Biology subjects

Perry, S.

Publications and source records attributed to Perry, S..

26 records · Page 2Linked to original sources

bioRxiv2020

Fitness benefits of providing services to others: Sociality predicts survival in a neotropical primate

Across multiple species of social mammals, a growing number of studies have found that that individual sociality is associated with survival. In long-lived species, like primates, lifespan is one of the main components of fitness. We used 18 years of data from the Lomas Barbudal Monkey project to quantify social integration in 11 capuchin (Cebus capucinus) groups and tested whether female survivorship was associated with females tendencies to interact with three types of partners: (1) all group members, (2) adult females, (3) adult males. We found strong evidence that females who engaged more with other females in affiliative interactions and foraged in close proximity experienced increased survivorship. We found some weak evidence that females might also benefit from engaging in more support in agonistic contexts with other females. These benefits were evident in models that account for the females rank and group size. Female interactions with all group members also increased survival, but the estimates of the effects were more uncertain. In interactions with adult males, only females who provided more grooming to males survived longer. The results presented here suggest that social integration may result in survival-related benefits. Females might enjoy these benefits through exchanging grooming for other currencies, such as coalitionary support or tolerance.

animal behavior and cognition↗

bioRxiv2020

Beyond orphaned infants: novel effects of maternal death in wild primates

Primate offspring often depend on their mothers well beyond the age of weaning, and offspring that experience maternal death in early life can suffer substantial reductions in fitness across the lifespan. Here we leverage data from eight wild primate populations (seven species) to examine two underappreciated pathways linking early maternal death and offspring fitness that are distinct from direct effects of orphaning on offspring survival. First, we show that, for five of the seven species, offspring face reduced survival during the years immediately preceding maternal death, while the mother is still alive. Second, we identify an intergenerational effect of early maternal loss in three species (muriquis, baboons, and blue monkeys), such that early maternal death experienced in one generation leads to reduced offspring survival in the next. Our results have important implications for the evolution of slow life histories in primates, as they suggest that maternal condition and survival are more important for offspring fitness than previously realized.

evolutionary biology↗

bioRxiv2020

Capuchin monkey rituals: an interdisciplinary study of form and function

Many white-faced capuchin monkey dyads in Lomas Barbudal, Costa Rica, practice idiosyncratic interaction sequences that are not part of the species-typical behavioural repertoire. These interactions often include uncomfortable or risky elements. These interactions exhibit the following characteristics commonly featured in definitions of rituals in humans: (1) they involve an unusual intensity of focus on the partner, (2) the behaviours have no immediate utilitarian purpose, (3) they sometimes involve "sacred objects", (4) the distribution of these behaviours suggests that they are invented and spread via social learning, and (5) many behaviours in these rituals are repurposed from other behavioural domains (e.g. extractive foraging). However, in contrast to some definitions of ritual, capuchin rituals are not overly rigid in their form, nor do the sequences have specific opening and closing actions. In our 9,260 hours of observation, ritual performance rate was uncorrelated with amount of time dyads spent in proximity but is (modestly) associated with higher relationship quality and rate of coalition formation across dyads. Our results suggest that capuchin rituals serve a bond-testing rather than a bond-strengthening function. Ritual interactions are exclusively dyadic, and between-dyad consistency in form is low, casting doubt on the alternative hypothesis that they enhance group-wide solidarity.

animal behavior and cognition↗

bioRxiv2019

Presynaptic depression maintains stable synaptic strength in developmentally arrested Drosophila larvae

Positive and negative modes of regulation typically constrain synaptic growth and function within narrow physiological ranges. However, it is unclear how synaptic strength is maintained when both pre- and post-synaptic compartments continue to grow beyond stages imposed by typical developmental programs. To address whether and how synapses can adjust to a novel life stage for which they were never molded by evolution, we have characterized synaptic growth, structure and function at the Drosophila neuromuscular junction (NMJ) under conditions where larvae are terminally arrested at the third instar stage. While wild type larvae transition to pupae after 5 days, arrested third instar (ATI) larvae persist for up to 35 days, during which NMJs exhibit extensive overgrowth in muscle size, presynaptic release sites, and postsynaptic glutamate receptors. Remarkably, despite this exuberant growth of both pre- and post-synaptic structures, stable neurotransmission is maintained throughout the ATI lifespan through a potent homeostatic reduction in presynaptic neurotransmitter release. Arrest of the larval stage in stathmin mutants reveals a degree of progressive instability and neurodegeneration that was not apparent during the typical larval period. Hence, during a period of unconstrained synaptic growth through an extended developmental period, a robust and adaptive form of presynaptic homeostatic depression can stabilize neurotransmission. More generally, the ATI manipulation provides an attractive system for studying neurodegeneration and plasticity across longer time scales. SIGNIFICANCE STATEMENTIt is unclear whether and how synapses adjust to a novel life stage for which they were never molded by evolution. We have characterized synaptic plasticity at the Drosophila neuromuscular junction in third instar larvae arrested in development for over 35 days. This approach has revealed that homeostatic depression stabilizes synaptic strength throughout the life of arrested third instars to compensate for excessive pre- and post-synaptic growth. This system also now opens the way for the study of synapses and degeneration over long time scales in this powerful model synapse.

