Comparative use of color vision for frugivory by sympatric species of platyrrhines

Ateles spp. and Alouatta spp. are often sympatric, and although they are mainly frugivorous and folivorous, respectively, they consume some of the same fruit species. However, they differ in terms of color vision, which is thought to be important for fruit detection. Alouatta spp. have routine trichromatic color vision, while Ateles spp. presents the classic polymorphism of platyrrhines: heterozygous females have trichromatic color vision, and males and homozygous females have dichromatic vision. Given these perceptual differences, one might expect Alouatta spp. to consume more reddish fruits than Ateles spp., since trichromats have an advantage for detecting fruits of that hue. Furthermore, since Ateles spp. have up to six different color vision phenotypes, as do most other platyrrhines, they might be expected to include fruits with a wider variety of hues in their diet than Alouatta spp. To test these hypotheses we studied the fruit foraging behavior of sympatric Alouatta palliata and Ateles geoffroyi in Costa Rica, and modeled the detectability of fruit via the various color vision phenotypes in these primates. We found little similarity in fruit diet between these two species (Morisita = 0.086). Furthermore, despite its polymorphism, A. geoffroyi consumed more reddish fruits than A. palliata, which consumed more greenish fruits. Our modeling results suggest that most fruit species included in the diet of A. geoffroyi can be discriminated by most color vision phenotypes present in the population. These findings show that the effect of polymorphism in platyrrhines on fruit detection may not be a disadvantage for frugivory. We suggest that routine trichromacy may be advantageous for other foraging tasks, such as feeding on young leaves.     

Sleep and nesting behavior in primates: A review

Sleep is a universal behavior in vertebrate and invertebrate animals, suggesting it originated in the very first life forms. Given the vital function of sleep, sleeping patterns and sleep architecture follow dynamic and adaptive processes reflecting trade-offs to different selective pressures. Here, we review responses in sleep and sleep-related behavior to environmental constraints across primate species, focusing on the role of great ape nest building in hominid evolution. We summarize and synthesize major hypotheses explaining the proximate and ultimate functions of great ape nest building across all species and subspecies; we draw on 46 original studies published between 2000 and 2017. In addition, we integrate the most recent data brought together by researchers from a complementary range of disciplines in the frame of the symposium “Burning the midnight oil” held at the 26th Congress of the International Primatological Society, Chicago, August 2016, as well as some additional contributors, each of which is included as a “stand-alone” article in this “Primate Sleep” symposium set. In doing so, we present crucial factors to be considered in describing scenarios of human sleep evolution: (a) the implications of nest construction for sleep quality and cognition; (b) the tree-to-ground transition in early hominids; (c) the peculiarities of human sleep. We propose bridging disciplines such as neurobiology, endocrinology, medicine, and evolutionary ecology, so that future research may disentangle the major functions of sleep in human and nonhuman primates, namely its role in energy allocation, health, and cognition.     

Interface Biology of Implants

Implants are widely used in various clinical disciplines to replace or stabilize organs. The challenge for the future is to apply implant materials to specifically control the biology of the surrounding tissue for repair and regeneration. This field of research is highly interdisciplinary and combines scientists from technical and life sciences disciplines. To successfully apply materials for regenerative processes in the body, the understanding of the mechanisms at the interface between cells or tissues and the artificial material is of critical importance. The research focuses on stem cells, design of material surfaces, and mechanisms of cell adhesion. For the third time around 200 scientists met in Rostock, Germany for the international symposium “Interface Biology of Implants”. The aim of the symposium is to promote the interdisciplinary dialogue between the scientists from the different disciplines to develop smart implants for medical use. In addition, researchers from basic sciences, notably cell biology presented new findings concerning mechanisms of cell adhesion to stimulate research in the applied field of implant technology.     

Color vision pigment frequencies in wild tamarins (Saguinus spp.)

The adaptive importance of polymorphic color vision found in many New World and some prosimian primates has been discussed for many years. Polymorphism is probably maintained in part through a heterozygote advantage for trichromatic females, as such individuals are observed to have greater foraging success when selecting ripe fruits against a background of forest leaves. However, recent work also suggests there are some situations in which dichromatic individuals may have an advantage, and that variation in color vision among individuals possessing different alleles may also be significant. Alleles that confer a selective advantage to individuals are expected to occur at a higher frequency in populations than those that do not. Therefore, analyzing the frequencies of color vision alleles in wild populations can add to our understanding of the selective advantages of some color vision phenotypes over others. With this aim, we used molecular techniques to determine the frequencies of color vision alleles in 12 wild tamarin groups representing three species of the genus Saguinus. Our results show that allele frequencies are not equal, possibly reflecting different selective regimes operating on different color vision phenotypes.     

