Light microscopical and cytochemical study on the adhesive and epidermal gland cell secretions of the branchiobdellid Cambarincola fallax (Annelida: Clitellata)

1988 ◽  
Vol 66 (9) ◽  
pp. 2057-2064 ◽  
Author(s):  
S. R. Gelder ◽  
J. P. Rowe
Keyword(s):  
Basic Protein ◽  
Gland Cell ◽  
Attachment Site ◽  
Cell Types ◽  
The Body ◽  
Protein Component ◽  
Cell Type ◽  
Gland Cells ◽  
Adhesive Organs ◽  
Epidermal Gland

Eight types of gland cells are present in six different epidermal glands in the branchiobdellid Cambarincola fallax. The anterior and posterior adhesive organs are both composed of viscid and releaser adhesive gland cell types, and their secretions open onto the anterior attachment site on the ventral surface of the ventral peristomial lip and onto the posterior attachment disc, respectively. The secretion granules of the viscid gland cell type are composed of neutral mucosubstances with basic proteins containing arginine and (or) lysine; the releaser gland cell type contains basic proteinaceous granules with a tryptophan component. These adhesive glands are very similar to duo-gland adhesive organs described elsewhere. Use of the term "sucker" should be discontinued as there is no suctorial mechanism at the anterior attachment site and only circumstantial evidence of such action at the posterior disc. Two epidermal gland cell types occur together in groups of two to four cells at sites scattered over the body surface except in trunk segments 6 and 7. One of these epidermal gland cell types produces granular secretions formed of neutral mucosubstances with a basic protein component, and the other produces globular secretions composed of a carboxylated acid mucosubstance. Secretions from the peristomial gland cells open onto the dorsal and ventral lips. The posterolateral gland cells form three pairs: two pairs in segment 8 and one pair in segment 9. Both peristomial and posterolateral gland cells have granular secretions composed of neutral mucosubstances with a basic protein component. The two types of clitellar gland cells are arranged in groups of 7 to 13 cells with a granular secretion type predominating over one with globular secretions. The granular type consists of neutral mucosubstances with amyloid-like and strong basic protein components, and the globular type consists of a carboxylated acid mucosubstance with a nonbasic protein component.

scholarly journals Th2 Cytokine Modulates Herpesvirus Reactivation in a Cell Type Specific Manner

2021 ◽  
Author(s):  
Guoxun Wang ◽  
Christina Zarek ◽  
Tyron Chang ◽  
Lili Tao ◽  
Alexandria Lowe ◽  
...  
Keyword(s):  
B Cells ◽  
Cell Types ◽  
The Body ◽  
Receptor Expression ◽  
Conditional Knockout ◽  
Interleukin 4 ◽  
Virus Reactivation ◽  
Cell Type ◽  
Murine Gammaherpesvirus ◽  
Cell Type Specific

Gammaherpesviruses, such as Epstein-Barr virus (EBV), Kaposi’s sarcoma associated virus (KSHV), and murine γ-herpesvirus 68 (MHV68), establish latent infection in B cells, macrophages, and non-lymphoid cells, and can induce both lymphoid and non-lymphoid cancers. Research on these viruses has relied heavily on immortalized B cell and endothelial cell lines. Therefore, we know very little about the cell type specific regulation of virus infection. We have previously shown that treatment of MHV68-infected macrophages with the cytokine interleukin-4 (IL-4) or challenge of MHV68-infected mice with an IL-4-inducing parasite leads to virus reactivation. However, we do not know if all latent reservoirs of the virus, including B cells, reactivate the virus in response to IL-4. Here we used an in vivo approach to address the question of whether all latently infected cell types reactivate MHV68 in response to a particular stimulus. We found that IL-4 receptor expression on macrophages was required for IL-4 to induce virus reactivation, but that it was dispensable on B cells. We further demonstrated that the transcription factor, STAT6, which is downstream of the IL-4 receptor and binds virus gene 50 N4/N5 promoter in macrophages, did not bind to the virus gene 50 N4/N5 promoter in B cells. These data suggest that stimuli that promote herpesvirus reactivation may only affect latent virus in particular cell types, but not in others. Importance Herpesviruses establish life-long quiescent infections in specific cells in the body, and only reactivate to produce infectious virus when precise signals induce them to do so. The signals that induce herpesvirus reactivation are often studied only in one particular cell type infected with the virus. However, herpesviruses establish latency in multiple cell types in their hosts. Using murine gammaherpesvirus-68 (MHV68) and conditional knockout mice, we examined the cell type specificity of a particular reactivation signal, interleukin-4 (IL-4). We found that IL-4 only induced herpesvirus reactivation from macrophages, but not from B cells. This work indicates that regulation of virus latency and reactivation is cell type specific. This has important implications for therapies aimed at either promoting or inhibiting reactivation for the control or elimination of chronic viral infections.

