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23
result(s) for
"Hofbauer, Maximilian"
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Megapixel camera arrays enable high-resolution animal tracking in multiwell plates
by
Stowers, John R.
,
Feriani, Luigi
,
Ding, Siyu Serena
in
631/114/1564
,
631/114/2163
,
631/154/1435/2417
2022
Tracking small laboratory animals such as flies, fish, and worms is used for phenotyping in neuroscience, genetics, disease modelling, and drug discovery. An imaging system with sufficient throughput and spatiotemporal resolution would be capable of imaging a large number of animals, estimating their pose, and quantifying detailed behavioural differences at a scale where hundreds of treatments could be tested simultaneously. Here we report an array of six 12-megapixel cameras that record all the wells of a 96-well plate with sufficient resolution to estimate the pose of
C. elegans
worms and to extract high-dimensional phenotypic fingerprints. We use the system to study behavioural variability across wild isolates, the sensitisation of worms to repeated blue light stimulation, the phenotypes of worm disease models, and worms’ behavioural responses to drug treatment. Because the system is compatible with standard multiwell plates, it makes computational ethological approaches accessible in existing high-throughput pipelines.
A multiplexed machine-vision-based tracking system enables the high-content analysis of C. elegans behavior in several 96-well plates at a time and shows its utility for comparisons across multiple genotypes and upon drug treatment, tackling the bottlenecks in behavioural quantification.
Journal Article
TMT-Opsins differentially modulate medaka brain function in a context-dependent manner
2021
Vertebrate behavior is strongly influenced by light. Light receptors, encoded by functional opsin proteins, are present inside the vertebrate brain and peripheral tissues. This expression feature is present from fishes to human and appears to be particularly prominent in diurnal vertebrates. Despite their conserved widespread occurrence, the nonvisual functions of opsins are still largely enigmatic. This is even more apparent when considering the high number of opsins. Teleosts possess around 40 opsin genes, present from young developmental stages to adulthood. Many of these opsins have been shown to function as light receptors. This raises the question of whether this large number might mainly reflect functional redundancy or rather maximally enables teleosts to optimally use the complex light information present under water. We focus on tmt-opsin1b and tmt-opsin2 , c-opsins with ancestral-type sequence features, conserved across several vertebrate phyla, expressed with partly similar expression in non-rod, non-cone, non-retinal-ganglion-cell brain tissues and with a similar spectral sensitivity. The characterization of the single mutants revealed age- and light-dependent behavioral changes, as well as an impact on the levels of the preprohormone sst1b and the voltage-gated sodium channel subunit scn12aa . The amount of daytime rest is affected independently of the eyes, pineal organ, and circadian clock in tmt-opsin1b mutants. We further focused on daytime behavior and the molecular changes in tmt-opsin1b/2 double mutants, and found that—despite their similar expression and spectral features—these opsins interact in part nonadditively. Specifically, double mutants complement molecular and behavioral phenotypes observed in single mutants in a partly age-dependent fashion. Our work provides a starting point to disentangle the highly complex interactions of vertebrate nonvisual opsins, suggesting that tmt-opsin -expressing cells together with other visual and nonvisual opsins provide detailed light information to the organism for behavioral fine-tuning. This work also provides a stepping stone to unravel how vertebrate species with conserved opsins, but living in different ecological niches, respond to similar light cues and how human-generated artificial light might impact on behavioral processes in natural environments.
Journal Article
Virtual reality for freely moving animals
2017
FreemoVR is a virtual reality system for freely moving animals. The versatile platform is demonstrated in various experiments with
Drosophila
, zebrafish, and mice.
Standard animal behavior paradigms incompletely mimic nature and thus limit our understanding of behavior and brain function. Virtual reality (VR) can help, but it poses challenges. Typical VR systems require movement restrictions but disrupt sensorimotor experience, causing neuronal and behavioral alterations. We report the development of FreemoVR, a VR system for freely moving animals. We validate immersive VR for mice, flies, and zebrafish. FreemoVR allows instant, disruption-free environmental reconfigurations and interactions between real organisms and computer-controlled agents. Using the FreemoVR platform, we established a height-aversion assay in mice and studied visuomotor effects in
Drosophila
and zebrafish. Furthermore, by photorealistically mimicking zebrafish we discovered that effective social influence depends on a prospective leader balancing its internally preferred directional choice with social interaction. FreemoVR technology facilitates detailed investigations into neural function and behavior through the precise manipulation of sensorimotor feedback loops in unrestrained animals.
