A morphometric study of the pituitary cell types in the freshwater stickleback, Gasterosteus aculeatus, form leiurus

1974 ◽  
Vol 152 (1) ◽  
Author(s):  
Michael Benjamin
Keyword(s):  
Gasterosteus Aculeatus ◽  
Cell Types ◽  
Pituitary Cell ◽  
Morphometric Study ◽  
Freshwater Stickleback

Control of secretion in anterior pituitary cells--linking ion channels, messengers and exocytosis

1988 ◽  
Vol 139 (1) ◽  
pp. 287-316
Author(s):  
W. T. Mason ◽  
S. R. Rawlings ◽  
P. Cobbett ◽  
S. K. Sikdar ◽  
R. Zorec ◽  
...  
Keyword(s):  
Ion Channels ◽  
Intracellular Calcium ◽  
Anterior Pituitary ◽  
Hormone Secretion ◽  
Cell Types ◽  
Pituitary Cell ◽  
Pituitary Cells ◽  
Calcium Activity ◽  
Anterior Pituitary Cells ◽  
Voltage Dependent

Normal anterior pituitary cells, in their diversity and heterogeneity, provide a rich source of models for secretory function. However, until recently they have largely been neglected in favour of neoplastic, clonal tumour cell lines of pituitary origin, which have enabled a number of studies on supposedly homogeneous cell types. Because many of these lines appear to lack key peptide and neurotransmitter receptors, as well as being degranulated with accompanying abnormal levels of secretion, we have developed a range of normal primary anterior pituitary cell cultures using dispersion and enrichment techniques. By studying lactotrophs, somatotrophs and gonadotrophs we have revealed a number of possible transduction mechanisms by which receptors for hypothalamic peptides and neurotransmitters may control secretion. In particular, the transduction events controlling secretion from pituitary cells may differ fundamentally from those found in other cell types. Patch-clamp recordings in these various pituitary cell preparations have revealed substantial populations of voltage-dependent Na+, Ca2+ and K+ channels which may support action potentials in these cells. Although activation of these channels may gate Ca2+ entry to the cells under some conditions, our evidence taken with that of other laboratories suggests that peptide-receptor interactions leading to hormone secretion occur independently of significant membrane depolarization. Rather, secretion of hormone and rises in intracellular calcium measured with new probes for intracellular calcium activity, can occur in response to hypothalamic peptide activation in the absence of substantial changes in membrane potential. These changes in intracellular calcium activity almost certainly depend on both intracellular and extracellular calcium sources. In addition, strong evidence of a role for multiple intracellular receptors and modulators in the secretory event suggests we should consider the plasma membrane channels important for regulation of hormone secretion to be predominantly agonist-activated, rather than of the more conventional voltage-dependent type. Likewise, evidence from new methods for recording single ion channels suggests the existence of intracellular sites for channel modulation, implying they too may play an important role in secretory regulation. We shall consider new data and new technology which we hope will provide key answers to the many intriguing questions surrounding the control of pituitary hormone secretion. We shall highlight our work with recordings of single ion channels activated by peptides, and recent experiments using imaging of intracellular ionized free calcium.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals SAT-298 Integrative Single-Cell Transcriptomic and Epigenomic Landscape of Mouse Anterior Pituitary Cell Types

2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Frederique Murielle Ruf-Zamojski ◽  
Michel A Zamojski ◽  
German Nudelman ◽  
Yongchao Ge ◽  
Natalia Mendelev ◽  
...  
Keyword(s):  
Single Cell ◽  
Cell Line ◽  
Anterior Pituitary ◽  
Cell Types ◽  
Chromatin Accessibility ◽  
Pituitary Cell ◽  
Integrated Analysis ◽  
Pituitary Cells ◽  
Rna Seq ◽  
Cell Type

