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Infectious bronchitis virus (IBV) induces severe economic losses in chicken farms due to the emergence of new variants leading to vaccine breaks. The studied IBV strains belong to Massachusetts (Mass), Canadian 4/91, and California (Cal) 1737 genotypes that are prevalent globally. This study was designed to compare the impact of these three IBV genotypes on primary and secondary lymphoid organs. For this purpose, one-week-old specific pathogen-free chickens were inoculated with Mass, Canadian 4/91, or Cal 1737 IBV variants, keeping a mock-infected control. We examined the IBV replication in primary and secondary lymphoid organs. The molecular, histopathological, and immunohistochemical examinations revealed significant differences in lesion scores and viral distribution in these immune organs. In addition, we observed B-cell depletion in the bursa of Fabricius and the spleen with a significant elevation of T cells in these organs. Further studies are required to determine the functional consequences of IBV replication in lymphoid organs.

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Background: The Harderian gland in domestic birds is a major paraocular excretory gland that has an important role in tear production as well as in the immune protection of the conjunctiva surface. Aim: The aim of this research was to investigate the arterial and venous supply of the gland in hens and provide valuable and useful information for future research. Methods: The research was conducted on 26 adult hens, provenience of Lohmann Brown. For the identification and determination of blood vessels, we used the vascular corrosion cast technique in conjunction with the transmission electron microscope (TEM). Results: The casts showed that the gland receives the arterial supply via branches of a. ophthalmotemporalis and a. nasalis communis and these arteries are accompanied by the corresponding veins. Ultrastructural analyses showed the presence of fenestrated capillaries, which indicates the possibility for permeability of larger molecules. Conclusion: The present research gives important and detailed information about the arterial and venous supply of the Harderian gland in hens that may serve as guidelines for future vascular and morphological investigations. [Open Vet J 2024; 14(7.000): 1553-1560]

Background: The Harderian gland in domestic birds is a major paraocular excretory gland that has an important role in tear production as well as in the immune protection of the conjunctiva surface. Aim: The aim of this research was to investigate the arterial and venous supply of the gland in hens and provide valuable and useful information for future research. Methods: The research was conducted on 26 adult hens, provenience of Lohmann Brown. For the identification and determination of blood vessels, we used the vascular corrosion cast technique in conjunction with the transmission electron microscope (TEM). Results: The casts showed that the gland receives the arterial supply via branches of a. ophthalmotemporalis and a. nasalis communis and these arteries are accompanied by the corresponding veins. Ultrastructural analyses showed the presence of fenestrated capillaries, which indicates the possibility for permeability of larger molecules. Conclusion: The present research gives important and detailed information about the arterial and venous supply of the Harderian gland in hens that may serve as guidelines for future vascular and morphological investigations. [ABSTRACT FROM AUTHOR]

This article provides a comprehensive classical overview of the avian immune system, highlighting its unique components and functions. Although fundamentally similar to mammals, the avian immune system possesses distinct features in its tissues, cells, molecules, and genes. The study elaborates on the innate and adaptive immune components and critical functions in birds, detailing and artistically drawing the various organs such as the Bursa of Fabricius, thymus, spleen, and Harderian gland and cells involved in immunity. It discusses the role of innate immune cells and molecules along with the significance of B-and T lymphocytes immunoglobulins, antigen-presenting cells (APCs), especially macrophages and dendritic cells (DCs) and their related cytokines, including interleukins (ILs), emphasizing their crucial role in adaptive immunity especially activating various T lymphocytes. The article also underscores the complexity and efficiency of the avian immune system in combating pathogens and highlights the evolutionary adaptations that distinguish those from mammalian immune systems. This knowledge contributes to a better understanding of avian immunology and should go beyond this classical immune system, which is vital for improving disease management and vaccination strategies in birds. [ABSTRACT FROM AUTHOR]

Background: The present study aimed at determining histological structure and histochemical properties of the henna partridge (Alectoris chukar) Harderian gland periodically. Objectives: For this purpose, the Harderian glands of 12 (6 females + 6 males) healthy henna partridges aged 3 and 6 months were used. Methods: Totally removed Harderian gland tissue samples were kept in 10% neutral formolin for 36 hours and fixed. After washing, dehydrating, and polishing with known histological techniques, tissue pieces were blocked in paraffin. Results: We found that a thin connective tissue capsule surrounds the Harderian gland of the henna partridge and that the capsule sends septums into the gland and divides the gland into lobes and lobules. It was observed that the corpus glandulae consist of low or high prismatic epithelial cells. Within each lobe, there is a single main draining channel which has a very large lumen along with primary draining channels. Primary and main draining channel epithelial cells have a single-layered cuboidal structure. By Gordon-Sweet staining, it was found that reticular fiber bundles started from the connective tissue capsule that surrounded the organ and spread by branching. The reticular fiber bundles extended in thin strands to the periphery of the corpus glandulae. These reticular fiber bundles in the regions where the connective tissue septums widened are thicker and form a network. The reticular fiber bundles are seen in the basal part of the epithelial cells forming the main draining channel and especially in the crypt areas. Reticular fibers are also found around blood vessels. Strong Alcian blue (AB)-positive epithelial cells are observed in the corpus glandulae in AB pH=2.5 staining, but no periodic acid-Schiff (PAS)- positive epithelial cells are observed in PAS staining. While the majority of primary draining channel cells show a strong AB-positive reaction, a few cells showed a weak PAS-positive reaction. Regarding the main draining channel epithelium, goblet cells show a weak and strong AB-positive reaction in AB pH=2.5 staining method, respectively and a weak PAS-positive reaction in PAS staining method. Conclusion: In line with these findings, no significant difference was found in terms of general histological structure and histochemical properties of the 3- and 6-month-old henna partridge Harderian gland. [ABSTRACT FROM AUTHOR]

Simple Summary: MafB protein is indispensable for fetal testis morphogenesis, and it is important for the differentiation of immune cells such as macrophages. However, our understanding of MafB in rodents remains limited. In this study, MafB cDNA was cloned, and MafB expression was assessed in hamsters (Mesocricetus auratus), including gene regulation mechanisms by sex steroids in endocrine and non-endocrine tissues. Furthermore, bioinformatic tools were used to evaluate molecular characterization, three-dimensional structure, and phylogenetic relationships. The study results suggest a possible participation of MafB in the differentiation of Harderian gland (HG) macrophages and pancreatic β cells. MafB is a transcription factor that regulates macrophage differentiation. Macrophages are a traditional feature of the hamster Harderian gland (HG); however, studies pertaining to MafB expression in the HG are scant. Here, the full-length cDNA of the MafB gene in hamsters was cloned and sequenced. Molecular characterization revealed that MafB encodes a protein containing 323 amino acids with a DNA-binding domain, a transactivation domain, and a leucine zipper domain. qPCR assays indicated that MafB was expressed in different tissues of both sexes. The highest relative expression levels in endocrine tissues were identified in the pancreas. Gonadectomy in male hamsters was associated with significantly higher mRNA levels in the HG; replacement with dihydrotestosterone restored mRNA expression. The HG in male hamsters contained twofold more MafB mRNA than the HG of female hamsters. Adrenals revealed similar mRNA relative expression levels during the estrous cycle. The estrous phase was associated with higher mRNA levels in the ovary. A significantly up-regulated expression and sexual dimorphism of MafB was found in the pancreas. Therefore, MafB in the HG may play an active role in the macrophage differentiation required for phagocytosis activity and intraocular repair. Additionally, sex steroids appear to strongly influence the MafB expression in the HG and pancreas. These studies highlight the probable biological importance of MafB in immunological defense and pancreatic β cell regulation. [ABSTRACT FROM AUTHOR]

