Specialized Organ Research Articles

The Coding Logic of Interoception.

Interoception, the ability to precisely and timely sense internal body signals, is critical for life. The interoceptive system monitors a large variety of mechanical, chemical, hormonal, and pathological cues using specialized organ cells, organ innervating neurons, and brain sensory neurons. It is important for maintaining body homeostasis, providing motivational drives, and regulating autonomic, cognitive, and behavioral functions. However, compared to external sensory systems, our knowledge about how diverse body signals are coded at a system level is quite limited. In this review, we focus on the unique features of interoceptive signals and the organization of the interoceptive system, with the goal of better understanding the coding logic of interoception.

Preface: Application of Mathematics in Technical and Natural Sciences 15th International Conference - AMiTaNS’23

The Euro-American Consortium for Promoting the Application of Mathematics in Technical and Natural Sciences organized its 15th annual conference of the series AMiTaNS (Application of Mathematics in Technical and Natural Sciences). The event took place during June 21-26, 2023 in the Congress Centre of Black-Sea resort of Albena, Bulgaria. Its aim was to foster existing and new personal contacts, scientific discussion as well as to provide a forum for the exchange of ideas and experience between specialists in the fields of Mathematics, Physics, Biology, Ecology, Economics, Computer Science and Technology. The event became a world conference covering 15 time zones between Chile and Nebraska through Texas, Indiana, Alabama, Florida, the UK, Europe, Cyprus, Russia, and China. The conference was managed from the Congress Centre in Albena where 40 participants and delegates were present in person and the other 40 attended the event via Zoom video platform.Interest in this conference is growing year by year. This year we registered 70 talks and scientific reports, more than 80 participants – contributors and delegates from 16 countries around the world, representing the continents of Europe, North and South America, and Asia. About 18% of them attended the conference for the first time, with 50% of them being young scientists. The accepted talks were delivered and attended both on-location at the big hall and Corolla hall in Flamingo Grand hotel and on-line. Every day the morning sessions started by plenary lectures followed by contributed sessions on the following topics: Applied Analysis, Biomathematics, Continuum Mechanics, Mathematical Physics, Numerical Methods, Scientific Computing. As part of the program, leaders of their respective fields organized three special sessions: Statistics & Modeling, Mathematical Methods in Reliability Theory, Algebraic and Geometric Aspects of Integrable Systems. A number of very interesting presentations were delivered, which sparked stimulating scientific discussions both on- and off-line. The reader can find comprehensive and detailed information about the talks and reports including their records on the conference website at http://2023.eac4amitans.eu.All contributed manuscripts were reviewed by anonymous independent referees via Morressier platform, and the approved revised manuscripts were accepted for publication in the present volume. The continued success of AMiTaNS in defiance of the extraordinary circumstances and challenges faced in the last few years undoubtedly enhances its reputation as an established annual meeting with an eminent and continuously growing core of contributors. Yet, the hybrid format turned out very flexible both for the organizers and contributors. It makes the conference accessible to all those who wish to attend either in person or remotely. We would like to thank the plenary speakers, who accepted our invitation and contributed to the conference through their elucidating lectures. We would also like to thank the special sessions organizers, hosts and co-hosts for the high scientific quality of the talks they selected, and for ensuring the smooth running of the conference in hybrid format. We are deeply indebted to the scores of anonymous referees all over the world, who approached their duties very professionally and thoroughly, and helped us to maintain high scientific standards. We highly appreciate the involvement of the members of the Program Committee and Steering Committee, who supported AMiTaNS from its inception, and worked tirelessly throughout the intensive labors of advertising, arranging, organizing, and reviewing. Special thanks go to our colleagues from the University of Essex at Colchester, UK, who worked with dedication so that parallel Zoom conference sessions could be held completely on-line.We are very grateful to our publisher Institute of Physics, Bristol, UK for the helpful cooperation during the preparation of this volume.List of Program Committee, Organizer, Sponsor, Participants are available in this Pdf.

