Biology subjects

Hauser, M.

Publications and source records attributed to Hauser, M..

6 recordsLinked to original sources

bioRxiv2026

Robust self-organization of livestock pluripotent stem cells into post-gastrulation embryo models with advanced neuronal and mesodermal structures

Mammalian body plan formation arises from the self-organization of pluripotent cells through conserved morphogenetic processes that are difficult to study in vivo. Stem cell-based embryo models (SEMs) offer accessible three-dimensional systems to investigate these events but are currently limited to mouse and human cells and largely recapitulate posterior embryonic structures. In addition, no in-vitro models exist for post-gastrulation development in ungulate species, whose early development differs from that of rodents and primates. Here, we establish SEMs for two common ungulates, sheep and pig, using pluripotent stem cell-derived aggregates. We generate ovine and porcine gastruloids that recapitulate key features of gastrulation, including germ layer specification, symmetry breaking, and axial elongation. We further develop ovine trunk-like structures (oTLSs) that robustly model post-gastrulation trunk development, exhibiting sustained elongation, neuromesodermal progenitor maintenance, segmented somite formation, and a central neural tube-like axis. Time-resolved single-cell RNA sequencing combined with immunostaining reveals coordinated emergence of neural, mesodermal, and intermediate mesodermal lineages arranged along an anteroposterior axis. Notably, oTLSs generate dorsal neural derivatives, anterior neuronal populations, and renal primordia, representing an expansion in the lineage repertoire reported for existing trunk models. Together, this work extends SEMs to livestock species and establishes a platform for comparative mammalian developmental studies, with potential applications in fundamental research, veterinary toxicology, and agricultural biotechnology.

developmental biology↗

bioRxiv2023

Cryptic diversity and signatures of domestication in the Black Soldier Fly (Hermetia illucens)

The Black Soldier Fly (Hermetia illucens) is the main species in the developing global industry of insects as food and feed, but little is known about its natural diversity or the genetic basis of its domestication. We obtained whole genome sequences for 54 individuals from both wild and captive populations. We identified two genetic lineages at least 3 million years divergent, revealing cryptic diversity within the species. Our study indicates that the most common populations used for commercial and academic applications are primarily derived from just one of these lineages, likely originating from a wild North American progenitor. We find that captive populations show strong reductions in genetic diversity, consistent with genome-wide effects of population bottlenecks and drift associated with rearing in captivity. Some limited evidence of gene flow between divergent lineages was observed, as well as evidence of hybridisation from domesticated populations into the wild. Our study suggests that natural genetic diversity could provide important variation for industrial purposes in this novel agricultural species. Author SummaryAnimals and plants have been domesticated by humans over thousands of years, shaping their genomes and yielding beneficial or improved traits for agriculture. Insect farming has recently reached industrial scales in order to recycle organic wastes into feed and food grade material. The Black Soldier Fly is the flagship insect species in this novel agriculture sector. However, the understanding of its evolutionary history and the genetic impact of intense farming has not been well studied to date. We examined whole genomes from populations sampled from across the worldwide distribution of Black Soldier Fly to investigate the impact of domestication and reveal the evolutionary history of the species. We found that farmed populations show distinct genomic regions showing reduced variation that could represent signatures of selection or demographic effects. We also identify two distinct lineages of Black Soldier Fly that have been diverging for millions of years, comparable to divergence between different species in other insect groups, yet show evidence of genetic exchange, indicating a lack of reproductive incompatibility in the populations tested. This work is the first to describe the genetic impact of domestication in the Black Soldier Fly and provide evolutionary insights using whole genomes. These results imply that considerable wild diversity could be harnessed for improving agricultural efficiency.

genomics↗

bioRxiv2022

Macaque amygdala, claustrum and pulvinar support the cross-modal association of social audio-visual stimuli based on meaning