The mouse Harderian gland (HG) is a secretory gland that covers the posterior portion of the eyeball, opening at the base of the nictitating membrane. The HG serves to protect the eye surface from infection with its secretions. Mice open their eyelids at about 2 weeks of age, and the development of the HG primordium mechanically opens the eye by pushing the eyeball from its rear. Therefore, when HG formation is disturbed, the eye exhibits enophthalmos (the slit-eye phenotype), and a line of Fgf10+/− heterozygous loss-of-function mice exhibits slit-eye due to the HG atrophy. However, it has not been clarified how and when HGs degenerate and atrophy in Fgf10+/− mice. In this study, we observed the HGs in embryonic (E13.5 to E19), postnatal (P0.5 to P18) and 74-week-old Fgf10+/− mice. We found that more than half of the Fgf10+/− mice had markedly degenerated HGs, often unilaterally. The degenerated HG tissue had a melanized appearance and was replaced by connective tissue, which was observed by P10. The development of HGs was delayed or disrupted in the similar proportion of Fgf10+/− embryos, as revealed via histology and the loss of HG-marker expression. In situ hybridization showed Fgf10 expression was observed in the Harderian mesenchyme in wild-type as well as in the HG-lacking heterozygote at E19. These results show that the Fgf10 haploinsufficiency causes delayed or defective HG development, often unilaterally from the unexpectedly early neonatal period. [ABSTRACT FROM AUTHOR]

Introduction: Newcastle disease is a highly infectious disease caused by the Newcastle Disease Virus (NDV) and has a devastating financial impact on the global chicken industry. It was previously established that Leghorn and Fayoumi breeds of chicken exhibit variable resistance against NDV infection. The harderian gland is the less studied tissue of the chicken, known to play an essential role in the immune response.Methods: Our previous study, we reported differential gene expression and long noncoding RNAs (lncRNAs) between challenged and non-challenged chickens in the Harderian gland transcriptomic data. Now, we report the analysis of the same data studying the differential expression patterns between Leghorn and Fayoumi and between different timepoints during disease. First, the pipeline FHSpipe was used for identification of lncRNAs, followed by differential expression analysis by edgeR (GLM), functional annotation by OmicsBox, co-expression analysis using WGCNA and finally validation of selected lncRNAs and co-expressing genes using qRT-PCR.Results: Here, we observed that Leghorn showed a higher number of upregulated immune-related genes than Fayoumi in timepoint-based analysis, especially during the initial stages. Surprisingly, Fayoumi, being comparatively resistant, showed little difference between challenged and non-challenged conditions and different time points of the challenge. The breed-based analysis, which compared Leghorn with Fayoumi in both challenged and non-challenged conditions separately, identified several immune-related genes and positive co-expressing cis lncRNAs to be upregulated in Fayoumi when compared to Leghorn in both challenged and non-challenged conditions.Discussion: The current study shows that Leghorn, being comparatively more susceptible to NDV than Fayoumi, showed several immune-related genes and positive co-expressing cis lncRNAs upregulated in challenged Leghorn when compared to non-challenged Leghorn and also in different timepoints during challenge. While, breed-based analysis showed that there were more upregulated immune genes and positive cis-lncRNAs in Fayoumi than Leghorn. This result clearly shows that the differences in the expression of genes annotated with immune-related GO terms and pathways, i.e., immune-related genes and the co-expressing cis-lncRNAs between Leghorn and Fayoumi, and their role in the presence of differences in the resistance of Leghorn and Fayoumi chicken against NDV.Conclusion: These immune-genes and cis-lncRNAs could play a role in Fayoumi being comparatively more resistant to NDV than Leghorn. Our study elucidated the importance of lncRNAs during the host defense against NDV infection, paving the way for future research on the mechanisms governing the genetic improvement of chicken breeds.

Purpose: Instability of the tear film leads to evaporative dry eye disease (EDED), but the Harderian gland in some terrestrial vertebrates may produce novel lipids that stabilize the tear film and protect against dry eye. Here, the nonpolar lipids in the Harderian gland and tears of the rabbit but absent in human tears were identified and tested in preclinical studies to determine whether they could treat severe EDED. Methods: Lipids were identified primarily by atmospheric pressure chemical ionization mass spectrometry (MS) and fragmentation MS/MS. An identified lipid was synthesized and formulated as an emulsion and as a cyclodextrin (CD) clathrate. Following doses with test agents and controls, tear film breakup time (TBUT), tear production, corneal fluorescein staining, macrophage infiltration, and goblet cell survival were measured using standard tests at 0, 2 and 4 weeks in an animal model of EDED. Results: The lipid emulsion increased TBUT (P

MafB is a transcription factor that regulates macrophage differentiation. Macrophages are a traditional feature of the hamster Harderian gland (HG); however, studies pertaining to MafB expression in the HG are scant. Here, the full-length cDNA of the MafB gene in hamsters was cloned and sequenced. Molecular characterization revealed that MafB encodes a protein containing 323 amino acids with a DNA-binding domain, a transactivation domain, and a leucine zipper domain. qPCR assays indicated that MafB was expressed in different tissues of both sexes. The highest relative expression levels in endocrine tissues were identified in the pancreas. Gonadectomy in male hamsters was associated with significantly higher mRNA levels in the HG; replacement with dihydrotestosterone restored mRNA expression. The HG in male hamsters contained twofold more MafB mRNA than the HG of female hamsters. Adrenals revealed similar mRNA relative expression levels during the estrous cycle. The estrous phase was associated with higher mRNA levels in the ovary. A significantly up-regulated expression and sexual dimorphism of MafB was found in the pancreas. Therefore, MafB in the HG may play an active role in the macrophage differentiation required for phagocytosis activity and intraocular repair. Additionally, sex steroids appear to strongly influence the MafB expression in the HG and pancreas. These studies highlight the probable biological importance of MafB in immunological defense and pancreatic β cell regulation.

The mouse Harderian gland (HG) is a secretory gland that covers the posterior portion of the eyeball, opening at the base of the nictitating membrane. The HG serves to protect the eye surface from infection with its secretions. Mice open their eyelids at about 2 weeks of age, and the development of the HG primordium mechanically opens the eye by pushing the eyeball from its rear. Therefore, when HG formation is disturbed, the eye exhibits enophthalmos (the slit-eye phenotype), and a line of Fgf10+/− heterozygous loss-of-function mice exhibits slit-eye due to the HG atrophy. However, it has not been clarified how and when HGs degenerate and atrophy in Fgf10+/− mice. In this study, we observed the HGs in embryonic (E13.5 to E19), postnatal (P0.5 to P18) and 74-week-old Fgf10+/− mice. We found that more than half of the Fgf10+/− mice had markedly degenerated HGs, often unilaterally. The degenerated HG tissue had a melanized appearance and was replaced by connective tissue, which was observed by P10. The development of HGs was delayed or disrupted in the similar proportion of Fgf10+/− embryos, as revealed via histology and the loss of HG-marker expression. In situ hybridization showed Fgf10 expression was observed in the Harderian mesenchyme in wild-type as well as in the HG-lacking heterozygote at E19. These results show that the Fgf10 haploinsufficiency causes delayed or defective HG development, often unilaterally from the unexpectedly early neonatal period.

