scholarly journals Effects of Diethylstilbestrol on Zebrafish Gonad Development and Endocrine Disruption Mechanism

Biomolecules ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 941
Author(s):  
Xuan Liu ◽  
Xianyi Xie ◽  
Hongling Liu
Keyword(s):  
Sex Differentiation ◽  
Endocrine Disrupting Chemicals ◽  
Endocrine System ◽  
Gonadal Development ◽  
Development Stage ◽  
Maturity Stage ◽  
Gonadal Differentiation ◽  
Environmental Estrogen ◽  
Initial Development ◽  
Gonadal Maturity

Environmental estrogen is a substance that functions as an endocrine hormone in organisms and can cause endocrine system disruption. A typical environmental estrogen, diethylstilbestrol (DES), can affect normal sexual function and organism development. However, even though the effects of different exposure stages of DES on the endocrine system and gonadal development of zebrafish juveniles are unknown, sex determination is strongly influenced by endocrine-disrupting chemicals (EDCs). From 10–90 days post fertilization (dpf), juvenile zebrafish were exposed to DES (100 and 1000 ng/L) in three different stages (initial development stage (IDS), 10–25 dpf; gonadal differentiation stage (GDS), 25–45 dpf and gonadal maturity stage (GMS), 45–60 dpf). Compared with that of IDS and GMS, the growth indicators (body length, body weight, and others) decreased significantly at GDS, and the proportion of zebrafish females exposed to 100 ng/L DES was significantly higher (by 59.65%) than that of the control; in addition, the zebrafish were biased towards female differentiation. The GDS is a critical period for sex differentiation. Our results show that exposure to environmental estrogen during the critical gonadal differentiation period not only affects the development of zebrafish, but also affects the population development.

Primordial Germ Cell Migration and Histological and Molecular Characterization of Gonadal Differentiation in Pachón Cavefish Astyanax mexicanus

2021 ◽  
pp. 1-18
Author(s):  
Boudjema Imarazene ◽  
Séverine Beille ◽  
Elodie Jouanno ◽  
Adéle Branthonne ◽  
Violette Thermes ◽  
...  
Keyword(s):  
Germ Cell ◽  
Regulatory Network ◽  
Sex Differentiation ◽  
Expression Patterns ◽  
Primordial Germ Cells ◽  
Primordial Germ Cell ◽  
Gonadal Development ◽  
Individual Variability ◽  
Gonadal Differentiation ◽  
Astyanax Mexicanus

The genetic regulatory network governing vertebrate gonadal differentiation appears less conserved than previously thought. Here, we investigated the gonadal development of Astyanax mexicanus Pachón cavefish by looking at primordial germ cells (PGCs) migration and proliferation, gonad histology, and gene expression patterns. We showed that PGCs are first detected at the 80% epiboly stage and then reach the gonadal primordium at 1 day post-fertilization (dpf). However, in contrast to the generally described absence of PGCs proliferation during their migration phase, PGCs number in cavefish doubles between early neurula and 8–9 somites stages. Combining both gonadal histology and vasa (germ cell marker) expression patterns, we observed that ovarian and testicular differentiation occurs around 65 dpf in females and 90 dpf in males, respectively, with an important inter-individual variability. The expression patterns of dmrt1, gsdf, and amh revealed a conserved predominant male expression during cavefish gonadal development, but none of the ovarian differentiation genes, i. e., foxl2a, cyp19a1a, and wnt4b displayed an early sexually dimorphic expression, and surprisingly all these genes exhibited predominant expression in adult testes. Altogether, our results lay the foundation for further research on sex determination and differentiation in A. mexicanus and contribute to the emerging picture that the vertebrate sex differentiation downstream regulatory network is less conserved than previously thought, at least in teleost fishes.

scholarly journals Advances in Reproductive Endocrinology and Neuroendocrine Research Using Catfish Models

Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2807
Author(s):  
Balasubramanian Senthilkumaran ◽  
Sonika Kar
Keyword(s):  
Sex Differentiation ◽  
Endocrine System ◽  
Gonadal Development ◽  
Economic Importance ◽  
Hypoxia Tolerance ◽  
Scientific Publications ◽  
High Fecundity ◽  
Worldwide Distribution ◽  
New Information ◽  
Insight Into

