scholarly journals Transcriptional knockout of steroidogenic factor 1 in vivo in Oreochromis niloticus increased weight and suppressed gonad development using antisense RNA

2021 ◽  
Author(s):  
Zhe Cao ◽  
Jun Qiang ◽  
Jun Zhu ◽  
Hong Li ◽  
Yi Tao ◽  
...  
Keyword(s):  
Oreochromis Niloticus ◽  
Antisense Rna ◽  
Nile Tilapia ◽  
Gonad Development ◽  
External Genitalia ◽  
Cloning And Expression ◽  
Steroidogenic Factor 1 ◽  
And Function

Abstract Steroidogenic factor 1 (sf1) is an important regulator of gonad development and function in mammals. However, study of sf1 in fish is limited to cloning and expression and in vitro experiments. Using antisense RNA we knockout transcription of the sf1 gene in Nile tilapia Oreochromis niloticus, and obtain experimental fish in vivo. We demonstrate that antisense RNA can silence sf1 transcription and protein expression, and report suppression of sf1 transcription to affect gonad development and external genitalia formation in Nile tilapia. We also report disfunction of retinal metabolism and fatty acid metabolism to be important causes of weight gain and gonad abnormality with sf1 suppression. The feasibility of using antisense RNA for gene editing in fish is verified, and a new way of studying gene function and performing biological breeding is presented.

scholarly journals Efficacy and safety of boric acid as a preventive treatment against Saprolegnia infection in Nile tilapia (Oreochromis niloticus)

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Shimaa E. Ali ◽  
Amr A. A. Gamil ◽  
Ida Skaar ◽  
Øystein Evensen ◽  
Harrison Charo-Karisa
Keyword(s):  
Boric Acid ◽  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Negative Impact ◽  
Preventive Treatment ◽  
Economic Losses ◽  
Continuous Exposure ◽  
Prophylactic Measure

AbstractSaprolegniosis is a worldwide fungal-like infection affecting freshwater fishes and their eggs. Reports show high mortalities and subsequent economic losses annually from Saprolegnia infections. Most therapeutants against Saprolegnia spp. infections are inefficient and some have negative impact on the environment. In this study, we have investigated the ability of boric acid (BA) to prevent Saprolegnia infection in Nile tilapia (Oreochromis niloticus). BA inhibited radial growth of Saprolegnia hyphae in vitro. Complete in vitro growth inhibition was found at a concentration of ≥0.6 g/L. Inhibitory effects were also observed in vivo when Nile tilapia were experimentally challenged with Saprolegnia spores and followed over 10 days post challenge and under continuous exposure to different BA concentrations. No signs of saprolegniosis were observed in fish treated with BA at concentrations of 0.4 g/L and above. Comet assay revealed that BA has low toxicity in tilapia continuously exposed to concentrations of 0.2–0.6 g/L for 96 h. Additionally, no significant histomorphological changes were observed in BA-treated fish compared to non-treated controls. Alanine Aminotransferase (ALT) and Aspartate Aminotransferase (AST) enzyme levels indicated reduction in systemic tissue damage associated with Saprolegnia infection. This study demonstrates the potential of BA as a prophylactic measure against Saprolegnia infection in tilapia, and we recommend additional studies on environmental impact.

scholarly journals Shrimp lectin (Md-Lec) conjugated copper sulfide nanoparticles enhance the elimination of aquatic pathogens in infected Nile tilapia (Oreochromis niloticus)

RSC Advances ◽  
2020 ◽  
Vol 10 (72) ◽  
pp. 44216-44224
Author(s):  
Abdul Salam Rubeena ◽  
Sreeja Lakshmi ◽  
Digi George ◽  
Siva Bala Subramaniyan ◽  
Anbazhagan Veerappan ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Oreochromis Niloticus ◽  
Copper Sulfide ◽  
Nile Tilapia ◽  
Nile Tilapia Oreochromis Niloticus ◽  
Aquatic Pathogens

Synthesis of Md-Lec-pCuSNPs and its enhanced in vitro and in vivo antibacterial activity.

scholarly journals LECT2 Protects Nile Tilapia (Oreochromis niloticus) Against Streptococcus agalatiae Infection

2021 ◽  
Vol 12 ◽  
Author(s):  
Qi Li ◽  
Zhiqiang Zhang ◽  
Weiqi Fan ◽  
Yongxiong Huang ◽  
Jinzhong Niu ◽  
...  
Keyword(s):  
Immune Response ◽  
Bacterial Infection ◽  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Head Kidney ◽  
Transcriptional Level ◽  
Reading Frame ◽  
Tissue Damages