Infectious bronchitis virus (IBV) induces severe economic losses in chicken farms due to the emergence of new variants leading to vaccine breaks. The studied IBV strains belong to Massachusetts (Mass), Canadian 4/91, and California (Cal) 1737 genotypes that are prevalent globally. This study was designed to compare the impact of these three IBV genotypes on primary and secondary lymphoid organs. For this purpose, one-week-old specific pathogen-free chickens were inoculated with Mass, Canadian 4/91, or Cal 1737 IBV variants, keeping a mock-infected control. We examined the IBV replication in primary and secondary lymphoid organs. The molecular, histopathological, and immunohistochemical examinations revealed significant differences in lesion scores and viral distribution in these immune organs. In addition, we observed B-cell depletion in the bursa of Fabricius and the spleen with a significant elevation of T cells in these organs. Further studies are required to determine the functional consequences of IBV replication in lymphoid organs.

Long-term exposure to microgravity can cause alterations in the structure and function of the eyes, including the Harderian glands (HG) which are situated at the posterior part of the orbit in proximity to the eyeball. Whether microgravity will affect the morphology and function of HG and its mitochondrial homeostasis is not clear. In the present study, we investigated how tail suspension (TS) for 2 and 4 weeks (TS2 and TS4) affects mitochondrial ultrastructure and the underlying mechanisms involved in apoptosis, mitochondrial fission, autophagy, and fusion-related signaling in the HG. The results showed that after 2 weeks of TS treatment, the number of mitochondria in the HG of mice increased; however, the number of mitochondria in the TS4 group significantly decreased when compared to the TS2 group (p < 0.05). In the TS2 group, the rate of Parkin phosphorylation and the protein expression levels of OPA1, MFN1, and MFN2 were all found to be decreased. However, in the TS4 group, the rate of Parkin phosphorylation and the protein expression levels of OPA1 were increased compared with the TS2 group. In both TS groups, slight nuclear deformation and increased caspase-3 activity were observed. In general, the augmented quantity of mitochondria observed in the TS2 group may be attributed to reduced levels of mitochondrial autophagy and fusion. After 4 weeks of TS, the number of mitochondria decreased, which was attributed to an increase in the levels of mitochondrial autophagy and fusion. These findings indicate that mitochondria of HGs exhibit an adaptive response to the simulated microgravity environment, resulting in remodeling that enhances the completeness of mitochondrial morphology and structure. [ABSTRACT FROM AUTHOR]

The role of frataxin (FXN) has been studied extensively in Friedreich ataxia patients, however, the molecular bases underlining the sex steroid-dependent gene expression profiles of FXN in adult tissues are unknown. I describe the molecular characterization of hamster FXN by examining the sexually dimorphic expression and its regulation by sex steroids. Sequence analysis of FXN cDNA showed 630 bp-long ORF encoding 209 amino acids. qPCR analysis revealed that FXN is detected in a wide range of tissues, with the highest expression in the heart, liver, and epididymis, and the weakest expression in the lung, spleen, uterus, and gut. In the male Harderian gland (HG), castration decreased FXN expression, while dihydrotestosterone (DHT) administration reestablished levels. FXN expression levels were higher in the male HG than the female HG. Expression levels in endocrine tissues showed a certain degree of sexual dimorphism; the transcript in the testis was significantly higher than those in the ovary. The effects of the estrous cycle on FXN expression remained unchanged in the HG, ovary, and adrenal glands; however, in the pancreas, the FXN mRNA was overexpressed during proestrus and exhibited sexual dimorphism as compared to the male pancreas. The mRNA expression results indicated that Harderian FXN may play a dynamic role in intracellular Fe of heme required for processing cytochromes and other hemeproteins, also suggesting that the moderate sexual dimorphism present in the HG and gonads could be regulated by androgens, while sexually dimorphic expression of FXN in the female pancreas may be controlled by sex steroids. [ABSTRACT FROM AUTHOR]

Health risks from galactic cosmic rays (GCR) in space travel above low earth orbit remain a concern. For many years accelerator experiments investigating space radiation induced prevalence of murine Harderian gland (HG) tumorigenesis have been performed to help estimate GCR risks. Most studies used acute, relatively low fluence, exposures. Results on a broad spectrum of individual ions and linear energy transfers (LETs) have become available. However, in space, the crew are exposed simultaneously to many different GCR. Recent upgrades at the Brookhaven NASA Space Radiation Laboratory (NSRL) now allow mixtures in the form of different one-ion beams delivered in rapid sequence. This paper uses the results of three two-ion mixture experiments to illustrate conceptual, mathematical, computational, and statistical aspects of synergy analyses and also acts as an interim report on the mixture experiments' results. The results were interpreted using the following: (a) accumulated data from HG one-ion accelerator experiments; (b) incremental effect additivity synergy theory rather than simple effect additivity synergy theory; (c) parsimonious models for one-ion dose-effect relations; and (d), computer-implemented numerical methods encapsulated in freely available open source customized software. The main conclusions are the following. As yet, the murine HG tumorigenesis experimental studies show synergy in only one case out of three. Moreover, some theoretical arguments suggest GCR-simulating mixed beams are not likely to be synergistic. However, more studies relevant to possible synergy are needed by various groups that are studying various endpoints. Especially important is the possibility of synergy among high-LET radiations, since individual high-LET ions have large relative biological effectiveness for many endpoints. Selected terminology, symbols, and abbreviations. DER - dose-effect relation; E(d) - DER of a one-ion beam, where d is dose; HG prevalence p - in this paper, p is the number of mice with at least one Harderian gland tumor divided by the number of mice that are at risk of developing Harderian gland tumors (so that in this paper prevalence p can never, conceptually speaking, be greater than 1); IEA - incremental effect additivity synergy theory; synergy level - a specification, exemplified in Fig. 5, of how clear-cut an observed synergy is; mixmix principle - a consistency condition on a synergy theory which insures that the synergy theory treats mixtures of agent mixtures in a mathematically self-consistent way; NTE - non-targeted effect(s); NSNA - neither synergy nor antagonism; SEA - simple effect additivity synergy theory; TE - targeted effect(s); β* - ion speed relative to the speed of light, with 0 < β* < 1; SLI - swift light ion(s).

Disease has large negative impacts on poultry production. A more comprehensive understanding of host-pathogen interaction can lead to new and improved strategies to maintain health. In particular, host genetic factors can lead to a more effective response to pathogens, hereafter termed resistance. Fayoumi and Leghorn chicken lines have demonstrated relative resistance and susceptibility, respectively, to the Newcastle disease virus (NDV) vaccine strain and many other pathogens. This biological model was used to better understand the host response to a vaccine strain of NDV across three tissues and time points, using RNA-seq. Analyzing the Harderian gland, trachea, and lung tissues together using weighted gene co-expression network analysis (WGCNA) identified important genes that were co-expressed and associated with parameters including: genetic line, days post-infection (dpi), challenge status, sex, and tissue. Pathways and driver genes, such as EIF2AK2, MPEG1, and TNFSF13B, associated with challenge status, dpi, and genetic line were of particular interest as candidates for disease resistance. Overall, by jointly analyzing the three tissues, this study identified genes and gene networks that led to a more comprehensive understanding of the whole animal response to lentogenic NDV than that obtained by analyzing the tissues individually.