Diurnality and cone photopigment polymorphism in strepsirrhines: examination of linkage in Lemur catta

Trichromatic color vision is routine among catarrhine primates, but occurs only as a variant form of color vision in some individuals in most platyrrhine genera. This arises from a fundamental difference in the organization of X-chromosome cone opsin genes in these two lineages: catarrhines have two opsin genes specifying middle- and long-wavelength-sensitive cone pigments, while platyrrhines have only a single gene. Some female platyrrhine monkeys achieve trichromacy because of a species polymorphism that allows the possibility of different opsin gene alleles on the two X-chromosomes. Recently, a similar opsin gene polymorphism was detected in some diurnal strepsirrhines, while at the same time appearing to be absent in any nocturnal genera. The aim of this study was to assess whether cone pigment polymorphism is inevitably linked to diurnality in strepsirrhines. Cone photopigments were measured in a species usually classified as diurnal, the ring-tailed lemur (Lemur catta), using electroretinogram flicker photometry, a noninvasive electrophysiological procedure. Each of 12 animals studied was found to have the same middle-wavelength cone pigment, with peak sensitivity at about 547 nm. In conjunction with earlier results, this implies that cone pigment polymorphism is unlikely to exist in this species and that, accordingly, such variation is not a consistently predictable feature of vision in diurnal strepsirrhines.     

Interface Biology of Implants

Implants are widely used in various clinical disciplines to replace or stabilize organs. The challenge for the future is to apply implant materials to specifically control the biology of the surrounding tissue for repair and regeneration. This field of research is highly interdisciplinary and combines scientists from technical and life sciences disciplines. To successfully apply materials for regenerative processes in the body, the understanding of the mechanisms at the interface between cells or tissues and the artificial material is of critical importance. The research focuses on stem cells, design of material surfaces, and mechanisms of cell adhesion. For the third time around 200 scientists met in Rostock, Germany for the international symposium “Interface Biology of Implants.” The aim of the symposium is to promote the interdisciplinary dialogue between the scientists from the different disciplines to develop smart implants for medical use. In addition, researchers from basic sciences, notably cell biology presented new findings concerning mechanisms of cell adhesion to stimulate research in the applied field of implant technology.Key words: interface, implant, stem cells, adhesion, mechanics, surface, biomaterialMedical implants play a growing role in routine clinical practice. In addition to replace or stabilize injured tissue permanently or transiently, the application of implant materials to stimulate the regeneration of tissue is becoming a challenge in the field of regenerative medicine. The use of implant materials is based on the idea that biomaterials function not only as mechanical support for cells and tissue but also provide a matrix to induce signal transduction in the cells that control complex molecular mechanisms responsible for proliferation und differentiation. In this context, the interface between artificial materials and living cells or tissue is an exciting field of great scientific interest and constitutes one of the most dynamic and expanding field in science and technology. Progress in this field is mainly driven by the fundamental importance for clinical applications. The research is characterized by a multidisciplinary collaboration between physics, engineers, biologists and clinicians.In May 2009, for the third time after 2003 and 2006 around 200 scientists met in Rostock-Warnemünde for the symposium “Interface Biology of Implants” to discuss biointerface processes at a fundamental level. The main goals of this symposium are to simulate the interdisciplinary dialogue between scientists of the different disciplines and to introduce current knowledge of basic research in cell biology and material science into the applied field of implant technology. The programme was organized in invited presentations of 20 internationally renowned scientists and complemented by short talks of mostly young scientists selected from the submitted abstracts. In addition, 80 posters presented latest results in this multidisciplinary field.The symposium was opened with a keynote lecture presented by Hartmut Hildebrand (Lille). He gave an overview about the 7,000 years old history of application of implant materials. Rare photographs were shown which demonstrated that in these early times prostheses mainly made from metallic materials were used to restore teeth, extremities and the skull of the human body. These old documents stressed the historical relevance of medical application of implant materials.The symposium on two days was composed of four sessions covering the interdisciplinary research in the field. The session “Stem cells and biomaterials” discussed the biological response and signalling mechanism of stem cells in the interaction with a material surface. The session “Bioactivation of implant surfaces” focussed on the tailoring of surfaces to control the cell physiology. To stimulate the field by recent data in basic cell biology, talks were presented in the third session, dealing with molecular mechanisms involved in cell adhesion. A special session dealt with the role and mechanism of controlling cells by mechanics.     