Abstract The pituitary gland is a critical regulator of the neuroendocrine system. To further our understanding of the classification, cellular heterogeneity, and regulatory landscape of pituitary cell types, we performed and computationally integrated single cell (SC)/single nucleus (SN) resolution experiments capturing RNA expression, chromatin accessibility, and DNA methylation state from mouse dissociated whole pituitaries. Both SC and SN transcriptome analysis and promoter accessibility identified the five classical hormone-producing cell types (somatotropes, gonadotropes (GT), lactotropes, thyrotropes, and corticotropes). GT cells distinctively expressed transcripts for Cga, Fshb, Lhb, Nr5a1, and Gnrhr in SC RNA-seq and SN RNA-seq. This was matched in SN ATAC-seq with GTs specifically showing open chromatin at the promoter regions for the same genes. Similarly, the other classically defined anterior pituitary cells displayed transcript expression and chromatin accessibility patterns characteristic of their own cell type. This integrated analysis identified additional cell-types, such as a stem cell cluster expressing transcripts for Sox2, Sox9, Mia, and Rbpms, and a broadly accessible chromatin state. In addition, we performed bulk ATAC-seq in the LβT2b gonadotrope-like cell line. While the FSHB promoter region was closed in the cell line, we identified a region upstream of Fshb that became accessible by the synergistic actions of GnRH and activin A, and that corresponded to a conserved region identified by a polycystic ovary syndrome (PCOS) single nucleotide polymorphism (SNP). Although this locus appears closed in deep sequencing bulk ATAC-seq of dissociated mouse pituitary cells, SN ATAC-seq of the same preparation showed that this site was specifically open in mouse GT, but closed in 14 other pituitary cell type clusters. This discrepancy highlighted the detection limit of a bulk ATAC-seq experiment in a subpopulation, as GT represented ~5% of this dissociated anterior pituitary sample. These results identified this locus as a candidate for explaining the dual dependence of Fshb expression on GnRH and activin/TGFβ signaling, and potential new evidence for upstream regulation of Fshb. The pituitary epigenetic landscape provides a resource for improved cell type identification and for the investigation of the regulatory mechanisms driving cell-to-cell heterogeneity. Additional authors not listed due to abstract submission restrictions: N. Seenarine, M. Amper, N. Jain (ISMMS).

Immunocytochemical and Ultrastructural Identification of Pituitary Cell Types in the Protogynous Thalassoma duperrey during Adult Sexual Ontogeny

1998 ◽  
Vol 15 (2) ◽  
pp. 263-276 ◽  
Author(s):  
Ishwar S. Parhar ◽  
Yoshitaka Nagahama ◽  
E. Gordon Grau ◽  
Robert M. Ross
Keyword(s):  
Cell Types ◽  
Pituitary Cell ◽  
Thalassoma Duperrey

Postglacial evolution in lateral plate morphs in Norwegian freshwater populations of the threespine stickleback (Gasterosteus aculeatus)

1995 ◽  
Vol 73 (5) ◽  
pp. 898-906 ◽  
Author(s):  
Tom Klepaker
Keyword(s):  
Gasterosteus Aculeatus ◽  
Alternative Hypothesis ◽  
Morphological Variability ◽  
Threespine Stickleback ◽  
Evolutionary Stage ◽  
Lateral Plate ◽  
Land Uplift ◽  
Founding Population ◽  
Freshwater Stickleback ◽  
Age Range

Norwegian freshwater stickleback populations were founded after the last glacial period, and the progressive uplift of the land has produced an age range (1000 – 13 000 years) of the stickleback habitats. Most of the freshwater populations of today have probably been formed by isolation of marine sticklebacks in the process of land uplift. The freshwater threespine stickleback is known for its great morphological variability. Three distinct morphs ("low," "partial," and "complete") are recognized on the basis of variation in the lateral row of plates. Among the Norwegian populations, all three morphs were found, but the low morph was by far the most common and occurred mostly in monomorphic populations. The presence of the complete and partial morphs was mostly restricted to young lakes near the sea. It is likely that the plate polymorphism in this region is a transitionary evolutionary stage from a founding population dominated by complete to a monomorphic low population. The hypothesis of a polytypic origin of the low morph is discussed, and an alternative hypothesis is proposed. Within each plate morph, the number of plates also varied, and populations with exceptionally low plate numbers were mostly confined to three different areas. Within these areas, populations with plateless specimens also occurred. These plateless specimens tended to inhabit old lakes. The low plate number and plateless populations were found in parts of Norway that were deglaciated early. The advanced plate reduction can therefore be a result of a longer period of isolation and freshwater evolution. Other populations may be on their way towards extreme plate reduction, but have not yet reached the level of platelessness.

scholarly journals Melatonin Regulates Somatotrope and Lactotrope Function Through Common and Distinct Signaling Pathways in Cultured Primary Pituitary Cells From Female Primates

Endocrinology ◽  
2015 ◽  
Vol 156 (3) ◽  
pp. 1100-1110 ◽  
Author(s):  
Alejandro Ibáñez-Costa ◽  
José Córdoba-Chacón ◽  
Manuel D. Gahete ◽  
Rhonda D. Kineman ◽  
Justo P. Castaño ◽  
...  
Keyword(s):  
Calcium Channels ◽  
Signaling Pathways ◽  
Somatostatin Receptors ◽  
Cell Types ◽  
Pituitary Hormones ◽  
Pituitary Cell ◽  
Pituitary Cells ◽  
Primate Model ◽  
Direct Role ◽  
Precise Relationship