Abstract 17007: Unveiling the Immunological and Endocrine Transformations of Veins in Chronic Kidney Disease Through MYCN-AP1 Signaling Amplification

Introduction: The predominant selection of hemodialysis as the optimal treatment approach for patients with end-stage renal disease (ESRD) and advanced chronic kidney disease (CKD). Thus, upper extremity veins provide a functioning arteriovenous access to reduce dependence on central venous catheters. However, it is unknown whether CKD reprograms the transcriptome of veins and primes them for arteriovenous fistula (AVF) failure. Hypothesis: we hypothesized that CKD reprograms and transdifferentiates veins into a specialized immune endocrine organ thereby accelerating vascular inflammation. Methods: we performed transcriptomic analyses of bulk RNA sequencing data of veins isolated from 48 CKD patients and 20 non-CKD controls. Results: Our data showed that: 1) CKD induces vein conversion into immune organs through upregulation of 13 cytokine and chemokine genes, along with over 50 canonical and non-canonical secretome gene; 2) Enhancement of innate immune responses in CKD through upregulation of 12 innate immune response genes and 18 cell membrane protein genes, promoting intercellular communication including CX3CR1 chemokine signaling; 3) CKD induces upregulation of 5 endoplasmic reticulum protein-coding genes and 3 mitochondrial genes, resulting in impaired mitochondrial bioenergetics and immunometabolic reprogramming; 4) Altered fibrogenic processes in veins during CKD through upregulation of 20 fibroblast genes and 6 fibrogenic factors, leading to increased susceptibility to AVF failure; 5) Reprogramming of cell death and survival programs in CKD; 6) Reprogramming of protein kinase signal transduction pathways and upregulation of SRPK3 and CHKB in CKD; and 7) Transcriptomic reprogramming of veins and upregulation of MYCN, AP1, and Additional 11 transcription factors in CKD: implications for embryonic organ development, positive regulation of developmental growth, and vein muscle structure development. Conclusion: The findings unveil veins as immune-endocrine organs and illuminate the impact of CKD in upregulation of secretomes, immune cell differentiation, and vascular cell dynamics.

Acid and Alkali Taste Sensation.

Living organisms rely on pH levels for a multitude of crucial biological processes, such as the digestion of food and the facilitation of enzymatic reactions. Among these organisms, animals, including insects, possess specialized taste organs that enable them to discern between acidic and alkaline substances present in their food sources. This ability is vital, as the pH of these compounds directly influences both the nutritional value and the overall health impact of the ingested substances. In response to the various chemical properties of naturally occurring compounds, insects have evolved peripheral taste organs. These sensory structures play a pivotal role in identifying and distinguishing between nourishing and potentially harmful foods. In this concise review, we aim to provide an in-depth examination of the molecular mechanisms governing pH-dependent taste responses, encompassing both acidic and alkaline stimuli, within the peripheral taste organs of the fruit fly, Drosophila melanogaster, drawing insights from a comprehensive analysis of existing research articles.

The larynx in 3 dimensions: A digital anatomical model derived from radiographic imaging, refined with peer-reviewed literature, and optimized with medical illustration

ObjectivesDevelopment of an anatomically accurate three-dimensional (3D) digital model of the human larynx derived from published literature and radiographic imaging. Materials and MethodsThe laryngeal framework was segmented from a computed tomography (CT) angiogram of a healthy 29-year-old female. Data derived from published anatomical studies were compiled to provide additional anatomical detail to each structure. Anatomical details beyond the resolution of the imaging study or which could not be elucidated from the study were refined according to descriptions in the anatomic literature. The 3D model was refined by the medical illustrator, and its mesh was reformatted to optimize online viewing and manipulation. ResultsDue to the small size of the laryngeal muscles, there was no attempt to segment these muscles using radiographic imaging. All intrinsic laryngeal muscles were generated de novo, as were the superior laryngeal nerve and recurrent laryngeal nerve. CT imaging was utilized to generate meshes of the hyoid bone, epiglottis, thyroid cartilage, cricoid cartilage, and thyrohyoid membrane. Additionally, the airway space was segmented to provide size and spatial location to the vallecula, false vocal folds, true vocal folds, piriform sinus, subglottis, and a scaffold for the mucosa. These meshes were processed to limit radiographic artifact and serve as a foundation for the construction of the remainder of the laryngeal anatomy. The model was uploaded to a 3D repository, which can be accessed here (https://shorturl.at/nJPYZ). ConclusionThe larynx is a highly specialized organ essential for speech, swallowing, and airway protection. This study describes a digital 3D model of the larynx, created by combining radiographic imaging with critical review of anatomic literature. Utilizing the expertise of neuroradiology, laryngeal surgery, and medical illustration, we highlight surgically-relevant anatomic relationships and important aspects to consider during laryngeal surgery.

