Maintenance Of Cohesion Research Articles

Stereocilia fusion pathology in the cochlear outer hair cells at the nanoscale level.

The hair bundle of cochlear hair cells comprises specialized microvilli, the stereocilia, which fulfil the role of mechanotransduction. Genetic defects and environmental noise challenge the maintenance of hair bundle structure, critically contributing to age-related hearing loss. Stereocilia fusion is a major component of the hair bundle pathology in mature hair cells, but its role in hearing loss and its molecular basis are poorly understood. Here, we utilized super-resolution expansion microscopy to examine the molecular anatomy of outer hair cell stereocilia fusion in mouse models of age-related hearing loss, heightened endoplasmic reticulum stress and prolonged noise exposure. Prominent stereocilia fusion in our model of heightened endoplasmic reticulum stress, Manf (Mesencephalic astrocyte-derived neurotrophic factor)-inactivated mice in a background with Cadherin 23missense mutation, impaired mechanotransduction and calcium balance in stereocilia. This was indicated by reduced FM1-43 dye uptake through the mechanotransduction channels, reduced neuroplastin/PMCA2 expression and increased expression of the calcium buffer oncomodulin inside stereocilia. Sparse BAIAP2L2 and myosin 7a expression was retained in the fused stereocilia but mislocalized away from their functional sites at the tips. These hair bundle abnormalities preceded cell soma degeneration, suggesting a sequela from stereociliary molecular perturbations to cell death signalling. In the age-related hearing loss and noise-exposure models, stereocilia fusion was more restricted within the bundles, yet both models exhibited oncomodulin upregulation at the fusion sites, implying perturbed calcium homeostasis. We conclude that stereocilia fusion is linked with the failure to maintain cellular proteostasis and with disturbances in stereociliary calcium balance. KEY POINTS: Stereocilia fusion is a hair cell pathology causing hearing loss. Inactivation of Manf, a component of the endoplasmic reticulum proteostasis machinery, has a cell-intrinsic mode of action in triggering outer hair cell stereocilia fusion and the death of these cells. The genetic background with Cadherin 23missense mutation contributes to the high susceptibility of outer hair cells to stereocilia fusion, evidenced in Manf-inactivated mice and in the mouse models of early-onset hearing loss and noise exposure. Endoplasmic reticulum stress feeds to outer hair cell stereocilia bundle pathology and impairs the molecular anatomy of calcium regulation. The maintenance of the outer hair cell stereocilia bundle cohesion is challenged by intrinsic and extrinsic stressors, and understanding the underlying mechanisms will probably benefit the development of interventions to promote hearing health.

Transcriptome and differential expression analysis of chemosensory genes in the antennae and heads of Apis cerana cerana drones

The olfactory system plays a critical role in honey bee adaptation to complex and constantly changing environments, as well as in the maintenance of social cohesion. Honey bees have evolved a sophisticated chemical communication system to regulate their intricate social interactions. Despite there is a preliminary understanding of the components, cells, and physiological pathways involved in pheromone response, the molecular mechanisms underlying honey bee drones’ mating behavior and pheromone communication remain largely unknown. This study presented the first comprehensive transcriptome analysis of the antennae and heads of Apis cerana cerana drones in response to 9-ODA. Based on gene ontology and KEGG pathway, we found the majority of differentially expressed genes associated with molecular functions and signal transduction. Additionally, we identified 153 genes closely related to olfaction in the transcriptome datasets, including 111 odorant receptors (ORs), 16 odorant-binding proteins (OBPs), nine ionotropic receptors (IRs), 10 gustatory receptors (GRs), five chemosensory proteins (CSPs), and two sensory neuron membrane proteins (SNMPs), and most of them showed relatively high expression levels in the drone antennae. The reliability of these differential genes was validated using RT-qPCR. Our results will contribute to detect the molecular mechanisms of odorant and investigate olfactory functions in the Asian honey bees.

Molecular evolution of the mammalian kinetochore complex.

