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Muscles of the mesopelagic copepod Gaussia princeps (Arthropoda, Crustacea, Calanoida) are responsible for repetitive movements of feeding and swimming appendages that are too fast to be followed by eye. This paper provides a comparative functional and ultrastructural description of five muscles that have different contraction speeds and are located within different anatomical sites. All are very fast, as indicated by a thick:thin filament ratio of 3:1 and sarcomere lengths that vary between 1 and 3 μm. Measured lengths of thin and thick filaments indicate classification of the muscles into three distinct groups (short, medium and long) and predict a difference in speed of up to threefold between fibers with the shortest and longest sarcomeres. Indeed, the kicking movement of the posterior legs (with the shortest sarcomere length) is approximately three-fold faster than the simultaneous back-folding of the antennae (with the longest length). Thus, a specific relationship between speed of movement and sarcomere length is established and we can use the latter to predict the former. Regulatory systems of contraction (sarcoplasmic reticulum (SR) and transverse (T) tubules) match the different contractile properties, varying in frequency of distribution and overall content in parallel to sarcomere variations. All muscles from appendages and body musculature show a unique disposition of contractile material, SR, and T tubules found only in copepod muscles: muscle filaments are grouped in large supermyofibrils, that are riddled with frequent cylindrical shafts containing SR and T tubules. This arrangement insures a high spatial frequency of regulatory components. This article is protected by copyright. All rights reserved.
This article was published in the following journal.
Name: Anatomical record (Hoboken, N.J. : 2007)
Type I secretion systems are widespread in Gram-negative bacteria and mediate the one-step translocation of a large variety of proteins serving for diverse purposes, including nutrient acquisition or ...
Intramembrane proteases hydrolyze peptide bonds within the membrane as a regulatory paradigm that is conserved across all forms of cellular life. Many of these enzymes are thought to be oligomeric, an...
The selection of favorable environmental conditions for gravity-driven membrane (GDM) systems is crucial to their widespread application. In this study, GDM systems operated under different light inte...
We developed an asymmetrically porous membrane with a leaf-stacked structure (LSS membrane; top with nano-sized pores and bulk/bottom with leaf-stacked structure) via immersion-precipitation using pol...
Methods to differentially label cell-surface and intracellular membrane proteins are indispensable for understanding their function and the regulation of their trafficking. We present an efficient str...
Elderly patients presenting with myocardial infarction (MI) and multivessel disease are the highest risk population with the worst prognosis. No trial has ever been designed to optimize th...
One major study objective is, using 2 study arms (data-driven health coaching plus RC vs. RC only), to evaluate the efficacy of data-driven health coaching. 'RC only' will serve as the con...
This research study aims to improve the standard exam called Focused Assessment with Sonography in Trauma (FAST). The FAST exam is an ultrasound test used to identify an abdominal bleed. T...
The goal of this project is to determine the effects of 6-week dietary supplementation with one of two doses of citicoline (250 mg/d, 500 mg/d) or placebo on prefrontal cortical membrane d...
This study evaluates the clinical ease of use of the Femoral Antegrade Starting Tool (FAST).
Bacterial secretion systems found in bacteria that have a MYCOLIC ACID-containing outer membrane such as MYCOBACTERIACEAE; Corynebacteriaceae; and NOCARDIACEAE. These are also known as ESX secretion systems because the first to be discovered is involved in secreting major virulence factors EsxA and EsxB. There are several subtypes of T7SSs including ESX-1, ESX-2, ESX-3, ESX-4, and ESX-5 secretion systems. The subtypes share some core components including an inner membrane channel-forming ATPase complex, a membrane-anchored mycosin, and a second channel that spans the outer mycolic acid-containing membrane.
Gram-negative bacterial secretion systems which translocate effectors in a single step across the inner and outer membranes. The one-step secretion is carried out by a channel that passes from the CYTOPLASM, through the inner membrane, PERIPLASMIC SPACE, and outer membrane, to the EXTRACELLULAR SPACE. The specificity of type I secretions systems are determined by the specificity of the three subcomponents forming the channel - an ATP transporter (ATP-BINDING CASSETTE TRANSPORTERS); a membrane fusion protein (MEMBRANE FUSION PROTEINS); and an outer membrane protein (BACTERIAL OUTER MEMBRANE PROTEINS.)
Functionally and structurally differentiated, purple-pigmented regions of the cytoplasmic membrane of some strains of Halobacterium halobium. The membrane develops under anaerobic conditions and is made almost entirely of the purple pigment BACTERIORHODOPSINS. (From Singleton & Sainsbury Dictionary of Microbiology and Molecular Biology, 2d ed)
Fluid propulsion systems driven mechanically, electrically, or osmotically that are used to inject (or infuse) over time agents into a patient or experimental animal; used routinely in hospitals to maintain a patent intravenous line, to administer antineoplastic agents and other drugs in thromboembolism, heart disease, diabetes mellitus (INSULIN INFUSION SYSTEMS is also available), and other disorders.
Loss of detectable antigen from the surface of a cell after incubation with antibodies. This is one method in which some tumors escape detection by the immune system. Antigenic modulation of target antigens also reduces the therapeutic effectiveness of treatment by monoclonal antibodies.
Arthritis Fibromyalgia Gout Lupus Rheumatic Rheumatology is the medical specialty concerned with the diagnosis and management of disease involving joints, tendons, muscles, ligaments and associated structures (Oxford Medical Diction...