Mutational changes in S-cone opsin genes common to both nocturnal and cathemeral Aotus monkeys

Aotus is a platyrrhine primate that has been classically considered to be nocturnal. Earlier research revealed that this animal lacks a color vision capacity because, unlike all other platyrrhine monkeys, Aotus has a defect in the opsin gene that is required to produce short-wavelength sensitive (S) cone photopigment. Consequently, Aotus retains only a single type of cone photopigment. Other mammals have since been found to show similar losses and it has often been speculated that such change is in some fashion tied to nocturnality. Although most species of Aotus are indeed nocturnal, recent observations show that Aotus azarai, an owl monkey species native to portions of Argentina and Paraguay, displays a cathemeral activity pattern being active during daylight hours as frequently as during nighttime hours. We have sequenced portions of the S-cone opsin gene in A. azarai and Aotus nancymaae, the latter a typically nocturnal species. The S-cone opsin genes in both species contain the same fatal defects earlier detected for Aotus trivirgatus. On the basis of the phylogenetic relationships of these three species these results imply that Aotus must have lost a capacity for color vision early in its history and they also suggest that the absence of color vision is not compulsively linked to a nocturnal lifestyle.     

Color distance derived from a receptor model of color vision in the honeybee

A model calculation is presented for investigating the domain between the two well-examined fields of color vision in the bee, i.e. choice behavior with respect to color stimuli, and photoreceptor physiology. Based on the properties of the receptors, the model explains quantitatively the results obtained in color discrimination experiments. The model predicts curved lines which connect the loci of most similar color stimuli in the receptor plane and makes quantitative predictions about the magnitude of the Bezold-Abney hue shift. A measure for color difference is derived from the number of the just-noticeabledifference (jnd) steps determined by the noise thresholds of the photoreceptor cells.     

Mate Choice and Colored Beak Spots of King Penguins

The theory of sexual selection explains sexual dimorphisms in ornaments used in mate choice. Mutual mate choice is a form of sexual selection that might explain sexually monomorphic ornamental traits. Under mutual mate choice, both sexes select partners based on the same ornament. We tested the mutual mate choice hypothesis in a mutually ornamented seabird, the king penguin (Aptenodytes patagonicus), through observations of the pair formation process in the field. Penguins that were ready to mate formed displaying pairs at the edge of the colony. Some of these pairs moved into the breeding colony and produced an egg (definitive pairs), while other pairs separated and often switched to another potential partner (temporary pairs). Colored ornaments were quantified using color vision modeling. We predicted that birds would mate assortatively by their elaborate ornamental traits (specifically, colors of beak spots, auricular patches of feathers, and breast patch of feathers). We also predicted that definitive pairs would exhibit more elaborate ornaments than temporary pairs. The mutual mate choice hypothesis was supported by assortative pairing for color of the beak spots, but not for color or size of the auricular patches or for the color of the breast patch. An alternative hypothesis was also consistent with our results, that female choice for a male ornamental trait and superior female condition associated with the same trait produced assortative pairing patterns. More UV‐ and yellow‐colored beak spots for females in definitive than temporary pairs supported the female choice hypothesis over the mutual mate choice hypothesis, but previous experimental results from altered beak spot colors supported the latter. Evidence to date thus supports both the mutual mate choice and female choice hypotheses.     

Evolution and genetic architecture of disassortative mating at a locus under heterozygote advantage

The evolution of mate choice is a major topic in evolutionary biology because it is thought to be a key factor in trait and species diversification. Here, we aim at uncovering the ecological conditions and genetic architecture enabling the puzzling evolution of disassortative mating based on adaptive traits. This rare form of mate choice is observed for some polymorphic traits but theoretical predictions on the emergence and persistence of this behavior are largely lacking. Thus, we developed a mathematical model to specifically understand the evolution of disassortative mating based on mimetic color pattern in the polymorphic butterfly Heliconius numata. We confirm that heterozygote advantage favors the evolution of disassortative mating and show that disassortative mating is more likely to emerge if at least one allele at the trait locus is free from any recessive deleterious mutations. We modeled different possible genetic architectures underlying mate choice behavior, such as self‐referencing alleles, or specific preference or rejection alleles. Our results showed that self‐referencing or rejection alleles linked to the color pattern locus enable the emergence of disassortative mating. However, rejection alleles allow the emergence of disassortative mating only when the color pattern and preference loci are tightly linked.     

