scholarly journals INDUCCIÓN DE LA MADUREZ GONADAL DEL PARGO PALMERO LUTJANUS ANALIS (PISCES: LUTJANIDAE) MEDIANTE LA APLICACIÓN DE UN FOTOTERMOPERIODO ARTIFICIAL DE ACONDICIONAMIENTO

Author(s):  
Julián Botero Arango ◽  
Fabio Castaño Rivera

An experimental group (N=7) of three females and four males of mutton snapper Lutjanus analis captured in the wild, whose gonadal development entered in a state of latency because of its confinement in the lab, was maintained under an artificial photothermal cycle of 10 months between October 2001 and July 2002 in order to unblock and estimulate again their sexual maturation. Another group of equal number of fish was used as a control, being maintained during the same time without manipulation of temperature and photoperiod parameters. After eight months the three females of the experimental group showed positive gonadal development signs, their oocyte mean diameters (Ø) reaching 122 ± 76; 86 ± 40; and 122 ± 87 μm respectively. During the tenth month one female reached the state III of gonadal development (Ø = 327 ± 67 μm) and was induced to final maturation and spawning by a single injection of 1,000 IU/kg of HCG. The spawning occurred 64 h after the injection with approximately 25,000 eggs (Ø = 713 ± 56 μm) which reached the early gastrula stage 4:35 h after fertilization. The artificial photothermal cycle applied showed to be effective to unblock and stimulate gonadal development of the captive fish, preliminary result that must be confirmed by further research and which could constitute an important step in the development of a technology for the artificial reproduction of the mutton snapper.

Author(s):  
Ewa Sokołowska ◽  
Ewa Kulczykowska

Environmental influence on maturation and dominance relationships in the three-spined stickleback (In this study, the influence of a combination of different photoperiods and temperatures on the final maturation and social interactions in three-spined sticklebacks was investigated. Water temperature appears to be the principal signal affecting gonadal development and breeding activity of sticklebacks in pre-spawning and spawning periods. Males can mature independently of photoperiod and a stimulatory effect of high temperature is not diminished by light deprivation. On the other hand, low temperature can inhibit the development of secondary sexual characters in males exposed to long day or constant light. In females, lighting seems to be more decisive for complete maturation and the lack of light delays the maturation rate, even in high temperature. While kept under the same conditions, males mature quicker than females. The presence of light and visual information are crucial to establish the social position of individuals in the group. In light, a rigid social hierarchy with one dominant, sexually active male is observed. In constant darkness, however, several males in the group demonstrate every sign of sexual activity.


Development ◽  
1992 ◽  
Vol 116 (Supplement) ◽  
pp. 137-142 ◽  
Author(s):  
J. B. Gurdon ◽  
K. Kao ◽  
K. Kato ◽  
N. D. Hopwood

In Xenopus an early morphological marker of mesodermal induction is the elongation of the mesoderm at the early gastrula stage (Symes and Smith, 1987). We show here that the elongation of equatorial (marginal) tissue is dependent on protein synthesis in a mid blastula, but has become independent of it by the late blastula stage. In animal caps induced to become mesoderm, the time when protein synthesis is required for subsequent elongation immediately follows the time of induction, and is not related to developmental stage. For elongation, intercellular communication during the blastula stage is of primary importance. Current experiments involving cell transplantation indicate a need for further celhcell interactions during gastrulation, and therefore after the vegetal-animal induction during blastula stages. These secondary cell interactions are believed to take place among cells that have already received a vegetal induction, and may facilitate some of the later intracellular events known to accompany muscle gene activation.