Nanocomposite hydrogels: an optimistic insight towards the treatments of ocular disorders.

The distinct anatomy and physiology of the eye represent it as a specialized organ. The noumenal physiological barriers, whose prominent role is to prevent the entrance of extracellular substances, reduce the bioavailability of medicines taken locally. Nanocarriers offer many advantages, such as site-specific drug delivery, reduced dose-related side effects, more drug loading capacity, etc. Nanoparticles, nano micelles, Nanostructured Lipid Carriers (NLCs), Solid Lipid Nanoparticles (SLNs), liposomes, polymeric nanoparticles, microspheres, microemulsions, etc., have all undergone significant analysis to overcome numerous static and dynamic obstacles. Among the several methods of delivering drugs, one of the most captivating and demanding is ocular drug delivery (ODD). The intent of developing formulations for an extended period can be partially achieved via thermoresponsive hydrogels. It is feasible to store fluids inside a cross-linked gel system for efficient long-term administration owing to hydrogels, which are hydrophilic polymeric networks with excellent three-dimensional structures and water or biological fluid absorption capacities. Hydrogels can be incorporated into nanocarriers to achieve site-specific action and prolonged release. Related patents and research reports with various platforms like Science Direct, Springer, PubMed, Google Scholar, Shodhganga, and Patseer were used to gather the data, and a search methodology was availed. The paper thoroughly summarizes the strategies for incorporating drugs with hydrogel into a nanocarrier to provide sustained release and prolonged therapeutic effects. According to the comprehensive review of literature and patents like (US2015374633A1), (US10980882B2), and (WO2011018800A2), nanocarrier-loaded thermoresponsive hydrogels show promising results. Due to their propensity to alter state in reaction to temperature changes, thermoresponsive hydrogels can improve medication bioavailability. Intervening nanocarriers loaded hydrogels directly on the targeted site displays local intervention and site-specificity. Thus, the use of nanocarriers in ocular drug delivery is encouraging.

To protect or to hide: Why not both? An investigation of fire-related strategies in Cerrado woody species

Two key strategies enable woody species persistence and survival in fire-prone ecosystems after fire: the aboveground protection of stems and buds by thick bark and the allocation of biomass belowground to specialized bud bearing storage organs – both strategies allowing plants to resprout new branches after the aboveground parts are damaged by fire. Here we investigate whether those two strategies can be combined with each other. We compared 24 woody species from the Cerrado (tropical savannas from Brazil) and analyzed their underground storage organs (USOs) in relation to their aboveground bark production and aerial bud protection – two key traits allowing species to first survive and then persist after fire – together with plant potential height. We then compared if bark growth rate, aerial bud protection and plant potential height are linked to the ecological function of the underground storage organs (on spot persistence vs clonal growth through lateral spreading). Species with woody rhizomes (capable of spreading laterally) better protected their aboveground stems with thicker bark when compared to species with xylopodium and root-crown organs (adapted for on spot basal resprouting). A clear division was found concerning how well species are protecting their aerial buds and the type of underground storage organ, with species spreading laterally displaying a greater aerial bud protection. The results suggest that the presence of a specialized organ belowground does not appear to be mutually exclusive with producing thick bark on aboveground stems. It does exist, however, a different expression of bark production and aerial bud protection between species displaying lateral spread and those persisting on spot, suggesting the existence of a trade-off between above- and belowground strategies in species displaying on spot persistence. This highlights that Cerrado species can combine different fire-survival strategies, further questioning which fire conditions promote each strategy and their combination and in which cases trade-offs occur.

