Mitosis and meiosis in Rhodnius Prolixus: The fine structure of the spindle and diffuse kinetochore

1967 ◽  
Vol 18 (5-6) ◽  
pp. 489-501 ◽  
Author(s):  
Robert C. Buck
Keyword(s):  
Fine Structure ◽  
Rhodnius Prolixus ◽  
Mitosis And Meiosis

The Dermal Glands of Rhodnius Prolixus

1969 ◽  
Vol 27 ◽  
pp. 258-259
Author(s):  
J. E. Lai-Fook
Keyword(s):  
Fine Structure ◽  
Secretory Activity ◽  
Rhodnius Prolixus ◽  
Outermost Layer ◽  
Cement Layer ◽  
Dermal Glands

Dermal glands are epidermal derivatives which are reported to secrete either the cement layer, which is the outermost layer of the epicuticle or some component of the moulting fluid which digests the endocuticle. The secretions do not show well-defined staining reactions and therefore they have not been positively identified. This has contributed to another difficulty, namely, that of determining the time of secretory activity. This description of the fine structure of the developing glands in Rhodnius was undertaken to determine the time of activity, with a view to investigating their function.

Fine structure of the abdominal neurosecretory organs of Rhodnius prolixus Stål.

1981 ◽  
Vol 59 (5) ◽  
pp. 765-770 ◽  
Author(s):  
J. E. Kuster ◽  
K. G. Davey
Keyword(s):  
Fine Structure ◽  
Connective Tissue ◽  
Rhodnius Prolixus ◽  
Neurosecretory Neurons ◽  
Neurohaemal Areas

Abdominal segments II–V of female Rhodnius prolixus adults each contain a pair of abdominal neurosecretory organs (ANO). They are attached to the anterolateral borders of their respective tergites and sternites. The ANO consist of neurosecretory neurons containing granules approximately 120 nm in diameter, together with glial and connective tissue elements. Apparent neurohaemal areas are located dorsally.

Observations on the Fine Structure and Development of the Spindle at Mitosis and Meiosis in a Marine Centric Diatom (Lithodesmium Undulatum)

1969 ◽  
Vol 5 (1) ◽  
pp. 271-298
Author(s):  
IRENE MANTON ◽  
K. KOWALLIK ◽  
H. A. VON STOSCH
Keyword(s):  
Fine Structure ◽  
Chromosome Structure ◽  
Centric Diatom ◽  
Serial Sections ◽  
Ground Plan ◽  
Living Culture ◽  
Full Discussion ◽  
Two Stages ◽  
Mitosis And Meiosis ◽  
Spindle Structure

Various cytoplasmic phenomena, including spindle structure and development during prophase of the first meiotic division, are described and illustrated. The living culture is represented by a timed sequence of photographs continuing those previously published with respect to mitotic stages in the same filament. The meiotic preliminaries include the so-called swelling phase, by which the parental frustule is forced open, liberating the contained spermatocytes. This occurs during pachytene on evidence of chromosome structure which is illustrated. A spindle precursor is shown to be present before opening of the frustule; this resembles structurally the mitotic equivalent though the ground plan is oblong instead of square. Growth of the precursor continues until after opening of the frustule, when the spindle itself begins to be laid down. Two stages of developing spindles during the later prophases are illustrated by sections cut in three planes and by serial sections. Preliminary comparisons are made with metaphase I and with mitosis, both qualitatively and quantitatively, but a full discussion is deferred pending completion of the record for the later meiotic stages.

scholarly journals THE FINE STRUCTURE OF THE VENTRAL INTERSEGMENTAL ABDOMINAL MUSCLES OF THE INSECT RHODNIUS PROLIXUS DURING THE MOLTING CYCLE

1968 ◽  
Vol 37 (2) ◽  
pp. 462-481 ◽  
Author(s):  
Paul A. Toselli ◽  
Frank A. Pepe
Keyword(s):  
Skeletal Muscle ◽  
Fine Structure ◽  
Chick Embryo ◽  
Muscle Cell ◽  
Cross Sections ◽  
Rhodnius Prolixus ◽  
Abdominal Muscles ◽  
Constant Ratio ◽  
Molting Cycle ◽  
Line Material

The development of the ventral intersegmental abdominal muscles of Rhodnius prolixus is triggered by feeding. The early muscle (1 day after feeding) contains essentially nonstriated fibrils. However, in cross-sections, areas indicating early I bands, Z lines, and A bands can be recognized. Interdigitating thick and thin myofilaments do not assemble into a precise lattice until sometime between 4 and 5 days after feeding. As development continues, the number of fibrils increases, the region corresponding to the Z line increases in density, and the fibrils contain more recognizable striations. The newly formed fibrils broaden as myofilaments are added peripherally. At all stages throughout development, the ratio of thin to thick myofilaments is always 6:1. The formation of fibrils in the abdominal muscles of Rhodnius is different from that in chick embryo skeletal muscle. The major differences are that at all stages in Rhodnius there are (1) a constant ratio of thin to thick myofilaments, and (2) detectable Z-line material. Other findings in Rhodnius suggest (1) that fusion of mononucleated cells with the multinucleated muscle cell occurs, (2) that microtubules develop in the tendon cell concomitantly with development of myofibrils in the associated muscle cell, and (3) that filaments 55A in diameter aggregate into microtubules.

scholarly journals THE FINE STRUCTURE OF THE VENTRAL INTERSEGMENTAL ABDOMINAL MUSCLES OF THE INSECT RHODNIUS PROLIXUS DURING THE MOLTING CYCLE

1968 ◽  
Vol 37 (2) ◽  
pp. 445-461 ◽  
Author(s):  
Paul A. Toselli ◽  
Frank A. Pepe
Keyword(s):  
Fine Structure ◽  
Insect Flight ◽  
Motor Nerve ◽  
Thick Filament ◽  
Rhodnius Prolixus ◽  
Abdominal Muscles ◽  
Molting Cycle ◽  
Thin Filaments ◽  
Characteristic Structure ◽  
Thick Filaments

Rhodnius prolixus, a South American insect, molts five times in its development to an adult after emerging from the egg. Each molting cycle is triggered with a blood-meal. The ventral intersegmental abdominal muscles of Rhodnius develop during each molting cycle and are functional at molting. The fine structure of these fully developed muscles from fourth stage larval insects is studied. They have the characteristic structure of slow muscles. They have multiple motor nerve endings, and the myofibrils are poorly defined in cross-section. Longitudinal sections show long sarcomeres (8–10 µ), irregular Z-lines, and no apparent H zones. No M line is seen. Transverse sections through the A-band region show that each hexagonally arranged thick filament is surrounded by 12 thin filaments. Two thin filaments are shared by two neighboring thick filaments. The ratio of thin to thick filaments is 6:1. This structure is related to that found in vertebrate skeletal muscle and insect flight muscle.

The Fine Structure of Cells of Rhodnius prolixus During Molting

1964 ◽  
Vol 96 (1-2) ◽  
pp. 101-101 ◽  
Author(s):  
W. E. Beckel
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Cell Membranes ◽  
Instar Nymph ◽  
Rhodnius Prolixus ◽  
Epidermal Cells

During intermolt in the fifth instar nymph the epidermal cells are compact, with many mitochondria which appear dense, lack well defined cristae, and are considered relatively inactive. The cell membranes are much folded and show plasmodesmata and microvilli at the juxtaposition of two cell membranes. The endoplasmic reticulum is well formed and well supplied with ribosomes; in the compacted cells the reticular membranes may assume bizarre shapes such as a ball of concentric rings. The nuclei are small with inconspicuous nucleoli.

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