Reptilian Skin and Its Special Histological Structures

Reptilian skin is covered with scales forming armor that makes it watertight and enables reptiles to live on land in contrast to amphibians. An important part of the skin is the horny epidermis, with thick stratum corneum in which waxes are arranged in membrane-like layers. In lizards and snakes, the whole skin is covered in overlapping epidermal scales and in turtles and crocodiles in dermal scutes. The cornified part of the epidermis is strengthened by β-keratin and sometimes α-keratin. In crocodiles and many turtles, the outer scale surface consists of β-keratin and the hinge region containing α-keratin. In lizards and snakes, both keratins form continuous layers with the α-keratin below the β-keratin. Some reptiles have developed a sensitive mechanosensory system in the skin. The colors of reptile skin are produced by melanocytes and three types of chromatophores: melanophores, xanthophores, and iridophores. The color patterns may be fixed or the chromatophores may provide rapid color change. Skin from different species of reptiles, turtles (red-eared slider (Trachemys scripta elegans)), snakes (Emerald tree boa (Corallus caninus) and Burmese python (Python bivittatus)), Cuvier’s dwarf caiman (Paleosuchus palpebrosus), lizards (Leopard Gecko (Eublepharis macularius)), and Green iguana (Iguana iguana), were examined with histology techniques and compared

Critical Impact of Different Conserved Endoplasmic Retention Motifs and Dopamine Receptor Interacting Proteins (DRIPs) on Intracellular Localization and Trafficking of the D2 Dopamine Receptor (D2-R) Isoforms

The type 2 dopamine receptor D2 (D2-R), member of the G protein-coupled receptor (GPCR) superfamily, exists in two isoforms, short (D2S-R) and long (D2L-R). They differ by an additional 29 amino acids (AA) in the third cytoplasmic loop (ICL3) of the D2L-R. These isoforms differ in their intracellular localization and trafficking functionality, as D2L-R possesses a larger intracellular pool, mostly in the endoplasmic reticulum (ER). This review focuses on the evolutionarily conserved motifs in the ICL3 of the D2-R and proteins interacting with the ICL3 of both isoforms, specifically with the 29 AA insert. These motifs might be involved in D2-R exit from the ER and have an impact on cell-surface and intracellular localization and, therefore, also play a role in the function of dopamine receptor signaling, ligand binding and possible homo/heterodimerization. Our recent bioinformatic data on potential new interaction partners for the ICL3 of D2-Rs are also presented. Both are highly relevant, and have clinical impacts on the pathophysiology of several diseases such as Parkinson’s disease, schizophrenia, Tourette’s syndrome, Huntington’s disease, manic depression, and others, as they are connected to a variety of essential motifs and differences in communication with interaction partners

Avian Cardiovascular Disease Characteristics, Causes and Genomics

Cardiovascular disease is common in avian species and increasing commercial economic losses and demand for healthcare in the household/smallholding veterinary sector has resulted in increased research into these disorders. This in turn has highlighted the importance of breeding, genetic testing and possibilities for future prognostic and diagnostic testing. Research into avian cardiovascular genetics has rapidly accelerated. Previously much work was undertaken in mammals with information extrapolated and transferred to birds. Birds have also been used to model cardiovascular disease and therefore knowledge has become enriched due to this endeavour. Increasingly, the avian genome is being analysed in its own right. This work is assisted by the growing number of avian genomes being published. In 2015, Nature published news on the ‘Bird 10K’ project, which aims to sequence 10,500 extant bird species. By 2018, the Avian Genomes Consortium had published the sequences of 45 species/34 orders. This review investigates a range of avian cardiovascular disorders in order to highlight their pathologies, epidemiology and genetics in addition to avian models of heart disease. With the availability of more reference genomes, increases in the number and magnitude of avian studies and more advanced technologies, the genetics behind avian cardiovascular disorders is being unravelled

The Anatomy, Histology and Physiology of the Healthy and Lame Equine Hoof

Satisfactory investigations of the equine foot appear to be limited by the histo-morphological complexity of internal hoof structures. Foot lameness is considered to be one of the most debilitating pathological disorders of the equine foot. In most species, foot lameness is traditionally linked to hoof deformity, and a set of molecular events have been defined in relation to the disease. So far, there is controversy regarding the incidence of foot lameness in horses, as it is unclear whether it is foot lameness that triggers hoof distortions or vice-versa. In order to develop a better understanding of foot lameness, we review both the healthy and lame foot anatomy, cell biology and vascularisation and using micro-computed tomography show new methods of visualising internal structures within the equine foot

