scholarly journals Functional characterization and related evolutionary implications of invertebrate gonadotropin-releasing hormone/corazonin in a well-established model species

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
István Fodor ◽  
Réka Svigruha ◽  
Zsolt Bozsó ◽  
Gábor K. Tóth ◽  
Tomohiro Osugi ◽  
...  
Keyword(s):  
Lymnaea Stagnalis ◽  
Functional Characterization ◽  
Gonadotropin Releasing Hormone ◽  
Egg Laying ◽  
Pond Snail ◽  
Model Species ◽  
Releasing Hormone ◽  
Active Peptide

AbstractIn vertebrates, gonadotropin-releasing hormone (GnRH) peptide is the central mediator of reproduction. Homologous peptides have previously also been identified in molluscan species. However, emerging evidence suggests that these molecules might serve diverse regulatory functions and proposes to consider them as corazonin (CRZ). We previously isolated the full-length cDNA of the invGnRH/CRZ peptide (termed ly-GnRH/CRZ) in the well-established invertebrate model species, the great pond snail Lymnaea stagnalis; however, its predicted functions remain to be verified. In this study, we first confirmed the presence of the deduced active peptide from the central nervous system of L. stagnalis. Further, we performed in vivo and in vitro studies to explore the functions of ly-GnRH/CRZ. Injection of sexually mature specimens with synthetic active peptide had an inhibitory effect on locomotion and an acceleratory effect on egg-laying, but had no effect on feeding. The previously predicted modulatory effect of ly-GnRH/CRZ was supported by its identified co-localization with serotonin on the surface of the heart atria. Lastly, we demonstrated not only the presence of ly-GnRH/CRZ in the penial complex but also that ly-GnRH/CRZ-containing neurons project to the efferent penis nerve, suggesting ly-GnRH/CRZ may directly modulate the motor output of this peripheral tissue. Overall, our findings strongly support that ly-GnRH/CRZ is a multifunctional neuropeptide. These results contribute to the understanding of the GnRH superfamily and, more broadly, disciplines such as comparative endocrinology and neurobiology.

NEURONAL FEEDBACK IN EGG-LAYING BEHAVIOUR OF THE POND SNAIL LYMNAEA STAGNALIS

1993 ◽  
Vol 178 (1) ◽  
pp. 251-259 ◽  
Author(s):  
G. P. Ferguson ◽  
A. W. Pieneman ◽  
R. F. Jansen ◽  
A. Ter Maat
Keyword(s):  
Lymnaea Stagnalis ◽  
Aplysia Californica ◽  
Experimental System ◽  
Egg Laying ◽  
Neuroendocrine Cells ◽  
Behaviour Pattern ◽  
Pond Snail ◽  
Egg Laying Behaviour

The egg-laying behaviour of gastropod molluscs is controlled by peptidergic neuroendocrine cells and has provided an important experimental system for behavioural neurobiology. The genes that code for multiple peptides have been sequenced and the peptides themselves have been identified, thus enabling us to investigate how they act on the nervous system to produce the overt behavioural pattern (reviewed by Geraerts et al. 1988). The two animals that have been studied most extensively are the opisthobranch Aplysia californica and the pulmonate Lymnaea stagnalis. In both cases, the peptidergic neurones controlling egg laying are normally electrically silent (both in vivo and in vitro; Kupfermann, 1967; Pinsker and Dudek, 1977; Kits, 1980; Ter Maat et al. 1986) and produce multiple peptides (Rothman et al. 1983; Geraerts et al. 1985; Sigvardt et al. 1986), which are cleaved from a common protein precursor (Scheller et al. 1983; Vreugdenhil et al. 1988). Before egg laying, the cells produce a long-lasting discharge of action potentials (Pinsker and Dudek, 1977; Ter Maat et al. 1986). This electrical discharge initiates egg-laying behaviour, and during it the peptides (one of which initiates ovulation) are released into the blood. The demonstration, in Aplysia californica, that these peptides could have various effects on the activity of central neurones (reviewed by Mayeri and Rothman, 1985) led to the hypothesis that egg-laying behaviour is a neuroendocrine fixed action pattern controlled and coordinated by the concerted actions of the released peptides (Scheller and Axel, 1984). This hypothesis is also thought to apply to Lymnaea stagnalis (Vreugdenhil et al. 1988) because of the structural similarities between precursors of Aplysia californica and Lymnaea stagnalis egg-laying hormones. In this paper we investigate how the sequence of the various components of the egg-laying behaviour pattern is achieved.

scholarly journals Live View of Gonadotropin-Releasing Hormone Containing Neuron Migration