Integration of structural and functional genomics

This paper introduces a special issue of Animal Genetics , which is devoted to the recent symposium held at Iowa State University entitled 'Integration of Structural and Functional Genomics'. We describe issues and needs that confront the animal genomics community, and describe how this symposium was structured to address these issues by improving communication and collaboration across species and disciplines. The session topics and oral presentations are briefly described for all invited speakers.     

金乌贼的生物学特性及增殖技术

金乌贼广泛分布于俄罗斯远东海海域,中国沿海,日本本州、四国、九州海域,朝鲜西海岸、南海岸海域,以及菲律宾群岛海域。它不仅是中国沿岸渔业的重要捕捞对象,也是一种具有较高经济价值的优良品种。本文综述了国内外关于金乌贼生物学和增殖技术的研究,着重介绍了金乌贼形态学、渔业生物学、行为生态学及遗传学的研究内容,探讨了金乌贼受精卵的人工孵化、幼体发育及产卵基的材质、形状、稳定性和颜色等对金乌贼附卵的影响。提出了目前在金乌贼增殖技术研究中存在的一些问题以及今后的研究方向。     

Evolutionary changes in Primate sensory capacities

This paper is a review of laboratory research on sensory capacities in Primates with emphasis on evolutionary changes in the capacities. Man, great apes and Old World monkeys have virtually identical color vision, a result consistent with the generalization that these relatively diverse species have reached a plateau in the evolution of color vision, Capuchin and squirrel monkeys are protonomalous trichromats thus suggesting a widespread relative insensitivity to red among New World monkeys. Of the prosimians, only tree shrews have been extensively tested for color vision capability and they are deuteranopic dichromats.There is clear evidence of a decline in the upper audible frequencies and the most audible frequencies during Primate evolution. Although the olfactory portion of the brain has declined markedly in relative size during Primate evolution, there is no corresponding research showing difference in olfactory sensitivity across the living Primate genera. Existing research on gustatory sensitivity in Primates is too limited to permit any evolutionary conclusions.     

A quantitative model of successive color induction in the honeybee

Intensity discrimination experiments are performed with individual walking honeybees trained to color stimuli (UV, blue and green) of constant intensity. The choice behavior to stimuli of identical wavelength spectrum but different intensities is tested. A graded choice behavior is found. The training intensity is chosen with the highest probability in most cases. Phototaxis as well as brightness discrimination can be excluded. The choice behavior is explained exclusively by discrimination of chromaticness (hue and saturation) according to the Bezold-Brücke shift.The bees adapt to the chromatic stimuli during their choices. From the behavioral data, it is concluded that in adaptation, adjustment in photoreceptor sensitivity in one receptor also affects the sensitivity of the other receptors (co-adaptation). The linear adaptation model corresponding to the von Kries Coefficient Law used up to now to describe adaptation to white light in the honeybee does not describe this type of adaptation.A quantitative model of adaptation to chromatic stimuli extending the linear adaptation model is developed.The most reasonable mechanism of co-adaptation is optical coupling by lateral filtering. Other mechanisms such as electrical coupling are unlikely, since their effects on color vision would lead to effects inconsistent with Graßmann's Laws.     

APBioNet: the Asia-Pacific regional consortium for bioinformatics

Bioinformatics and computational biology, along with the related fields of genomics, proteomics, functional genomics and systems biology are new wave scientific disciplines that harness composite computational power across networks to advance biological knowledge at the most basic level and to direct traditional laboratory-based research efforts in the biomedical sciences. 'Fostering the growth of bioinformatics and allied disciplines in the Asia-Pacific region' is the motto of the first regional bioinformatics society, the Asia-Pacific Bioinformatics Network (APBioNet). APBioNet addresses the issues of hardware, software, databases and networks pertaining to bioinformatics, with the additional layer of pertinent education, training and research. Recent milestones achieved include hosting an international bioinformatics symposium in Asia and setting up large-scale regional grid-computing projects.     