Development ◽  
1989 ◽  
Vol 106 (4) ◽  
pp. 675-683 ◽  
Author(s):  
J.P. Saint-Jeannet ◽  
F. Foulquier ◽  
C. Goridis ◽  
A.M. Duprat

The appearance and localization of N-CAM during neural induction were studied in Pleurodeles waltl embryos and compared with recent contradictory results reported in Xenopus laevis. A monoclonal antibody raised against mouse N-CAM was used. In the nervous system of Pleurodeles, it recognized two glycoproteins of 180 and 140×10(3) M(r) which are the Pleurodeles equivalent of N-CAM-180 and -140. Using this probe for immunohistochemistry and immunocytochemistry, we showed that N-CAM was already expressed in presumptive ectoderm at the early gastrula stage. In late gastrula embryos, a slight increase in staining was observed in the neurectoderm, whereas the labelling persisted in the noninduced ectoderm. When induced ectodermal cells were isolated at the late gastrula stage and cultured in vitro up to 14 days, a faint polarized labelling of cells was observed initially. During differentiation, the staining increased and became progressively restricted to differentiating neurons.


Development ◽  
1985 ◽  
Vol 90 (1) ◽  
pp. 79-99
Author(s):  
J. H. Cleine ◽  
K. E. Dixon

Eggs of X. laevis were rotated (sperm entrance point downwards) either through 90° (1×90 embryos) or 180° in two 90° steps (2×90 embryos) at approximately 25–30 min postfertilization after cooling to 13°C. The embryos were kept in their off-axis orientation and cooled until the early gastrula stage. Rotation resulted in relocation of egg constituents with slight changes in the distribution of outer cortical and subcortical components and major changes in inner constituents where the heavy yolk and cytoplasm appeared to reorient as a single coherent unit to maintain their relative positions with respect to gravity. Development of rotated embryos was such that regions of the egg which normally give rise to posterior structures instead developed into anterior structures and vice versa. Germ plasm was displaced in the vegetal-dorsal-animal direction (the direction of rotation) and was segregated into dorsal micromeres and intermediate zone cells in 2×90 embryos and dorsal macromeres and intermediate zone cells in 1×90 embryos. In consequence, at the gastrula stage, cells containing germ plasm were situated closer to the dorsal lip of the blastopore after rotation — in 2×90 gastrulas around and generally above the dorsal lip. Hence, in rotated embryos, the cells containing germ plasm were invaginated earlier during gastrulation and therefore were carried further anteriorly in the endoderm to a mean position anterior to the midpoint of the endoderm. The number of cells containing germ plasm in rotated embryos was not significantly different from that in controls at all stages up to and including tail bud (stage 25). However at stages 46, 48 and 49 the number of primordial germ cells was reduced in 1×90 embryos in one experiment of three and in 2×90 embryos in all experiments. We tested the hypothesis that the decreased number of primordial germ cells in the genital ridges was due to the inability of cells to migrate to the genital ridges from their ectopic location in the endoderm. When anterior endoderm was grafted into posterior endodermal regions the number of primordial germ cells increased slightly or not at all suggesting that the anterior displacement of the cells containing germ plasm was not the only factor responsible for the decreased number of primordial germ cells in rotated embryos. Other possible explanations are discussed.


2016 ◽  
Vol 73 (5) ◽  
pp. 737-746 ◽  
Author(s):  
Michaela W. Haring ◽  
Tom A. Johnston ◽  
Murray D. Wiegand ◽  
Aaron T. Fisk ◽  
Trevor E. Pitcher

Each year, millions of hatchery-raised juvenile salmon are released into the wild to help bolster salmon populations all over North America. These fish often differ from their wild-origin conspecifics in terms of survival and reproductive success after release, but our understanding of their reproductive investment is limited. We examined differences in egg number (gonad mass and fecundity) and quality (mass, lipids, fatty acids) between spawning hatchery- and wild-origin Chinook salmon (Oncorhynchus tshawytscha) from Lake Ontario. Hatchery-origin females were found to not differ significantly in body size, age, egg total lipids, and fatty acid content of eggs relative to wild-origin females, but hatchery-origin females allocated significantly less body mass and neutral lipids into egg and gonadal development compared with wild-origin females. We also examined diets of both groups of females using stable isotopes and found that carbon and nitrogen stable isotopes suggested limited differences in the diet between hatchery- and wild-origin adult females. The results from the present study provide evidence that the differing environmental conditions and associated selection pressures of captive environments during early life in hatchery settings can alter certain life-history traits later in adult development, namely gonad mass and egg size, and could contribute to differences in their performance in the wild.


