scholarly journals Spicule formation in calcareous sponges: Coordinated expression of biomineralization genes and spicule-type specific genes

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Oliver Voigt ◽  
Maja Adamska ◽  
Marcin Adamski ◽  
André Kittelmann ◽  
Lukardis Wencker ◽  
...  
Keyword(s):  
Calcareous Sponges ◽  
Spicule Formation ◽  
Coordinated Expression

scholarly journals Memoirs: Studies in Spicule Formation

1908 ◽  
Vol s2-52 (205) ◽  
pp. 139-157
Author(s):  
W. WOODLAND
Keyword(s):  
Thin Film ◽  
Single Cells ◽  
Siliceous Sponge ◽  
Sponge Spicule ◽  
Calcareous Sponges ◽  
Stage Of Development ◽  
Spicule Formation

1. The earliest stages in development of the Hexactinellid spicule are at present unknown, but there exist reasons for supposing that it originates as a granule enclosed by a spherical syncytium in which cell-outlines are absent, and that the six rays of the hexact grow out from this granule. 2. The earliest stage of development yet discovered is the small hexact, the rays of which do not extend to the periphery of the enveloping syncytium. 3. The rays of the hexact elongate, causing the spherical syncytium at first "to present a more or less octahedral shape, with somewhat concave surfaces and with rounded corners" (Ijima). 4. The rays at length extend beyond the spherical contour of the syncytium (the scleroblast mass), the scleroplasm of which, however, persistently adheres to the rays as a thin film, which occasionally includes nuclei. 5. The peripheral growth of the megasclere type of spicule causes the spherical syncytium enveloping the point of junction of the six rays to dwindle and finally to disappear on account of the distension involved. The whole of the microsclere, with the exception of the terminals, remains permanently enveloped by the spherical syncytium. 6. All tetractinellid and monactinellid spicules originate as granules contained within single cells. In a few instances the spicule arises from several granules within the cell and then consists of separate parts (dragmata, for example). 7. All growth is accretionary. There is no well-authenticated instance of a siliceous sponge-spicule being formed by the fusion of at-first-separate parts--such as occurs in calcareous sponges, for example. 8. With the exception of very large spicules, the nucleus of the distended scleroblast remains single throughout growth. 9. It is a significant fact that spicule formation proceeds on very different lines in each of the three great groups of sponges--the Tetraxonida, Triaxonida, and Calcarea.

scholarly journals Xenorhabdus nematophila Requires an Intact iscRSUA-hscBA-fdx Operon To Colonize Steinernema carpocapsae Nematodes

2003 ◽  
Vol 185 (12) ◽  
pp. 3678-3682 ◽  
Author(s):  
Eric C. Martens ◽  
Joseph Gawronski-Salerno ◽  
Danielle L. Vokal ◽  
Molly C. Pellitteri ◽  
Megan L. Menard ◽  
...  
Keyword(s):  
Steinernema Carpocapsae ◽  
Xenorhabdus Nematophila ◽  
Coordinated Expression

ABSTRACT An insertion between iscA and hscB of the Xenorhabdus nematophila iscRSUA-hscBA-fdx locus, predicted to encode Fe-S assembly machinery, prevented colonization of Steinernema carpocapsae nematodes. The insertion disrupted cotranscription of iscA and hscB, but did not reduce hscBA expression, suggesting that X. nematophila requires coordinated expression of the isc-hsc-fdx locus for colonization.

scholarly journals The Coordinated Upregulated Expression of Genes Involved in MEP, Chlorophyll, Carotenoid and Tocopherol Pathways, Mirrored the Corresponding Metabolite Contents in Rice Leaves during De-Etiolation

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1456
Author(s):  
Xin Jin ◽  
Can Baysal ◽  
Margit Drapal ◽  
Yanmin Sheng ◽  
Xin Huang ◽  
...  
Keyword(s):  
Higher Plants ◽  
Expression Patterns ◽  
Regulatory Elements ◽  
Isoprenoid Biosynthesis ◽  
Promoter Regions ◽  
Expression Of Genes ◽  
Coordinated Expression ◽  
Rice Leaves ◽  
Mechanistic Basis ◽  
Phosphate Synthase

Light is an essential regulator of many developmental processes in higher plants. We investigated the effect of 4-hydroxy-3-methylbut-2-enyl diphosphate reductase 1/2 genes (OsHDR1/2) and isopentenyl diphosphate isomerase 1/2 genes (OsIPPI1/2) on the biosynthesis of chlorophylls, carotenoids, and phytosterols in 14-day-old etiolated rice (Oyza sativa L.) leaves during de-etiolation. However, little is known about the effect of isoprenoid biosynthesis genes on the corresponding metabolites during the de-etiolation of etiolated rice leaves. The results showed that the levels of α-tocopherol were significantly increased in de-etiolated rice leaves. Similar to 1-deoxy-D-xylulose-5-phosphate synthase 3 gene (OsDXS3), both OsDXS1 and OsDXS2 genes encode functional 1-deoxy-D-xylulose-5-phosphate synthase (DXS) activities. Their expression patterns and the synthesis of chlorophyll, carotenoid, and tocopherol metabolites suggested that OsDXS1 is responsible for the biosynthesis of plastidial isoprenoids in de-etiolated rice leaves. The expression analysis of isoprenoid biosynthesis genes revealed that the coordinated expression of the MEP (2-C-methyl-D-erythritol 4-phosphate) pathway, chlorophyll, carotenoid, and tocopherol pathway genes mirrored the changes in the levels of the corresponding metabolites during de-etiolation. The underpinning mechanistic basis of coordinated light-upregulated gene expression was elucidated during the de-etiolation process, specifically the role of light-responsive cis-regulatory motifs in the promoter region of these genes. In silico promoter analysis showed that the light-responsive cis-regulatory elements presented in all the promoter regions of each light-upregulated gene, providing an important link between observed phenotype during de-etiolation and the molecular machinery controlling expression of these genes.

scholarly journals Spicule formation by cultured embryonic cells from the sea urchin.

