scholarly journals ON THE ROLE OF THE EVOLUTIONARY-CONSERVATIVE MULTIFUNCTIONAL FACTOR STAUFEN IN THE ACTIVE TRANSPORT OF MRNA IN EARLY EMBRYOGENESIS AND NEUROGENESIS OF DROSOPHILA AS A MODEL OBJECT

2021 ◽  
Author(s):  
Alexander Spirov ◽  
Ekaterina Myasnikova
Keyword(s):  
Active Transport ◽  
Early Embryogenesis ◽  
Model Object

Role of Auxin in Early Embryogenesis of Plants

2014 ◽  
Vol 48 (4) ◽  
pp. 371-380
Author(s):  
Song Lizhen ◽  
Wang Yi ◽  
Yang Qinghua ◽  
Cheng Youfa
Keyword(s):  
Early Embryogenesis

The role of neurohumours in early embryogenesis

Development ◽  
1970 ◽  
Vol 23 (3) ◽  
pp. 549-569
Author(s):  
G. A. Buznikov ◽  
A. N. Kost ◽  
N. F. Kucherova ◽  
A. L. Mndzhoyan ◽  
N. N. Suvorov ◽  
...  
Keyword(s):  
Sea Urchin ◽  
Functional Activity ◽  
Early Onset ◽  
Active Sites ◽  
Physiological Effect ◽  
Early Embryogenesis ◽  
Dopamine Synthesis ◽  
Direct Involvement ◽  
Misgurnus Fossilis

In previous papers (Buznikov, Chudakova & Zvezdina, 1964; Buznikov, Chudakova, Berdysheva & Vyazmina, 1968) we reported that fertilized eggs of the sea-urchin Strongylocentrotus dröbachiensis synthesized a number of neurohumours, such as serotonin (5-hydroxytryptamine, 5-HT), acetylcholine (ACh), adrenalin (A), noradrenalin (NA) and dopamine. Synthesis of 5-HT was also demonstrated in the fertilized eggs of the loach Misgurnus fossilis and some marine Invertebrata. In experiments with sea-urchin embryos we were able to trace regular changes in the level of 5-HT, ACh, A and NA, related to the first cleavage divisions. This early onset of neurohumour synthesis, as well as regular changes in their level, suggests their direct involvement in the regulation of the first cleavage divisions. The functional activity of neurohumours (M) in adult organisms is realized through their reaction with the active sites of corresponding receptors (R) according to the following equation:The magnitude of the physiological effect under certain conditions is linearly proportional to the number of complexes MR formed (Turpayev, 1962; Ariëns, 1964).

Chromatin Diminution in Cyclops kolensis Lill. (Copepoda, Crustacea) as a Radical Way to Inactivate Redundant Genome in Somatic Cells

2018 ◽  
Vol 156 (3) ◽  
pp. 165-172 ◽  
Author(s):  
Andrey K. Grishanin ◽  
Maxim V. Zagoskin
Keyword(s):  
Chromosome Number ◽  
Repetitive Sequences ◽  
Early Embryogenesis ◽  
Chromosome Size ◽  
Chromatin Diminution ◽  
Elimination Process ◽  
Dna Elimination ◽  
Molecular Studies ◽  
Cyclops Kolensis

Chromatin diminution (CD) is a phenomenon of programmed DNA elimination which takes place in early embryogenesis in some eukaryotes. The mechanism and biological role of CD remain largely unknown. During CD in the freshwater copepod Cyclops kolensis, the genome of cells of the somatic lineage is reorganized and reduced in size by more than 90% without affecting the genome of germline cells. Although the diploid chromosome number is unchanged, chromosome size is dramatically reduced by CD. The eliminated DNA consists primarily of repetitive sequences and localizes within granules during the elimination process. In this review, we provide an overview of CD in C. kolensis including both cytological and molecular studies.