scholarly journals A community-based transcriptomics classification and nomenclature of neocortical cell types

2020 ◽  
Vol 23 (12) ◽  
pp. 1456-1468 ◽  
Author(s):  
Rafael Yuste ◽  
Michael Hawrylycz ◽  
Nadia Aalling ◽  
Argel Aguilar-Valles ◽  
Detlev Arendt ◽  
...  
Keyword(s):  
Data Aggregation ◽  
Developmental Stages ◽  
Cell Types ◽  
The Body ◽  
Cortical Circuits ◽  
Cell Type ◽  
Community Based ◽  
Cortical Cells ◽  
Molecular Features ◽  
Definition Of

AbstractTo understand the function of cortical circuits, it is necessary to catalog their cellular diversity. Past attempts to do so using anatomical, physiological or molecular features of cortical cells have not resulted in a unified taxonomy of neuronal or glial cell types, partly due to limited data. Single-cell transcriptomics is enabling, for the first time, systematic high-throughput measurements of cortical cells and generation of datasets that hold the promise of being complete, accurate and permanent. Statistical analyses of these data reveal clusters that often correspond to cell types previously defined by morphological or physiological criteria and that appear conserved across cortical areas and species. To capitalize on these new methods, we propose the adoption of a transcriptome-based taxonomy of cell types for mammalian neocortex. This classification should be hierarchical and use a standardized nomenclature. It should be based on a probabilistic definition of a cell type and incorporate data from different approaches, developmental stages and species. A community-based classification and data aggregation model, such as a knowledge graph, could provide a common foundation for the study of cortical circuits. This community-based classification, nomenclature and data aggregation could serve as an example for cell type atlases in other parts of the body.

scholarly journals Alternative Splicing Shapes the Phenotype of a Mutation inBBS8To Cause Nonsyndromic Retinitis Pigmentosa

2015 ◽  
Vol 35 (10) ◽  
pp. 1860-1870 ◽  
Author(s):  
Daniel Murphy ◽  
Ratnesh Singh ◽  
Saravanan Kolandaivelu ◽  
Visvanathan Ramamurthy ◽  
Peter Stoilov
Keyword(s):  
Alternative Splicing ◽  
Retinitis Pigmentosa ◽  
Genetic Disorder ◽  
Photoreceptor Cells ◽  
Cell Types ◽  
The Body ◽  
Specific Cell ◽  
Cell Type ◽  
Multiple Systems ◽  
Reading Frame

Bardet-Biedl syndrome (BBS) is a genetic disorder affecting multiple systems and organs in the body. Several mutations in genes associated with BBS affect only photoreceptor cells and cause nonsyndromic retinitis pigmentosa (RP), raising the issue of why certain mutations manifest as a systemic disorder whereas other changes in the same gene affect only a specific cell type. Here, we show that cell-type-specific alternative splicing is responsible for confining the phenotype of the A-to-G substitution in the 3′ splice site ofBBS8exon 2A (IVS1-2A>G mutation) in theBBS8gene to photoreceptor cells. The IVS1-2A>G mutation leads to missplicing ofBBS8exon 2A, producing a frameshift in theBBS8reading frame and thus eliminating the protein specifically in photoreceptor cells. Cell types other than photoreceptors skip exon 2A from the matureBBS8transcript, which renders them immune to the mutation. We also show that the splicing ofBbs8exon 2A in photoreceptors is directed exclusively by redundant splicing enhancers located in the adjacent introns. These intronic sequences are sufficient for photoreceptor-cell-specific splicing of heterologous exons, including an exon with a randomized sequence.

scholarly journals Histological and histochemical characterization of the secretory cells of Choeradoplana iheringi Graff, 1899 (Platyhelminthes: Tricladida: Terricola)