Abstract Melatonin (MT) is secreted by the pineal gland and exhibits a striking circadian rhythm in its release. Depending on the species studied, some pituitary hormones also display marked circadian/seasonal patterns and rhythms of secretion. However, the precise relationship between MT and pituitary function remains controversial, and studies focusing on the direct role of MT in normal pituitary cells are limited to nonprimate species. Here, adult normal primate (baboons) primary pituitary cell cultures were used to determine the direct impact of MT on the functioning of all pituitary cell types from the pars distalis. MT increased GH and prolactin (PRL) expression/release in a dose- and time-dependent fashion, a response that was blocked by somatostatin. However, MT did not significantly affect ACTH, FSH, LH, or TSH expression/release. MT did not alter GHRH- or ghrelin-induced GH and/or PRL secretions, suggesting that MT may activate similar signaling pathways as ghrelin/GHRH. The effects of MT on GH/PRL release, which are likely mediated through MT1 receptor, involve both common (adenylyl cyclase/protein kinase A/extracellular calcium-channels) and distinct (phospholipase C/intracellular calcium-channels) signaling pathways. Actions of MT on pituitary cells also included regulation of the expression of other key components for the control of somatotrope/lactotrope function (GHRH, ghrelin, and somatostatin receptors). These results show, for the first time in a primate model, that MT directly regulates somatotrope/lactotrope function, thereby lending support to the notion that the actions of MT on these cells might substantially contribute to the define daily patterns of GH and PRL observed in primates and perhaps in humans.

Histochemical Differentiation of Anterior Pituitary Cell Types by Contrasting Azocoupling and Mucoprotein Stains

1956 ◽  
Vol 31 (5) ◽  
pp. 193-196 ◽  
Author(s):  
Benjamin H. Landing ◽  
Hazel E. Hall
Keyword(s):  
Anterior Pituitary ◽  
Cell Types ◽  
Pituitary Cell ◽  
Anterior Pituitary Cell

scholarly journals Cell Type-Specific Metabolism of Peptidylglycineα -Amidating Monooxygenase in Anterior Pituitary*

Endocrinology ◽  
2000 ◽  
Vol 141 (8) ◽  
pp. 3020-3034 ◽  
Author(s):  
Rajaa El Meskini ◽  
Richard E. Mains ◽  
Betty A. Eipper
Keyword(s):  
Anterior Pituitary ◽  
Secretory Granules ◽  
Primary Cultures ◽  
Cell Types ◽  
Pituitary Cell ◽  
Male Rat ◽  
Pituitary Cells ◽  
Cell Type ◽  
Cell Content ◽  
Monooxygenase Activity

Peptidylglycine α-amidating monooxygenase (PAM) is a bifunctional enzyme expressed in each major anterior pituitary cell type. We used primary cultures of adult male rat anterior pituitary to examine PAM expression, processing, and secretion in the different pituitary cell types and to compare these patterns to those observed in transfected AtT-20 corticotrope tumor cells. Immunostaining and subcellular fractionation identified PAM in pituitary secretory granules and additional vesicular compartments; in contrast, in AtT-20 cells, transfected PAM was primarily localized to the trans-Golgi network. PAM expression was highest in gonadotropes, with moderate levels in somatotropes and thyrotropes and lower levels in corticotropes and lactotropes. Under basal conditions, less than 1% of the cell content of monooxygenase activity was secreted per h, a rate comparable to the basal rate of release of individual pituitary hormones. General secretagogues stimulated PAM secretion 3- to 5-fold. Stimulation with specific hypothalamic releasing hormones demonstrated that different pituitary cell types secrete characteristic sets of PAM proteins. Gonadotropes and thyrotropes release primarily monofunctional monooxygenase. Somatotropes secrete primarily bifunctional PAM, whereas corticotropes secrete a mixture of mono- and bifunctional proteins. As observed in transfected AtT-20 cells, pituitary cells rapidly internalize the PAM/PAM-antibody complex from the cell surface. The distinctly different steady-state localizations of endogenous PAM in primary pituitary cells and transfected PAM in AtT-20 cell lines may simply reflect the increased storage capacity of primary pituitary cells.

scholarly journals All day-long: Sticklebacks effectively forage on whitefish eggs during all light conditions

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0255497
Author(s):  
Jan Baer ◽  
Sarah Maria Gugele ◽  
Joachim Bretzel ◽  
J. Tyrell DeWeber ◽  
Alexander Brinker
Keyword(s):  
Egg Production ◽  
Gasterosteus Aculeatus ◽  
Energy Content ◽  
Stomach Content Analysis ◽  
Pelagic Zone ◽  
Light Conditions ◽  
Egg Predation ◽  
Large Numbers ◽  
Potential Benefits ◽  
Freshwater Stickleback