Endocrinology ◽  
2005 ◽  
Vol 146 (1) ◽  
pp. 463-468 ◽  
Author(s):  
Elizabeth P. Bless ◽  
Heather J. Walker ◽  
Kwok W. Yu ◽  
J. Gabriel Knoll ◽  
Suzanne M. Moenter ◽  
...  
Keyword(s):  
Real Time ◽  
Direct Evidence ◽  
Gonadotropin Releasing Hormone ◽  
Releasing Hormone ◽  
Reproductive Axis ◽  
Gnrh Neurons ◽  
Migratory Route ◽  
The Brain

Neurons that synthesize GnRH control the reproductive axis and migrate over long distances and through different environments during development. Prior studies provided strong clues for the types of molecules encountered and movements expected along the migratory route. However, our studies provide the first real-time views of the behavior of GnRH neurons in the context of an in vitro preparation that maintains conditions comparable to those in vivo. The live views provide direct evidence of the changing behavior of GnRH neurons in their different environments, showing that GnRH neurons move with greater frequency and with more changes in direction after they enter the brain. Perturbations of guiding fibers distal to moving GnRH neurons in the nasal compartment influenced movement without detectable changes in the fibers in the immediate vicinity of moving GnRH neurons. This suggests that the use of fibers by GnRH neurons for guidance may entail selective signaling in addition to mechanical guidance. These studies establish a model to evaluate the influences of specific molecules that are important for their migration.

252 EFFECT OF SUPERSTIMULATORY TREATMENT TO DONOR COWS IN OXYGEN CONSUMPTION OF MATURED OOCYTES

2013 ◽  
Vol 25 (1) ◽  
pp. 273
Author(s):  
K. Imai ◽  
S. Sugimura ◽  
M. Ohtake ◽  
Y. Aikawa ◽  
Y. Inaba ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Prostaglandin F2α ◽  
Gonadotropin Releasing Hormone ◽  
Oestrous Cycle ◽  
Control Group ◽  
Releasing Hormone ◽  
And Control ◽  
Bovine Oocytes

We previously reported that follicular wave synchronization and follicular growth treatment (FGT) before ovum pick-up (OPU) were effective in improving oocyte competence, which was associated with an increase in related embryos obtained by somatic cell nuclear transfer (Sugimura et al. 2012 Cell. Reprogram. 14, 29–37). However, oxygen consumption in oocytes remained unknown. The present study was designed to examine the differences in oxygen consumption between bovine oocytes obtained by OPU with or without FGT after in vitro maturation. Holstein dry cows (n = 8) were reared under the same feeding and environmental conditions. Two OPU sessions were conducted in each cow to collect immature oocytes, as described by Sugimura et al. (2012). The first OPU session (OPU group) was performed in cows on arbitrary days of the oestrous cycle, using a 7.5-MHz linear transducer with the needle connected to an ultrasound scanner. Follicles larger than 8 mm in diameter were then aspirated and a controlled internal drug release device (CIDR) was inserted on Day 5 (the day of the first OPU session = Day 0). Then 30 Armour units (AU) of FSH (Antrin, Kyoritsu Seiyaku, Tokyo, Japan) was administrated to cows twice a day from Day 7 to 10 in decreasing doses (6, 6, 4, 4, 3, 3, 2, 2 AU day–1). Cloprostenol (prostaglandin F2α; 0.75 mg) was administered in the morning of Day 9. The second OPU session (FGT-OPU group) was performed 48 h after prostaglandin F2α administration (Day 11), and only follicles larger than 5 mm in diameter were aspirated. The CIDR was removed from the cows just before OPU. Collected cumulus–oocyte complexes in the OPU and FGT-OPU groups were matured in vitro as described by Imai et al. [2006 J. Reprod. Dev. 52(Suppl.), S19–S29]. To collect in vivo-matured oocytes (control group), the CIDR was inserted into the cows on arbitrary days of the oestrous cycle (= Day 0), and oestradiol benzoate (0.8 mg) was administered on Day 1. The cows received the FGT treatment (as described above) from Day 6 to 10; however, the CIDR was removed in the evening of Day 8. Buserelin (gonadotropin-releasing hormone; 200 µg) was then administrated in the morning of Day 10, and OPU was performed at 24 h after gonadotropin-releasing hormone administration (Day 11). Oxygen consumption of matured oocytes was measured noninvasively with a scanning electron microscopy system (HV-405SP; Hokuto Denko Co., Tokyo, Japan). Data were analysed by ANOVA followed by a Tukey-Kramer test. There was no difference in the mean oxygen consumption between the FGT-OPU group (0.34 ± 0.02 × 10–14 mol–1, mean ± SEM) and control group (0.40 ± 0.01 × 10–14 mol–1). However, oxygen consumption in the FGT-OPU and control groups was significantly lower (P < 0.01) than that in the OPU group (0.50 ± 0.02 × 10–14 mol–1). These results revealed significantly lower oxygen consumption in OPU-derived in vitro-matured bovine oocytes after FGT treatment compared with those obtained without FGT treatment. Oxygen consumption of oocytes obtained from FGT-OPU was similar to that of in vivo-matured oocytes, which may reflect their cytoplasmic maturation status with high developmental competence.