Social communication draws on several cognitive functions such as perception, emotion recognition and attention. In a previous study, we demonstrated that macaques associate audiovisual information when processing their species-specific communicative signals. Specifically, cortical activation is inhibited when there is a mismatch between vocalisations and social visual information whereas activation is enhanced in the lateral sulcus, superior temporal sulcus as well as a larger network composed of early visual and prefrontal areas when vocalisations and social visual information match. Here, we use a similar task and functional magnetic resonance imaging to assess the role of subcortical structures. We identify three subcortical regions involved in audio-visual processing of species-specific communicative signal: the amygdala, the claustrum and the pulvinar. Like the cortex, these subcortical structures are not activated when there is a mismatch between visual and acoustic information. In contrast, the amygdala and claustrum are activated by visual, auditory congruent and audio-visual stimulations. The pulvinar responds in a task-dependent manner, along a specific spatial sensory gradient. Anterior pulvinar responds to auditory stimuli, medial pulvinar is activated by auditory, audio-visual and visual stimuli and the dorsal lateral pulvinar only responds to visual stimuli in a pure visual task. The medial pulvinar and the amygdala are the only subcortical structures integrating audio-visual social stimuli. We propose that these three structures belong to a multisensory network that modulates the perception of visual socioemotional information and vocalizations as a function of the relevance of the stimuli in the social context. Significance StatementUnderstanding and correctly associating socioemotional information across sensory modalities, such that happy faces predict laughter and escape scenes screams, is essential when living in complex social groups. Using functional magnetic imaging in the awake macaque, we identify three subcortical structures - amygdala, claustrum and pulvinar - that only respond to auditory information that matches the ongoing visual socioemotional context, such as hearing positively valenced coo calls and seeing positively valenced grooming monkeys. We additionally describe task-dependent activations in the pulvinar, organizing along a specific spatial sensory gradient, supporting its role as a network regulator.

neuroscience↗

bioRxiv2021

Neural correlates of audio-visual integration of socially meaningful information in macaque monkeys

Social interactions rely on the ability to interpret semantic and emotional information, often from multiple sensory modalities. In human and nonhuman primates, both the auditory and visual modalities are used to generate and interpret communicative signals. In individuals with autism, not only are there deficits in social communication, but in the integration of audio-visual information. At present, we know little about the neural mechanisms that subserve the interpretation of complex social events, including the audio-visual integration that is often required with accompanying communicative signals. Based on heart rate estimates and fMRI in two macaque monkeys (Macaca mulatta), we show that individuals systematically associate affiliative facial expressions or social scenes with corresponding affiliative vocalizations, aggressive facial expressions or social scenes with corresponding aggressive vocalizations and escape visual scenes with scream vocalizations. In contrast, vocalizations that are incompatible with the visual information are fully suppressed, suggesting top-down regulation over the processing of sensory input. The process of binding audio-visual semantic and contextual information relies on a core functional network involving the superior temporal sulcus (STS) and lateral sulcus (LS). Peak activations in both sulci co-localize with face or voice patches that have been previously described. While all of these regions of interest (ROIs) respond to both auditory and visual information, LS ROIs have a preference for auditory and audio-visual congruent stimuli while STS ROIs equally respond to auditory, visual and audio-visual congruent stimuli. To further specify the cortical network involved in the control of this semantic association, we performed a whole brain gPPI functional connectivity analysis on the LS and STS cumulated ROIs. This gPPI analysis highlights a functional network connected to the LS and STS, involving the anterior cingulate cortex (ACC), area 46 in the dorsolateral prefrontal cortex (DLPFC), the orbitofrontal cortex (OFC), the intraparietal sulcus (IPS), the insular cortex and subcortically, the amygdala and the hippocampus. Comparing human and macaque results, we propose that the integration of audio-visual information for congruent, meaningful social events involves homologous neural circuitry, specifically, an emotional network composed of the STS, LS, ACC, OFC, and limbic areas, including the amygdala, and an attentional network including the STS, LS, IPS and DLPFC. As such, these networks are critical to the amodal representation of social meaning, thereby providing an explanation for some of deficits observed in autism.

neuroscience↗

bioRxiv2020

Automated video-based heart rate tracking for the anesthetized and behaving monkey