Journal Article
Megapixel camera arrays for high-resolution animal tracking in multiwell plates
Tracking small laboratory animals such as flies, fish, and worms is used for phenotyping in neuroscience, genetics, disease modelling, and drug discovery. Current imaging systems are limited either in spatial resolution or throughput. A system capable of imaging a large number of animals with sufficient resolution to estimate their pose would enable a new class of experiments where detailed behavioural differences are quantified but at a scale where hundreds of treatments can be tested simultaneously. Here we report a new imaging system consisting of an array of six 12-megapixel cameras that can simultaneously record from all the wells of a 96-well plate with a resolution of 80 pixels/mm at 25 frames per second. We show that this resolution is sufficient to estimate the pose of nematode worms including head identification and to extract high-dimensional phenotypic fingerprints. We use the system to study behavioural variability across wild isolates, the sensitisation of worms to repeated blue light stimulation, the phenotypes of worm disease models, and worms’ behavioural responses to drug treatment. Because the system is compatible with standard multiwell plates, it makes computational ethological approaches accessible in existing high-throughput pipelines and greatly increases the scale of possible phenotypic screening experiments in C. elegans.
TMT-Opsins differentially modulate medaka brain function in a context-dependent manner
by
Al-Rawi, Mariam
,
Gallach, Miguel
,
Reithofer, Florian
in
Behavior
,
Conserved sequence
,
Daylength
2020
Abstract Vertebrate behavior is strongly influenced by light. Light receptors, encoded by functional Opsin proteins, are present inside the vertebrate brain and peripheral tissues. This expression feature is present from fishes to human and appears to be particularly prominent in diurnal vertebrates. Despite their conserved widespread occurrence, the non-visual functions of Opsins are still largely enigmatic. This is even more apparent when considering the high number of Opsins. Teleosts possess around 40 Opsin genes, present from young developmental stages to adulthood. Many of these Opsins have been shown to function as light receptors. This raises the question, if this large number might mainly reflect functional redundancy or rather maximally enables teleosts to optimally use the complex light information present under water. We focus on tmt-opsin1b and tmt-opsin2, c-Opsins with ancestral-type sequence features, conserved across several vertebrate phyla, expressed with partly similar expression in non-rod, non-cone, non-RGCs brain tissues and a similar spectral sensitivity. The characterization of the single mutants revealed age- and light-dependent behavioral changes, as well as an impact on the levels of the preprohormone sst1b and the voltage-gated sodium channel subunit scn12aa. The amount of day-time rest is affected independently of eyes, pineal and the circadian clock in tmt-opsin1b mutants. We further focused on day-time behavior and the molecular changes in tmt-opsin1b/2 double mutants, and revealed that – despite their similar expression and spectral features– these Opsins interact in part non-additively. Specifically, double mutants complement molecular and (age-dependently) behavioral phenotypes observed in single mutants.Our work provides a starting point to disentangle the highly complex interactions of vertebrate non-visual Opsins, suggesting that tmt-opsin-expressing cells together with other visual and non-visual Opsins provide detailed light information to the organism for behavioral fine-tuning. This work also provides a stepping stone to unravel how vertebrate species with conserved Opsins, but in different ecological niches respond to similar light cues and how human generated artificial light might impact on behavioral processes in natural environments. Competing Interest Statement The authors have declared no competing interest. Footnotes * ↵* Contact Information kristin.tessmaratmfpl.ac.at
Follow-up of men with a PI-RADS 4/5 lesion after negative MRI/Ultrasound fusion biopsy
2022
Magnetic resonance imaging/Ultrasound
(
MRI/US) fusion targeted biopsy (TB) in combination with a systematic biopsy (SB) improves cancer detection but limited data is available how to manage patients with a Prostate Imaging-Reporting and Data System (PI-RADS) ≥ 4 lesion and a negative biopsy. We evaluate the real-world management and the rate of clinically significant Prostate Cancer (csPCa) during follow-up. 1546 patients with a multi-parametric MRI (mpMRI) and a PI-RADS ≥ 3 who underwent SB and TB between January 2012 and May 2017 were retrospectively analyzed. 222 men with a PI-RADS ≥ 4 and a negative biopsy were included until 2019. For 177/222 (80%) complete follow-up data was obtained. 66/84 (78%) had an initial PI-RADS 4 and 18 (22%) a PI-RADS 5 lesion. 48% (84/177) received a repeat mpMRI; in the follow-up mpMRI, 39/84 (46%) lesions were downgraded to PI-RADS 2 and 11 (13%) to PI-RADS 3; three cases were upgraded and 28 lesions remained consistent. 18% (32/177) men underwent repeated TB and csPCa was detected in 44% (14/32). Our study presents real world data on the management of men with a negative TB biopsy. Men with a positive mpMRI and lesions with high suspicion (PI-RADS4/5) and a negative targeted biopsy should be critically reviewed and considered for repeat biopsy or strict surveillance. The optimal clinical risk assessment remains to be further evaluated.
