Hormone-sensitive stages in the sexual differentiation of laryngeal muscle fiber number in Xenopus laevis

Development ◽  
1990 ◽  
Vol 110 (3) ◽  
pp. 703-711 ◽  
Author(s):  
M.L. Marin ◽  
M.L. Tobias ◽  
D.B. Kelley
Keyword(s):  
Xenopus Laevis ◽  
Muscle Fiber ◽  
Muscle Fibers ◽  
Laryngeal Muscle ◽  
African Clawed Frog ◽  
Fiber Number ◽  
Hormone Sensitive ◽  
Muscle Fiber Number ◽  
Clawed Frog ◽  
Fiber Addition

The number of muscle fibers in the vocal organ of the adult male African clawed frog, Xenopus laevis, exceeds that of adult females. This sex difference is the result of rapid fiber addition in males between the end of metamorphosis, post-metamorphic stage 0 (PM0) and PM2. At PM0, male and female frogs have similar numbers of laryngeal muscle fibers. Males then add more muscle fibers than females and achieve an adult value that is 1.7 times the female number. Males castrated at PM0 have the same fiber number as females. Ovariectomy at PM0 does not alter muscle fiber addition in females. Gonadectomy at PM2 has no effect on fiber addition in either sex. Females attain masculine muscle fiber number if their ovaries are replaced with a testis at metamorphosis. Exogenous testosterone treatment at PM0 significantly increases fiber number in females but not in males. Exogenous testosterone given at PM2 has no effect on fiber number in females but decreases fiber number in males. We conclude that the testes are necessary for the marked addition of laryngeal muscle fibers seen in male X. laevis between PM0 and PM2. The masculine pattern of muscle fiber addition can be induced in females provided with a testis. Androgen secretion from the testes most probably accounts for masculinization of laryngeal muscle fiber number. After PM2, androgens are no longer necessary for muscle fiber addition and cannot increase fiber number in females.

Differences in muscle characteristics of piglets related to the sow parity

2013 ◽  
Vol 93 (4) ◽  
pp. 471-475 ◽  
Author(s):  
A. da Silva ◽  
D. Dalto ◽  
A. Lozano ◽  
E. de Oliveira ◽  
D. Gavioli ◽  
...  
Keyword(s):  
Muscle Fiber ◽  
Muscle Fibers ◽  
Average Weight ◽  
Muscle Area ◽  
Muscle Weight ◽  
Fiber Number ◽  
Muscle Fiber Number

da Silva, A., Dalto, D., Lozano, A., de Oliveira, E., Gavioli, D., de Oliveira, J., Jamile, Romero, N. and da Silva, C. 2013. Differences in muscle characteristics of piglets related to the sow parity. Can. J. Anim. Sci. 93: 471–475. Two hundred forty-three piglets were obtained from 81, 1st through 7th parity sows to determine the influence of sow's parity on piglets’ myogenesis. Those piglets weighing close to or equal to the average weight of their litter were sacrificed, and their semitendinosus muscles were collected to determine the secondary muscle fiber number, area and weight. The number of secondary muscle fibers was correlated with muscle weight (P<0.05; 0.39) and muscle area (P<0.001; 0.63), and muscle area and weight were also correlated (P<0.001; 0.64). Weights of piglets at birth had a correlation with number of muscle fibers (P<0.05; 0.39), muscle area (P<0.001; 0.54) and muscle weight (P<0.001; 0.73). The piglets’ birthweights and muscle weight, muscle area and muscle secondary fiber numbers increased quadratically as parity increased (R 2=0.56, 0.36, 0.44, 0.64 and 0.54; P<0.05, respectively). The results of this study indicate that parity influences the pre-natal development of piglets and that the best muscle characteristics of piglets born from 3rd and 4th parity sows were responsible for their higher weight at birth.

scholarly journals Developmental changes of purinergic control of intestinal motor activity during metamorphosis in the African clawed frog, Xenopus laevis

2007 ◽  
Vol 292 (5) ◽  
pp. R1916-R1925 ◽  
Author(s):  
Monika Sundqvist
Keyword(s):  
Xenopus Laevis ◽  
Motor Activity ◽  
Receptor Antagonist ◽  
Circular Muscle ◽  
Developmental Changes ◽  
Disulfonic Acid ◽  
Developmental Phase ◽  
African Clawed Frog ◽  
Low Concentrations ◽  
Clawed Frog