Patterns of human and porcine gammaherpesvirus-encoded BILF1 receptor endocytosis

The viral G-protein-coupled receptor (vGPCR) BILF1 encoded by the Epstein–Barr virus (EBV) is an oncogene and immunoevasin and can downregulate MHC-I molecules at the surface of infected cells. MHC-I downregulation, which presumably occurs through co-internalization with EBV-BILF1, is preserved among BILF1 receptors, including the three BILF1 orthologs encoded by porcine lymphotropic herpesviruses (PLHV BILFs). This study aimed to understand the detailed mechanisms of BILF1 receptor constitutive internalization, to explore the translational potential of PLHV BILFs compared with EBV-BILF1

The Function of Seven Transmembrane Receptors in the Cardiovascular System and Their Role in the Development of Cardiomyopathy

The G-protein-coupled receptors (GPCRs, also called seven-transmembrane receptor, 7TMRs, or heptahelical receptor) are a conserved family of seven transmembrane receptors which are essential not only in the healthy heart and blood vessels but also in for treatment and therapy of cardiovascular disease and failure. Heart failure is a global leading cause of morbidity and death and as such understanding 7TMRs, their functions, structures and potential for therapy is essential. This review will investigate the roles of the receptors in the healthy functioning cardiovascular system, and in cardiac disorders with an emphasis in cardiomyopathy. It will also explore the role of autoimmunity and autoantibodies against the G-protein-coupled receptors in cardiomyopathy

Computational Modeling and Characterization of Peptides Derived from Nanobody Complementary-Determining Region 2 (CDR2) Targeting Active-State Conformation of the β2-Adrenergic Receptor (β2AR)

This study assessed the suitability of the complementarity-determining region 2 (CDR2) of the nanobody (Nb) as a template for the derivation of nanobody-derived peptides (NDPs) targeting active-state β2-adrenergic receptor (β2AR) conformation. Sequences of conformationally selective Nbs favoring the agonist-occupied β2AR were initially analyzed by the informational spectrum method (ISM). The derived NDPs in complex with β2AR were subjected to protein–peptide docking, molecular dynamics (MD) simulations, and metadynamics-based free-energy binding calculations. Computational analyses identified a 25-amino-acid-long CDR2-NDP of Nb71, designated P4, which exhibited the following binding free-energy for the formation of the β2AR:P4 complex (ΔG = −6.8 ± 0.8 kcal/mol or a Ki = 16.5 μM at 310 K) and mapped the β2AR:P4 amino acid interaction network. In vitro characterization showed that P4 (i) can cross the plasma membrane, (ii) reduces the maximum isoproterenol-induced cAMP level by approximately 40% and the isoproterenol potency by up to 20-fold at micromolar concentration, (iii) has a very low affinity to interact with unstimulated β2AR in the cAMP assay, and (iv) cannot reduce the efficacy and potency of the isoproterenol-mediated β2AR/β-arrestin-2 interaction in the BRET2-based recruitment assay. In summary, the CDR2-NDP, P4, binds preferentially to agonist-activated β2AR and disrupts Gαs-mediated signaling

Effect of Immunocastration on Performance of Slovenian Pig Fatteners

The influence of the immunocastration (immunisation against GnRH) on pig performance (growth, carcass and meat quality traits) was investigated in two parallel experiments (on two farms) with two crossbreeds – G1 (50% Duroc) and G2 (50% Pietrain). Within the crossbreed, the pigs were assigned to three experimental groups; entire males (EM, n=49), immunocastrates (IC, n=45) and surgical castrates (SC, n=45). Those assigned to IC group were vaccinated at the age of 12 and 19 weeks. Pigs were individually housed, their feed intake (ad libitum) and weight (at 12, 19 and 24 weeks) were recorded. At the age of 24 weeks, the pigs were slaughtered and their carcass and meat quality traits were assessed. We hypothesized that treatment response could have been different in two crossbreeds. However the interaction was insignificant, thus the treatment effect is presented on pooled results for both crossbreeds. Until the revaccination, IC were similar to EM pigs, thereafter they exhibited an increase in feed intake and growth rate. Overall, they presented an advantage in growth rate and feed efficiency as compared to SC. They also exhibited better carcass properties as SC without any major effect on meat quality. The present study provides the initial information on the immunocastration effect in Slovenian herds that should further be supported by testing it in usual rearing conditions and group housing