Journal Article
Loss of chromosome Y is unrelated to the composition of the tumor microenvironment and patient prognosis in muscle-invasive urothelial bladder cancers
2025
Background
Loss of chromosome Y (LOY) has recently been proposed to be associated with cancer aggressiveness, altered T-cell function, and poor prognosis in bladder carcinomas.
Methods
Chromosome Y was analyzed using fluorescence
in-situ
hybridization on a tissue microarray containing 2,071 urothelial carcinomas of the urinary bladder from male patients, including 487 patients who had undergone cystectomy for muscle-invasive disease and for whom follow-up data were available. Data on tumor microenvironment were obtained from a previous study.
Results
LOY was found in 26.0% of 1,704 analyzable cancers. In non-invasive cancers, LOY frequency was comparable in pTa G2 (22.8%) and pTa G3 (24.1%,
p
= 0.8036) carcinomas and slightly increased from pTa to pT2 - 4 carcinomas (23.1% for pTa and 27.2% for pT2 - 4) but these differences were not significant (
p
= 0.0794). In muscle-invasive cancers, LOY frequency slightly increased from pT2 (25.5%) to pT4 cancers (33.0%), but this association was not significant (
p
= 0.1814). Among pT2 - 4 cancers, LOY was associated with venous invasion (
p
= 0.0010) but unrelated to pT, pN, and L-status, as well as to overall, recurrence-free, and cancer-specific survival. Muscle-invasive urothelial carcinomas with and without LOY did not show significant differences in the number of CD8 positive lymphocytes, fraction of CD8 positive intraepithelial lymphocytes, number of macrophages and dendritic cells, and fraction of T helper and T regulatory cells.
Conclusion
The lack of a clear association of LOY with histopathological parameters of cancer aggressiveness, patient prognosis, and parameters describing the tumor microenvironment strongly argues against the driving role of LOY in bladder cancer progression and cancer-associated immune reactions.
Journal Article
GATA3 amplification is associated with high grade disease in non-invasive urothelial bladder cancer but unrelated to patient prognosis
2025
Purpose
We aimed to assess the impact of GATA3 binding protein (GATA3) gene copy number alterations on tumor aggressiveness, patient prognosis, and GATA3 protein expression in a large urothelial bladder cancer cohort.
Methods
A tissue microarray containing over 2,700 urothelial bladder cancers (pTa-pT4) was analyzed retrospectively using dual-labeling fluorescence in-situ hybridization (FISH) with probes for
GATA3
(10p14) and centromere 10.
GATA3
copy number gains were categorized as
GATA3
elevation (ratio
GATA3
/centromere ≥ 2/≤4), low-level amplification (ratio > 4/≤12), and high-level amplification (ratio > 12) and deletions were divided between homozygous and heterozygous.
Results
GATA3
copy number gain was detected in 9.9% of 2,213 interpretable tumors, including 2.0% with
GATA3
elevation, 3.2% with low-level amplification, and 4.7% with high-level amplification. The frequency of high-level amplification increased from pTa G2 low (0%) to pTa G3 tumors (12% [CI 0.07;0.21];
p
< 0.0001 pTa G2 low vs. pTaG2 high) but decreased in advanced-stage carcinomas pT2-4 with 5.4% [CI 0.07;0.21] (
p
< 0.0001, pTa vs. pT2-4). In muscle-invasive carcinomas,
GATA3
amplification was not linked to tumor aggressiveness or patient survival. Overall, no homozygous
GATA3
deletion was detected and heterozygous
GATA3
deletion was only observed in 1.1%; of 1,432 pT2-4 tumors without any association to cancer progression. While
GATA3
copy number was significantly correlated with GATA3 expression (
p
< 0.0001), the relationship was not strong. Only 2.3% of
GATA3
-negative cancers had a deletion, and 42.1% of strong GATA3-expressing cancers exhibited high-level amplification.