Background Heart rate is extremely valuable in the study of complex behaviours and their physiological correlates in non-human primates. However, collecting this information is often challenging, involving either invasive implants or tedious behavioural training.New Method In the present study, we implement a Eulerian Video Magnification (EVM) heart tracking method in the macaque monkey combined with wavelet transform. This is based on a measure of image to image fluctuations in skin reflectance due to changes in blood influx.Results We show a strong temporal coherence and amplitude match between EVM-based heart tracking and ground truth ECG, from both color (RGB) and infrared (IR) videos, in anesthetized macaques, to a level comparable to what can be achieved in humans. We further show that this method allows to identify consistent heart rate changes following the presentation of conspecific emotional voices or faces.Comparison with Existing Method(s) Eulerian Video Magnification (EVM) is used to extract heart rate in humans but has never been applied to non-human primates. Video photoplethysmography allows to extract awake macaques heart rate from RGB videos. In contrast, our method allows to extract awake macaques heart rate from both RGB and IR videos and is particularly resilient to the head motion that can be observed in awake behaving monkeys.Conclusions Overall, we believe that this method can be generalized as a tool to track heart rate of the awake behaving monkey, for ethological, behavioural, neuroscience or welfare purposes.HighlightsHeart rate varies during complex non-human primate (NHP) behaviour and cognition.We apply Eulerian Video Magnification to track NHP heart rate (EVM-HR).EVM-HR can be used with RGB & IR videos, and anesthetized or awake NHPs.NHP EVM-HR vary with emotional content of presented stimuli.EVM-HR is of interest to ethology, behavioural, neuroscience & welfare purposes.Competing Interest StatementThe authors have declared no competing interest.View Full Text

animal behavior and cognition↗

bioRxiv2019

Relapse prevention through health technology program reduces hospitalization in schizophrenia

ImportancePsychiatric hospitalization is a major driver of cost in the treatment of schizophrenia. Symptom relapses are a frequent cause of hospitalization and both are primary source of burden to patients and their supporters.\n\nObjectiveTo determine whether a novel, multicomponent, and technology-enhanced approach to relapse prevention in outpatients following a psychiatric hospitalization could reduce days spent in a hospital after discharge.\n\nDesignThe Improving Care and Reducing Cost (ICRC) study was a quasi-experimental clinical trial in outpatients with schizophrenia conducted between February 2013 and April 2015 at 10 different sites in the US. Data were obtained from 89 participants who received usual relapse prevention services, followed by a second cohort of 349 participants who received the technology-enhanced relapse prevention program. Both groups were followed for 6 months.\n\nSettingOutpatient setting.\n\nParticipantsPatients were between 18 and 60 years old; had a diagnosis of schizophrenia, schizoaffective disorder, or psychotic disorder not otherwise specified; and were currently hospitalized or had been hospitalized within the past 30 days.\n\nInterventionPatients received usual care or a technology-enhanced relapse prevention program during a 6-month period after discharge.\n\nMain Outcome(s) and Measure(s)Days spent in a psychiatric hospital during 6 months after discharge.\n\nResultsThe study included 438 patients. Control participants (N = 89; 37 females) were enrolled first and received usual care for relapse prevention, and followed by 349 participants (128 females) who received technology-enhanced relapse prevention. Days of hospitalization were reduced by 4 days (Mean days: b = -4.25, 95% CI: -8.29; -0.21, P = 0.039) during follow-up in the intervention condition compared to control.\n\nConclusions and RelevanceThe reduction in days spent in the hospital for participants in the technology-informed relapse prevention program compared to those who received usual care, and the previously reported high satisfaction and usability suggest that technology-enhanced relapse prevention is an effective and feasible way to reduce rehospitalization days among patients with schizophrenia.\n\nKey pointsO_ST_ABSQuestionC_ST_ABSCan rehospitalizations in schizophrenia be prevented at reduced cost by innovative mobile technology-delivered interventions?\n\nFindingsIn this clinical trial with 438 patients, a technology-enhanced relapse prevention program compared to usual services reduced an average of four days of hospitalization per patient during the first 6 months following an index hospitalization.\n\nMeaningRelapse prevention through a health technology may improve care while reducing costs associated with hospitalization.

neuroscience↗