scholarly journals Experimentally induced differentiation of slow tonic and fast twitch muscles in the chick

1979 ◽  
Vol 36 (1) ◽  
pp. 137-154
Author(s):  
D.E. Ashhurst ◽  
G. Vrbova

The anterior latissimus dorsi (ALD) muscle of chickens is a slow tonic muscle, while the posterior latissimus dorsi (PLD) is a fast twitch muscle. These muscles on opposite sides of a 3-week-old chick were removed, minced and replaced in the site of the other muscle and left to regenerate. The regenerating muscles were examined at various periods from 4 days onwards and their contractile properties were found to resemble those typical of the muscle they replaced and not the original muscle. The regenerating muscles from 8 days onwards displayed the morphological features of the control muscles in the contralateral site. By 14 days, differentiation was almost complete and neuromuscular junctions were seen. It is suggested that the physiological and morphological characteristics of a muscle are determined by its position and possibly also by its innervation.

1998 ◽  
Vol 275 (1) ◽  
pp. C155-C162 ◽  
Author(s):  
Dawn A. Lowe ◽  
Troy Lund ◽  
Stephen E. Alway

Myogenic regulatory factors (MRFs) are a family of skeletal muscle-specific transcription factors that regulate the expression of several muscle genes. This study was designed to determine whether MRF transcripts were increased in hypertrophy-stimulated muscle of adult quails and whether equivalent increases occurred in muscles of older quails. Slow-tonic anterior latissimus dorsi and fast-twitch patagialis muscles of adult, middle-aged, aged, and senescent quails were stretch overloaded for 6, 24, or 72 h, with contralateral muscles serving as controls. RNase protection assays showed that MRF4 and MyoD transcript levels were increased and myogenin and Myf5 transcripts were induced in stretch-overloaded muscles. However, MRF4 and MyoD increases were significantly attenuated in patagialis muscles of older quails. RT-PCR analyses of three MRF-regulated genes showed that increases in the transcription of these genes occurred with stretch overload, but the increases were less in muscles of older quails. In summary, attenuated MRF responses in muscles from aged animals may partially explain why muscles from older animals do not hypertrophy to the same extent as muscles from younger animals.


2017 ◽  
Vol 23 (1) ◽  
Author(s):  
MAMTA KUMARI ◽  
SUSHIL KUMAR

The heteroptera is an important suborder of order hemiptera and includes a large number of aquatic and semiaquatic forms, which are of a taxonomic importance. The study recorded 14 families namely Napidae, Notonectidae Pleidae, Belostomatidae, Naucoridae, Corixidae, Gelastocoreidae, Ochtaridae, Hydrometridae, Velidae Mesoveliidae, Gerridae, Saldidae and Herbridae. Aquatic and semiaquatic heteropteran insects are of variable sizes from 1.5 mm. to 110 mm long living mainly in lentic and lotic fresh water. Some even live in brackish water, only a few species are marine. These are different in morphology and feeding habits from their terrestrial forms. Some are truly aquatic, provided with effective swimming respiratory structure along with modification of body shape and size. Besides the genitalia and copulatory complex of all the species studied has been dealt. The other morphological features of taxonomic significance were also studied. This study finds various morphological features in the members of different aquatic and semiaquatic families of heteroptera.


1983 ◽  
Vol 96 (1) ◽  
pp. 297-300 ◽  
Author(s):  
F C Reinach ◽  
T Masaki ◽  
D A Fischman

Specific isoforms of myofibrillar proteins are expressed in different muscles and in various fiber types within a single muscle. We have isolated and characterized monoclonal antibodies against C-proteins from slow tonic (anterior latissimus dorsi, ALD) and fast twitch (pectoralis major) muscles of the chicken. Although the antibody against "fast" C-protein (MF-1) did not bind to the "slow" isoform and the antibody to the "slow" C-protein (ALD-66) did not bind to the "fast" isoform, we observed that both antibodies bound C-protein from the posterior latissimus dorsi (PLD) muscle. Here we demonstrate that in the PLD muscle the binding sites of these two antibodies reside in two different C-protein isoforms which have different molecular weights and can be separated by hydroxylapatite column chromatography. Since we have shown previously that both these antibodies stain all myofibers and myofibrils derived from PLD muscle, we conclude that all myofibers in this muscle contain both isoforms with all sarcomeres.


1976 ◽  
Vol 157 (1) ◽  
pp. 87-95 ◽  
Author(s):  
J F Y Hoh ◽  
P A McGrath ◽  
R I White

1. A method is described for the electrophoretic analysis of intact myosin in polyacrylamide gel in a buffer system containing 0.02 M-pyrophosphate and 10% (v/v) glycerol, pH 8.8. 2. In this system chicken skeletal-muscle myosins reveal five distinct electrophoretic components, three components from the fast-twitch posterior latissimus dorsi muscle and two slower-migrating components from the slow-twitch anterior latissimus dorsi muscle. 3. The Ca2+-activated ATPase (adenosine triphosphatase) activity of myosin components was measured by densitometric scanning of the gel for the Ca3(PO4)2 precipitate formed during the ATPase reaction and subsequently for stained protein. Each component from the same muscle appears to have identical ATPase activity, but components from the fast-twitch muscle had an activity 2.2 times higher than those from the slow-twitch muscle. 4. On re-electrophoresis in the same buffer system, individual fractions of fast-twitch myosin did not reproduce the three-band pattern of the original myosin, but migrated at rates consistent with their original mobility. 5. Analysis of the mobility of the three fast-twitch myosin components in gels of different concentrations suggests that they are not stable oligomers of each other. 6. It is suggested that these components of fast-twitch myosin and slow-twitch myosin are isoenzymes of myosin.


