡)F.velutina Torr与美国白蜡F.americana Linn.等,目前白蜡窄吉丁的防治是森林害虫防控研究的重点内容之一。感觉器官在昆虫生命活动中发挥着重要的作用,特别是嗅觉和视觉在白蜡窄吉丁交配、产卵与寄主定位过程中起到了关键的作用。本文综述了昆虫视觉和嗅觉感受系统和感受机制的研究现状,总结了白蜡窄吉丁嗅觉和视觉的应用研究,列出了白蜡窄吉丁信息素与寄主植物挥发物的鉴定结果以及嗅觉感受蛋白和视觉感受蛋白的鉴定情况。同时对白蜡窄吉丁视觉和嗅觉的综合作用机理研究提出了展望,旨在为完善利用嗅觉和视觉防治白蜡窄吉丁的研究提供基础。

Analysis of phototactic responses in Spodoptera frugiperda using Helicoverpa armigera as control

Light traps are widely utilized to monitor and manage insect pest populations.In late 2018,the fall armyworm(FAW),Spodoptera frugiperda,invaded China through Yunnan Province representing a huge threat to grain production.To estimate the efficiency of light traps on FAW moths,we first identified the opsin genes from FAW by using the transcriptome.Phylogenetic analysis indicated that the four opsins of FAW were clustered with those of other Noctuidae species.The expressed levels of opsins in S.frugiperda were lower than in Helicoverpa armigera,suggesting a different phototactic response between the two species.Then,we determined the phototactic behavior of FAW using H.armigera as a control,which is widely monitored and managed using light traps in China.Our results indicated that the two moths species showed significantly different phototactic behavior and both female and male FAW displayed faster flight-to-light speed than H.armigera.This may be due to a faster flight capacity in FAW compared to H.armigera.However,the capture rate of both female and male of S.frugiperda was significantly lower than that of H.armigera,which was consistent with the expression levels of opsins.These results support the positive phototaxis of S.frugiperda moths and suggest light traps could be used for monitoring and managing the pests,but with a lower efficiency than H.armigera.

Predicted visual sensitivity for short-wavelength light in the brood parasitic cuckoos of New Zealand

Different lineages of birds show varying sensitivity to light in the ultraviolet(UV) wavelengths.In several avian brood parasite-host systems,UV-re ectance of the parasite eggs is important in discriminating own from foreign eggs by the hosts.In turn,for parasitic females it may be bene cial to lay eggs into host clutches where eggs more closely match the parasite's own eggs.While the visual sensitivities of numerous cuckoo-and cowbird-host species have been described,less is known about those of their respective parasites.Such sensory characterization is important for understanding the mechanisms underlying potential perceptual coevolutionary processes between hosts and parasites,as well as for better understanding each species' respective visual sensory ecology.We sequenced the short wavelength-sensitive type 1(SWS1) opsin gene to predict the degree of UVsensitivity in both of New Zealand's obligate parasitic cuckoo species,the Shining Cuckoo(Chalcites [Chrysococcyx] lucidus) and the Long-tailed Cuckoo(Urodynamis [Eudynamis] taitensis).We show that both species are predicted to possess SWS1 opsins with maximal sensitivity in the human-visible violet portion of the short-wavelength light spectrum,and not in the UV.Future studies should focus on the(mis)matching in host-parasite visual sensitivities with respect to host-parasite egg similarity as perceived by the avian visual system and the behavioral outcomes of foreign egg rejection.

Molecular Evolution of Visual Opsin Genes during the Behavioral Shifts between Different Photic Environments in Geckos

Reptiles are the most morphologically and physiologically diverse tetrapods,with the squamates having the most diverse habitats.Lizard is an important model system for understanding the role of visual ecology,phylogeny and behavior on the structure of visual systems.In this study,we compared three opsin genes(RH2,LWS and SWS1)among 49 reptile species to detect positively selected genes as well as amino acid sites.Our results indicated that visual opsin genes have undergone divergent selection pressures in all lizards and RH2 and LWS suffered stronger positive selection than SWS1.Twelve positively selected sites were picked out for RH2 and LWS.Moreover,many diagnostic sites were found between geckos and non-gecko lizards,most of which were located near the positively selected sites and some of them have already been reported to be responsible for significant shifts of the wavelength of maximum absorption(λ_(max)).The results indicated that the gecko lineage accelerated the evolution of these genes to adapt to the dim-light environment or nocturnality as well as the switch between nocturnality and diurnality.