The tonus of autonomous centers reflected in the morpho-functional features of the organs in mammals. The study aimed to establish the influence of the autonomous regulation and its’ typological peculiarities on the structural features of the rabbits’ Harderian gland. Clinically healthy male rabbits, four months old, weighing 3.6-3.9 kg, were selected for the research. Based on the study of heart rate variability, three types of autonomous regulation were outlined, according to which three groups of rabbits were formed: ST rabbits (sympathetic dominant regulation), PS rabbits (parasympathetic dominant regulation), and NT rabbits (combined sympathetic and parasympathetic regulation). After euthanasia, the Harderian gland was dissected in all animals. Histological specimens were prepared and a morphometric examination was performed. ST rabbits corresponded to the minimal indicators in the tubular alveoli in both parts of the gland, as well as the maximum indicators of capsule thickness. NT rabbits corresponded to the maximum values of the acini area in the pink lobe, and in the white lobe - the maximal values of the cross-sectional area of the tubular alveoli, its wall area, and the epithelium height. The maximum acini area corresponded to PS rabbits in the white lobe, and in the pink lobe - the maximum indicators of the tubular alveoli cross-sectional area, and epithelial height. The pink and white lobes’ structure of the rabbit’s Harderian gland was affected by the combined tonus of the sympathetic and parasympathetic centers. The findings elucidate the regulatory and trophic effects on the Harderian gland in rabbits.

Background: The orbital glands, viz. lacrimal gland, superficial and deep gland of third eyelid (LG, SGT and HG), are important for normal eye functions. These glands have different functions in various animals. The information about the enzyme histochemical nature of prenatal orbital glands in Indian buffalo seems to be unavailable. Therefore, the study was planned on orbital glands of six full term recently died fetuses from animals with dystocia. Methods: The frozen sections of all these glands were subjected to standard localization protocols for Alkaline Phosphatase (AKPase), Glucose 6 phosphatase (G-6-Pase), Lactate dehydrogenase (LDH), Succinate dehydrogenase (SDH), Glucose 6 phosphate dehydrogenase (G-6-PD), Nicotinamide Adenine Dinucleotide Hydrogen Diaphorase (NADHD), Nicotinamide Adenine Dinucleotide Phosphate Hydrogen diaphorase (NADPHD), Dihydroxy phenylalanine oxidase (DOPA-O), Tyrosinase, non-specific esterase (NSE) and Carbonic anhydrase (CAse). Results: The results revealed a mixed spectrum of reaction for the above enzymes in LG, SGT and HG which ranged from moderate (for LDH in SGT) to intense (for most of the enzymes in all three glands). However, DOPA-O, Tyrosinase and CAse did not show any reaction. From the present study, it can be postulated that the orbital glands of fetus have a high activity of metabolism as it has many developmental and functional activities which were mediated with the higher activity of the enzymes involved. [ABSTRACT FROM AUTHOR]

Infectious laryngotracheitis (ILT) is an acute respiratory disease of poultry caused by infectious laryngotracheitis virus (ILTV). Control of the disease with live attenuated vaccines administered via eye drop build upon immune responses generated by the eye-associated lymphoid tissues. The aim of this study was to assess cytokine and lymphocyte changes in the conjunctiva-associated lymphoid tissues (CALT) and Harderian gland (HG) stimulated by the ocular inoculation of the ILTV chicken embryo origin (CEO) vaccine strain and virulent strain 63140. This study offers strong evidence to support the roles that the CALT and HG play in the development of protective ILTV immune responses. It supports the premise that ILTV-mediated immunomodulation favors the B cell response over those of T cells. Further, it provides evidence that expansions of CD8α+ cells, with the concomitant expression of the Granzyme A gene, are key to reducing viral genomes in the CALT and halting ILTV cytolytic replication in the conjunctiva. Ultimately, this study revealed that the early upregulation of interleukin (IL)-12p40 and Interferon (IFN)-γ cytokine genes, which shape the antigen-specific cell-mediated immune responses, retarded the decline of virus replication, and enhanced the development of lesions in the conjunctiva epithelium.

Experimental studies reporting murine Harderian gland (HG) tumourigenesis have been a NASA concern for many years. Studies used particle accelerators to produce beams that, on beam entry, consist of a single isotope also present in the galactic cosmic ray (GCR) spectrum. In this paper synergy theory is described, potentially applicable to corresponding mixed-field experiments, in progress, planned, or hypothetical. The "obvious" simple effect additivity (SEA) approach of comparing an observed mixture dose-effect relationship (DER) to the sum of the components' DERs is known from other fields of biology to be unreliable when the components' DERs are highly curvilinear. Such curvilinearity may be present at low fluxes such as those used in the one-ion HG experiments due to non-targeted ('bystander') effects, in which case a replacement for SEA synergy theory is needed. This paper comprises in silico modeling of published experimental data using a recently introduced, arguably optimal, replacement for SEA: incremental effect additivity (IEA). Customized open-source software is used. IEA is based on computer numerical integration of non-linear ordinary differential equations. To illustrate IEA synergy theory, possible rapidly-sequential-beam mixture experiments are discussed, including tight 95% confidence intervals calculated by Monte-Carlo sampling from variance-covariance matrices. The importance of having matched one-ion and mixed-beam experiments is emphasized. Arguments are presented against NASA over-emphasizing accelerator experiments with mixed beams whose dosing protocols are standardized rather than being adjustable to take biological variability into account. It is currently unknown whether mixed GCR beams sometimes have statistically significant synergy for the carcinogenesis endpoint. Synergy would increase risks for prolonged astronaut voyages in interplanetary space.

BackgroundNewcastle disease virus, in its most pathogenic form, threatens the livelihood of rural poultry farmers where there is a limited infrastructure and service for vaccinations to prevent outbreaks of the virus. Previously reported studies on the host response to Newcastle disease in chickens have not examined the disease under abiotic stressors, such as heat, which commonly experienced by chickens in regions such as Africa. The objective of this study was to elucidate the underlying biological mechanisms that contribute to disease resistance in chickens to the Newcastle disease virus while under the effects of heat stress.ResultsDifferential gene expression analysis identified genes differentially expressed between treated and non-treated birds across three time points (2, 6, and 10 days post-infection) in Fayoumi and Leghorn birds. Across the three time points, Fayoumi had very few genes differentially expressed between treated and non-treated groups at 2 and 6 days post-infection. However, 202 genes were differentially expressed at 10 days post-infection. Alternatively, Leghorn had very few genes differentially expressed at 2 and 10 days post-infection but had 167 differentially expressed genes at 6 days post-infection. Very few differentially expressed genes were shared between the two genetic lines, and pathway analysis found unique signaling pathways specific to each genetic line. Fayoumi had significantly lower viral load, higher viral clearance, higher anti-NDV antibody levels, and fewer viral transcripts detected compared to Leghorns. Fayoumis activated immune related pathways including SAPK/JNK and p38 MAPK signaling pathways at earlier time points, while Leghorn would activate these same pathways at a later time. Further analysis revealed activation of the GP6 signaling pathway that may be responsible for the susceptible Leghorn response.ConclusionsThe findings in this study confirmed our hypothesis that the Fayoumi line was more resistant to Newcastle disease virus infection compared to the Leghorn line. Within line and interaction analysis demonstrated substantial differences in response patterns between the two genetic lines that was not observed from the within line contrasts. This study has provided novel insights into the transcriptome response of the Harderian gland tissue during Newcastle disease virus infection while under heat stress utilizing a unique resistant and susceptible model.