2004 ◽  
Vol 64 (3a) ◽  
pp. 511-522 ◽  
Author(s):  
S. A. de Souza ◽  
A. M. Leal-Zanchet
Keyword(s):  
Secretory Cell ◽  
Basic Protein ◽  
Cell Types ◽  
Secretory Cells ◽  
Mucous Secretion ◽  
Cell Type ◽  
The Common ◽  
First Time ◽  
Histochemical Characterization

The present study aims at providing a detailed description of the histology, as well as the first histochemical characterization, of the secretory cells of the epidermis, pharynx, and copulatory organs of Choeradoplana iheringi, in order to give further support to studies on the physiology of these organs. The secretory cells are distinguished on the basis of secretion morphology and its staining properties, using trichrome methods and histochemical reactions. Four cell types open through the epidermis of Ch. iheringi, three of them secreting basic protein and a fourth containing glycosaminoglycan mucins. The epidermal lining cells store glycogen. In the pharynx, four secretory cell types were distinguished. Two types produce glycoprotein, a third type secretes basic protein, and another one produces glycosaminoglycan mucins. In the male copulatory organs, the prostatic vesicle receives four secretory cell types containing basic protein, except for one type which produces glycoprotein. The two secretory cell types opening into the male atrium secrete, respectively, glycoprotein, and glycosaminoglycan mucins. In the female copulatory organs, the female atrium and its proximal diverticulum, the vagina, receive two types of secretory cells producing, respectively, basic protein and glycosaminoglycan mucins. Another secretory cell type constitutes the so-called shell glands which open into the common glandular duct, secreting basic protein. The lining cells of the male and female atria produce a mucous secretion containing glycosaminoglycans. In addition, the lining epithelium of the female atrium presents an apical secretion of a proteic nature. The occurrence of a kind of spermatophore is reported for the first time for a species of Choeradoplana. This structure is located in the male or female atria in different specimens, and characterized by erythrophil, xanthophil, and/or mixed secretions associated with sperm.

The defensive adaptations of Lima hians (Mollusca, Bivalvia)

1967 ◽  
Vol 47 (1) ◽  
pp. 209-221 ◽  
Author(s):  
T. H. J. Gilmour
Keyword(s):  
Hydrostatic Pressure ◽  
Soft Tissues ◽  
The Body ◽  
Nest Building ◽  
Defensive Behaviour ◽  
Bivalve Molluscs ◽  
Free Swimming ◽  
Gland Cells ◽  
Adductor Muscles ◽  
Epidermal Gland

The inability of Lima Mans Gmelin to enclose the soft tissues of the body within the shell is correlated with the development of other defensive adaptations.L, Mans can automize entire pallial tentacles or parts of tentacles which subsequently secrete a viscous mucus distasteful to potential predators. Autotomy takes place at transverse septa along the length of the tentacles and mucus is secreted by epidermal gland cells.The transverse septa of the tentacles also regulate the hydrostatic pressure of blood within the tentacles and permit the performance of complex locomotory movements. It is suggested that the septa were originally developed to serve this locomotory function and, secondarily, function as planes of weakness at which autotomy may take place.L. Mans builds protective nests. The nests are constructed by burrowing into a gravel substratum and consolidating the walls of the burrow with byssal threads. When disturbed in the nest L. Mans performs locomotory movements which lead to enlargement of the nest. If the nest is broken the locomotory activities result in free swimming followed by attempts to burrow into the substratum to form a new nest. It is unlikely that L. Mans swims freely in nature except when displaced from the nest.IntroductionMost bivalve molluscs react to unfavourable stimuli by retracting the soft parts of the body within the shell valves and contracting the adductor muscles to oppose the valve margins. In Lima hians Gmelin the mantle margin, even with its numerous long tentacles fully retracted, cannot be accommodated within the shell valves. In this paper the inability of L. hians to retract the soft parts within the valves is correlated with two types of defensive behaviour: (i) the secretion of mucus by the tentacles of the mantle margin and the autotomy of these tentacles, and (ii) the interrelated activities of swimming and nest-building.

scholarly journals INTERACTION OF ESTROGEN AND PROGESTERONE IN CHICK OVIDUCT DEVELOPMENT