Stimulating brain tissue with bright light alters functional connectivity in brain at the resting state

Light is considered to modulate human brain function only via the retinal pathway, a way of thinking that we aimed to challenge in the present study. Literature provides evidence of inherent phototransduction for instance in the rat brain and there are potentially photosensitive opsin proteins like melanopsin and panopsin in the human brain too. In order to investigate a short term response, functional connectivity changes of the brain were studied in the resting state with functional magnetic resonance imaging during bright light stimulus via the ear canal. Lateral visual and sensorimotor networks showed increased functional connectivity in the light stimulus group compared to sham controls. The lateral visual network demonstrated slowly increasing functional connectivity on average and the same temporal characteristic was shared by diverse cerebellar brain regions. Hypothetical phototransduction signal pathways leading to responses in brain function are discussed as well as some observed effects and their possible link to the findings. Findings from this study together with the plausible photoreceptor candidates suggest that the brain possesses photosensitive properties, which will have interesting implications for the modulation of brain function and understanding the basic physiology of the brain.

The Antidepressant Effect of Light Therapy from Retinal Projections

Observations from clinical trials have frequently demonstrated that light therapy can be an effective therapy for seasonal and non-seasonal major depression. Despite the fact that light therapy is known to have several advantages over antidepressant drugs like a low cost,minimal side-effects, and fast onset of therapeutic effect,the mechanism underlying light therapy remains unclear.So far, it is known that light therapy modulates mood states and cognitive functions, involving circadian and noncircadian pathways from retinas into brain. In this review,we discuss the therapeutic effect of light on major depression and its relationship to direct retinal projections in the brain. We finally emphasize the function of the retino-raphe projection in modulating serotonin activity,which probably underlies the antidepressant effect of light therapy for depression.

Sensory and immune genes identification and analysis in a widely used parasitoid wasp Trichogramma dendrolimi （Hymenoptera： Trichogrammatidae）

Trichogramma dendrolimi Matsumura （Hymenoptera： Trichogrammatidae） is one of the preponderant egg parasitoids of Dendrolimus spp., which are important defoliators of coniferous forests. This parasitoid wasp has been widely released to control pine caterpillar and other lepidopteran pests, but its control efficiency needs to be improved. Sensory systems are crucial for T dendrolimi to locate hosts, and immunity is probably involved after egg deposition in the host cavity; however, few reports have focused on the molecular mechanism of olfactory detection and survival of T. dendrolimi. It is necessary to identify these genes before further functional research is conducted. In this study, we assembled and analyzed the transcriptome of T. dendrolimi using next-generation sequencing technology. The sequencing and assembly resulted in 38 565 contigs with N50 of 3422 bp. Sequence comparison indicate that T dendrolimi sequences are very similar to those of another parasitoid Nasonia vitripennis. Then the olfactory, vision, and immune- related gene families were identified, and phylogenetic analyses were performed with these genes from T. dendrolimi and other model insect species. Furthermore, phylogenetic tree with odorant binding proteins of T. dendrolimi and their host Dendrolimus was constructed to determine whether convergent evolution exists. These genes can be valid targets for further gene function research. The present study may help us to understand host location and survival mechanisms of T dendrolimi and to use them more efficiently for pest control in the future.

Differentially-expressed opsin genes identified in Sinocyclocheilus cavefish endemic to China

Eye degeneration is a common troglomorphic character of cave-dwelling organisms. Comparing the morphology and molecular biology of cave species and their close surface relatives is a powerful tool for studying regressive eye evolution and other adaptive phenotypes. We compared two co-occurring and closely-related species of the fish genus Sinocyclocheilus, which is endemic to China and includes both surface- and cave-dwelling species. Sinocyclocheilus tileihornes, a cave species, had smaller eyes than Sinocyclocheilus angustiporus, a surface species. Histological and immunohistochemical analyses revealed that the cave- fish had shorter cones and more disorderly rods than did the surface-dwelling species. Using quantitative PCR and in situ hybri- dization, we found that rhodopsin and a long-wavelength sensitive opsin had significantly lower expression levels in the cavefish. Furthermore, one of two short-wavelength-sensitive opsins was expressed at significantly higher levels in the cavefish. Changes in the expression ofopsin genes may have played a role in the degeneration of cavefish eyes [Current Zoology 59 （2）： 170-174, 2013].

Reviewing guppy color vision： integrating the molecular and physiological variation in visual tuning of a classic system for sensory drive

Sensory drive predicts coevolution of mate choice signals with the sensory systems detecting those sig nals. Guppies are a classic model for sensory drive as mate preferences based on coloration differ across individuals and populations. A large body of work has identified variation in color vision, yet we lack a dir ect tie between how such variation in color vision influences variation in color preference. Here we bring together studies that have investigated guppy vision over the past 40years to： （1） highlight our current understanding of where variation occurs in the guppy color vision pathway and （2） suggest future ave nues of research into sources of visual system variation that could influence guppy color preference. This will allow researchers to design careful studies that couple measures of color preference with measures of visual system variation from the same individual or population. Such studies will finally provide im portant answers as to what sets the direction and speed of mate preference evolution via sensory drive.

