Effects of neurohypophyseal and adenohypophyseal hormones, steroids, eicosanoids, and extrafollicular tissue on ovulation in vitro of guppy (Poecilia reticulata) embryos

1992 ◽  
Vol 87 (1) ◽  
pp. 20-27 ◽  
Author(s):  
B. Venkatesh ◽  
C.H. Tan ◽  
T.J. Lam
Keyword(s):  
Poecilia Reticulata ◽  
Adenohypophyseal Hormones

scholarly journals Arg-Vasotocin Directly Activates Isotocin Receptors and Induces COX2 Expression in Ovoviviparous Guppies

2021 ◽  
Vol 12 ◽  
Author(s):  
Li Kang Lyu ◽  
Jian Shuang Li ◽  
Xiao Jie Wang ◽  
Yi Jia Yao ◽  
Ji Fang Li ◽  
...  
Keyword(s):  
Poecilia Reticulata ◽  
Intraperitoneal Administration ◽  
Gene Expression Measurement ◽  
Reproductive Behaviors ◽  
Prostaglandin F ◽  
Rate Limiting ◽  
Cox2 Expression ◽  
Expression Measurement

Oxytocin (OT) is a crucial regulator of reproductive behaviors, including parturition in mammals. Arg-vasopressin (AVP) is a nonapeptide homologous to Arg-vasotocin (AVT) in teleosts that has comparable affinity for the OT receptor. In the present study, ovoviviparous guppies (Poecilia reticulata) were used to study the effect of AVT on delivery mediated by the activation of prostaglandin (PG) biosynthesis via isotocin (IT) receptors (ITRs). One copy each of it and avt and two copies of itrs were identified in guppies. The results of the affinity assay showed that various concentrations of AVT and IT (10−6, 10−7, and 10−8 mol/L) significantly activated itr1 (P < 0.05). In vitro experiments revealed significant upregulation (P < 0.05) of cyclooxygenase 2 (cox2), which is the rate-limiting enzyme involved in PG biosynthesis, and itr1 by AVT and IT. Furthermore, dual in situ hybridization detected positive signals for itr1 and cox2 at the same site, implying that ITR1 may regulate cox2 gene expression. Measurement of prostaglandin F2a (PGF2a) concentrations showed that AVT induced PGF2a synthesis (P < 0.05) and that the effect of IT was not significant. Finally, intraperitoneal administration of PGF2a significantly induced premature parturition of guppies. This study is the first to identify and characterize AVT and ITRs in guppies. The findings suggest that AVT promotes PG biosynthesis via ITR and that PGF2a induces delivery behavior in ovoviviparous guppies.

scholarly journals Comparison of in vitro (fish cell line) and in vivo (fish and crustacean) acute toxicity tests in aquatic toxicology

2021 ◽  
Author(s):  
J Kolarova ◽  
J Velisek ◽  
Z Svobodova
Keyword(s):  
Acute Toxicity ◽  
Cell Line ◽  
Cell Lines ◽  
Poecilia Reticulata ◽  
Cost Effective ◽  
Neutral Red ◽  
Toxicity Tests ◽  
Fish Cell

The use of in vitro (fish cell lines) is a cost-effective, very rapid, and informative tool for toxicological assessments. Using the neutral red (NR) assay, we compared the in vitro acute toxicity (20hEC50) of twenty-six chemical substances on a rainbow trout gonad cell line (RTG-2) with their in vivo acute toxicity to Barbados Millions Poecilia reticulata (48hLC50, OECD 203) and crustacean Daphnia magna (48hEC50, OECD 202). The 20hEC50 values obtained by the NR assay were higher in nearly all the cases when compared to the 48hLC50 in P. reticulata and the 48hEC50 in D. magna, indicating that the sensitivity of the RTG-2 cell line was lower compared to P. reticulata and D. magna. A high (r = 0.89) and significant (P < 0.001) correlation was recorded between the 20hEC50 values of the RTG-2 and the 48hEC50 values of D. magna. The correlation between the 20hEC50 values of the RTG-2 and the 48hLC50 values of P. reticulata was lower (r = 0.65; P < 0.001), but also significant. The authors recommend use of the NR assay on the RTG-2 cell lines as a screening protocol to evaluate the toxicity of xenobiotics in aquatic environments to narrow the spectrum of the concentrations for the fish toxicity test.