1971 ◽  
Vol 50 (3) ◽  
pp. 598-615 ◽  
Author(s):  
Richard D. Palmiter ◽  
Joan T. Wrenn
Keyword(s):  
Electron Microscopy ◽  
Amino Acids ◽  
Gland Cell ◽  
Cell Types ◽  
Egg White ◽  
Egg White Protein ◽  
Gland Cells ◽  
Normal Transition ◽  
Tubular Gland ◽  
Wet Weight

Administration of estrogen (E) to immature chicks triggers the cytodifferentiation of tubular gland cells in the magnum portion of the oviduct epithelium; these cells synthesize the major egg-white protein, ovalbumin. Electron microscopy and immunoprecipitation of ovalbumin from oviduct explants labeled with radioactive amino acids in tissue culture were used to follow and measure the degree of tubular gland cell cytodifferentiation. Ovalbumin is undetectable in the unstimulated chick oviduct and in oviducts of chicks treated with progesterone (P) for up to 5 days. Ovalbumin synthesis is first detected 24 hr after E administration, and by 5 days it accounts for 35% of the soluble protein being synthesized. Tubular gland cells begin to synthesize ovalbumin before gland formation which commences after 36 hr of E treatment. When E + P are administered together there is initially a synergistic effect on ovalbumin synthesis, however, after 2 days ovalbumin synthesis slows and by 5 days there is only 1/20th as much ovalbumin per magnum as in the E-treated controls. Whereas the magnum wet weight doubles about every 21 hr with E alone, growth stops after 3 days of E + P treatment. Histological and ultrastructural observations show that the partially differentiated tubular gland cells resulting from E + P treatment never invade the stroma and form definitive glands, as they would with E alone. Instead, these cells appear to transform into other cell types—some with cilia and some with unusual flocculent granules. We present a model of tubular gland cell cytodifferentiation and suggest that a distinct protodifferentiated stage exists. P appears to interfere with the normal transition from the protodifferentiated state to the mature tubular gland cell.

scholarly journals Whole-animal connectome and cell-type complement of the three-segmented Platynereis dumerilii larva

2020 ◽  
Author(s):  
Csaba Verasztó ◽  
Sanja Jasek ◽  
Martin Gühmann ◽  
Réza Shahidi ◽  
Nobuo Ueda ◽  
...  
Keyword(s):  
Network Architecture ◽  
Level Structure ◽  
Neuronal Cell ◽  
Cell Types ◽  
Companion Paper ◽  
The Body ◽  
Whole Body ◽  
Pigment Cells ◽  
Cell Type ◽  
Platynereis Dumerilii

AbstractNervous systems coordinate effectors across the body during movements. We know little about the cellular-level structure of synaptic circuits for such body-wide control. Here we describe the whole-body synaptic connectome and cell-type complement of a three-segmented larva of the marine annelid Platynereis dumerilii. We reconstructed and annotated over 1,500 neurons and 6,500 non-neuronal cells in a whole-body serial electron microscopy dataset. The differentiated cells fall into 180 neuronal and 90 non-neuronal cell types. We analyse the modular network architecture of the entire nervous system and describe polysynaptic pathways from 428 sensory neurons to four effector systems – ciliated cells, glands, pigment cells and muscles. The complete somatic musculature and its innervation will be described in a companion paper. We also investigated intersegmental differences in cell-type complement, descending and ascending pathways, and mechanosensory and peptidergic circuits. Our work provides the basis for understanding whole-body coordination in annelids.

scholarly journals Tabula Microcebus: A transcriptomic cell atlas of mouse lemur, an emerging primate model organism

2021 ◽  
Author(s):  
◽  
Camille Ezran ◽  
Shixuan Liu ◽  
Stephen Chang ◽  
Jingsi Ming ◽  
...  
Keyword(s):  
Expression Profiles ◽  
Model Organism ◽  
Cell Types ◽  
The Body ◽  
Mouse Lemur ◽  
Human Model ◽  
Model Organisms ◽  
Cell Type ◽  
Primate Model ◽  
Primate Cell