Mammalian centromeres are satellite-rich chromatin domains that serve as sites for kinetochore complex assembly. Centromeres are highly variable in sequence and satellite organization across species, but the processes that govern the co-evolutionary dynamics between rapidly evolving centromeres and their associated kinetochore proteins remain poorly understood. Here, we pursue a course of phylogenetic analyses to investigate the molecular evolution of the complete kinetochore complex across primate and rodent species with divergent centromere repeat sequences and features. We show that many protein components of the core centromere associated network (CCAN) harbor signals of adaptive evolution, consistent with their intimate association with centromere satellite DNA and roles in the stability and recruitment of additional kinetochore proteins. Surprisingly, CCAN and outer kinetochore proteins exhibit comparable rates of adaptive divergence, suggesting that changes in centromere DNA can ripple across the kinetochore to drive adaptive protein evolution within distant domains of the complex. Our work further identifies kinetochore proteins subject to lineage-specific adaptive evolution, including rapidly evolving proteins in species with centromere satellites characterized by higher-order repeat structure and lacking CENP-B boxes. Thus, features of centromeric chromatin beyond the linear DNA sequence may drive selection on kinetochore proteins. Overall, our work spotlights adaptively evolving proteins with diverse centromere-associated functions, including centromere chromatin structure, kinetochore protein assembly, kinetochore-microtubule association, cohesion maintenance, and DNA damage response pathways. These adaptively evolving kinetochore protein candidates present compelling opportunities for future functional investigations exploring how their concerted changes with centromere DNA ensure the maintenance of genome stability.

Chromatin-associated cohesin turns over extensively and forms new cohesive linkages in Drosophila oocytes during meiotic prophase

In dividing cells, accurate chromosome segregation depends on sister chromatid cohesion, protein linkages that are established during DNA replication. Faithful chromosome segregation in oocytes requires that cohesion, first established in S phase, remain intact for days to decades, depending on the organism. Premature loss of meiotic cohesion in oocytes leads to the production of aneuploid gametes and contributes to the increased incidence of meiotic segregation errors as women age (maternal age effect). The prevailing model is that cohesive linkages do not turn over in mammalian oocytes. However, we have previously reported that cohesion-related defects arise in Drosophila oocytes when individual cohesin subunits or cohesin regulators are knocked down after meiotic S phase. Here, we use two strategies to express a tagged cohesin subunit exclusively during mid-prophase in Drosophila oocytes and demonstrate that newly expressed cohesin is used to form de novo linkages after meiotic S phase. Cohesin along the arms of oocyte chromosomes appears to completely turn over within a 2-day window during prophase, whereas replacement is less extensive at centromeres. Unlike S-phase cohesion establishment, the formation of new cohesive linkages during meiotic prophase does not require acetylation of conserved lysines within the Smc3 head. Our findings indicate that maintenance of cohesion between S phase and chromosome segregation in Drosophila oocytes requires an active cohesion rejuvenation program that generates new cohesive linkages during meiotic prophase.

An RNAi screen to identify proteins required for cohesion rejuvenation during meiotic prophase in Drosophila oocytes.

Accurate chromosome segregation during meiosis requires the maintenance of sister chromatid cohesion, initially established during premeiotic S phase. In human oocytes, DNA replication and cohesion establishment occur decades before chromosome segregation and deterioration of meiotic cohesion is one factor that leads to increased segregation errors as women age. Our previous work led us to propose that a cohesion rejuvenation program operates to establish new cohesive linkages during meiotic prophase in Drosophila oocytes and depends on the cohesin loader Nipped-B and the cohesion establishment factor Eco. In support of this model, we recently demonstrated that chromosome-associated cohesin turns over extensively during meiotic prophase and failure to load cohesin onto chromosomes after premeiotic S phase results in arm cohesion defects in Drosophila oocytes. To identify proteins required for prophase cohesion rejuvenation but not S phase establishment, we conducted a Gal4-UAS inducible RNAi screen that utilized two distinct germline drivers. Using this strategy, we identified 29 gene products for which hairpin expression during meiotic prophase, but not premeiotic S phase, significantly increased segregation errors. Prophase knockdown of Brahma or Pumilio, two positives with functional links to the cohesin loader, caused a significant elevation in the missegregation of recombinant homologs, a phenotype consistent with premature loss of arm cohesion. Moreover, fluorescence in situ hybridization confirmed that Brahma, Pumilio, and Nipped-B are required during meiotic prophase for the maintenance of arm cohesion. Our data support the model that Brahma and Pumilio regulate Nipped-B-dependent cohesin loading during rejuvenation. Future analyses will better define the mechanism(s) that govern meiotic cohesion rejuvenation and whether additional prophase-specific positives function in this process.