2018 ◽  
Author(s):  
Satoru Tanaka ◽  
Akihiro Okamura ◽  
Naomi Mikawa ◽  
Yoshiaki Yamada ◽  
Noriyuki Horie ◽  
...  

It is generally believed that parent freshwater eels (Anguilla sp.) die soon after spawning on the assumption that eels are a semelparous (or monocyclic) fish (spawn once at the last stage of life) like Pacific salmonids. However, we observed for the first time a post-spawning female Anguilla japonica again possessed developing oocytes reaching the final maturation stage in captivity five months after the last spawning even without hormonal treatment. Here we describe information on this female about its biological characteristics including gonadal histology and endocrine profiles. The data suggest that lowering water temperature for a period of time is one of the important factors influencing spontaneous gonadal development in this specimen. We also discuss the possibility of induced multiple spawning of this species in captivity.


2021 ◽  
Vol 11 (10) ◽  
pp. 242-251
Author(s):  
E. Bestanchuk ◽  
A. Gozhenko ◽  
O. Kashchenko ◽  
T. Narbutova ◽  
O. Berezovskyi ◽  
...  

The aim of the study was to evaluate the effect of a single injection of bleomycin on the heart Material and methods. The study was conducted in the Research Institute of Transport Medicine during 2016-2021. The experimental model of the cardiotoxic effect of the bleomycin was performed using the medication "Bleocin" manufactured by Nippon Kayaku Co., Ltd. (Japan). According to the task, the study was performed on 10 mature rats of both sexes of the Wistar line with a body weight of 237 ± 20 g. Rats were housed in standard vivarium conditions of Odessa National Medical University. Animals were divided into 2 groups: experimental group (n = 5) and control (n = 5). Bleomycin animals of the experimental group were obtained intraperitoneally at a dose of 0.5 IU / kg once. Withdrawal of animals from the experiment was performed on the 5th day of the experiment, followed by morphological and morphometric examination. Statistical processing of the obtained data was performed by methods of variance, correlation and regression analysis using Statistica 14.0 software (TIBCO, USA) Results. Single administration os bleomycin causes changes in macroscopic parameters (myocardial weight, visual changes) are minimal. The main changes at the microscopic level are represented by contractural degeneration with segmental and / or partial-lateral lysis, ie there is not total but partial myocardial damage. Conclusion. A single injection of bleomycin can cause inflammatory-dystrophic changes of the myocardium.


Development ◽  
1967 ◽  
Vol 17 (1) ◽  
pp. 171-175
Author(s):  
W. N. Adams Smith ◽  
M. T. Peng

The influence of the testis and of testosterone upon the development of the male genitalia has been extensively investigated and a number of reviews of this work have been published (Jost, 1960; Burns, 1961). However, Witschi (1957) has stressed the need to distinguish between adult sex hormones, such as testosterone, and the secretions of the immature gonad. The formation of corpora lutea in the ovaries transplanted to adult male rats which had been castrated at birth, and the absence of corpus luteum formation in ovaries transplanted to male hosts bearing transplanted testes in the neck from birth, was reported by Pfeiffer in 1936. Similar observations have been reported by Yazaki (1960) and Harris (1964). A single injection of testosterone propionate has been found to lead to permanent sterility and a loss of corpus luteum formation in the ovaries of mice (Barraclough & Leathern, 1954) and rats (Barraclough, 1961).


Development ◽  
1981 ◽  
Vol 63 (1) ◽  
pp. 67-74
Author(s):  
John G. Bluemink ◽  
Jean-Claude Beetschen

Embryos of the ac/ac maternal-effect mutant in Pleurodeles waltl show disturbed epibolic movement during gastrulation. At the early gastrula stage, ectoderm cells begin to sink in at random sites in the animal half of the embryo. At the advanced gastrula stage the ectodermal pits develop into grooves. Electron microscopical analysis shows that many cells in the bottom of the pits and grooves have narrowed apices and bear many microvilli, while the cortical cytoplasm is dense, filamentous and underlain by a stratum of vesicles. These findings are interpreted as indicating that ectoderm cells contract rather than expand leading to disturbed epibolic movement.


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