Catfishes, belonging to the order siluriformes, represent one of the largest groups of freshwater fishes with more than 4000 species and almost 12% teleostean population. Due to their worldwide distribution and diversity, catfishes are interesting models for ecologists and evolutionary biologists. Incidentally, catfish emerged as an excellent animal model for aquaculture research because of economic importance, availability, disease resistance, adaptability to artificial spawning, handling, culture, high fecundity, hatchability, hypoxia tolerance and their ability to acclimate to laboratory conditions. Reproductive system in catfish is orchestrated by complex network of nervous, endocrine system and environmental factors during gonadal growth as well as recrudescence. Lot of new information on the molecular mechanism of gonadal development have been obtained over several decades which are evident from significant number of scientific publications pertaining to reproductive biology and neuroendocrine research in catfish. This review aims to synthesize key findings and compile highly relevant aspects on how catfish can offer insight into fundamental mechanisms of all the areas of reproduction and its neuroendocrine regulation, from gametogenesis to spawning including seasonal reproductive cycle. In addition, the state-of-knowledge surrounding gonadal development and neuroendocrine control of gonadal sex differentiation in catfish are comprehensively summarized in comparison with other fish models.

Effect of dietary administration of letrozole and tamoxifen on gonadal development, sex differentiation and biochemical changes in common carp (Cyprinus carpio L.)

2015 ◽  
Vol 27 (3) ◽  
pp. 449 ◽  
Author(s):  
Atul K. Singh ◽  
P. P. Srivastava ◽  
Rita Verma ◽  
Sharad C. Srivastava ◽  
Dinesh Kumar ◽  
...  
Keyword(s):  
Cyprinus Carpio ◽  
Sex Differentiation ◽  
Gonadal Development ◽  
Tamoxifen Treatment ◽  
Testicular Development ◽  
Cholesterol Levels ◽  
Gonadal Maturity ◽  
Letrozole Treatment ◽  
Total Haemoglobin ◽  
Somatic Index

The effect of letrozole and tamoxifen on the specific growth rate (SGR; % day–1), gonado–somatic index (GSI), total haemoglobin (g%), gonadal and serum protein as well as lipid, sex differentiation and 17β-oestradiol levels were studied in sexually undifferentiated Cyprinus carpio fingerlings 30 days post fertilisation (30 dpf) for 60 days. Results showed decreased GSI with tamoxifen treatment whereas letrozole increased it. There were reduced protein, lipid, triglyceride and cholesterol levels after treatment with tamoxifen and letrozole during gonadal development. Tamoxifen (200 mg kg–1 feed) induced 82.5% masculinisation, whereas letrozole in the same dose produced 98.5% males. Gonadal 17β-oestradiol significantly declined from 86.0 ± 1.41 pg per 100 mg (control) to 45.5 ± 1.94 pg per 100 mg with tamoxifen and 36.0 ± 0.72 pg per 100 mg with letrozole treatment. Similarly, serum 17β-oestradiol levels also decreased after tamoxifen and letrozole treatments. Testicular development in 37.8% of fish treated with tamoxifen and letrozole was found to be more advanced (spermatocytes) than in the control (spermatogonium); however, there was reduced ovarian growth and increased atresia. It was concluded that letrozole and tamoxifen both significantly affect sex differentiation and gonadal maturity in C. carpio leading to the production of sex-reversed males, yet the effect of letrozole was more potent.

scholarly journals Physicochemical And Antioxidant Activity of Fruit Harvested From Eight Jujube (Ziziphus Jujuba Mill.) Cultivars At Different Development Stages

2021 ◽  
Author(s):  
Min Yan ◽  
Yan Wang ◽  
Ritesh Balaso Watharkar ◽  
Yunfeng Pu ◽  
Cuiyun Wu ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Radical Scavenging ◽  
Development Stage ◽  
Maturity Stage ◽  
Total Polyphenols ◽  
Initial Development ◽  
Regular Trend ◽  
Jujube Fruit ◽  
Ziziphus Jujuba ◽  
Camp And Cgmp

Abstract Jujube is a crop highly resistant to drought and salinity, making it the main fruit tree in Xinjiang. The present study was to investigate the effect of development stage on physicochemical and antioxidant activity of fruit harvested from eight jujube cultivars situated in Xinjiang, China. The content of water, ascorbic acid, total polyphenols, catechin, epicatechin, proanthocyanidin and rutin decreased during development of jujube fruit harvested from the eight cultivars, while the contents of fructose, glucose, sucrose, cAMP, and cGMP greatly increased. The antioxidant activity determined by DPPH and ABTS radical scavenging decreased through the whole growth phase. After the early stages of development, a regular trend in changes of physicochemical and antioxidant characteristic was identified, while the differences among jujube cultivars gradually reduced with complete fruit development. This work contributes to understanding the changes that take place during the development of jujube fruit, indicating that development stage influenced the change in physicochemical and antioxidant activity more than cultivar, and the initial development stage was found to be rich in AA, phenolic compounds, and antioxidant activity, whereas the red maturity stage was rich in sugars, cAMP, and cGMP.

scholarly journals Endocrine Disrupting Chemicals: Current Understanding, New Testing Strategies and Future Research Needs

