Endocrine regulation of sperm release in an anuran amphibian by Joan Margaret Whittier Download PDF EPUB FB2
The most important regulator of anuran reproduction is environmental temperature. Like most vertebrates, reproductive function in anuran amphibians depends on interactions between the hypothalamus, adenohypophysis, and gonads that are mediated by neural pathways operating across a classic endocrine circuitry.
Amphibians as a Model for the Study of Endocrine Disruptors Werner Kloas Department of Inland Fisheries, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, D Berlin, Germany Evidence shows that environmental compounds can interfere with the endocrine systems of Cited by: Hormonal regulation of ion and water transport in anuran amphibians Article Literature Review in General and Comparative Endocrinology (1) June with 62.
Interestingly, Cb1−/− mice exhibit endocrine features in common with hpg and ArKO models: (1) down regulation of GnRH and GnRH-R mRNA, (2) low LH release and low expression of FSHβ mRNA, (3. Tools available for research in amphibian metamorphosis. The two most popular amphibians used to study metamorphosis have been X.
laevis and the bullfrog Rana most of the 20th century the bullfrog was favored for biochemical studies because of the availability and large size of the mature tadpoles that can be purchased from supply houses.
In most species of animals, embryonic development leads to a larval stage with characteristics very different from those of the adult organism. Very often, larval forms are specialized for some function, such as growth or dispersal. The pluteus larva of the sea urchin, for instance, can travel on ocean currents, whereas the adult urchin leads a sedentary by: 2.
October 7, If you have ever picked up a male cane toad (Rhinella marina) you likely heard it make a noise termed a 'release call'. It is thought these calls send a message to other males- "I'm a male, release me!"– if a male cane toad is grasped by another male to mate.
Pages where the terms "Historic" (textbooks, papers, people, recommendations) appear on this site, and sections within pages where this disclaimer appears, indicate that the content and scientific understanding are specific to the time of means that while some scientific descriptions are still accurate, the terminology and interpretation of the developmental mechanisms reflect.
Sperm collection and storage for the sustainable management of amphibian biodiversity. Theriogenology, Comparative Analysis of Anuran Amphibian Skin Microbiomes Across Inland and Coastal Wetlands.
Microbial Ecology, 78(2), Xenopus laevis as a Bioindicator of Endocrine Disruptors in. AMPHIBIAN METAMORPHOSIS is a spectacular postembryonic developmental process that is governed by thyroid hormones (TH). In the classical model Xenopus laevis as well as in other species, a peak of the circulating concentration of TH coincides with the climax of metamorphosis (1; reviewed in Refs.
2 and 3).Furthermore, the administration of TH in anuran tadpoles, even before the Cited by: We observed a slight drop in the growth of Xenopus laevis and Pseudacris triseriata larvae following acute exposure ( h) during egg development to three concentrations of TCDD (,μg/l).
Our exposure protocol was modeled on a previous investigation that was designed to mimic the effects of maternal deposition of TCDD. The doses selected were consistent with known rates of Cited by: 8.
Perchlorate. Perchlorate is a well-characterised inhibitor of the sodium-iodide symporter (NIS) that is expressed in the basal membrane of thyroid follicular cells and is critical for iodide uptake ().Two other NIS inhibitor classes, nitrates and thiocyanates, are found at significant levels in human fluids, but in molar terms, they are respectively and 15 times less active than Cited by: Oviducal Pars Recta as Factor in Fertilization Properties and Hormonal Regulation in the A.H., Salomon de Legname, H., Miceli, D.C., Sanchez, S.S.
and Sanchez Riera, A.N. Endocrine control of amphibian oocyte metabolism. and Cabada, M.O. Acrosome reaction and proteolytic activity in the spermatozoa of an anuran amphibian Cited by: 5.
Objective. The biological effects of the herbicide atrazine on freshwater vertebrates are highly controversial. In an effort to resolve the controversy, we conducted a qualitative meta-analysis on the effects of ecologically relevant atrazine concentrations on amphibian and fish survival, behavior, metamorphic traits, infections, and immune, endocrine, and reproductive by: Infertility is a global disease affecting one out of six couples of reproductive age in the world, with a male factor involved in half the cases.
