Organelle Systems and Biological Organization

Ehret, Charles F.

doi:10.1126/science.132.3420.115

Cited by 29 publications

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“…Many publications have helped us to plan the procedures and formulate the interpretations presented here, especially the following: Bang & Bang( I ) , Borysko (3,4). Ehret ( 7 ) , FaurC-Fremiet and his colleagues( l o ) , King,Beams,et al( 19), Pitelka( 22), Randall & Jackson (24,26), Roth ( 2 7.28), Sleigh (30), . The following reviews * Present address: Laboratory of Biology of Viruses, National Institute of Allergy and Infectious Diseases, N.I.H., Bethesda, Md., where some of this research was done.…”

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Electron Microscopy of the Ectoplasm and Infraciliature of Spirostomum ambiguum

Finley

Brown

Daniel

1964

The Journal of Protozoology

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SYNOPSIS. A study of the ectoplasm and infraciliature of Spirostomum ambiguum has been made with light and electron microscopy. Proceeding from the exterior, the cortex is described as the highly structured ectoplasmic portion of Spirostomum consisting of ectoplasmic ridge components and ectoplasmic furrow components. The pellicle invests the ectoplasmic ridges, ectoplasmic furrows, cilia, and adoral membranelles. Electron micrographs show that the cell surface is bounded by two membranes, for the most part parallel. The outer one is continuous with the unit membrane of each cilium; the course of the inner membrane has not been determined in areas bearing cilia. The ridge components are: (i) a collection of fibrils called peripheral ectomyonemes, situated beneath the inner membrane of the cell surface, oriented parallel with the organism's longitudinal axis and following the peripheral contours of each ridge; (ii) distinct rows of tubular fibrils which form a longitudinal bundle called lateral ectomyonemes, situated in the lower portion of each ridge and oriented parallel to its spiral course; (iii) cytoplasmic matrix suspending and surrounding components (i) and (ii). Mitochondria and unidentified electron‐opaque oval‐shaped or round bodies called X‐bodies are dispersed in the ectoplasmic ridges but they also occur in the endoplasm; therefore, they are considered to be transient inclusions instead of constituents of the ridges. The furrow components are: (i) the body cilia and adoral membranelles; (ii) the kinetosomes; (iii) root fibrils, called kinetodesmal strands, of the adoral membranelles; (iv) cytoplasmic matrix suspending and surrounding the furrow components. A trabecular band of randomly oriented filaments, called the endomyoneme is described as possibly the structure called M‐band by Randall and Jackson, 1958, and contractile fibrillar system by Yagiu and Shigenaka, 1963. It is suggested that collections of distinct fibrils in Spirostomum be called fibrillar complexes. Acceptance of this suggestion will lead to the designation of four distinct fibrillar complexes in heterotrichs; all four complexes have been described or mentioned in previous studies. Some findings of previous investigators are discussed and confirmed (especially pertaining to Randall and Jackson, also Yagiu and Shigenaka, cited above). Inferences from these independently derived findings are discussed.

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Electron Microscopy of the Ectoplasm and Infraciliature of Spirostomum ambiguum

Finley

Brown

Daniel

1964

The Journal of Protozoology

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“…Often, but not always, correlated with but slight elongation of these kineties is failure of the new gullet to invaginate: its kineties remain up on the body surface more or less posterior to Role of Preformed Structure in Cell Heredity 193 the preexisting vestibule, mouth, and gullet. We have not previously mentioned this invagination process, which has been noted by Ehret and Powers (1959), and the other details of the transformation of the rudiment into a functional normal oral apparatus because much is still obscure. But invagination of the gullet, the rudiments of which develop in the cortex near the old mouth-vestibule juncture, is part of the story.…”

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“…Doubts have long existed, especially among students of the ciliated protozoa (Sonneborn, 1951(Sonneborn, , 1960Wiesz, 1954;Ehret, 1960;Tartar, 1941Tartar, , 1961, as to the sufficiency of so simple a hypothesis in the light of evidences for the essential role of a fourth factor, a specific preformed organization of the cell or its parts. This organization seems unable to arise de novo by gene action in any noncellular milieu or unorganized cell "soup."…”

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“…The dorsal side of the gullet is made up of a group of four rows of kinetosomes, the quadrulus. Between quadrulus and endoral kinety, the right side of the gullet is composed of what is called the ribbed wall ( Ehret and Powers, 1959), believed to consist of an unknown number of highly modified kineties. The ribbed wall is located to the observer's left of the endoral kinety in Fig.…”

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“…Second, a kinetodesmal fiber passes from the kinetosome to the right and anteriorly. Third, on the right side of each kinetosome (or longitudinally disposed pair of kinetosomes) is another structure known as the parasomal sac ( Ehret and Powers, 1959 ) . The kinety, its anteroposterior direction, and its right-left orientation are unambiguously defined by these criteria, as microscopic examination of any short part of a kinety clearly reveals.…”

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The nature of biological diversity

Allen¹

1963

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of The University of Michigan, who spent much time in planning the lecture series from which this book is derived.Darwin and Wallace proposed the theory of evolution almost simultaneously and quite independently. They and their numerous followers of the past century have demonstrated that, given an organism of the most primitive type, all the species of today and of past geological periods could and did evolve from such cells. We are beginning to understand the processes by which inherited characteristics are carried from generation to generation by means of deoxyribonucleic acids, and also we understand how variations in species of animals and plants occur. Many details remain, but the broad outline has become clearer during recent years and decades. Also, we find marked biochemical similarities between all living things, indicating tbat they are all part of a single evolutionary process. These fundamental biochemical processes were established in the distant past before the time of the oldest fossils, namely, some 500 million or more years ago.At least after the development of sexual reproduction, evolution must have occurred by mutation in one individual, it is true, but tbc 1 c Energy, source , % , cal cm " yr Total radiation from sun 260.000

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Acetylcholinkreis

Fischer¹

1971

Vergleichende Pharmakologie Von Überträgersubstanzen in Tiersystematischer Darstellung

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Organelle Systems and Biological Organization

Abstract: Structural and developmental evidence leads to a new look at our concepts of biological organization.

Cited by 29 publications

References 54 publications

Electron Microscopy of the Ectoplasm and Infraciliature of Spirostomum ambiguum

Electron Microscopy of the Ectoplasm and Infraciliature of Spirostomum ambiguum

The nature of biological diversity

Acetylcholinkreis

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