Background The orbital glands, viz. lacrimal gland, superficial and deep gland of third eyelid (LG, SGT and HG), are important for normal eye functions. These glands have different functions in various animals. The information about the enzyme histochemical nature of prenatal orbital glands in Indian buffalo seems to be unavailable. Therefore, the study was planned on orbital glands of six full term recently died fetuses from animals with dystocia. Methods The frozen sections of all these glands were subjected to standard localization protocols for Alkaline Phosphatase (AKPase), Glucose 6 phosphatase (G-6-Pase), Lactate dehydrogenase (LDH), Succinate dehydrogenase (SDH), Glucose 6 phosphate dehydrogenase (G-6-PD), Nicotinamide Adenine Dinucleotide Hydrogen Diaphorase (NADHD), Nicotinamide Adenine Dinucleotide Phosphate Hydrogen diaphorase (NADPHD), Dihydroxy phenylalanine oxidase (DOPA-O), Tyrosinase, non-specific esterase (NSE) and Carbonic anhydrase (CAse). Results The results revealed a mixed spectrum of reaction for the above enzymes in LG, SGT and HG which ranged from moderate (for LDH in SGT) to intense (for most of the enzymes in all three glands). However, DOPA-O, Tyrosinase and CAse did not show any reaction. From the present study, it can be postulated that the orbital glands of fetus have a high activity of metabolism as it has many developmental and functional activities which were mediated with the higher activity of the enzymes involved.

The Harderian gland (HG) of Rattus norvegicus is an orbital gland secreting lipids that accumulate in excess under condition of increased lipid metabolism. To study the response elicitated by lipid overload in rat HG, we housed the animals in thermoneutral conditions (28−30°C) in association to high fat diet (HFD). In HFD rats alterated blood lipid levels result in lipid accumulation in HG as demonstrated by the increased gland weight and histochemical/ultrastructural analyses. The HFD‐caused oxidative stress forces the gland to trigger antioxidant defense mechanisms and autophagic process, such as lipophagy and mitophagy. Induction of mitochondrial DNA (mtDNA) damage and repair was stronger in HFD‐rat HGs. An increase in marker expression levels of mitochondrial biogenesis, fission, and fusion occurred to counteract mtDNA copy number reduction and mitophagy. Therefore, the results demonstrate that rat HG activates autophagy as survival strategy under conditions of increased lipid metabolism and suggest a key role for mitophagy and membrane dynamics in the mitochondrial adaptive response to HFD. [ABSTRACT FROM AUTHOR]

This study used both anatomical and histological techniques to investigate the orbital gland's topographic relationship with the surrounding system, using the hoopoe and cattle egret as biological models. Hoopoe has a spindle‐shaped lacrimal gland that is suspended on the lateral edge of the frontal bone, whereas cattle egret has a tiny lacrimal gland that is embedded posteriorly within the periorbital fascia. The hoopoe's lacrimal gland has a single duct that runs parallel to the nasolacrimal duct and opens into the posterior nostril hole. In the cattle egret, the tubule‐alveolar secretory components comprise neutral and acid glycosaminoglycan. In addition, the Harderian gland is found in both these species, but their draining ducts differ; the Harderian gland of the hoopoe opens into the anterodorsal to the conjunctival fornix, whereas the Harderian gland of the egret opens anteriorly. In both hoopoe and egret, the secretions of Harderian gland include neutral and acid glycosaminoglycan. The Harderian gland is categorized as type II in hoopoe and type I in cattle egrets. The present results concluded that both orbital glands of two bird species studied play an essential role in eye health, where cleaning and lubrication of the cornea surface. Furthermore, the lacrimal gland's location and secretory features may strengthen the olfactory sensitivity of hoopoe, which relies heavily on scent to locate their food, whereas egret relies heavily on visual cues. [ABSTRACT FROM AUTHOR]

Behind each eye of the chicken resides a unique lymph tissue, the Harderian gland, for which RNA sequencing (RNA-seq) analysis is novel. We characterized the response of this tissue to Newcastle disease virus (NDV) in two inbred lines with different susceptibility to NDV across three time points. Three-week-old relatively resistant (Fayoumi) and relatively susceptible (Leghorn) birds were inoculated with a high-titered (107EID50) La Sota strain of NDV via an oculonasal route. At 2, 6, and 10 days post infection (dpi) Harderian glands were collected and analyzed via RNA-seq. The Fayoumi had significantly more detectable viral transcripts in the Harderian gland at 2 dpi than the Leghorn, but cleared the virus by 6 dpi. At all three time points, few genes were declared differentially expressed (DE) between the challenged and nonchallenged birds, except for the Leghorns at 6 dpi, and these DE genes were predicted to activate an adaptive immune response. Relative to the Leghorn, the Fayoumi was predicted to activate more immune pathways in both challenged and nonchallenged birds suggesting a more elevated immune system in the Fayoumis under homeostatic conditions. Overall, this study helped characterize the function of this important tissue and its response to NDV.

LatY136F knock-in mice were recently proposed as an animal model for immunoglobulin G4 (IgG4)-related disease. In this study, we investigated whether LatY136F knock-in mice exhibit ophthalmic lesions, specifically in the lacrimal and Harderian glands. Lacrimal glands, Harderian glands, and adherent lymphoid follicle lesions were dissected from LatY136F knock-in mice and wild type (WT) C57BL/6 mice between 6 and 24 weeks of age. Tissues were stained with hematoxylin-eosin, immunoglobulin G (IgG), and anti-IgG1, a homologue of human IgG4, for histopathological analysis. In LatY136F knock-in mice, IgG1-positive cells infiltrated the space between the lacrimal gland acinar cells at 6, 9, 12, and 20 weeks or order, and the number of IgG1-positive cells did not differ significantly between these age groups. Infiltration of IgG1-positive inflammatory cell was also observed in the Harderian glands of LatY136F knock-in mice at all ages. The ratio of IgG1/IgG-positive cells averaged 80 and 67% in the lacrimal and Harderian glands, respectively. Dense IgG1-positive lesions were also seen in tissues adjacent to the lacrimal and Harderian glands in some LatY136F knock-in mice. In contrast, there were almost no IgG1-positive cell infiltrates in the lacrimal and Harderian glands of WT mice. IgG1-positive cells infiltrate the lacrimal and Harderian glands of LatY136F knock-in mice, indicating that LatY136F knock-in mice could be a representative animal model for IgG4-related ophthalmic disease. [ABSTRACT FROM AUTHOR]

The tonus of autonomous centers reflected in the morpho-functional features of the organs in mammals. The study aimed to establish the influence of the autonomous regulation and its' typological peculiarities on the structural features of the rabbits' Harderian gland. Clinically healthy male rabbits, four months old, weighing 3.6-3.9 kg, were selected for the research. Based on the study of heart rate variability, three types of autonomous regulation were outlined, according to which three groups of rabbits were formed: ST rabbits (sympathetic dominant regulation), PS rabbits (parasympathetic dominant regulation), and NT rabbits (combined sympathetic and parasympathetic regulation). After euthanasia, the Harderian gland was dissected in all animals. Histological specimens were prepared and a morphometric examination was performed. ST rabbits corresponded to the minimal indicators in the tubular alveoli in both parts of the gland, as well as the maximum indicators of capsule thickness. NT rabbits corresponded to the maximum values of the acini area in the pink lobe, and in the white lobe - the maximal values of the cross-sectional area of the tubular alveoli, its wall area, and the epithelium height. The maximum acini area corresponded to PS rabbits in the white lobe, and in the pink lobe - the maximum indicators of the tubular alveoli cross-sectional area, and epithelial height. The pink and white lobes' structure of the rabbit's Harderian gland was affected by the combined tonus of the sympathetic and parasympathetic centers. The findings elucidate the regulatory and trophic effects on the Harderian gland in rabbits. [ABSTRACT FROM AUTHOR]