There is still much to know about the regulation of human male fertility and thus we decided to focus on two peptide families that seem to play a key role in this function: tachykinins and : Víctor Blasco, Francisco M.
Pinto, Cristina González-Ravina, Esther Santamaría-López, Luz Candenas. Learn more about BioOne, the nonprofit publisher behind BioOne Complete. The BioOne Career Center connects top employers across the globe with highly qualified jobseekers across the sciences.
Whether you're looking for a new position, or for the perfect candidate, use the. In response to androgenic chemicals, observations of hyperproduction of sperm in male fish and a decrease in yolk deposition in female fish have been observed (U.S. EPA, a). These alterations in gonadal histopathology were classified as Rank 2 endpoints because while these changes may result from endocrine exposure, they are not necessarily Cited by: Introduction.
Rodents, non-human primates, dogs, cats, and farm animals have long been the preferred animal models in biomedical research. their behavioral repertoire and physiological responses to stimuli are more similar to human systems than are lower organisms.
Billard, R., and Peter, R. Gonadotropin release after implantation of anti-estrogens in the pituitary and hypothalamus of goldfish, Carassius auratus. General and Comparative Endocrinology,32, Cited by: The current review focuses on the molecular mechanisms and developmental roles of thyroid hormone receptors (TRs) in gene regulation and metamorphosis in Xenopus laevis and discusses implications for TR function in vertebrate development and diversity.
Questions addressed are: (1) what are the molecular mechanisms of gene regulation by TR, (2) what are the developmental roles of TR.
Endocrine titers and cuticle progression during embryonic development Comparison of hemi- and holometabolous endocrine events during postembryonic development The “status-quo” action of juvenile hormone and its signal transduction The broad gene and specification of the pupal stage Molecular aspects of Broad action Background.
Amphibian population declines were first recognized as a global phenomenon in the early s ().We now know that current extinction rates for amphibians may be as much as times higher than background (Roelants et al., ).With 32% of the world's nearly amphibian species threatened with extinction, 43% experiencing declines and another 22% with insufficient data (Stuart.
This banner text can have markup. web; books; video; audio; software; images; Toggle navigation. The American bullfrog (Lithobates catesbeianus), often simply known as the bullfrog in Canada and the United States, is an amphibious frog, a member of the family Ranidae, or "true frogs".This frog has an olive green back and sides blotched with brownish markings and a whitish belly spotted with yellow or grey.
The upper lip is often bright green and males have yellow : Ranidae. Full text of "General embryological information service" See other formats. Visit to get more information about this book, to buy it in print, or to download it as a free PDF. FrogLog. Issue number (April ) ISSN: eISSN: Vol number 2 Promoting Conservation, Research and Education for the World’s Amphibians.
The objectives of this research were to observe the effects of specific contaminants on different amphibian species at various times of their life cycles, namely metamorphosis and fertilization. The effects of a non-ionic surfactant, Nonylphenol (NP), on Rana catesbeiana (bullfrog) tadpole metamorphic staging and tail resorption were examined, along with the effects of pH, osmolality and a.
This good textbook entitles Vertebrate Biology by Donald W. Linzey (). Its title is not as above. As the author addressed "Vertebrate biology is a broad field: there is no reason to ignore parts that may be currently unpopular or that do not engage us personally. Endocrine disruption in testicular cells can result in adverse effects, including epigenetic ones, on reproduction, including decreased sperm count and increased abnormal sperm (Clair et al a).
In biology, paternal care is parental investment provided by a male to his own is a complex social behaviour in vertebrates associated with animal mating systems, life history traits, and ecology. Paternal care may be provided in concert with the mother (biparental care) or, more rarely, by the male alone (so called exclusive paternal care).Figure The life cycle of an anuran amphibian.
The remaining two groups of amphibians constitute the more familiar salamanders (Caudata) and frogs (Anura).
The first of these is largely restricted to the Northern Hemisphere and achieves its greatest diversity in North America, where eight of the nine families are represented.5/5(1).SETAC Latin America 11th Biennial Meeting Abstract Book Birmingham / School of Biosciences; J. Chipman, The University of Birmingham / School of Biosciences Methylation of cytosine nucleotide plays an important role in the regulation and stability of gene expression, providing a cellular “memory” especially for longterm silencing of genes.