Alternative models for two crystal structures of bovine rhodopsin

Two crystal structures of rhodopsin that were originally described using trigonal symmetry can be interpreted in a hexagonal unit cell with a smaller asymmetric unit

The Role of Mortality Salience and Social Identity in Police Officers and Students Reporting Misconduct

Over the past several decades, high-profile police shootings, police brutality, and police misconduct have contributed to a decreased trust in policing in the United States. Beyond the severity and abuse of power, many of these incidents have also revealed that officers have covered up these incidents from the public. The refusal of police officers to both report misconduct or cover it up is well established and known as the “blue wall of silence.” However, no previous studies have examined the psychological processes behind this failure to report fellow officer misconduct. Two psychological theories that may explain this failure are Terror Management Theory (TMT), specifically mortality salience, and Social Identity Theory. Mortality salience suggests that reminders of one’s death increases the likelihood of protecting in-group members. Social Identity Theory has also established that increased group identification decreases the likelihood of punishing fellow in-group members. Current police training emphasizes the allegedly dangerous nature of the job while simultaneously emphasizing the importance of protecting fellow officers’ lives. The current set of studies manipulated mortality salience and social identity to identify the role each may play in the likelihood of police reporting fellow officer misconduct. As it is unclear the role that police training and culture may have on reporting fellow officer misconduct, identifying how students interested in a career in law enforcement are impacted by mortality salience and social identity on the likelihood of reporting misconduct provides opportunities to implement evidence-based policy reforms focused on increasing the likelihood of police reporting misconduct. Through two studies, this research explored the influence that morality salience and social identity had on the likelihood that police officers and students would report misconduct. Study 1 manipulated mortality salience and social identity and assessed the likelihood that police officers would report fellow officer misconduct. Contrary to previous research, police officers overwhelmingly stated they would report fellow officer misconduct. However, the results revealed an effect of the guardian mindset of policing on predicting the likelihood of police reporting misconduct. Surprisingly, officers also rated themselves as significantly more likely than other officers to report the misconduct. Study 2 tested whether students interested in a career in law enforcement failed to report fellow student misconduct because of mortality salience or social identity. Results from Study 2 found that students stated they would not report the misconduct, regardless of the attempted manipulations of both mortality salience and social identity. The results of the two studies did not find the predicted effects of mortality salience and social identity on the likelihood of reporting misconduct. However, it did raise further questions about the role of police training in reporting misconduct and the disconnect between the findings of officers’ ratings of the likelihood of reporting and the numerous real-world examples of police failing to report misconduct. I discuss implications of these findings and future directions for research

Inflammatory Pseudotumors Induced by AdCre in Transgenic Oncopigs After In Situ Induction

https://openworks.mdanderson.org/sumexp23/1106/thumbnail.jp

Tumor Stiffness is Associated with Reduced CD45+ Immune Cell Penetration of Tumors in a Rat Hepatocellular Carcinoma Model

https://openworks.mdanderson.org/sumexp23/1108/thumbnail.jp

Ontogeny of cone photoreceptor mosaics in zebrafish

Cone photoreceptors in fish are typically arranged into a precise, reiterated pattern known as a “cone mosaic.” Cone mosaic patterns can vary in different fish species and in response to changes in habitat, yet their function and the mechanisms of their development remain speculative. Zebrafish ( Danio rerio ) have four cone subtypes arranged into precise rows in the adult retina. Here we describe larval zebrafish cone patterns and investigate a previously unrecognized transition between larval and adult cone mosaic patterns. Cone positions were determined in transgenic zebrafish expressing green fluorescent protein (GFP) in their UV-sensitive cones, by the use of multiplex in situ hybridization labelling of various cone opsins. We developed a “mosaic metric” statistical tool to measure local cone order. We found that ratios of the various cone subtypes in larval and adult zebrafish were statistically different. The cone photoreceptors in larvae form a regular heterotypic mosaic array; i.e., the position of any one cone spectral subtype relative to the other cone subtypes is statistically different from random. However, the cone spectral subtypes in larval zebrafish are not arranged in continuous rows as in the adult. We used cell birth dating to show that the larval cone mosaic pattern remains as a distinct region within the adult retina and does not reorganize into the adult row pattern. In addition, the abundance of cone subtypes relative to other subtypes is different in this larval remnant compared with that of larvae or canonical adult zebrafish retina. These observations provide baseline data for understanding the development of cone mosaics via comparative analysis of larval and adult cone development in a model species. J. Comp. Neurol. 518:4182–4195, 2010. © 2010 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77982/1/22447_ftp.pd