Exploring the role of vocalizations in regulating group dynamics.

Because of the diverging needs of individuals, group life can lead to disputes and competition, but it also has many advantages, such as reduced predation risk, information sharing and increased hunting success. Social animals have to maintain group cohesion and need to synchronize activities, such as foraging, resting, social interactions and movements, in order to thrive in groups. Acoustic signals are highly relevant for social dynamics, some because they are long-ranging and others because they are short-ranging, which may serve important within-group functions. However, although there has been an increase in studies concentrating on acoustic communication within groups in the past decade, many aspects of how vocalizations relate to group dynamics are still poorly understood. The aim of this review is to present an overview of our current knowledge on the role of vocalizations in regulating social group dynamics, identify knowledge gaps and recommend potential future research directions. We review the role that vocalizations play in (i) collective movement, (ii) separation risk and cohesion maintenance, (iii) fission-fusion dynamics, and (iv) social networks. We recommend that future studies aim to increase the diversity of studied species and strengthen the integration of state-of-the-art tools to study social dynamics and acoustic signals. This article is part of the theme issue 'The power of sound: unravelling how acoustic communication shapes group dynamics'.

Pastoral Aspects of the Occasional Services

This study examines the casualias as central to the ministry of the church from the perspective of pastoral care. At the root of the casualias is ritual, which, according to Emile Durkheim, has as its true function the strengthening and maintenance of group cohesion and solidarity, the expression of unity, the weaving of bonds between the individual and society. Pastoral psychology studies of casualias have shown that they play an important role in the community and relational experience, as communication and correlation take place between the transcendent and the human, between man and man: the individual is strengthened and experiences the welcoming, supportive, and helping presence of the community. The individual is no longer alone with his or her problems and difficulties, as he or she has a burden-relieving experience of being in contact with the community. This connection is not only embodied in words but also brought to life through non-verbal moments and ancient symbols. I will point out that providing help, according to pastoral psychology, is a communal task, which is why rituals and casualias have therapeutic and pastoral care potential. Keywords: casualia, pastoral psychology, ritual, community, experiential society

APPLICATION OF REGIONAL MANAGEMENT INSTRUMENTS TO ENSURE TERRITORIAL COHESION IN THE REGIONS AND COMMUNITIES OF UKRAINE

APPLICATION OF REGIONAL MANAGEMENT INSTRUMENTS TO ENSURE TERRITORIAL COHESION IN THE REGIONS AND COMMUNITIES OF UKRAINE

One Village, One Family: Social Cohesion in Rural Slovakia

This article is focused on mechanisms associated with social cohesion of Roman-Catholics in rural Slovakia. The article presents an analysis of ethnographic data gathered during field research in a municipality situated in White Carpathian mountains from June 2017 to July 2019. The data was collected from 38 residents of the selected denomination during semi-structured interviews. The primary aim of the article is to identify factors that help maintain social cohesion and factors that cause its disruption in concrete rural community in Slovakia. The data analysis based on the Grounded Theory method was performed in Atlas.ti. It showed that it is the help of friends, family, and neighbours, as well as family gatherings, religious tolerance, and baptism that contribute to the maintenance of social cohesion. The social cohesion is distorted by divorces, mobility of local inhabitants, ongoing industrialization, consumerism, and transformation of traditions.

CDK11 facilitates centromeric transcription to maintain centromeric cohesion during mitosis.