Herein is reported, for the first time in the rat Harderian gland (HG), the counteractive action of melatonin (Mlt), a well‐known antioxidant radical scavenger, on the increased oxidative stress damages induced by a pro‐oxidant substance, cadmium (Cd), an environmental pollutant also considered as endocrine disruptor. HG, an infraorbital gland present in almost all terrestrial vertebrates, produces a lipid secretion to lubricate the eyeball, as well as porphyrin/Mlt as light transducers. Moreover, HG is an extra‐gonadal source of steroid sex hormones. Via ex vivo experiments lasting for 24 h, we verified the increased lipid peroxidation in Cd‐treated glands, producing morphological alteration of the glandular epithelium, as well as an increased porphyrins accumulation. Moreover, Cd also induced a decreased protein level of the steroidogenic enzymes steroidogenic acute regulatory (StAR) and 3βHSD, and an increased mast cell number. Results obtained with Mlt cotreatment demonstrated that it decreased the levels of Cd‐induced oxidative damage, with reversal of all the observed modification. Furthermore, the TUNEL assay showed that the increased number of apoptotic cells in Cd‐treated HG was counteracted by the contemporaneous Mlt administration. Results confirmed that Mlt treatment restored the levels of two autophagy markers, LC3 and p62, counteracting the autophagy Cd‐induced. Interestingly, the positive effects of Mlt alone were highlighted by the decreased rate of lipid peroxidation as compared with the control, confirming its antioxidant action. Combined data further confirmed the antioxidant action of Mlt in counteracting the degeneration provoked by reactive oxygen species (ROS) in the rat HG, a tissue extremely susceptible to oxidative stress condition. Research Highlights: –Oxidative stress Cd‐induced produces morphological and biochemical alteration in the rat Harderian gland.–Melatonin cotreatment counteracts all the damages provoked by oxidative disorders.–Melatonin alone reduces the rate of lipid peroxidation, thanks to its antioxidant properties. [ABSTRACT FROM AUTHOR]

Complex mixed radiation fields exist in interplanetary space, and little is known about their late effects on space travelers. In silico synergy analysis default predictions are useful when planning relevant mixed-ion-beam experiments and interpreting their results. These predictions are based on individual dose-effect relationships (IDER) for each component of the mixed-ion beam, assuming no synergy or antagonism. For example, a default hypothesis of simple effect additivity has often been used throughout the study of biology. However, for more than a century pharmacologists interested in mixtures of therapeutic drugs have analyzed conceptual, mathematical and practical questions similar to those that arise when analyzing mixed radiation fields, and have shown that simple effect additivity often gives unreasonable predictions when the IDER are curvilinear. Various alternatives to simple effect additivity proposed in radiobiology, pharmacometrics, toxicology and other fields are also known to have important limitations. In this work, we analyze upcoming murine Harderian gland (HG) tumor prevalence mixed-beam experiments, using customized open-source software and published IDER from past single-ion experiments. The upcoming experiments will use acute irradiation and the mixed beam will include components of high atomic number and energy (HZE). We introduce a new alternative to simple effect additivity, "incremental effect additivity", which is more suitable for the HG analysis and perhaps for other end points. We use incremental effect additivity to calculate default predictions for mixture dose-effect relationships, including 95% confidence intervals. We have drawn three main conclusions from this work. 1. It is important to supplement mixed-beam experiments with single-ion experiments, with matching end point(s), shielding and dose timing. 2. For HG tumorigenesis due to a mixed beam, simple effect additivity and incremental effect additivity sometimes give default predictions that are numerically close. However, if nontargeted effects are important and the mixed beam includes a number of different HZE components, simple effect additivity becomes unusable and another method is needed such as incremental effect additivity. 3. Eventually, synergy analysis default predictions of the effects of mixed radiation fields will be replaced by more mechanistic, biophysically-based predictions. However, optimizing synergy analyses is an important first step. If mixed-beam experiments indicate little synergy or antagonism, plans by NASA for further experiments and possible missions beyond low earth orbit will be substantially simplified.

This report describes a 4-year-old, male, intact African pygmy hedgehog (Atelerix albiventris) that was presented for evaluation of left-sided exophthalmos with swelling and protrusion of the nictitating membrane. A suspected neoplasm, presumed to originate from the Harderian gland, was identified in the ventromedial orbit in association with the nictitating membrane. The mass was surgically removed and diagnosed as an acinic cell carcinoma, but reoccurred 5 months post-operatively. Humane euthanasia was elected, and a necropsy with histopathology confirmed the initial diagnosis of acinic cell carcinoma. This case suggests that acinic cell carcinoma should be on the differential list for a non-painful orbital mass in the African pygmy hedgehog. [ABSTRACT FROM AUTHOR]

Increased cancer risk remains a primary concern for travel into deep space and may preclude manned missions to Mars due to large uncertainties that currently exist in estimating cancer risk from the spectrum of radiations found in space with the very limited available human epidemiological radiation-induced cancer data. Existing data on human risk of cancer from X-ray and gamma-ray exposure must be scaled to the many types and fluences of radiations found in space using radiation quality factors and dose-rate modification factors, and assuming linearity of response since the shapes of the dose responses at low doses below 100 mSv are unknown. The goal of this work was to reduce uncertainties in the relative biological effect (RBE) and linear energy transfer (LET) relationship for space-relevant doses of charged-particle radiation-induced carcinogenesis. The historical data from the studies of Fry et al. and Alpen et al. for Harderian gland (HG) tumors in the female CB6F1 strain of mouse represent the most complete set of experimental observations, including dose dependence, available on a specific radiation-induced tumor in an experimental animal using heavy ion beams that are found in the cosmic radiation spectrum. However, these data lack complete information on low-dose responses below 0.1 Gy, and for chronic low-dose-rate exposures, and there are gaps in the LET region between 25 and 190 keV/μm. In this study, we used the historical HG tumorigenesis data as reference, and obtained HG tumor data for 260 MeV/u silicon (LET ∼70 keV/μm) and 1,000 MeV/u titanium (LET ∼100 keV/μm) to fill existing gaps of data in this LET range to improve our understanding of the dose-response curve at low doses, to test for deviations from linearity and to provide RBE estimates. Animals were also exposed to five daily fractions of 0.026 or 0.052 Gy of 1,000 MeV/u titanium ions to simulate chronic exposure, and HG tumorigenesis from this fractionated study were compared to the results from single 0.13 or 0.26 Gy acute titanium exposures. Theoretical modeling of the data show that a nontargeted effect model provides a better fit than the targeted effect model, providing important information at space-relevant doses of heavy ions.

Abstract Background The aim of the present study is to describe the morphological and histological features of Harderian gland (HG) in long-legged wadding bird (ibis) and different domestic birds (duck, goose, and pigeon). The HG of forty adult male and female from the four avian species constituted the material of the study. Result The HG extended from the optic nerve to the rostral part of the eyeball presents two extremities, one posterior and other anterior, from which the excretory duct was arisen. Between two extremities of the gland, middle groove is present in case of duck and geese, while middle isthmus is present in case of ibis. In pigeon, the gland appeared pointed oval in shape. Microscopically, the HG was multilobular; each lobule was composed of secretory acini that were lined by a single layer of columnar epithelium. In all studied birds, a single duct located centrally with an irregular lumen. In goose, there were crypts along the duct while in duck, the central lumen had villi-like folds projected into the central canal of the tubules. In ibis, the irregular lumen was narrow and elongated while in pigeon, the gland had a central cavity that collected the secretion from tubules arranged radially around the cavity; also, the gland mainly contained both acidic and neutral mucopolysaccharides. Conclusion This work revealed that the histological structure of HG in the four avian species showed characteristic features and thus explained the relationship between their habits and behavior on the structure of this gland.