Statistical and molecular analyses of evolutionary significance of red-green color vision and color blindness in vertebrates

Red-green color vision is strongly suspected to enhance the survival of its possessors. Despite being red-green color blind, however, many species have successfully competed in nature, which brings into question the evolutionary advantage of achieving red-green color vision. Here, we propose a new method of identifying positive selection at individual amino acid sites with the premise that if positive Darwinian selection has driven the evolution of the protein under consideration, then it should be found mostly at the branches in the phylogenetic tree where its function had changed. The statistical and molecular methods have been applied to 29 visual pigments with the wavelengths of maximal absorption at approximately 510-540 nm (green- or middle wavelength-sensitive [MWS] pigments) and at approximately 560 nm (red- or long wavelength-sensitive [LWS] pigments), which are sampled from a diverse range of vertebrate species. The results show that the MWS pigments are positively selected through amino acid replacements S180A, Y277F, and T285A and that the LWS pigments have been subjected to strong evolutionary conservation. The fact that these positively selected M/LWS pigments are found not only in animals with red-green color vision but also in those with red-green color blindness strongly suggests that both red-green color vision and color blindness have undergone adaptive evolution independently in different species.     

Shifting plant phenology in response to global change

Plants are finely tuned to the seasonality of their environment, and shifts in the timing of plant activity (i.e. phenology) provide some of the most compelling evidence that species and ecosystems are being influenced by global environmental change. Researchers across disciplines have observed shifting phenology at multiple scales, including earlier spring flowering in individual plants and an earlier spring green-up' of the land surface revealed in satellite images. Experimental and modeling approaches have sought to identify the mechanisms causing these shifts, as well as to make predictions regarding the consequences. Here, we discuss recent advances in several fields that have enabled scaling between species responses to recent climatic changes and shifts in ecosystem productivity, with implications for global carbon cycling.     

Factors Affecting Group Spread within Wild Mixed-Species Troops of Saddleback and Mustached Tamarins

We examined group spread and interindividual spacing within wild mixed-species troops of saddleback (Saguinus fuscicollis) and mustached (Saguinus mystax) tamarins. Mustached tamarin groups were spread over larger areas than those of saddleback tamarins. Group size and behavior affected group spread and interspecific proximity: larger groups of both species were dispersed over greater areas, and the larger troop had the lowest degree of interspecific proximity. Behavior also affected group spread and interspecific proximity: when traveling individuals were spread over a larger area, and the distance between heterospecifics was greater than when stationary. We examined spatial proximity using data on the distance from nearest neighbor. Overall, distance to nearest neighbor was not affected by group size. Based on specific behaviors, foraging saddleback tamarins were significantly nearer conspecifics than to mustached tamarins. Tamarins have polymorphic color vision, and trichromats—having 3 types of visual pigment—versus dichromatic individuals—with two types of pigment—may be better at perceiving yellow or russet colored predators and conspecifics than their dichromatic counterparts are. Color vision status affected spatial positioning, with vigilant trichromats being further from their neighbors than their dichromatic conspecifics were. We discuss the findings with respect to the ecology of the species. Specifically, interspecific differences in group spread and spatial proximity are related to differences in the supports used, and the effect of troop size on interspecific proximity is related to increased resource competition. The finding that trichromats are further from their neighbors represents the first example of a behavioral correlate of color vision ability in a wild species with polymorphic color vision, and is explained through the perception of predation risk.     

Opsin Genes and Visual Ecology in a Nocturnal Folivorous Lemur

Primate color vision has traditionally been examined in the context of diurnal activity, but recent genetic and ecological studies suggest that color vision plays a role in nocturnal primate behavior and ecology as well. In this study, we united molecular analyses of cone visual pigment (opsin) genes with visual modeling analyses of food items to explore the evolution of color vision in the folivorous woolly lemur (genus Avahi). Previous studies have shown that leaf quality, e.g., protein content, leaf toughness, and protein/toughness ratio, is significantly correlated with green-red and blue-yellow chromatic differences, suggesting a potential role of color in leaf discrimination in Avahi, and, consequently, a potential adaptive advantage to color vision in this taxon. Phylogenetic selection tests determined that the strength of selection on the SWS1 opsin gene to retain blue-sensitive SWS cones did not significantly differ in Avahi compared to day-active primates. Genotyping of the M/LWS opsin gene in 60 individuals from nine species found that the 558-nm-sensitive (red-sensitive) allele is conserved across all Avahi. Finally, we measured spectral reflectance from five species of young leaves consumed by Avahi and background foliage in Ranomafana National Park and modeled performance of possible S and M/L pigment pairs for detecting these food items under different nocturnal illuminations (e.g. twilight, moonlight). We found that the observed cone pigment pair in Avahi was optimally tuned for color-based detection of young green leaves in all nocturnal light environments, suggesting a potential adaptive role of nocturnal color vision in selection for dichromacy in this genus.