Actively-transcribing RNA polymerase (RNAP)II is remained on centromeres to maintain centromeric cohesion during mitosis, although it is largely released from chromosome arms. This pool of RNAPII plays an important role in centromere functions. However, the mechanism of RNAPII retention on mitotic centromeres is poorly understood. We here demonstrate that Cyclin-dependent kinase (Cdk)11 is involved in RNAPII regulation on mitotic centromeres. Consistently, we show that Cdk11 knockdown induces centromeric cohesion defects and decreases Bub1 on kinetochores, but the centromeric cohesion defects are partially attributed to Bub1. Furthermore, Cdk11 knockdown and the expression of its kinase-dead version significantly reduce both RNAPII and elongating RNAPII (pSer2) levels on centromeres and decrease centromeric transcription. Importantly, the overexpression of centromeric α-satellite RNAs fully rescues Cdk11-knockdown defects. These results suggest that the maintenance of centromeric cohesion requires Cdk11-facilitated centromeric transcription. Mechanistically, Cdk11 localizes on centromeres where it binds and phosphorylates RNAPII to promote transcription. Remarkably, mitosis-specific degradation of G2/M Cdk11-p58 recapitulates Cdk11-knockdown defects. Altogether, our findings establish Cdk11 as an important regulator of centromeric transcription and as part of the mechanism for retaining RNAPII on centromeres during mitosis.

Cohesion depends on kinship but no permanent leadership in larval societies of a Neotropical butterfly.

In gregarious species, coordinated responses to environmental stimuli are important for a successful habitat and/or food selection. In this sense, maintenance of group cohesion after stochastic disturbances and during collective movements is expected to be advantageous, as is the existence of group leaders. Through laboratory experiments, we examined whether clusters of early instars of Mechanitis polymnia casabranca have both leaders and followers, as well as whether larvae are able to reaggregate depending on neighbors' degree of kinship. In the leadership experiment, clusters of second and third instars were placed in a trail arena having a stimulus leaf at its ending point. Every larva moving ahead from the group was recorded as a leader, and the remaining ones were followers. We also examined whether leaders were temporary or permanent. Of the 195 larvae tested, 22 were permanent leaders (11.28%), 71 larvae were assigned as temporary leaders (36.41%), and 102 larvae never behaved as leaders (52.31%). In the larval cohesion experiment, three treatments were assigned: (i) sibling larvae reared and tested together, (ii) sibling larvae separated after eclosion and tested together, and (iii) non-sibling larvae reared separated and tested together. Sibling larvae reaggregated significantly more compared to non-siblings, regardless of whether they were reared together or separately. Our results show that early instars of M. polymnia casabranca from the same egg cluster are able to recompose aggregations after disrupting disturbances and that group decision-making is mostly dependent on transient leaders.

Foraging history of individual elephants using DNA metabarcoding.

Individual animals should adjust diets according to food availability. We used DNA metabarcoding to construct individual-level dietary timeseries for elephants from two family groups in Kenya varying in habitat use, social position and reproductive status. We detected at least 367 dietary plant taxa, with up to 137 unique plant sequences in one fecal sample. Results matched well-established trends: elephants tended to eat more grass when it rained and other plants when dry. Nested within these switches from 'grazing' to 'browsing' strategies, dietary DNA revealed seasonal shifts in food richness, composition and overlap between individuals. Elephants of both families converged on relatively cohesive diets in dry seasons but varied in their maintenance of cohesion during wet seasons. Dietary cohesion throughout the timeseries of the subdominant 'Artists' family was stronger and more consistently positive compared to the dominant 'Royals' family. The greater degree of individuality within the dominant family's timeseries could reflect more divergent nutritional requirements associated with calf dependency and/or priority access to preferred habitats. Whereas theory predicts that individuals should specialize on different foods under resource scarcity, our data suggest family bonds may promote cohesion and foster the emergence of diverse feeding cultures reflecting links between social behaviour and nutrition.

Social recapitulation: Moulting can restore social tolerance in aggressive spiderlings.

In many taxa, the subsocial route is considered the main pathway to permanent sociality but the relative contribution of offspring interactions and parental care to the maintenance of cohesion and tolerance at advanced developmental stages remains poorly studied. Spiders are relevant models for this question because all exhibit a transient gregarious phase prior to dispersal and permanent sociality, which involves about 20 of the 50,000 species, is assumed to rely on the subsocial route. Using spiderlings of the solitary species Agelena labyrinthica, we manipulated the social context to demonstrate that tolerance in aggressive juveniles can be restored when exposed to siblings after moulting. We propose that moulting can reopen closed critical periods and renew the imprinting to social cues and thus lead to the reacquisition of tolerance. Our study highlights the critical role of contacts between juveniles in the expression of tolerance, which opens novel avenues for understanding social transitions.