The three-spined stickleback Gasterosteus aculeatus invaded Lake Contance in the 1940s and expanded in large numbers from an exclusively shoreline habitat into the pelagic zone in 2012. Stickleback abundance is very high in the pelagic zone in winter near the spawning time of pelagic whitefish Coregonus wartmanni, and it is hypothesized that this is triggered by the opportunity to consume whitefish eggs. Field sampling has qualitatively confirmed predation of whitefish eggs by stickleback, but quantification has proven difficult due to stormy conditions that limit sampling. One fundamental unknown is if freshwater stickleback, known as visual feeders, can successfully find and eat whitefish eggs during twilight and night when whitefish spawn. It is also unknown how long eggs can be identified in stomachs following ingestion, which could limit efforts to quantify egg predation through stomach content analysis. To answer these questions, 144 individuals were given the opportunity to feed on whitefish roe under daylight, twilight, and darkness in controlled conditions. The results showed that stickleback can ingest as many as 100 whitefish eggs under any light conditions, and some individuals even consumed maximum numbers in complete darkness. Furthermore, eggs could be unambiguously identified in the stomach 24 hours after consumption. Whitefish eggs have 28% more energy content than the main diet of sticklebacks (zooplankton) based on bomb-calorimetric measurements, underlining the potential benefits of consuming eggs. Based on experimental results and estimates of stickleback abundance and total egg production, stickleback could potentially consume substantial proportions of the total eggs produced even if relatively few sticklebacks consume eggs. Given the evidence that stickleback can feed on eggs during nighttime spawning and may thereby hamper recruitment, future studies aimed at quantifying actual egg predation and resulting effects on the whitefish population are urgently needed.

scholarly journals Single-cell RNA sequencing reveals micro-evolution of the stickleback immune system

2021 ◽  
Author(s):  
Lauren E Fuess ◽  
Daniel I Bolnick
Keyword(s):  
Immune System ◽  
Single Cell ◽  
Immune Cells ◽  
Gasterosteus Aculeatus ◽  
Immune Cell ◽  
Expression Profiles ◽  
Cell Types ◽  
Model Systems ◽  
System Structure ◽  
Ecological Processes

Pathogenic infection is an important driver of many ecological processes. Furthermore, variability in immune function is an important driver of differential infection outcomes. New evidence would suggest that immune variation extends to broad cellular structure of immune systems. However, variability at such broad levels is traditionally difficult to detect in non-model systems. Here we leverage single cell transcriptomic approaches to document signatures of microevolution of immune system structure in a natural system, the three-spined stickleback (Gasterosteus aculeatus). We sampled nine adult fish from three populations with variability in resistance to a cestode parasite, Schistocephalus solidus, to create the first comprehensive immune cell atlas for G. aculeatus. Eight major immune cell types, corresponding to major vertebrate immune cells, were identified. We were also able to document significant variation in both abundance and expression profiles of the individual immune cell types, among the three populations of fish. This variability may contribute to observed variability in parasite susceptibility. Finally, we demonstrate that identified cell type markers can be used to reinterpret traditional transcriptomic data. Combined our study demonstrates the power of single cell sequencing to not only document evolutionary phenomena (i.e. microevolution of immune cells), but also increase the power of traditional transcriptomic datasets.

Genetic variability in freshwater and anadromous sticklebacks (Gasterosteus aculeatus) of southern British Columbia

1985 ◽  
Vol 63 (3) ◽  
pp. 528-533 ◽  
Author(s):  
R. E. Withler ◽  
J. D. McPhail
Keyword(s):  
British Columbia ◽  
Gasterosteus Aculeatus ◽  
Electrophoretic Variation ◽  
Average Heterozygosity ◽  
Polymorphic Loci ◽  
Allelic Frequencies ◽  
Marine Habitats ◽  
Freshwater Habitats ◽  
Threespine Sticklebacks ◽  
Freshwater Stickleback

Electrophoretic variation at eight loci was compared between anadromous and freshwater populations of threespine sticklebacks (Gasterosteus aculeatus) collected from 56 sites in southwestern British Columbia and northwestern Washington. Allelic frequencies at five polymorphic loci were heterogeneous among populations and the average allelic frequencies at four loci differed between anadromous and freshwater sticklebacks. The average number of polymorphic loci was greater in anadromous (4.6) than in freshwater (3.2) populations. The average heterozygosity was 0.113 ± 0.001 in anadromous and 0.117 ± 0.003 in freshwater stickleback populations. Anadromous populations were more polymorphic but less heterogeneous than freshwater populations. The standardized genetic variance indicated only moderate differentiation among anadromous populations from marine habitats, but considerable differentiation among populations from freshwater habitats. Our data are consistent with the hypothesis of postglacial polyphyletic origins for freshwater populations of Gasterosteus, but also indicate that selection favours different alleles in marine and freshwater environments, at least at the Mdh-1 locus.

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