Photokinesis and Djopsin gene expression analysis during the regeneration of planarian eyes

Planarians provide the ideal model for studying eye development,with their simple eye structure and exceptionally rapid regeneration.Here,we observed the eye morphogenesis,photophobic behavior,spectral sensitivity and expression pattern of Djopsin in the freshwater planarian Dugesia japonica.The results showed that:(i)Djopsin encoding the putative protein belonged to the rhabdomeric opsins group and displayed high conservation during animal evolution;(ii)planarians displayed diverse photophobic response to different visible wavelengths and were more sensitive to light blue(495 nm)and yellow(635 nm);(iii)the morphogenesis and functional recovery of eyes were related to the expression pattern of Djopsin during head regeneration;and(iv)Djopsin gene plays a major role in functional recovery during eye regeneration and visual system maintenance in adult planarians.

Opsin3糖基化位点的鉴定及糖基化修饰功能

为鉴定Opsin3(OPN3)的糖基化位点,通过使用衣霉素(tunicamycin)以及N-糖酰胺酶F(PNGase F)处理发现OPN3存在糖基化修饰;通过预测以及蛋白质氨基酸位点点突变鉴定OPN3的糖基化位点;利用SNAP标签蛋白构建了SNAP-Opsin3(SNAP-OPN3)重组蛋白,使用SNAP-OPN3重组蛋白进行糖基化修饰对OPN3功能影响的研究。在表达SNAP-OPN3重组蛋白后,使用SNAP-tag的反应底物SNAP-Surface;549以及SNAP-Cell;OregonGreen;通过荧光共聚焦显微镜观察OPN3以及OPN3糖基化位点突变体是否能够成熟转运至细胞膜。结果表明,OPN3的N82位点为OPN3的糖基化位点;SNAP标签不影响OPN3功能的正常发挥;使用SNAP反应底物可以清楚地观察到糖基化位点突变的OPN3不能正常转运至细胞膜。本研究首次鉴定了OPN3的糖基化位点,并构建了SNAP-OPN3重组蛋白,发现SNAP标签并不影响OPN3的成熟转运,并利用SNAP底物验证了糖基化修饰影响OPN3蛋白的成熟转运。

Cichlid fish visual systems: mechanisms of spectral tuning

Hundreds of species of cichlid fishes have evolved in the Great Lakes of Africa.These colorful fishes are known for their ecological diversity.Here,we discuss the diversity of their visual systems.Cichlids have seven unique cone opsin genes,which produce visual pigments sensitive from the ultraviolet to the red end of the spectrum.Different species typically express three visual pigments to produce a trichromatic visual system.Because species differ in which sets of opsin genes they express,visual sensitivities can differ widely.In addition to the large visual pigment shifts from changing gene expression,cichlids can also more finely tune visual pigments through altera-tions in opsin amino acid sequence.Both of these tuning mechanisms likely play an important role in cichlid ecology and could contribute to the evolution of cichlid diversity through speciation.

A neuropsin-based optogenetic tool for precise control of Gq signaling

G_(q)-coupled receptors regulate numerous physiological processes by activating enzymes and inducing intracellular Ca^(2+)signals.There is a strong need for an optogenetic tool that enables powerful experimental control over G_(q) signaling.Here,we present chicken opsin 5(cOpn5)as the long sought-after,single-component optogenetic tool that mediates ultra-sensitive optical control of intracellular G_(q) signaling with high temporal and spatial resolution.Expressing cOpn5 in HEK 293T cells and primary mouse astrocytes enables blue light-triggered,G_(q)-dependent Ca^(2+) release from intracellular stores and protein kinase C activation.Strong Ca^(2+) transients were evoked by brief light pulses of merely 10 ms duration and at 3 orders lower light intensity of that for common optogenetic tools.Photostimulation of cOpn5-expressing cells at the subcellular and single-cell levels generated fast intracellular Ca^(2+)transition,thus demonstrating the high spatial precision of cOpn5 optogenetics.The cOpn5-mediated optogenetics could also be applied to activate neurons and control animal behavior in a circuit-dependent manner.cOpn5 optogenetics may find broad applications in studying the mechanisms and functional relevance of G_(q) signaling in both non-excitable cells and excitable cells in all major organ systems.