2021 ◽  
Vol 22 (2) ◽  
pp. 933
Author(s):  
Maria E. Street ◽  
Karine Audouze ◽  
Juliette Legler ◽  
Hideko Sone ◽  
Paola Palanza
Keyword(s):  
Endocrine Disrupting Chemicals ◽  
Endocrine System ◽  
Current Understanding ◽  
Future Research ◽  
Developmental Origins ◽  
Research Needs ◽  
Important Class ◽  
Testing Strategies ◽  
Endocrine Disrupting ◽  
Health And Disease

Endocrine disrupting chemicals (EDCs) are exogenous chemicals which can disrupt any action of the endocrine system, and are an important class of substances which play a role in the Developmental Origins of Health and Disease (DOHaD) [...]

scholarly journals Müllerian Inhibiting Substance Is Required for Germ Cell Proliferation during Early Gonadal Differentiation in Medaka (Oryzias latipes)

Endocrinology ◽  
2007 ◽  
Vol 149 (4) ◽  
pp. 1813-1819 ◽  
Author(s):  
Eri Shiraishi ◽  
Norifumi Yoshinaga ◽  
Takeshi Miura ◽  
Hayato Yokoi ◽  
Yuko Wakamatsu ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Germ Cell ◽  
Germ Cells ◽  
Sex Differentiation ◽  
Somatic Cells ◽  
Oryzias Latipes ◽  
Cell Number ◽  
Gonadal Differentiation ◽  
Loss Of Function ◽  
Germ Cell Proliferation

Müllerian inhibiting substance (MIS) is a glycoprotein belonging to the TGF-β superfamily. In mammals, MIS is responsible for the regression of Müllerian ducts in the male fetus. However, the role of MIS in gonadal sex differentiation of teleost fish, which have no Müllerian ducts, has yet to be clarified. In the present study, we examined the expression pattern of mis and mis type 2 receptor (misr2) mRNAs and the function of MIS signaling in early gonadal differentiation in medaka (teleost, Oryzias latipes). In situ hybridization showed that both mis and misr2 mRNAs were expressed in the somatic cells surrounding the germ cells of both sexes during early sex differentiation. Loss-of-function of either MIS or MIS type II receptor (MISRII) in medaka resulted in suppression of germ cell proliferation during sex differentiation. These results were supported by cell proliferation assay using 5-bromo-2′-deoxyuridine labeling analysis. Treatment of tissue fragments containing germ cells with recombinant eel MIS significantly induced germ cell proliferation in both sexes compared with the untreated control. On the other hand, culture of tissue fragments from the MIS- or MISRII-defective embryos inhibited proliferation of germ cells in both sexes. Moreover, treatment with recombinant eel MIS in the MIS-defective embryos dose-dependently increased germ cell number in both sexes, whereas in the MISRII-defective embryos, it did not permit proliferation of germ cells. These results suggest that in medaka, MIS indirectly stimulates germ cell proliferation through MISRII, expressed in the somatic cells immediately after they reach the gonadal primordium.

scholarly journals Epigenetic Modifications During Sex Change Repress Gonadotropin Stimulation of Cyp19a1a in a Teleost Ricefield Eel (Monopterus albus)

Endocrinology ◽  
2013 ◽  
Vol 154 (8) ◽  
pp. 2881-2890 ◽  
Author(s):  
Yang Zhang ◽  
Shen Zhang ◽  
Zhixin Liu ◽  
Lihong Zhang ◽  
Weimin Zhang
Keyword(s):  
Dna Methylation ◽  
Binding Protein ◽  
Sex Change ◽  
Gonadal Development ◽  
Proximal Region ◽  
Histone Deacetylation ◽  
Epigenetic Mechanisms ◽  
Gonadal Differentiation ◽  
Stimulation Of

Abstract In vertebrates, cytochrome P450 aromatase, encoded by cyp19a1, converts androgens to estrogens and plays important roles in gonadal differentiation and development. The present study examines whether epigenetic mechanisms are involved in cyp19a1a expression and subsequent gonadal development in the hermaphroditic ricefield eel. The expression of the ricefield eel cyp19a1a was stimulated by gonadotropin via the cAMP pathway in the ovary but not the ovotestis or testis. The CpG within the cAMP response element (CRE) of the cyp19a1a promoter was hypermethylated in the ovotestis and testis compared with the ovary. The methylation levels of CpG sites around CRE in the distal region (region II) and around steroidogenic factor 1/adrenal 4 binding protein sites and TATA box in the proximal region (region I) were inversely correlated with cyp19a1a expression during the natural sex change from female to male. In vitro DNA methylation decreased the basal and forskolin-induced activities of cyp19a1a promoter. Chromatin immunoprecipitation assays indicated that histone 3 (Lys9) in both regions I and II of the cyp19a1a promoter were deacetylated and trimethylated in the testis, and in contrast to the ovary, phosphorylated CRE-binding protein failed to bind to these regions. Lastly, the DNA methylation inhibitor 5-aza-2′-deoxycytidine reversed the natural sex change of ricefield eels. These results suggested that epigenetic mechanisms involving DNA methylation and histone deacetylation and methylation may abrogate the stimulation of cyp19a1a by gonadotropins in a male-specific fashion. This may be a mechanism widely used to drive natural sex change in teleosts as well as gonadal differentiation in other vertebrates.