A Naturally Occurring Mutation of the Opsin Gene (T4R) in Dogs Affects Glycosylation and Stability of the G Protein-Coupled Receptor

Rho (rhodopsin; opsin plus 11-cis-retinal) is a prototypical G protein-coupled receptor responsible for the capture of a photon in retinal photoreceptor cells. A large number of mutations in the opsin gene associated with autosomal dominant retinitis pigmentosa have been identified. The naturally occurring T4R opsin mutation in the English mastiff dog leads to a progressive retinal degeneration that closely resembles human retinitis pigmentosa caused by the T4K mutation in the opsin gene. Using genetic approaches and biochemical assays, we explored the properties of the T4R mutant protein. Employing immunoaffinity-purified Rho from affected RHOT4R/T4R dog retina, we found that the mutation abolished glycosylation at Asn2, whereas glycosylation at Asn15 was unaffected, and the mutant opsin localized normally to the rod outer segments. Moreover, we found that T4R Rho* lost its chromophore faster as measured by the decay of meta-rhodopsin II and that it was less resistant to heat denaturation. Detergent-solubilized T4R opsin regenerated poorly and interacted abnormally with the G protein transducin (Gt). Structurally, the mutation affected mainly the “plug” at the intradiscal (extracellular) side of Rho, which is possibly responsible for protecting the chromophore from the access of bulk water. The T4R mutation may represent a novel molecular mechanism of degeneration where the unliganded form of the mutant opsin exerts a detrimental effect by losing its structural integrity

An EvoDevo Study of Salmonid Visual Opsin Dynamics and Photopigment Spectral Sensitivity

Salmonids are ideal models as many species follow a distinct developmental program from demersal eggs and a large yolk sac to hatching at an advanced developmental stage. Further, these economically important teleosts inhabit both marine- and freshwaters and experience diverse light environments during their life histories. At a genome level, salmonids have undergone a salmonid-specific fourth whole genome duplication event (Ss4R) compared to other teleosts that are already more genetically diverse compared to many non-teleost vertebrates. Thus, salmonids display phenotypically plastic visual systems that appear to be closely related to their anadromous migration patterns. This is most likely due to a complex interplay between their larger, more gene-rich genomes and broad spectrally enriched habitats; however, the molecular basis and functional consequences for such diversity is not fully understood. This study used advances in genome sequencing to identify the repertoire and genome organization of visual opsin genes (those primarily expressed in retinal photoreceptors) from six different salmonids [Atlantic salmon (Salmo salar), brown trout (Salmo trutta), Chinook salmon (Oncorhynchus tshawytcha), coho salmon (Oncorhynchus kisutch), rainbow trout (Oncorhynchus mykiss), and sockeye salmon (Oncorhynchus nerka)] compared to the northern pike (Esox lucius), a closely related non-salmonid species. Results identified multiple orthologues for all five visual opsin classes, except for presence of a single short-wavelength-sensitive-2 opsin gene. Several visual opsin genes were not retained after the Ss4R duplication event, which is consistent with the concept of salmonid rediploidization. Developmentally, transcriptomic analyzes of Atlantic salmon revealed differential expression within each opsin class, with two of the long-wavelength-sensitive opsins not being expressed before first feeding. Also, early opsin expression in the retina was located centrally, expanding dorsally and ventrally as eye development progressed, with rod opsin being the dominant visual opsin post-hatching. Modeling by spectral tuning analysis and atomistic molecular simulation, predicted the greatest variation in the spectral peak of absorbance to be within the Rh2 class, with a ∼40 nm difference in λmax values between the four medium-wavelength-sensitive photopigments. Overall, it appears that opsin duplication and expression, and their respective spectral tuning profiles, evolved to maximize specialist color vision throughout an anadromous lifecycle, with some visual opsin genes being lost to tailor marine-based vision.publishedVersio