Mouse lemurs are the smallest, fastest reproducing, and among the most abundant primates, and an emerging model organism for primate biology, behavior, health and conservation. Although much has been learned about their physiology and their Madagascar ecology and phylogeny, little is known about their cellular and molecular biology. Here we used droplet- and plate-based single cell RNA-sequencing to profile 226,000 cells from 27 mouse lemur organs and tissues opportunistically procured from four donors clinically and histologically characterized. Using computational cell clustering, integration, and expert cell annotation, we defined and biologically organized over 750 mouse lemur molecular cell types and their full gene expression profiles. These include cognates of most classical human cell types, including stem and progenitor cells, and the developmental programs for spermatogenesis, hematopoiesis, and other adult tissues. We also described dozens of previously unidentified or sparsely characterized cell types and subtypes. We globally compared cell type expression profiles to define the molecular relationships of cell types across the body, and explored primate cell type evolution by comparing mouse lemur cell profiles to those of the homologous cells in human and mouse. This revealed cell type specific patterns of primate cell specialization even within a single tissue compartment, as well as many cell types for which lemur provides a better human model than mouse. The atlas provides a cellular and molecular foundation for studying this primate model organism, and establishes a general approach for other emerging model organisms.

scholarly journals Identification of tissue-specific cell death using methylation patterns of circulating DNA

2016 ◽  
Vol 113 (13) ◽  
pp. E1826-E1834 ◽  
Author(s):  
Roni Lehmann-Werman ◽  
Daniel Neiman ◽  
Hai Zemmour ◽  
Joshua Moss ◽  
Judith Magenheim ◽  
...  
Keyword(s):  
Cell Death ◽  
Minimally Invasive ◽  
Dna Sequences ◽  
Cell Types ◽  
The Body ◽  
Specific Cell ◽  
Circulating Dna ◽  
Cell Type ◽  
Tissue Specific ◽  
Methylation Patterns

Minimally invasive detection of cell death could prove an invaluable resource in many physiologic and pathologic situations. Cell-free circulating DNA (cfDNA) released from dying cells is emerging as a diagnostic tool for monitoring cancer dynamics and graft failure. However, existing methods rely on differences in DNA sequences in source tissues, so that cell death cannot be identified in tissues with a normal genome. We developed a method of detecting tissue-specific cell death in humans based on tissue-specific methylation patterns in cfDNA. We interrogated tissue-specific methylome databases to identify cell type-specific DNA methylation signatures and developed a method to detect these signatures in mixed DNA samples. We isolated cfDNA from plasma or serum of donors, treated the cfDNA with bisulfite, PCR-amplified the cfDNA, and sequenced it to quantify cfDNA carrying the methylation markers of the cell type of interest. Pancreatic β-cell DNA was identified in the circulation of patients with recently diagnosed type-1 diabetes and islet-graft recipients; oligodendrocyte DNA was identified in patients with relapsing multiple sclerosis; neuronal/glial DNA was identified in patients after traumatic brain injury or cardiac arrest; and exocrine pancreas DNA was identified in patients with pancreatic cancer or pancreatitis. This proof-of-concept study demonstrates that the tissue origins of cfDNA and thus the rate of death of specific cell types can be determined in humans. The approach can be adapted to identify cfDNA derived from any cell type in the body, offering a minimally invasive window for diagnosing and monitoring a broad spectrum of human pathologies as well as providing a better understanding of normal tissue dynamics.

Endothelial cells in human cytomegalovirus infection: One host cell out of many or a crucial target for virus spread?

2009 ◽  
Vol 102 (12) ◽  
pp. 1057-1063 ◽  
Author(s):  
Christian Sinzger ◽  
Barbara Adler
Keyword(s):  
Endothelial Cells ◽  
Human Cytomegalovirus ◽  
Cell Types ◽  
The Body ◽  
Cell Type ◽  
Cell Culture Systems ◽  
Human Cytomegalovirus Infection ◽  
Productive Replication

SummaryEndothelial cells (EC) are assumed to play a central role in the spread of human cytomegalovirus (HCMV) throughout the body. Results from in-situ analyses of infected tissues and data from cell culture systems together strongly suggest that vascular EC can support productive replication of HCMV and thus contribute to its haematogeneous dissemination. By inducing an angiogenic response, HCMV may even promote growth of its own habitat. The particular role of EC is further supported by the fact that entry of HCMV into EC is dependent on a complex of the envelope glycoproteins gH and gL with a set of proteins (UL128–131A) which is dispensable for HCMV entry into most other cell types. These molecular requirements may also be reflected by cell type-dependent differences in entry routes, i.e. endocytosis versus fusion at the plasma membrane. An animal model with trackable murine CMV is now available to clarify the pathogenetic role of EC during haematogeneous dissemination of this virus.

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