Fruit scent and observer colour vision shape food-selection strategies in wild capuchin monkeys

The senses play critical roles in helping animals evaluate foods, including fruits that can change both in colour and scent during ripening to attract frugivores. Although numerous studies have assessed the impact of colour on fruit selection, comparatively little is known about fruit scent and how olfactory and visual data are integrated during foraging. We combine 25 months of behavioural data on 75 wild, white-faced capuchins (Cebus imitator) with measurements of fruit colours and scents from 18 dietary plant species. We show that frequency of fruit-directed olfactory behaviour is positively correlated with increases in the volume of fruit odours produced during ripening. Monkeys with red-green colour blindness sniffed fruits more often, indicating that increased reliance on olfaction is a behavioural strategy that mitigates decreased capacity to detect red-green colour contrast. These results demonstrate a complex interaction among fruit traits, sensory capacities and foraging strategies, which help explain variation in primate behaviour.https://www.nature.com/articles/s41467-019-10250-9Published versio

Signal and reward in wild fleshy fruits : does fruit scent predict nutrient content?

The study examines the relationship between olfactory signals and nutrient rewards in 28 fruiting plant species in Madagascar. Previous work has shown that lemurs are the main seed dispersers in the ecosystem, relying on fruit scent to identify ripe fruits. The relative amounts of four chemical classes in fruit scent are measured using gas chromatography and mass spectrometry, as well as the relative amounts of sugar and protein in fruit pulp. The project tests the phylogenetic signal to examine whether closely related taxa tend to be similar, and compares the nutritional content of lemur‐ and bird‐dispersed fruits. The relationships reported here are across species, not within them

Identification of novel DNA-damage tolerance genes reveals regulation of translesion DNA synthesis by nucleophosmin

Cells cope with replication-blocking lesions via translesion DNA synthesis (TLS). TLS is carried out by low-fidelity DNA polymerases that replicate across lesions, thereby preventing genome instability at the cost of increased point mutations. Here we perform a twostage siRNA-based functional screen for mammalian TLS genes and identify 17 validated TLS genes. One of the genes, NPM1, is frequently mutated in acute myeloid leukaemia (AML). We show that NPM1 (nucleophosmin) regulates TLS via interaction with the catalytic core of DNA polymerase-eta (pol eta), and that NPM1 deficiency causes a TLS defect due to proteasomal degradation of pol eta. Moreover, the prevalent NPM1c+ mutation that causes NPM1 mislocalization in similar to 30% of AML patients results in excessive degradation of pol eta. These results establish the role of NPM1 as a key TLS regulator, and suggest a mechanism for the better prognosis of AML patients carrying mutations in NPM1

Identification of novel DNA-damage tolerance genes reveals regulation of translesion DNA synthesis by nucleophosmin

Cells cope with replication-blocking lesions via translesion DNA synthesis (TLS). TLS is carried out by low-fidelity DNA polymerases that replicate across lesions, thereby preventing genome instability at the cost of increased point mutations. Here we perform a twostage siRNA-based functional screen for mammalian TLS genes and identify 17 validated TLS genes. One of the genes, NPM1, is frequently mutated in acute myeloid leukaemia (AML). We show that NPM1 (nucleophosmin) regulates TLS via interaction with the catalytic core of DNA polymerase-eta (pol eta), and that NPM1 deficiency causes a TLS defect due to proteasomal degradation of pol eta. Moreover, the prevalent NPM1c+ mutation that causes NPM1 mislocalization in similar to 30% of AML patients results in excessive degradation of pol eta. These results establish the role of NPM1 as a key TLS regulator, and suggest a mechanism for the better prognosis of AML patients carrying mutations in NPM1

Fruit Scent: Biochemistry, Ecological Function, and Evolution

Fruit scent plays an important role in human preference and has thus been studiedprimarily in the context of agricultural science. In wild species, fruit scent haslong been speculated to play a role in mediating the mutualistic interactionbetween plants and fruit-eating animals that disperse their seeds. Yet untilrecently, empirical studies addressing this hypothesis have been all but absent.Studies in the past decade emphasized the ecological role of fruit scent as ananimal attractant, as well as its evolution as a ripeness signal. But data are stilllimited and many questions remain open. This chapter summarizes recent developmentsin the study of the chemical ecology and evolution of wild fruit scent.It explores the chemistry and biochemistry of fruit scent, its use by various important seed dispersal vectors, its evolution, and other functions it may fulfill.We end with recommendation for future studies, in the hope that the next decadewill be at least as fruitful as the previous one

The sensory ecology of fear: African elephants show aversion to olfactory predator signals

Human–elephant conflict is a persistent problem across elephant home ranges, that results in economic damage to commercial and subsistence farmers, and physical harm and death to humans and elephants. This problem is likely to intensify with increased development, dwindling of natural habitats, and climate change-driven environmental shifts. Various methods to mitigate human–elephant conflict have been employed, but to date these have been hampered by financial and logistical considerations. Based on the fact that African elephants are predated by lions and possess a remarkable sense of smell, we hypothesize that elephants are strongly averse to olfactory signals of lion presence, and that this can be utilized to create invisible barriers which elephants will not cross. We conducted a series of tests that show that lion dung is an effective deterrent of elephants. We conducted chemical analyses of lion dung and identified the main compounds. We then used synthetic mixtures containing these compounds, and show that they successfully elicit the deterrence effect, even in miniscule concentrations. These results indicate that elephants can be deterred using simple and low-concentration mixtures based on available commercial products, that can be developed into products that offer a safe, sustainable, and cost-effective method to mitigate human– elephant conflict

What drives seed dispersal effectiveness?

Abstract Seed dispersal is a critical phase in plant reproduction and forest regeneration. In many systems, the vast majority of woody species rely on seed dispersal by fruit‐eating animals. Animals differ in their size, movement patterns, seed handling, gut physiology, and many other factors that affect the number of seeds they disperse, the quality of treatment each individual seed receives, and consequently their relative contribution to plant fitness. The seed dispersal effectiveness framework (SDE) was developed to allow systematic and standardized quantification of these processes, offering a potential for understanding the large‐scale dynamics of animal–plant interactions and the ecological and evolutionary consequences of animal behavior for plant reproductive success. Yet, despite its wide acceptance, the SDE framework has primarily been employed descriptively, almost always in the context of local systems. As such, the drivers of variation in SDE across systems and the relationship between its components remain unknown. We systematically searched studies that quantified endozoochorous SDE for multiple animal species dispersing one or more plant species in a given system and offered an integrative examination of the factors driving variation in SDE. Specifically, we addressed three main questions: (a) Is there a tradeoff between high dispersal quality and quantity? (b) Does animal body mass affect SDE or its main components? and (c) What drives more variation in SDE, seed dispersal quality, or quantity? We found that: (a) the relationship between quality and quantity is mediated by body size; (b) this is the result of differential relationships between body mass and the two components, while total SDE is unaffected by body mass; (c)neither quality nor quantity explain more variance in SDE globally. Our results also highlight the need for more standardized data to assess large‐scale patterns in SDE