Introduction: Newcastle disease is a highly infectious disease caused by the Newcastle Disease Virus (NDV) and has a devastating financial impact on the global chicken industry. It was previously established that Leghorn and Fayoumi breeds of chicken exhibit variable resistance against NDV infection. The harderian gland is the less studied tissue of the chicken, known to play an essential role in the immune response. Methods: Our previous study, we reported differential gene expression and long noncoding RNAs (lncRNAs) between challenged and non-challenged chickens in the Harderian gland transcriptomic data. Now, we report the analysis of the same data studying the differential expression patterns between Leghorn and Fayoumi and between different timepoints during disease. First, the pipeline FHSpipe was used for identification of lncRNAs, followed by differential expression analysis by edgeR (GLM), functional annotation by OmicsBox, co-expression analysis using WGCNA and finally validation of selected lncRNAs and co-expressing genes using qRT-PCR. Results: Here, we observed that Leghorn showed a higher number of upregulated immune-related genes than Fayoumi in timepoint-based analysis, especially during the initial stages. Surprisingly, Fayoumi, being comparatively resistant, showed little difference between challenged and non-challenged conditions and different time points of the challenge. The breed-based analysis, which compared Leghorn with Fayoumi in both challenged and non-challenged conditions separately, identified several immune-related genes and positive co-expressing cis lncRNAs to be upregulated in Fayoumi when compared to Leghorn in both challenged and non-challenged conditions. Discussion: The current study shows that Leghorn, being comparatively more susceptible to NDV than Fayoumi, showed several immune-related genes and positive co-expressing cis lncRNAs upregulated in challenged Leghorn when compared to non-challenged Leghorn and also in different timepoints during challenge. While, breed-based analysis showed that there were more upregulated immune genes and positive cis-lncRNAs in Fayoumi than Leghorn. This result clearly shows that the differences in the expression of genes annotated with immune-related GO terms and pathways, i.e., immune-related genes and the co-expressing cis-lncRNAs between Leghorn and Fayoumi, and their role in the presence of differences in the resistance of Leghorn and Fayoumi chicken against NDV. Conclusion: These immune-genes and cis-lncRNAs could play a role in Fayoumi being comparatively more resistant to NDV than Leghorn. Our study elucidated the importance of lncRNAs during the host defense against NDV infection, paving the way for future research on the mechanisms governing the genetic improvement of chicken breeds., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Vanamamalai, Priyanka, Kannaki and Sharma.)

Purpose: The study aims to characterize the robustness of distinct clinical assessments in identifying the underlying conditions of dry eye disease (DED), with a specific emphasis on the involvement of conjunctival goblet cells., Methods: Seven rabbits receiving surgical removal of the lacrimal and Harderian glands were divided into two groups, one with ablation of conjunctival goblet cells by topical soaking of trichloroacetic acid (TCA) to the bulbar conjunctiva ( n  = 3) and one without ( n  = 4), and the conditions of DED were assessed weekly using Schirmer test, tear breakup time (TBUT), tear osmolarity, and National Eye Institute (NEI) fluorescein staining grading. After 8 weeks, the rabbits were sacrificed, and the eyes were enucleated for histopathological examination., Results: Histopathological analysis revealed corneal epithelial thinning in both groups. While TCA soaking significantly decreased the density of conjunctival goblet cells, DED rabbits without TCA also showed a partial reduction in goblet cell density, potentially attributable to dacryoadenectomy. Both groups showed significant decreases in Schirmer test and TBUT, as well as an increase in tear osmolarity. In DED rabbits with TCA soaking, tear osmolarity increased markedly, suggesting that tear osmolarity is highly sensitive to loss and/or dysfunction of conjunctival goblet cells. Fluorescein staining was gradually and similarly increased in both groups, suggesting that fluorescein staining may not reveal an early disruption of the tear film until the prolonged progression of DED., Conclusion: The Schirmer test, TBUT, tear osmolarity, and NEI fluorescein grading are distinct, yet complementary, clinical assessments for the evaluation of DED. By performing these assessments in definitive DED rabbit models, both with and without ablation of conjunctival goblet cells, the role of these cells in the homeostasis of tear osmolarity is highlighted. Characterizing the robustness of these assessments in identifying the underlying conditions of DED will guide a more appropriate management for patients with DED.

PurposeTo determine the source(s) of vitamin D in tear fluid and examine the expression of the endocytic proteins and putative vitamin D transporters megalin and cubilin in lacrimal and Harderian glands.MethodsWild-type, heterozygous, and vitamin D receptor (VDR) knockout C57BL/6 mice were used, with a subset of knockout mice fed a replenishment diet for some studies. Mouse lacrimal and Harderian glands from each group were used to measure megalin and cubilin by RT-PCR, Western blot, and immunohistochemistry. New Zealand white rabbits were used to collect lacrimal and accessory gland fluid for vitamin D mass spectroscopy measurements.ResultsTen-week-old knockout mice were significantly (P < 0.05) smaller than wild-type mice. Real-time PCR and Western blot showed decreased expression of megalin and cubilin in select VDR knockout mouse groups. Immunohistochemistry showed apical duct cell megalin staining and weaker megalin staining in VDR knockout mice compared with controls. Vitamin D2 was more prevalent in rabbit lacrimal and accessory gland fluid than vitamin D3, and greater amounts of Vitamin D2 were found in in tear fluid obtained directly from lacrimal and accessory glands as compared with plasma concentrations.ConclusionsThis is the first study to demonstrate the presence of megalin and cubilin in lacrimal and accessory glands responsible for producing tear fluid. The results strengthen the hypothesis that megalin and cubilin are likely involved in the secretory pathway of vitamin D into tear fluid by the duct cells.

ObjectiveTo describe the lacrimal system of snakes using contrast micro-computed tomography (micro-CT) with 3-dimensional reconstruction, fluorescein passage ('Jones') testing, histology, and gross dissection.Animals studiedOne royal python and 19 snake cadavers representing 10 species.ProceduresDirect observation following injection of fluorescein into the subspectacular space, micro-CT following injection of three contrast agents into the subspectacular space, gross dissection following injection of latex into the subspectacular space, and histopathology.ResultsInjection of fluorescein confirmed patency, but not course of the lacrimal duct. Barium enabled clear visualization of the lacrimal duct, whereas two iodinated contrast agents proved inadequate. Collectively, micro-CT, anatomic dissections, and histology suggest tears are produced by a single, large, serous, retrobulbar gland, released into the subspectacular space via several ductules, and drained through a single punctum originating in the ventronasal subspectacular space, and the lacrimal duct, which takes one of three routes of variable tortuosity before opening into the oral cavity in close association with the opening of the duct of the vomeronasal organ.ConclusionsThe ophidian lacrimal duct has a generally tortuous course, and the details of its anatomy are species-variable. The tortuous course of the duct likely predisposes snakes to duct occlusion and must be considered when planning medical and surgical interventions in snakes with pseudobuphthalmos and subspectacular abscessation.