scholarly journals Isolation and characterisation of virulent Serratia marcescens associated with a disease outbreak in farmed ornamental fish, Poecilia reticulata in Kerala, India

2017 ◽  
Vol 64 (4) ◽  
Author(s):  
Arathi Dharmaratnam ◽  
Raj Kumar ◽  
V. S. Basheer ◽  
Neeraj Sood ◽  
T. Raja Swaminathan ◽  
...  
Keyword(s):  
Serratia Marcescens ◽  
Poecilia Reticulata ◽  
Multiple Drug Resistance ◽  
Clinical Signs ◽  
Ornamental Fish ◽  
Multiple Drug ◽  
Rrna Gene ◽  
Biochemical Tests

Pathogenic strain of Serratia marcescens (NPSM-1) with multiple drug resistance was isolated from guppy Poecilia reticulata with clinical signs of fin rot and was confirmed by biochemical tests and 16S rRNA gene sequencing. The extra cellular proteins (ECP) of the bacteria exhibited marked cytotoxic activity in vitro on Cyprinus carpio koi fin (CCKF) cell line. The in vivo challenge studies confirmed that the isolate was highly pathogenic to fish when the fishes were injected with1 x 104 CFU/fish and the same bacterium was re-isolated from infected fish, post-challenge. S. marcescens produced large zones of haemolysis on 10% sheep blood agar. The bacteria was found to carry virulence genes; extracellular metalloprotease gene (Pr596) and AHL synthase gene (SpnI). The bacterial isolate was tested to determine sensitivity against 16 antibiotics and was sensitive to only 5 viz., cefixime, chloramphenicol, ciprofloxacin, gentamycin and erythromycin. The study indicates that S. marcescens can cause disease in ornamental fish and the bacterium being a known human pathogen, may also cause infections in humans having direct contact with infected fishes. This is the first report describing S. marcescens as a pathogen of freshwater ornamental fish in India.

scholarly journals Studies of In Vitro Embryo Culture of Guppy (Poecilia reticulata)

2014 ◽  
Vol 18 (3) ◽  
pp. 139-143
Author(s):  
LiLi Liu ◽  
Ki-Young Lee
Keyword(s):  
Embryo Culture ◽  
Poecilia Reticulata

In vitro culture of embryonic hearts from guppy fish (Poecilia reticulata)

2001 ◽  
Vol 46 (19) ◽  
pp. 1638-1641 ◽  
Author(s):  
Qiya Zhang ◽  
Zhenqiu Li ◽  
Jianfang Gui
Keyword(s):  
In Vitro Culture ◽  
Poecilia Reticulata ◽  
Guppy Fish

scholarly journals In vitro culture of embryos of the guppy,Poecilia reticulata

2006 ◽  
Vol 235 (3) ◽  
pp. 617-622 ◽  
Author(s):  
Ulrike Martyn ◽  
Detlef Weigel ◽  
Christine Dreyer
Keyword(s):  
In Vitro Culture ◽  
Poecilia Reticulata

Ultrastructural Investigations of the Contractile Filaments of Amoebae

1974 ◽  
Vol 32 ◽  
pp. 188-189
Author(s):  
P.L. Moore
Keyword(s):  
Cytoplasmic Streaming ◽  
Three Dimensional ◽  
Freeze Fracture ◽  
Amoeboid Movement ◽  
Different Types ◽  
Chemical Conditions ◽  
Complete Interpretation

Previous freeze fracture results on the intact giant, amoeba Chaos carolinensis indicated the presence of a fibrillar arrangement of filaments within the cytoplasm. A complete interpretation of the three dimensional ultrastructure of these structures, and their possible role in amoeboid movement was not possible, since comparable results could not be obtained with conventional fixation of intact amoebae. Progress in interpreting the freeze fracture images of amoebae required a more thorough understanding of the different types of filaments present in amoebae, and of the ways in which they could be organized while remaining functional.The recent development of a calcium sensitive, demembranated, amoeboid model of Chaos carolinensis has made it possible to achieve a better understanding of such functional arrangements of amoeboid filaments. In these models the motility of demembranated cytoplasm can be controlled in vitro, and the chemical conditions necessary for contractility, and cytoplasmic streaming can be investigated. It is clear from these studies that “fibrils” exist in amoeboid models, and that they are capable of contracting along their length under conditions similar to those which cause contraction in vertebrate muscles.

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