The Application of Engineered Nanomaterials in Perinatal Therapeutics.

Pregnancy is a vulnerable life stage for the mother and developing fetus. Because of this dual concern, approved therapeutic options for pre-existing conditions or pregnancy-induced pathologies, placental deformities, or fetal concerns are extremely limited. These cases often leave patients and clinicians having to choose between maternal health and fetal development. Recent advancements in nanomedicine and nanotherapeutic devices have made the development of perinatal therapeutics an attractive objective. However, perinatal medicine requires a multifaceted approach given the interactions between maternal, placental, and fetal physiology. Maternal-fetal interactions are centralized to the placenta, a specialized transient barrier organ, to allow for nutrient and waste exchange. Perinatal nanotherapeutics must be designed for placental avoidance or uptake. In this review, pregnancy-related conditions, experimental models, and modes of drug delivery during pregnancy are discussed.

Categorizing Molecular Features of Venom Toxins Using Bioinformatics Tools

Poisonous organisms are represented in many taxa, including kingdom Animalia. During evolution, animals have developed special organs for production and injection of venoms. Animal venoms are complex mixtures, compositions of which depend on species producing venom. The most known and studied poisonous terrestrial animals are snakes, scorpions and snails. Venomous animals produce a myriad of important pharmacological components. The individual components, or venoms (toxins), are used in ion channel and receptor studies, drug discovery, and formulation of insecticides. Knowing the key clinical applications of venom, the present investigation was carried out to understand the molecular basis of venom toxins of animals like snake (L-amino acid oxidases), cone snail (Contulakin-G) and scorpion (Chlorotoxin) by retrieving the protein sequence information, deducing various physicochemical properties, predicting secondary structural elements, homology modelling and depicting the potent antigenic regions using various bioinformatics tools and soft-wares. Because of their remarkable molecular diversity, venoms are key, albeit challenging, resource for pharmacological discovery that contribute to the development of drugs that act as anti-tumor agents, heart stimulants and therapies for neurological diseases. Venom-informatics is a systematic bioinformatics approach in which classified, consolidated and cleaned venom data are stored into repositories and integrated with advanced bioinformatics tools for the analysis of structure and function of toxins. Venom-informatics complements experimental studies and helps reduce the number of essential experiments.

Bloodstained flowers and bloodthirsty flies.

This article is a Commentary on Heiduk et al. (2023), 239:1490–1504.

Functional genomics of the human epididymis: Further characterization of efferent ducts and model systems by single-cell RNA sequencing analysis.

The human epididymis is poorly studied due to the lack of availability of tissue samples. Our understanding of its structure and function depends upon anatomical and histological observations of archived material. Here we used single-cell RNA sequencing (scRNA-seq) technologies to elucidate the identity of cells within the human efferent ducts (EDs) and compared them to caput epididymis cells. We also compared the cellularity of primary tissues with those of 2D and 3D (organoid) culture models used for functional studies. Human epididymis tissue was dissected to separate different anatomical regions and digested to release single cells for processing on the 10X Genomics Chromium platform. Primary human epididymis epithelial (HEE) cells and HEE organoids were grown as described previously and subjected to scRNA-seq. scRNA-seq data were processed by standard bioinformatics pipelines and used for comparative analysis. We define the cell types in the EDs which include specialized epithelial cells, connective tissue stromal cells, vascular endothelial cells, smooth muscle cells, and immune cells, but lack basal cells that are seen in the caput epididymis. Furthermore, we identify a sub-population of epithelial cells which have marker genes found in the bladder and urothelium. Comparative genomics analysis of the 2D and 3D culture models shows cellular identities adapted to the culture environment while still maintaining similarity to the primary tissue. Our data suggest that EDs are lined with a transitional epithelium, which like the urothelium is able to stretch and contract depending on luminal volume. This is consistent with its primary role in seminal fluid resorption and sperm concentration. Moreover, we describe the cellularity of models to study the human epididymis epithelium in vitro. Single-cell RNA-seq data from the human epididymis make a valuable contribution to our understanding of this highly specialized organ.