Photoperiod is an important factor of mammalian seasonal rhythm. The Harderian gland (HG) appears to act as a “standby” structure of the retinal-pineal axis, mediating light signals in vitro and neuroendocrine regulation in vivo; however, the effect of photoperiod on the HG is not clear. Here, we studied morphological differences in the HG of female striped dwarf hamsters (Cricetulus barabensis), a small mammal that experiences an annual rhythm, under different photoperiods (i.e., SP, short photoperiod; MP, moderate photoperiod; LP, long photoperiod), and further investigated the molecular mechanisms related to these morphological differences. Results showed that body weight, carcass weight, and HG weight were higher in the SP and LP groups than that in the MP group. Protein expression of hydroxyindole-o-methyltransferase, a key enzyme in melatonin synthesis, was higher in the SP group than in the other two groups. Somatostatin showed highest expression in the LP group. Furthermore, comparison of changes in the HG ultrastructure demonstrated autolysosome formation in the SP group. Protein aggregation and mRNA expression of LC3 and protein expression of LC3II/LC3I were higher in the SP group than in the MP group, indicating elevated autophagy under SP. Chromatin agglutination and mitochondrial damage were observed and bax/bcl2 and cytochrome C expression increased at the protein and mRNA levels in the SP and LP groups, suggesting increased apoptosis. Protein expression of dynamin-related protein 1 and mitochondrial fission factor (Mff) were highest in the SP group, suggesting elevated mitochondrial fission. Protein expression levels of adenosine triphosphate (ATP) synthase and citrate synthase were lower in the LP group than in the SP and MP groups. These results indicated that autophagy and apoptosis imbalance under SP and LP conditions may have led to HG weight loss and up-regulation of mitochondrial apoptosis may have weakened mitochondrial function under LP conditions. Finally, melatonin synthesis appeared to be positively correlated with the time hamsters entered darkness.

Disease has large negative impacts on poultry production. A more comprehensive understanding of host–pathogen interaction can lead to new and improved strategies to maintain health. In particular, host genetic factors can lead to a more effective response to pathogens, hereafter termed resistance. Fayoumi and Leghorn chicken lines have demonstrated relative resistance and susceptibility, respectively, to the Newcastle disease virus (NDV) vaccine strain and many other pathogens. This biological model was used to better understand the host response to a vaccine strain of NDV across three tissues and time points, using RNA-seq. Analyzing the Harderian gland, trachea, and lung tissues together using weighted gene co-expression network analysis (WGCNA) identified important genes that were co-expressed and associated with parameters including: genetic line, days post-infection (dpi), challenge status, sex, and tissue. Pathways and driver genes, such as EIF2AK2, MPEG1, and TNFSF13B, associated with challenge status, dpi, and genetic line were of particular interest as candidates for disease resistance. Overall, by jointly analyzing the three tissues, this study identified genes and gene networks that led to a more comprehensive understanding of the whole animal response to lentogenic NDV than that obtained by analyzing the tissues individually.

Abstract Background Newcastle disease virus, in its most pathogenic form, threatens the livelihood of rural poultry farmers where there is a limited infrastructure and service for vaccinations to prevent outbreaks of the virus. Previously reported studies on the host response to Newcastle disease in chickens have not examined the disease under abiotic stressors, such as heat, which commonly experienced by chickens in regions such as Africa. The objective of this study was to elucidate the underlying biological mechanisms that contribute to disease resistance in chickens to the Newcastle disease virus while under the effects of heat stress. Results Differential gene expression analysis identified genes differentially expressed between treated and non-treated birds across three time points (2, 6, and 10 days post-infection) in Fayoumi and Leghorn birds. Across the three time points, Fayoumi had very few genes differentially expressed between treated and non-treated groups at 2 and 6 days post-infection. However, 202 genes were differentially expressed at 10 days post-infection. Alternatively, Leghorn had very few genes differentially expressed at 2 and 10 days post-infection but had 167 differentially expressed genes at 6 days post-infection. Very few differentially expressed genes were shared between the two genetic lines, and pathway analysis found unique signaling pathways specific to each genetic line. Fayoumi had significantly lower viral load, higher viral clearance, higher anti-NDV antibody levels, and fewer viral transcripts detected compared to Leghorns. Fayoumis activated immune related pathways including SAPK/JNK and p38 MAPK signaling pathways at earlier time points, while Leghorn would activate these same pathways at a later time. Further analysis revealed activation of the GP6 signaling pathway that may be responsible for the susceptible Leghorn response. Conclusions The findings in this study confirmed our hypothesis that the Fayoumi line was more resistant to Newcastle disease virus infection compared to the Leghorn line. Within line and interaction analysis demonstrated substantial differences in response patterns between the two genetic lines that was not observed from the within line contrasts. This study has provided novel insights into the transcriptome response of the Harderian gland tissue during Newcastle disease virus infection while under heat stress utilizing a unique resistant and susceptible model.

Johann Jacob Harder first described the Harderian gland in 1694 in deer. It is found in most terrestrial animals and is located within the variable aspects of the orbit. It is believed that this gland is involved in diverse functions. Among these, it has been held to be a site of immune response, a source of thermoregulatory lipids and pheromones, act as photoprotective organ as well as part of a retinal-pineal axis. In birds, this glad was reported first in sparrow in 1918. The Harderian gland is covered by capsule and the connective tissue septa that divide the gland into numerous unequal-sized lobes and lobules. Plasma cells are found in the interacinar space and the lumina of lobules. The recent studies suggest that the Harderian gland act as an immunopotent organ in birds, and that the gland in scavenging birds contains more immunoglobulin-containing plasma cells due to their scavenging nature. Moreover, this gland shows considerable species/strain differences in terms of macro anatomy, microanatomy as well as in the dynamics of immunoglobulin-containing plasma cells among different birds. In this review, these species and strain differences are discussed based on recent studies and several goals of future research are identified. [ J Adv Biotechnol Exp Ther 2018; 1(2.000): 55-60]

The article discusses the comparative morphohistological features of harderian gland of three species of birds, the birds were Native chicken, Coot bird, and Quail. Topics include that the histological harderian gland in three species of birds is covered by thin connective tissue capsule; and that gland in three species are found in different shapes and sizes; and the absence of Russell bodies in harderian gland of coot bird.

Background: The aim of the present study is to describe the morphological and histological features of Harderian gland (HG) in long-legged wadding bird (ibis) and different domestic birds (duck, goose, and pigeon). The HG of forty adult male and female from the four avian species constituted the material of the study. Result: The HG extended from the optic nerve to the rostral part of the eyeball presents two extremities, one posterior and other anterior, from which the excretory duct was arisen. Between two extremities of the gland, middle groove is present in case of duck and geese, while middle isthmus is present in case of ibis. In pigeon, the gland appeared pointed oval in shape. Microscopically, the HG was multilobular; each lobule was composed of secretory acini that were lined by a single layer of columnar epithelium. In all studied birds, a single duct located centrally with an irregular lumen. In goose, there were crypts along the duct while in duck, the central lumen had villi-like folds projected into the central canal of the tubules. In ibis, the irregular lumen was narrow and elongated while in pigeon, the gland had a central cavity that collected the secretion from tubules arranged radially around the cavity; also, the gland mainly contained both acidic and neutral mucopolysaccharides. Conclusion: This work revealed that the histological structure of HG in the four avian species showed characteristic features and thus explained the relationship between their habits and behavior on the structure of this gland. [ABSTRACT FROM AUTHOR]