Effects of Ghrelin upon Gonadotropin-Releasing Hormone and Gonadotropin Secretion in Adult Female Rats: In vivo and in vitro Studies

2005 ◽  
Vol 82 (5-6) ◽  
pp. 245-255 ◽  
Author(s):  
Rafael Fernández-Fernández ◽  
Manuel Tena-Sempere ◽  
Víctor M. Navarro ◽  
María L. Barreiro ◽  
Juan M. Castellano ◽  
...  
Keyword(s):  
Adult Female ◽  
Gonadotropin Releasing Hormone ◽  
In Vitro Studies ◽  
Female Rats ◽  
Gonadotropin Secretion ◽  
Releasing Hormone

86 Comparison of in vivo and in vitro embryo production in Bonsmara donors

2019 ◽  
Vol 31 (1) ◽  
pp. 168
Author(s):  
B. H. Bernal ◽  
J. L. Barajas ◽  
J. A. Ortega ◽  
A. Cedeño ◽  
S. Andrada ◽  
...  
Keyword(s):  
Bos Taurus ◽  
Gonadotropin Releasing Hormone ◽  
P Value ◽  
In Vitro Production ◽  
Embryo Production ◽  
Releasing Hormone ◽  
Gradient Technique ◽  
Vitro Production

A retrospective analysis of embryo production records from 2013 to 2017 was carried out to evaluate the in vivo and in vitro production (IVP) of embryos in donors of the Bonsmara breed (i.e. tropically adapted Bos taurus). Only donors with production records of both in vivo and in vitro embryos during the same period were used. A total of 127 superovulations and ova/embryo collections of 19 donors were evaluated. The donors were superstimulated with the following protocol: on Day 0 they received a device with 1g of progesterone (DIB, Zoetis, Argentina), 50mg of rogesterone (Progestar, Zoetis), and 5mg of oestradiol-17β (17ßOestradiol, Rio de Janeiro, Argentina) or 2mg of oestradiol benzoate (Gonadiol, Zoetis) intramuscularly (IM) at the same time. Superstimulatory treatments were initiated on the morning of Day 4 with Folltropin-V (Vetoquinol, France; total dose=240 to 340mg IM) in twice-daily decreasing doses over 4 days. All donors received 2 IM injections of 500µg of cloprostenol (Ciclase DL, Zoetis) on the morning and afternoon of Day 6 and; the intravaginal devices were removed on the morning of Day 7 and 100µg of Gonadorelin (gonadotropin-releasing hormone, Gonasyn gdr, Zoetis) was given on the morning of Day 8. Donors were inseminated using semen from 9 Bonsmara bulls, 12 and 24h after gonadotropin-releasing hormone. On Day 15, ova/embryos were collected and classified according to IETS standards. A total of 89 follicular aspirations (ovum pickup) of 19 donors for IVP were evaluated. The ovum pickups were performed at random stages of oestrous cycle, without superstimulation or other hormone treatments. A total of 1109 viable oocytes (12.5±0.9 per ovum pickup) were collected and matured for 24h in 100-µL drops of maturation medium (TCM-199, supplemented with hormones) under mineral oil and incubated at 38.5°C in 5.5% CO2 and humidity at saturation. Fertilization was performed using 3 Bonsmara bulls that were also used for in vivo embryo production. Viable sperm were obtained using the percoll gradient technique (45-90%). The sperm pellet was dissolved in TL-Sperm, centrifuged, and then diluted to a final concentration of 1.5×106 sperm/mL. Zygotes were stripped and placed in drops of 100µL of SOF medium supplemented with 0.4% BSA under oil at 38.8°C, 5.5% CO2, 7% O2, and humidity at saturation for 7 days. The culture medium was renewed on Days 3 and 5. The data were analysed using the GLM procedure of SAS (SAS Institute Inc., Cary, NC, USA), a P-value &lt;0.05 was considered significant. The mean (±standard error of the means) number of CL, ova/embryos collected, fertilized ova, and transferable embryos were 12.9±0.6, 8.8±0.6, 6.6±0.5, and 4.7±0.4, respectively. A total of 662 oocytes (66.3±2.4%) cleaved 48h post-IVF. On Day 7, an average of 4.4±0.3 embryos were produced. No differences were detected in the number of transferable embryos produced in vivo v. those produced in vitro. Furthermore, no significant differences were found between the techniques or bulls on the proportion of embryos produced in relation to the ova/embryos or oocytes obtained (in vivo 51.5±3.2% v. in vitro 42.9±2.5%). In conclusion, the in vivo and in vitro production of embryos are both effective alternatives to increase the number of offspring from valuable Bonsmara donors.

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