Thermal and non-thermal treatments in the processing of cagaita nectar - Eugenia dysenterica.

This work aimed to analyze cagaita nectar subjected to different thermal and non-thermal treatments regarding its quality over 30 days of storage (5 °C). Ultra (U) and thermosonication (T) were the techniques used for 30 and 60 minutes of processing samples. These techniques proved to be effective to preserve physicochemical quality, regarding rheology and texture, since ultra and thermosonicated samples had their consistency increased when compared to the pasteurized sample over 30 days, a desirable factor for a fruit nectar. Samples treated more intensely with ultrasound and temperature (Pasteurized, U 25 °C/60 min and T 60 °C/ 30 min) showed higher soluble solids content. The sample U 25 °C/60 min increased its brightness, reduced its firmness and also its consistency after 30 storage days. For all samples there was an increase in carotenoids content and a maintenance of viscosity and cohesiveness (texture) over 30 days, thus indicating that the used treatments can be feasible instead of pasteurization, maintaining the shelf life of cagaita nectar in the time evaluated.

Probable signature whistle production in Atlantic white‐sided (Lagenorhynchus acutus) and short‐beaked common (Delphinus delphis) dolphins near Cape Cod, Massachusetts

Probable signature whistle production in Atlantic white‐sided (<i>Lagenorhynchus acutus</i>) and short‐beaked common (<i>Delphinus delphis</i>) dolphins near Cape Cod, Massachusetts

CoFee-L: A Model of Animal Displacement in Large Groups Combining Cohesion Maintenance, Feeding Area Search and Transient Leadership

Simple SummaryIn the current context of climate change and forest cover degradation, the dispersal potential of trees is an issue of great importance. This is particularly the case in the tropics, where trees often need animals to disperse their seeds, as this increases the chances of survival of the progeny and allows migration in the face of climate change. An accurate representation of animal movement is therefore necessary to study the colonization potential of trees in new areas. We have conceived an innovative mathematical model describing the individual movement of gregarious animals, integrating several fundamental features of collective behaviors: cohesion maintenance, feeding area search and leadership. The model was applied to simulate the movements of a wild-ranging troop of primates in a nature reserve. As a result, the model allowed us to simulate the movement of the troop, taking into account the movement and individual characteristics of each member, which is important to consider when the group is composed of many individuals. In the future, this model could be used to improve existing zoochoric seed dispersal models and can be coupled with dynamic vegetation models to predict the shifts of trees species distribution under future climate hypotheses.In the tropics, the conservation of tree species is closely linked to that of animals, as a large proportion of trees are zoochoric and therefore rely on the movement of animals to disperse their seeds in order to increase the chances of the survival of progeny and to allow migration in the face of climate change. Research into the prediction of animal movements is therefore critical but has so far focused only on particular features of collective behavior. In contrast, we included the concepts of cohesion maintenance, feeding area search and transient leadership in a single model, CoFee-L, and tested it to simulate the movement of a wild-ranging troop of primates (Macaca leonina). We analyzed and compared observations and simulations with a statistical physics tool (mean squared displacement) and with histograms and χ2 (for the step length and turning angle distributions). CoFee-L allowed us to simulate the physical properties of the troop’s center of mass trajectory as well as the step length and angle distributions of the field data. The parametrization of CoFee-L was rather straightforward, as it was sufficient to fix a set of parameters easily observable in the field and then to adjust the values of four parameters that have biological meaning.

Embodied Interaffectivity in the Emergence and Maintenance of Group Cohesion.