Little is known about the purinergic regulation of intestinal motor activity in amphibians. Purinergic control of intestinal motility is subject to changes during development in mammals. The aim of this study was to investigate purinergic control of intestinal smooth muscle in the amphibian Xenopus laevis and explore possible changes in this system during the developmental phase of metamorphosis. Effects of purinergic compounds on mean force and contraction frequency in intestinal circular muscle strips from prometamorphic, metamorphic, and juvenile animals were investigated. Before metamorphosis, low concentrations of ATP reduced motor activity, whereas the effects were reversed at higher concentrations. ATP-induced relaxation was not inhibited by the P2-receptor antagonist pyridoxalphosphate-6-azophenyl-2′,4′-disulfonic acid (PPADS) but was blocked by the ecto-nucleotidase inhibitor 6- N, N-diethyl-d-β,γ-dibromomethylene ATP ( ARL67256 ), indicating that an ATP-derived metabolite mediated the relaxation response at this stage. Adenosine induced relaxation before, during, and after metamorphosis, which was blocked by the A1-receptor antagonist 1,3-dipropyl-8-cyclopentylxanthine (DPCPX). The stable ATP-analog adenosine 5′-[γ-thio]-triphosphate (ATPγS) and 2-methylthioATP (2-MeSATP) elicited contractions in the circular muscle strips in prometamorphic tadpoles. However, in juvenile froglets, 2-MeSATP caused relaxation, as did ATPγS at low concentrations. The P2Y11/P2X1-receptor antagonist NF157 antagonized the ATPγS-induced relaxation. The P2X-preferring agonist α-β-methyleneadenosine 5′-triphosphate (α-β-MeATP) evoked PPADS-sensitive increases in mean force at all stages investigated. This study demonstrates the existence of an adenosine A1-like receptor mediating relaxation and a P2X-like receptor mediating contraction in the X. laevis gut before, during, and after metamorphosis. Furthermore, the development of a P2Y11-like receptor-mediated relaxation during metamorphosis is shown.

scholarly journals Toxic effects of carbendazim andn-butyl isocyanate, metabolites of the fungicide benomyl, on early development in the African clawed frog,Xenopus laevis

2008 ◽  
Vol 23 (1) ◽  
pp. 131-144 ◽  
Author(s):  
Chun-Sik Yoon ◽  
Jung-Hyo Jin ◽  
Joo-Hung Park ◽  
Chang-Yeol Yeo ◽  
Song-Ja Kim ◽  
...  
Keyword(s):  
Xenopus Laevis ◽  
Early Development ◽  
Toxic Effects ◽  
African Clawed Frog ◽  
Clawed Frog

scholarly journals First parasitological study of the African clawed frog (Xenopus laevis, Amphibia) in Chile

2017 ◽  
Vol 26 (2) ◽  
pp. 243-247 ◽  
Author(s):  
Cristóbal Castillo ◽  
Gabriel Lobos ◽  
Daniel González-Acuña ◽  
Lucila Moreno ◽  
Cynthya Elizabeth González ◽  
...  
Keyword(s):  
Xenopus Laevis ◽  
Introduced Species ◽  
Batrachochytrium Dendrobatidis ◽  
First Record ◽  
Central Chile ◽  
African Clawed Frog ◽  
Parasite Richness ◽  
Native Birds ◽  
Clawed Frog ◽  
Parasitological Study

Abstract Introduced species can arrive into new territories with parasites; however, these species are expected to face lower parasite richness than in their original regions. Both introduced hosts and parasites can affect native fauna. Since their release into the wild in Chile following laboratory use, Xenopus laevis Daudin, 1802 has widely spread throughout central Chile. The only pathogen described on the host is the fungus Batrachochytrium dendrobatidis Longcore, Pessier, Nichols, 1999; thus, this is the first parasitological study of this species in Chile. In 10 localities in central Chile, 179 specimens of X. laevis were captured and examined for parasites in the gastrointestinal tube, cavities, lungs, liver, and skin. Only nine specimens of the genus Contracaecum Railliet, Henry, 1912 were found in six specimens of X. laevis from a private dam in La Patagua. It is likely that these parasites originated from species of native birds. This is the first record of Contracaecum sp. in Chilean amphibians.

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