ROLE OF THE OVIDUCT DURING EARLY EMBRYOGENESIS

1993 ◽  
Vol 28 (3) ◽  
pp. 189-192 ◽  
Author(s):  
F. Gandolfi ◽  
T. A. L. Brevini ◽  
S. Modina ◽  
R. Bianchi ◽  
L. Passoni
Keyword(s):  
Early Embryogenesis

Transmembrane potentials and fluxes in isolated rabbit atria

1959 ◽  
Vol 196 (6) ◽  
pp. 1292-1296 ◽  
Author(s):  
R. L. Klein ◽  
W. C. Holland
Keyword(s):  
Action Potential ◽  
Active Transport ◽  
Terminal Phase ◽  
Transmembrane Potentials ◽  
Unidirectional Fluxes ◽  
Rabbit Atria

Data are presented from a study of transmembrane potentials and unidirectional fluxes of K42 under identical conditions in isolated rabbit atria. The effects of acetylcholine and varying extracellular concentrations of Na, K and Ca were investigated. Particular emphasis has been placed on the role of Ca and on the terminal phase of repolarization of the action potential, namely the negative after potential. Data are given which support the contention that the duration of the negative after potential depends on an active transport of K or Na, or both.

Role of ATP in respiratory control and active transport in tobacco hornworm midgut

1980 ◽  
Vol 238 (1) ◽  
pp. C10-C14 ◽  
Author(s):  
L. J. Mandel ◽  
T. G. Riddle ◽  
J. M. Storey
Keyword(s):  
Active Transport ◽  
Respiratory Control ◽  
Intermediate Form ◽  
Decay Kinetics ◽  
Kinetic Rates ◽  
Fresh Frozen ◽  
The Difference ◽  
Redox Level ◽  
K Transport

The intracellular ATP, ADP, AMP, and orthophosphate (Pi) levels were measured in the midgut of Manduca sexta. The nucleotide levels were identical in tissues either “fresh” frozen or equilibrate in regular (32 mM) K or low (8 mM) K solutions. The calculated [ATP]/[ADP][Pi]ratio was approximately 300 M-1, which is low compared to other tissues. Given the ability of this ratio to control the respiratory rate, it is speculated that this low value may cause the maximal uncontrolled respiration normally observed in the midgut. The kinetics to anoxia of active transport (Isc) and the redox level of the mitochondrial cytochromes were measured simultaneously in the midgut. The cytochromes became reduced with a time constant of 0.75 +/- 0.15 min, whereas that for Isc inhibition was 2.1 +/- 0.15 min after a delay of 0.25 min. The difference between these two kinetic rates indicates that an intermediate form of energy exists in this tissue to energize active K transport. Measurements of ATP levels during the transition to anoxia indicate that its decay kinetics are sufficiently slow for ATP to be the immediate energy source for active transport in this tissue.

Role of metabolism in K-induced tension changes in guinea pig taenia coli

1965 ◽  
Vol 208 (6) ◽  
pp. 1203-1205 ◽  
Author(s):  
M. Pfaffman ◽  
N. Urakawa ◽  
W. C. Holland
Keyword(s):  
Guinea Pig ◽  
Active Transport ◽  
Underlying Mechanism ◽  
Taenia Coli ◽  
Na Transport ◽  
Phasic Response ◽  
Metabolic Intermediates ◽  
Substrate Removal ◽  
Insight Into

Further insight into the underlying mechanism(s) of the K-induced phasic and tonic contractions of the taenia coli of the guinea pig was obtained by examining the effects of various metabolic intermediates, inhibitors of metabolism and active transport, on these responses. Evidence is presented to support the thesis that the tonic response is dependent on the aerobic breakdown of carbohydrates and is abolished by substrate removal, a decrease of temperature, DNP, lithium, and ouabain. These same factors have little or no effect on the phasic response. From the evidence presented, it is concluded that the phasic response is a passive process, whereas the tonic contracture is an active one depending on metabolism and possibly linked to active Na transport.

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