Group cohesion is an affect-laden construct, with a large body of research indicating its importance for success of teams. Surprisingly, it has received scant attention in collaborative learning contexts, and little is known about its development as dynamically emergent in the spontaneous, interdependent actions of actors during groupwork. This paper details an illustrative case analysis which took an embodied perspective to explore the role of interaffectivity in the emergence and maintenance of cohesion in one small group of university students who reported a highly positive and productive experience of collaborative science activities over a semester. The case analysis made visible group cohesion as unfolding and enactive in the myriad ephemeral and seemingly inconsequential microlevel behaviors that evolved into macro-temporal patterns of positive embodied interaffectivity, magnifying their visibility and collective impact. A fine-grained embodiment lens unveiled how participants cocreated collaborative affordances in actions that involved corporeal orientation as well as use of space, task, and other material artifacts. Task-related humor within routine task interaction offered the potential for establishing group cohesion in early group life, but also posed a potential threat to task-focused cohesiveness, requiring careful modulation at critical task points. Attentiveness not only to the task but importantly, to one another as interpersonal attentiveness, appeared to be a key factor in developing and maintaining group cohesion, also demonstrating collaborative learning as a process of orienting to and understanding tasks through one another. An embodiment lens highlighted mutual attentiveness in the ongoing orienter-orientee microprocesses that facilitated group orientation early in group life, and in reorienting to positive embodied interaffectivity when the group reconvened for their joint science activities in subsequent weeks.

The Impact of Social Media on Social Cohesion: A Double-Edged Sword

Social media plays a major role in public communication in many countries. Therefore, it has a large impact on societies and their cohesion. This thematic issue explores the impact social media has on social cohesion on a local or national level. The nine articles in this issue focus on both the potential of social media usage to foster social cohesion and the possible drawbacks of social media which could negatively influence the development and maintenance of social cohesion. In the articles, social cohesion is examined from different perspectives with or without the background of crisis, and on various social media platforms. The picture that emerges is that of social media as, to borrow a phrase used in one of the articles, a double-edged sword.

Movement behaviour after birth demonstrates precocial abilities of African savannah elephant, Loxodonta africana, calves

Living in groups has many benefits including predator protection and information sharing that can outweigh the associated costs. African savannah elephants live in a matriarchal fission–fusion social structure where groups merge or split depending on the relative costs of group living. However, elephants are also nonsynchronous breeders which may cause optimal movement patterns to differ between group members, particularly around parturition. Both the mother and the group must assess whether the benefits outweigh the costs of group cohesion. Understanding the impact of gestation, parturition and the presence of a newborn calf on the mother's movement patterns could provide key insights into the drivers of fission–fusion social dynamics. Here, we examined the relationship between reproductive state and movement using GPS tracking data collected during 23 parturitions from multiparous elephants (≥ second calving) and three from primiparous females. We analysed daily mean speed before, during and after parturition, and used a three-state hidden Markov model to determine whether parturition results in a distinctive change in speed. The results show that, although speed decreased on the estimated parturition date, parturition could only be detected in four of 23 multiparous parturition events when placed in the context of speed over a 2-month period. Furthermore, the speed on the day before and the day after parturition (i.e. first complete day of the calf's life) was not significantly different from the yearly mean. By contrast, a speed decrease was detected in the limited sample of primiparous females but was of short duration. Our results indicate that the precocial abilities of calves facilitate the maintenance of group cohesion within the matriarchal fission–fusion social structure of elephants. We speculate that, alongside cognitive development, elephants may have evolved a long gestation period to facilitate an advanced stage of fetal physical development. • We analysed the movement behaviour of parturient African savannah elephants. • Gestation, parturition and neonatal calves had little impact on mothers' movements. • We demonstrate the precocial abilities of elephant calves. • Movement after birth could be a significant advantage for a social species. • Extended gestation of elephants may have evolved for advanced fetal development.

Psychological Selfishness

Selfishness is central to many theories of human morality, yet its psychological nature remains largely overlooked. Psychologists often draw on classical conceptions of selfishness from evolutionary biology (i.e., selfish gene theory), economics (i.e., rational self-interest), and philosophy (i.e., psychological egoism), but such characterizations offer limited insight into the psychology of selfishness. To address this gap, we propose a novel framework in which selfishness is recast as a psychological construction. From this view, selfishness is perceived in ourselves and others when we detect a situation-specific desire to benefit the self that disregards others’ desires and prevailing social expectations for the situation. We argue that detecting and deterring such psychological selfishness in both oneself and others is crucial in social life—facilitating the maintenance of social cohesion and close relationships. In addition, we show how using this psychological framework offers a richer understanding of the nature of human social behavior. Delineating a psychological construct of selfishness can promote coherence in interdisciplinary research on selfishness and provide insights for interventions to prevent or remediate the negative effects of selfishness.