Molybdenum isotope signature of microbial nitrogen utilization in siboglinid tubeworms

Abstract Many chemosynthesis-based communities prospering in deep-sea environments rely on the metabolic activity of sulfide-oxidizing bacteria. This is the case for vestimentiferan siboglinid tubeworms, whose demand for nutrition is satisfied predominantly by their endosymbiotic bacteria harbored in a specialized organ called the trophosome. Such chemosymbiosis leads to a significantly lower nitrogen isotope composition of the trophosome than in other types of soft tissue. However, the specific process of nitrogen utilization by siboglinids remains unclear. As a key element in the relevant enzymes (nitrogenase and nitrate reductase), molybdenum (Mo) is indispensable in the biogeochemical cycling of nitrogen. The Mo isotope composition (δ98Mo) of siboglinids is thus a potential proxy for decoding the processes involved in nitrogen metabolism. In this study, we found δ98Mo values along the chitinous tube of the vestimentiferan siboglinid Paraescarpia echinospica from the Haima seeps of the South China Sea as negative as −4.59‰ (−1.13‰ ± 1.75‰, 1SD, n = 19)—the lowest δ98Mo value ever reported for any kind of natural material. It is suggested that this extremely negative Mo isotope composition is caused by preferential utilization of isotopically light Mo by the tubeworm’s endosymbionts or epibionts during nitrate reduction. Such Mo isotope signature could provide a means for identifying siboglinid tubeworms, a group of annelids that has previously escaped unambiguous identification due to the lack of mineralized skeleton, in the rock record.

Article Review on Histopathologic Features of Placenta and Adverse Outcome in Pregnant Women with COVID-19 Positive

<i>Introduction:</i> The placenta is the highly specialized organ of pregnancy that supports the normal growth and development of the fetus. During intrauterine fetal life placenta is the main metabolic, respiratory, excretory, and endocrine organ. Histologic features of normal placenta are differing according to the trimester of pregnancy. COVID-19 infection affects placenta and fetal membrane. Pregnant women with COVID-19 positive result in placental hyperfusion defects in maternal vessels and oxygenation in the intervillous space affecting perinatal outcome. <i>Methods:</i> Systematic reviews, meta-analysis, cross sectional and cohort studies were obtained through searches on PubMed, Medline, Science Direct, Google Scholar, library genesis, Scopus and Web of Science. Key words used for searching are “placenta”, “COVID-19”, “placenta development”, and “placenta histopathology”. <i>Result: </i>Total of 16 articles were included in this review. Many articles are reviewed whether the COVID-19 affects placenta histology and pregnancy adverse outcome in intrauterine life. Finally article which fulfills inclusion criteria are identified and reviewed. Review indicated that histopathologic features of placenta and adverse pregnancy outcome in COVID-19 confirmed pregnant women briefly. <i>Conclusion: </i>COVID-19 affects the placenta during pregnancy. Histopathologic findings of placenta in pregnant women with confirmed COVID-19 positive are fibrin deposition, micro classification, thrombus, avascular villi, infraction, and villous edema. Most common pregnancy adverse outcome are preterm birth, miscarriage and still birth.

Revisiting Aire and tissue-restricted antigens at single-cell resolution.

The thymus is a highly specialized organ that plays an indispensable role in the establishment of self-tolerance, a process characterized by the "education" of developing T-cells. To provide competent T-cells tolerant to self-antigens, medullary thymic epithelial cells (mTECs) orchestrate negative selection by ectopically expressing a wide range of genes, including various tissue-restricted antigens (TRAs). Notably, recent advancements in the high-throughput single-cell analysis have revealed remarkable heterogeneity in mTECs, giving us important clues for dissecting the mechanisms underlying TRA expression. We overview how recent single-cell studies have furthered our understanding of mTECs, with a focus on the role of Aire in inducing mTEC heterogeneity to encompass TRAs.