Analysis of Development Trends in Low Energy Advanced Convergence Building Technology

2017 ◽  
Vol 872 ◽  
pp. 125-129
Author(s):  
Young Duk Koo ◽  
Dae Hyun Jeong
Keyword(s):  
Technology Development ◽  
Development Stage ◽  
Low Energy ◽  
Maturity Stage ◽  
Joint Research ◽  
Building Technology ◽  
The Usa ◽  
Technology Convergence ◽  
Map Analysis ◽  
Technology Level

The purpose of this study is to conduct a technology-level analysis and draw implications regarding the development of low energy advanced convergence building technology by utilizing information in research papers. With this aim, a citation analysis, a technology development stage analysis, a network analysis, and a technology associative map analysis were undertaken. The results showed that countries including the USA and China have carried out much research in the development of low energy advanced convergence building technology, and the technology level was found to have reached the maturity stage. Also, joint research has been conducted by region, and technology development has been done actively through ICT technology convergence such as electric and electronics and information communication. These analyzed results are expected to furnish useful information for strategy building in the development of low energy advanced convergence building technology.

Prognostic criteria for Polar Lows

2021 ◽  
Author(s):  
Natalia Vazaeva ◽  
Otto Chkhetiani ◽  
Michael Kurgansky
Keyword(s):  
Numerical Simulation ◽  
Wind Velocity ◽  
Large Scale ◽  
Satellite Image ◽  
Development Stage ◽  
Mature Stage ◽  
Initial Development ◽  
Polar Lows ◽  
Prognostic Criteria ◽  
Main Challenge

<p>Polar lows (PLs) are important mesoscale (horizontal diameter up to 1000 km) maritime weather systems at high latitudes, forming pole ward from the polar front. We consider the possible prognostic criteria of PLs, in particular, the kinematic helicity as a quadratic characteristic related to the integral vortex formations and the kinematic vorticity number (KVN). To calculate such characteristics we use reanalysis data and the results of numerical simulation with the WRF-ARW model (Version 4.1.) for the PLs over the Nordic (Norwegian and Barents) seas. For comparison, experimental data are used.</p><p>Our estimate of helicity is based on the connection of an integral helicity (IH) in the Ekman layer with the geostrophic wind velocity, due to the good correlation between IH and half the sum of the wind velocity squared. We have chosen IH averaged over preselected area covering the locality of PLs genesis. This area was moving along with the centre of PL during the numerical simulation.</p><p>The genesis of PLs can be divided into three stages: (i) an initial development stage, in which a number of small vortices appear in a shear zone; (ii) a late development stage, characterized by the merger of vortices; (iii) a mature stage, in which only a single PL is present. Approximately one day before PL formation, a significant increase in helicity was observed. The average helicity bulk density of large-scale motions has values of 0.3 – 0.4 ms<sup>-2</sup>. The local changes in helicity are adjacent to the front side of the PLs. The IH criterion described facilitates the identification of the PLs genesis area. For a more detailed analysis of the PL genesis, it is recommended to apply KVN, which is the additional indicator of PL size and intensity. At the moment of maximum intensity of PLs KVN can reach values of 12 – 14 units. The advantage of using KVN is also in its clear change directly in the centre of the emerging PLs, which allows to precisely indicates the limits of the most intense part of PLs.</p><p>The main challenge is to make the operational forecast of PLs possible through the selection of the prognostic integral characteristics of PLs, sufficient for PLs identification and for analysis of their size and intensity in a convenient, usable and understandable way. The criteria associated with vorticity and helicity are reflected in the PLs genesis and development quite clearly. At this time, such a claim is only a hypothesis, which must be tested using a larger set of cases. Future work will need to extend these analyses to other active PL basins. Also, it would be interesting to compare the representation of PLs by using any other criteria. It is intended to use our combined criteria as a precursor to machine learning-based PLs identification procedure where satellite image analysis and capture of particular cloud patterns are currently applied in most of the cases. It would eliminate the time consuming first stage of collecting data sets.</p><p>This work was supported by the Russian Science Foundation (project No. 19-17-00248).</p>

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