1981 ◽  
Vol 256 (24) ◽  
pp. 13105-13111
Author(s):  
G.R. Mintz ◽  
S DeFrancesco ◽  
W.J. Lennarz
Keyword(s):  
Sea Urchin ◽  
Embryonic Cells ◽  
Spicule Formation

scholarly journals Assembly of Two Transgenes in an Artificial Chromatin Domain Gives Highly Coordinated Expression in Tobacco

Genetics ◽  
2002 ◽  
Vol 160 (2) ◽  
pp. 727-740
Author(s):  
Ludmila Mlynárová ◽  
Annelies Loonen ◽  
Elzbieta Mietkiewska ◽  
Ritsert C Jansen ◽  
Jan-Peter Nap
Keyword(s):  
Enzyme Activities ◽  
Firefly Luciferase ◽  
Chromatin Domain ◽  
Mrna Levels ◽  
Loop Model ◽  
Data Generation ◽  
Genome Data ◽  
The Matrix ◽  
Coordinated Expression ◽  
Firefly Luciferase Gene

Abstract The chromatin loop model predicts that genes within the same chromatin domain exhibit coordinated regulation. We here present the first direct experimental support for this model in plants. Two reporter genes, the E. coli β-glucuronidase gene and the firefly luciferase gene, driven by different promoters, were placed between copies of the chicken lysozyme A element, a member of the matrix-associated region (MAR) group of chromatin boundary elements, and introduced in tobacco (Nicotiana tabacum). In plants carrying A elements, quantitative enzyme activities and mRNA levels of both genes show high correlations compared to control plants. The A element thus creates an artificial chromatin domain that yields coordinated expression. Surprisingly, enzyme activities correlated poorly with their respective mRNA levels. We hypothesize that this indicates the occurrence of “error pipelines” in data generation: systematic errors of a given analytical method will point in the same direction and cancel out in correlation analysis, resulting in better correlations. In combining different methods of analysis, however, such errors do not cancel out and as a result relevant correlations can be masked. Such error pipelines will have to be taken into account when different types of (e.g., whole-genome) data sets are combined in quantitative analyses.

scholarly journals Inducible nitric oxide synthase inhibits oxygen consumption in collateral-dependent myocardium

2014 ◽  
Vol 306 (3) ◽  
pp. H356-H362 ◽  
Author(s):  
Yingjie Chen ◽  
Ping Zhang ◽  
Jingxin Li ◽  
Xin Xu ◽  
Robert J. Bache
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Inducible Nitric Oxide Synthase ◽  
Vascular Endothelial Cells ◽  
Coronary Artery Occlusion ◽  
Artery Occlusion ◽  
Coordinated Expression ◽  
Collateral Vessels ◽  
Oxide Synthase ◽  
Inducible Nitric Oxide

Following coronary artery occlusion growth of collateral vessels can provide an effective blood supply to the dependent myocardium. The ischemia, which results in growth of collateral vessels, recruits an inflammatory response with expression of cytokines and growth factors, upregulation of endothelial nitric oxide (NO) synthase (eNOS) in vascular endothelial cells, and expression of inducible nitric oxide synthase (iNOS) in both vessels and cardiac myocytes. Because NO is a potent collateral vessel dilator, this study examined whether NO derived from iNOS or constitutive NOS regulates myocardial blood flow (MBF) in the collateral region. Nonselective NOS inhibition with NG-nitro-l-arginine (LNA) caused vasoconstriction with a significant decrease in MBF to the collateral region during exercise. In contrast, the highly selective iNOS inhibitor 1400W caused a 21 ± 5% increase of MBF in the collateral region. This increase in MBF following selective iNOS blockade was proportionate to an increase in myocardial O2 consumption (MV̇o2). The results suggest that NO produced by iNOS inhibits MV̇o2 in the collateralized region, so that the increase in MBF following iNOS blockade was the result of metabolic vasodilation secondary to an increase in MV̇o2. Thus the coordinated expression of iNOS to restrain MV̇o2 and eNOS to maintain collateral vasodilation act to optimize the O2 supply-demand relationship and protect the collateralized myocardium from ischemia.

Fine details of the choanocyte filter apparatus in asconoid calcareous sponges (Porifera: Calcarea) revealed by ruthenium red fixation

Zoology ◽  
2022 ◽  
Vol 150 ◽  
pp. 125984
Author(s):  
Andrey I. Lavrov ◽  
Fyodor V. Bolshakov ◽  
Daria B. Tokina ◽  
Alexander V. Ereskovsky
Keyword(s):  
Ruthenium Red ◽  
Calcareous Sponges
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