2021 ◽  
Vol 52 (4) ◽  
pp. 1039-1049
Author(s):  
Al-Dobaissi & Al-Masoudi

The research was aimed to identify fruits morphological characteristics of 33 taxa belonging to the Lepidieae tribe from Brassicaceae. The characteristics of the fruit's general shape, apex shape, dimensions, colors, surface ornamentation, and beak were determined, the results indicated the importance of each of those characters in isolated species, In general, all the tribe's fruits were open capsule and short silicula. According to the dimensions of fruit, three species can be distinguished as a group with dimensions greater than 20mm, as in Brossardia, Coluteocarpus, and Didymophysa, and depending on the shape, it was possible to differentiate the species within this group, while the other species were less than 20 mm. in dimensions. They were distinguished by the general shapes, as the fruits of the Aethionema species were distinguished by their winged shaped, whereas the fruits of the genus Biscutella are bi-lobed, and the fruits have an inverted semi-triangular shape in the Capsella and peltate with prominent veins in the genus Horwoodia, or maybe peltate and longitudinally splintered with dark veins in Iberis, while the genus Sameraria fruit is circular to semi-circular characterized by intermediate appendages, while the individuals of the genus Isatis have linear-oblong fruits, and the species of both genus Lipidium and Hymenolobus were distinguished by their small and elliptic fruits and could be differentiated according to other fruits features. So could be conclude the importance of the characteristic of the general shape of the fruit firstly in species isolation then size, ornamentation, and some other traits.


2008 ◽  
Vol 36 (6) ◽  
pp. 1855-1863 ◽  
Author(s):  
Benoit Rossignol ◽  
Gildas Gueret ◽  
Jean-Pierre Pennec ◽  
Julie Morel ◽  
Fabrice Rannou ◽  
...  

1982 ◽  
Vol 242 (1) ◽  
pp. C52-C58 ◽  
Author(s):  
P. J. Reiser ◽  
B. T. Stokes

The development of the twitch and tetanic responses of the embryonic chick posterior latissimus dorsi muscle has been studied during the last week in ovo. Normalized twitch and tetanic forces increased 3- and 12-fold, respectively, during this period. The changes in the kinetics of the twitch and tetanic responses differed during this developmental period. The time to peak twitch force progressively decreased. The decrease in time to half-peak tetanic force and the increase in the time differential of force production of the tetanic response did not continue after day 18. A prolonged tonic contractile component was described for both the twitch and tetanic responses, particularly in muscles from the younger embryos (days 14-18). A large decrease in the time to one-half relaxation of the twitch response also takes place during the final week in ovo. This detailed description of the development of the contractile properties provides a model system of fast-twitch muscle development in which neurogenic and myogenic components of muscular differentiation can be studied from several approaches.


Author(s):  
I. R. Khuzina ◽  
V. N. Komarov

The paper considers a point of view, based on the conception of the broad understanding of taxons. According to this point of view, rhyncholites of the subgenus Dentatobeccus and Microbeccus are accepted to be synonymous with the genus Rhynchoteuthis, and subgenus Romanovichella is considered to be synonymous with the genus Palaeoteuthis. The criteria, exercising influence on the different approaches to the classification of rhyncholites, have been analyzed (such as age and individual variability, sexual dimorphism, pathological and teratological features, degree of disintegration of material), underestimation of which can lead to inaccuracy. Divestment of the subgenuses Dentatobeccus, Microbeccus and Romanovichella, possessing very bright morphological characteristics, to have an independent status and denomination to their synonyms, has been noted to be unjustified. An artificial system (any suggested variant) with all its minuses is a single probable system for rhyncholites. The main criteria, minimizing its negative sides and proving the separation of the new taxon, is an available mass-scale material. The narrow understanding of the genus, used in sensible limits, has been underlined to simplify the problem of the passing the view about the genus to the other investigators and recognition of rhyncholites for the practical tasks.


Author(s):  
Modest Guţu ◽  
Thomas Iliffe

Leptochelia Vatulelensis(Crustacea: Tanaidacea), A New Species From Anchialine Caves of the South-Western PacificLeptochelia vatulelensisn. sp., discovered on the small islands of Vatulele (Fijian group) and Ouvéa (Loyalty Islands, New Caledonia), is described and illustrated. The new species is distinguished from the others of the"Leptochelia-dubiagroup" (to which it is generally similar) by the following combination of morphological characteristics: (1) the presence of three to four distal setae on the maxilliped basis; (2) merus of pereopods III and IV with only a distosternal seta; (3) endopod of the uropods formed of four (rarely three) articles; (4) males with two (sometimes three) relatively short aesthetascs on the first five articles of the antennular flagellum; (5) male cheliped with a diminished dimorphism; (6) males with a vertical comb-row of setae on the cheliped propodus. Although it inhabits inland, anchialine caves, the new species lacks morphological features that are characteristic of some cave species.


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