A tissue specific-infection mouse model of SARS-CoV-2

Animal models play crucial roles in the rapid development of vaccines/drugs for the prevention and therapy of COVID-19, but current models have some deficits when studying the pathogenesis of SARS-CoV-2 on some special tissues or organs. Here, we generated a human ACE2 and SARS-CoV-2 NF/F knockin mouse line that constitutively expresses human ACE2 and specifically expresses SARS-CoV-2 N gene induced by Cre-recombinase. By crossing with Cre transgenic lines allowing for lung-specific and constitutive expression, we generated lung-specific (Sftpc-hACE2-NF/F) and constitutive SARS-CoV-2 N (EIIa-hACE2-NF/F) expressing mice. Upon intranasal infection with a SARS-CoV-2 GFP/ΔN strain which can only replicate in SARS-CoV-2 N expressed cells, we demonstrated that both the Sftpc-hACE2-NF/F and EIIa-hACE2-NF/F mice support viral replication. Consistent with our design, viral replication was limited to the lung tissues in Sftpc-hACE2-NF/F mice, while the EIIa-hACE2-NF/F mice developed infections in multiple tissues. Furthermore, our model supports different SARS-CoV-2 variants infection, and it can be successfully used to evaluate the effects of therapeutic monoclonal antibodies (Ab1F11) and antiviral drugs (Molnupiravir). Finally, to test the effect of SARS-CoV-2 infection on male reproduction, we generated Sertoli cell-specific SARS-CoV-2 N expressed mice by crossing with AMH-Cre transgenic line. We found that SARS-CoV-2 GFP/ΔN strain could infect Sertoli cells, led to spermatogenic defects due to the destruction of blood-testis barrier. Overall, combining with different tissue-specific Cre transgenic lines, the human ACE2 and SARS-CoV-2 NF/F line enables us to evaluate antivirals in vivo and study the pathogenesis of SARS-CoV-2 on some special tissues or organs.

Abstract LB026: Porcine brain-derived hydrogel carriers for intratumoral administration of cellular immunotherapies enhances anti-tumor potential in post-resection GBM

Abstract Glioblastoma (GBM) has shown remarkable resistance to peripherally administered CAR T cell therapy. This is in part because the nuanced requirements for successful CAR-T cell trafficking into brain tumors are not well understood. Intracranial administration has been shown to be both safe and effective in delivery of other anti- cancer drugs in GBM, with one example being Gliadel, involving the placement of carmustine chemotherapy-loaded wafers into the post-resection space for sustained release into local brain tissue. Recurrence of GBM is most often local, suggesting that regional therapies might both serve the immediate and long-term needs of the patients. Here we used extracellular matrix-based scaffolds to encapsulate and locally deliver CAR T cells to GBM for enhancement of CAR T cell infiltration and promotion of effector function against GBM. We decellularized and solubilized commercially procured fresh frozen porcine brain tissues to create temperature-responsive porcine brain matrix solutions that gelled at physiologic body temperatures. We confirmed extent of decellularization using DNA quantification of processed tissue and quantified major protein composition of solubilized product using mass spectrometry. Gelation kinetics and resulting hydrogel structures were quantified using turbidometry and rheology, with an average gelation time of 15± 8 min and comparable storage modulus range of 100-200 Pa to Matrigel or Collagen 1-based commercial hydrogel products. Both unmodified healthy donor T cells and donor T cells transduced with EGFRvIII-targeting CAR scFv were &amp;gt;75% viable over 4d in vitro, and release of doses ranging from 2M-5M CAR T cells after encapsulation were observed over 4d in vitro using Transwell inserts. Released CAR T cells were found to be potently cytotoxic in tumor-killing assays using EGFRvIII+ U87MG target cells at 1:1 E:T within impedance cytotoxicity assays, performing comparably to freshly made non-encapsulated CAR T cells and better than CAR T cells released from Matrigel or Collagen scaffolds at the same timepoints. We have developed a mouse model of GBM resection and recurrence to evaluate the efficacy of hydrogel-delivered CAR T cell treatment after resection surgery to capitalize on a currently underutilized treatment window. This injectable scaffold will support an immediate clinical need by supporting delivery, expansion, and actuation of CAR T function within the solid tumor microenvironment without the challenges of peripheral delivery to a specialized organ system. Citation Format: Meghan Logun, Zev Binder, Donald O'Rourke. Porcine brain-derived hydrogel carriers for intratumoral administration of cellular immunotherapies enhances anti-tumor potential in post-resection GBM [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr LB026.