Conclusion
High-level
GATA3
amplification is common in urothelial bladder cancer and correlates with grade progression in pTa tumors, while
GATA3
deletion is rare. Neither amplification nor deletion appears to be the primary driver of GATA3 expression dysregulation.
Clinical trial number
Not applicable.
Journal Article
MRI-targeted biopsy cores from prostate index lesions: assessment and prediction of the number needed
2023
BackgroundMagnetic resonance imaging (MRI) is used to detect the prostate index lesion before targeted biopsy. However, the number of biopsy cores that should be obtained from the index lesion is unclear. The aim of this study is to analyze how many MRI-targeted biopsy cores are needed to establish the most relevant histopathologic diagnosis of the index lesion and to build a prediction model.MethodsWe retrospectively included 451 patients who underwent 10-core systematic prostate biopsy and MRI-targeted biopsy with sampling of at least three cores from the index lesion. A total of 1587 biopsy cores were analyzed. The core sampling sequence was recorded, and the first biopsy core detecting the most relevant histopathologic diagnosis was identified. In a subgroup of 261 patients in whom exactly three MRI-targeted biopsy cores were obtained from the index lesion, we generated a prediction model. A nonparametric Bayes classifier was trained using the PI-RADS score, prostate-specific antigen (PSA) density, lesion size, zone, and location as covariates.ResultsThe most relevant histopathologic diagnosis of the index lesion was detected by the first biopsy core in 331 cases (73%), by the second in 66 cases (15%), and by the third in 39 cases (9%), by the fourth in 13 cases (3%), and by the fifth in two cases (<1%). The Bayes classifier correctly predicted which biopsy core yielded the most relevant histopathologic diagnosis in 79% of the subjects. PI-RADS score, PSA density, lesion size, zone, and location did not independently influence the prediction model.ConclusionThe most relevant histopathologic diagnosis of the index lesion was made on the basis of three MRI-targeted biopsy cores in 97% of patients. Our classifier can help in predicting the first MRI-targeted biopsy core revealing the most relevant histopathologic diagnosis; however, at least three MRI-targeted biopsy cores should be obtained regardless of the preinterventionally assessed covariates.
Journal Article
Loss of MTAP expression is strongly linked to homozygous 9p21 deletion, unfavorable tumor phenotype, and noninflamed microenvironment in urothelial bladder cancer
2025
Homozygous 9p21 deletions usually result in a complete loss of S‐methyl‐5′‐thioadenosine phosphorylase (MTAP) expression visualizable by immunohistochemistry (IHC). MTAP deficiency has been proposed as a marker for predicting targeted treatment response. A tissue microarray including 2,710 urothelial bladder carcinomas were analyzed for 9p21 deletion by fluorescence in situ hybridization and MTAP expression by IHC. Data were compared with data on tumor phenotype, patient survival, intratumoral lymphocyte subsets, and PD‐L1 expression. The 9p21 deletion rate increased from pTaG2 low (9.2% homozygous, 25.8% heterozygous) to pTaG2 high (32.6%, 20.9%; p < 0.0001) but was slightly lower in pTaG3 (16.7%, 16.7%) tumors. In pT2–4 carcinomas, 23.3% homozygous and 17.9% heterozygous deletions were found, and deletions were tied to advanced pT (p = 0.0014) and poor overall survival (p = 0.0461). Complete MTAP loss was seen in 98.4% of homozygous deleted while only 1.6% of MTAP negative tumors had retained 9p21 copies (p < 0.0001). MTAP loss was linked to advanced stage and poor overall survival in pT2–4 carcinomas (p < 0.05 each). The relationship between 9p21 deletions/MTAP loss and poor patient prognosis was independent of pT and pN (p < 0.05 each). The 9p21 deletions were associated with a noninflamed microenvironment (p < 0.05). Complete MTAP loss is strongly tied to homozygous 9p21 deletion, aggressive disease, and noninflamed microenvironment. Drugs targeting MTAP‐deficiency may be useful in urothelial bladder carcinoma. MTAP IHC is a near perfect surrogate for MTAP deficiency in this tumor type.
Journal Article