neuroscience↗

bioRxiv2019

Contributions of the conserved insect carbon dioxide receptor subunits to odor detection

The CO2 receptor in mosquitoes is broadly tuned to detect many diverse odorants. The receptor consists of three 7-TM subunits (Gr1, Gr2, and Gr3) in mosquitoes but only two subunits in Drosophila: Gr21a (Gr1 ortholog) and Gr63a (Gr3 ortholog). We demonstrate that Gr21a is required for CO2 responses in Drosophila as has been shown for Gr63a. Next, we generate a Drosophila double mutant for Gr21a and Gr63a, and in this background we functionally express combinations of Aedes Gr1, 2, and 3 genes in the \"CO2 empty neuron.\" Only two subunits, Gr2 and Gr3, suffice for response to CO2. Addition of Gr1 increases sensitivity to CO2 while it decreases the response to pyridine. The inhibitory effect of the antagonist isobutyric acid is observed upon addition of Gr1. Gr1 therefore increases the diversity of ligands of the receptor, and also modulates the response of the receptor complex.

neuroscience↗

bioRxiv2018

The sleep gene insomniac ubiquitinates targets at postsynaptic densities and is required for retrograde homeostatic signaling

The nervous system confronts challenges during development and experience that can destabilize information processing. To adapt to these perturbations, synapses homeostatically adjust synaptic strength, a process referred to as homeostatic synaptic plasticity. At the Drosophila neuromuscular junction, inhibition of postsynaptic glutamate receptors activates retrograde signaling that precisely increases presynaptic neurotransmitter release to restore baseline synaptic strength. However, the nature of the underlying postsynaptic induction process remains enigmatic. Here, we designed a forward genetic screen to identify factors necessary in the postsynaptic compartment to generate retrograde homeostatic signaling. This approach identified insomniac (inc), a gene that encodes a putative adaptor for the Cullin-3 ubiquitin ligase complex and is essential for normal sleep regulation. Intriguingly, we find that Inc rapidly traffics to postsynaptic densities and is required for increased ubiquitination following acute receptor inhibition. Our study suggests that Inc-dependent ubiquitination, compartmentalized at postsynaptic densities, gates retrograde signaling and provides an intriguing molecular link between the control of sleep behavior and homeostatic plasticity at synapses.

neuroscience↗

bioRxiv2017

Loss of Wt1 in the murine spinal cord alters interneuron composition and locomotion

Rhythmic and patterned locomotion is driven by spinal cord neurons that form neuronal circuits, referred to as central pattern generators (CPGs). Recently, dI6 neurons were suggested to participate in the control of locomotion. The dI6 neurons can be subdivided into three populations, one of which expresses the Wilms tumor suppressor gene Wt1. However, the role that Wt1 exerts on these cells is not understood. Here, we aimed to identify behavioral changes and cellular alterations in the spinal cord associated with Wt1 deletion. Locomotion analyses of mice with neuron-specific Wt1 deletion revealed that these mice ran slower than controls with a decreased stride frequency and an increased stride length. These mice showed changes in their fore-hindlimb coordination, which were accompanied by a loss of contralateral projections in the spinal cord. Neonates with Wt1 deletion displayed an increase in uncoordinated hindlimb movements and their motor neuron output was arrhythmic with a decreased frequency. The population size of dI6, V0 and V2a neurons in the developing spinal cord of conditional Wt1 mutants was significantly altered. These results show that the development of particular dI6 neurons depends on Wt1 expression and loss of Wt1 is associated with alterations in locomotion.

neuroscience↗

bioRxiv2017

Payoff-biased social learning underlies the diffusion of novel extractive foraging traditions in a wild primate

AO_SCPLOWBSTRACTC_SCPLOWThe type and variety of learning strategies used by individuals to acquire behaviours in the wild are poorly understood, despite the presence of behavioural traditions in diverse taxa. Social learning strategies such as conformity can be broadly adaptive, but may also retard the spread of adaptive innovations. Strategies like payoff-biased learning, in contrast, are effective at diffusing new behaviour but may perform poorly when adaptive behaviour is common. We present a field experiment in a wild primate, Cebus capucinus, that introduced a novel food item and documented the innovation and diffusion of successful extraction techniques. We develop a multilevel, Bayesian statistical analysis that allows us to quantify individual-level evidence for different social and individual learning strategies. We find that payoff-biased social learning and age-biased social learning are primarily responsible for the diffusion of new techniques. We find no evidence of conformity; instead rare techniques receive slightly increased attention. We also find substantial and important variation in individual learning strategies that is patterned by age, with younger individuals being more influenced by both social information and their own individual experience. The aggregate cultural dynamics in turn depend upon the variation in learning strategies and the age structure of the wild population.

animal behavior and cognition↗