Bones and Hormones: Interaction between Hormones of the Hypothalamus, Pituitary, Adipose Tissue and Bone.

The bony skeleton, as a structural foundation for the human body, is essential in providing mechanical function and movement. The human skeleton is a highly specialized and dynamic organ that undergoes continuous remodeling as it adapts to the demands of its environment. Advances in research over the last decade have shone light on the various hormones that influence this process, modulating the metabolism and structural integrity of bone. More recently, novel and non-traditional functions of hypothalamic, pituitary, and adipose hormones and their effects on bone homeostasis have been proposed. This review highlights recent work on physiological bone remodeling and discusses our knowledge, as it currently stands, on the systemic interplay of factors regulating this interaction. In this review, we provide a summary of the literature on the relationship between bone physiology and hormones including kisspeptin, neuropeptide Y, follicle-stimulating hormone (FSH), prolactin (PRL), adrenocorticotropic hormone (ACTH), thyroid-stimulating hormone (TSH), growth hormone (GH), leptin, and adiponectin. The discovery and understanding of this new functionality unveils an entirely new layer of physiologic circuitry.

Mechanisms Underpinning Morphogenesis of a Symbiotic Organ Specialized for Hosting an Indispensable Microbial Symbiont in Stinkbugs

Microbial mutualists are pivotal for insect adaptation, which often entails the evolution of elaborate organs for symbiosis. Addressing what mechanisms underpin the development of such organs is of evolutionary interest. Here, we investigated the stinkbug Plautia stali, whose posterior midgut is transformed into a specialized symbiotic organ. Despite being a simple tube in newborns, it developed numerous crypts in four rows, whose inner cavity hosts a specific bacterial symbiont, during the 1st to 2nd nymphal instar stages. Visualization of dividing cells revealed that active cell proliferation was coincident with the crypt formation, although spatial patterns of the proliferating cells did not reflect the crypt arrangement. Visualization of visceral muscles in the midgut, consisting of circular muscles and longitudinal muscles, uncovered that, strikingly, circular muscles exhibited a characteristic arrangement running between the crypts specifically in the symbiotic organ. Even in the early 1st instar stage, when no crypts were seen, two rows of epithelial areas delineated by bifurcated circular muscles were identified. In the 2nd instar stage, crossing muscle fibers appeared and connected the adjacent circular muscles, whereby the midgut epithelium was divided into four rows of crypt-to-be areas. The crypt formation proceeded even in aposymbiotic nymphs, revealing the autonomous nature of the crypt development. We propose a mechanistic model of crypt formation wherein the spatial arrangement of muscle fibers and the proliferation of epithelial cells underpin the formation of crypts as midgut evaginations. IMPORTANCE Diverse organisms are associated with microbial mutualists, in which specialized host organs often develop for retaining the microbial partners. In light of the origin of evolutionary novelties, it is important to understand what mechanisms underpin the elaborate morphogenesis of such symbiotic organs, which must have been shaped through interactions with the microbial symbionts. Using the stinkbug Plautia stali as a model, we demonstrated that visceral muscular patterning and proliferation of intestinal epithelial cells during the early nymphal stages are involved in the formation of numerous symbiont-harboring crypts arranged in four rows in the posterior midgut to constitute the symbiotic organ. Strikingly, the crypt formation occurred normally even in symbiont-free nymphs, revealing that the crypt development proceeds autonomously. These findings suggest that the crypt formation is deeply implemented into the normal development of P. stali, which must reflect the considerably ancient evolutionary origin of the midgut symbiotic organ in stinkbugs.

AGPs as molecular determinants of reproductive development.

Morphogenesis occurs through accurate interaction between essential players to generate highly specialized plant organs. Fruit structure and function are triggered by a neat transcriptional control involving distinct regulator genes encoding transcription factors (TFs) or signalling proteins, such as the C2H2/C2HC zinc-finger NO TRANSMITTING TRACT (NTT) or the MADS-box protein SEEDSTICK (STK), which are important in setting plant reproductive competence, feasibly by affecting cell wall polysaccharide and lipid distribution. Arabinogalactan proteins (AGPs) are major components of the cell wall and are thought to be involved in the reproductive process as important players in specific stages of development. The detection of AGPs epitopes in reproductive tissues of NTT and other fruit development-related TFs, such as MADS-box proteins including SHATTERPROOF1 (SHP1), SHP2 and STK, was the focus of this study. We used fluorescence microscopy to perform immunolocalization analyses on stk and ntt single mutants, on the ntt stk double mutant and on the stk shp1 shp2 triple mutant using specific anti-AGP monoclonal antibodies. In these mutants, the expression levels of selected AGP genes were also measured by quantitative real-time PCR and compared with the respective expression in wild-type (WT) plants. The present immunolocalization study collects information on the distribution patterns of specific AGPs in Arabidopsis female reproductive tissues, complemented by the quantification of AGP expression levels, comparing WT, stk and ntt single mutants, the ntt stk double mutant and the stk shp1 shp2 triple mutant. These findings reveal distinct AGP distribution patterns in different developmental mutants related to the female reproductive unit in Arabidopsis. The value of the immunofluorescence labelling technique is highlighted in this study as an invaluable tool to dissect the remodelling nature of the cell wall in developmental processes.

Variable organization of symbiont-containing tissue across planthoppers hosting different heritable endosymbionts.

Sap-feeding hemipteran insects live in associations with diverse heritable symbiotic microorganisms (bacteria and fungi) that provide essential nutrients deficient in their hosts' diets. These symbionts typically reside in highly specialized organs called bacteriomes (with bacterial symbionts) or mycetomes (with fungal symbionts). The organization of these organs varies between insect clades that are ancestrally associated with different microbes. As these symbioses evolve and additional microorganisms complement or replace the ancient associates, the organization of the symbiont-containing tissue becomes even more variable. Planthoppers (Hemiptera: Fulgoromorpha) are ancestrally associated with bacterial symbionts Sulcia and Vidania, but in many of the planthopper lineages, these symbionts are now accompanied or have been replaced by other heritable bacteria (e.g., Sodalis, Arsenophonus, Purcelliella) or fungi. We know the identity of many of these microbes, but the symbiont distribution within the host tissues and the bacteriome organization have not been systematically studied using modern microscopy techniques. Here, we combine light, fluorescence, and transmission electron microscopy with phylogenomic data to compare symbiont tissue distributions and the bacteriome organization across planthoppers representing 15 families. We identify and describe seven primary types of symbiont localization and seven types of the organization of the bacteriome. We show that Sulcia and Vidania, when present, usually occupy distinct bacteriomes distributed within the body cavity. The more recently acquired gammaproteobacterial and fungal symbionts generally occupy separate groups of cells organized into distinct bacteriomes or mycetomes, distinct from those with Sulcia and Vidania. They can also be localized in the cytoplasm of fat body cells. Alphaproteobacterial symbionts colonize a wider range of host body habitats: Asaia-like symbionts often colonize the host gut lumen, whereas Wolbachia and Rickettsia are usually scattered across insect tissues and cell types, including cells containing other symbionts, bacteriome sheath, fat body cells, gut epithelium, as well as hemolymph. However, there are exceptions, including Gammaproteobacteria that share bacteriome with Vidania, or Alphaproteobacteria that colonize Sulcia cells. We discuss how planthopper symbiont localization correlates with their acquisition and replacement patterns and the symbionts' likely functions. We also discuss the evolutionary consequences, constraints, and significance of these findings.