Leukocyte cell-derived chemotaxin 2 (LECT2) is a multifunctional cytokine that especially plays an important role in innate immune. However, the roles of LECT2 in the immune response of the economically important fish Nile tilapia (Oreochromis niloticus) against bacterial infection remains unclear. In this study, a lect2 gene from Nile tilapia (On-lect2) was identified, and its roles in the fish’s immune response against bacterial infection were determined and characterised. On-lect2 contains an open reading frame of 456 bp that encodes a peptide of 151 amino acids, as well as the conservative peptidase M23 domain. On-LECT2 is 62%–84% identical to other fish species and about 50% identical to mammals. The highest transcriptional level of On-lect2 was detected in the liver, whereas the lowest levels were detected in the other tissues. Moreover, the On-LECT2 protein is located mainly in the brain and head kidney. The transcriptional levels of On-lect2 substantially increased in the head kidney, brain, liver and spleen after Streptococcus agalactiae infection. Knockdown On-lect2 led to higher mortality due to liver necrosis or haemorrhage and splenomegaly. In vitro analysis indicated that the recombinant protein of On-LECT2 improved phagocytic activity of head kidney-derived macrophages. In vivo challenge experiments revealed several functions of On-LECT2 in the immune response of Nile tilapia against bacterial infection, including promotion of inflammation, reduction of tissue damages and improvement of survival rate.

scholarly journals Blocking of progestin action disrupts spermatogenesis in Nile tilapia (Oreochromis niloticus)

2014 ◽  
Vol 53 (1) ◽  
pp. 57-70 ◽  
Author(s):  
Gang Liu ◽  
Feng Luo ◽  
Qiang Song ◽  
Limin Wu ◽  
Yongxiu Qiu ◽  
...  
Keyword(s):  
Sertoli Cells ◽  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Phylogenetic Analyses ◽  
Pcr Analysis ◽  
Steroidogenic Enzymes ◽  
Spermatogonial Cell

In vitrostudies have indicated that the maturation-inducing hormone 17α,20β-dihydroxy-4-pregnen-3-one (17α,20β-DP, DHP), probably through nuclear progestin receptor (Pgr), might be involved in the proliferation of spermatogonial cells and the initiation of meiosis in several fish species. However, furtherin vivoevidence is required to elucidate the role of DHP in spermatogenesis during sexual differentiation in teleosts. In this study, we clonedpgrand analyzed its expression in Nile tilapia (Oreochromis niloticus) and treated XY fish with RU486 (a synthetic Pgr antagonist) from 5 days after hatching (dah) to determine the role of DHP in spermatogenesis. Sequence and phylogenetic analyses revealed that the Pgr identified in tilapia is a genuine Pgr. Pgr was found to be expressed in the Sertoli cells surrounding spermatogonia and spermatids in the testis of tilapia. Real-time PCR analysis revealed that the expression ofpgrin the testis was significantly upregulated from 10 dah, further increased at 50 dah, and persisted until adulthood in fish. In the testis of RU486-treated fish, the transcript levels of germ cell markers and a meiotic marker were substantially reduced. However, the expression of markers in Sertoli cells remained unchanged. Moreover, the production of 11-ketotestosterone and the expression of genes encoding various steroidogenic enzymes were also not altered. In contrast, the expression ofcyp17a2, encoding one of the critical steroidogenic enzymes involved in DHP biosynthesis, declined significantly, possibly indicating the inhibition of DHP production by RU486. RU486 treatment given for 2 months did not affect spermatogenesis; however, treatment given for more than 3 months resulted in a decrease in spermatogonial cell numbers and depletion of later-phase spermatogenic cells. Simultaneous excessive DHP supplementation restored spermatogenesis in RU486-treated XY fish. Taken together, our data further indicated that DHP, possibly through Pgr, might be essential for spermatogonial cell proliferation and spermatogenesis in fish.

In vitro and in vivo screening of herbal extracts against Streptococcus agalactiae in Nile tilapia (Oreochromis niloticus)

Aquaculture ◽  
2019 ◽  
Vol 503 ◽  
pp. 412-421 ◽  
Author(s):  
Wei-Liang Guo ◽  
Heng-Wei Deng ◽  
Fei Wang ◽  
Shi-Feng Wang ◽  
Zhi-Hong Zhong ◽  
...  
Keyword(s):  
Streptococcus Agalactiae ◽  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Herbal Extracts ◽  
In Vivo Screening ◽  
Nile Tilapia Oreochromis Niloticus

scholarly journals Interaction Between Dax-1 and Steroidogenic Factor-1 in Vivo: Increased Adrenal Responsiveness to ACTH in the Absence of Dax-1

Endocrinology ◽  
2002 ◽  
Vol 143 (2) ◽  
pp. 665-673 ◽  
Author(s):  
Poda Suresh Babu ◽  
David L. Bavers ◽  
Felix Beuschlein ◽  
Sonalee Shah ◽  
Baxter Jeffs ◽  
...  
Keyword(s):  
In Vitro Assays ◽  
Acth Stimulation ◽  
Steroidogenic Factor 1 ◽  
Protein Levels ◽  
Cellular Hypertrophy ◽  
Acth Receptor ◽  
Adrenal Hypoplasia ◽  
And Function

Abstract Two nuclear receptors, dosage-sensitive sex reversal adrenal hypoplasia congenita, critical region on the X chromosome gene-1 (Dax-1) and steroidogenic factor-1 (SF-1), are required for adrenal development and function. In vitro assays suggest that Dax-1 represses SF-1 mediated transcription. In this study, we generated SF-1+/−: Dax-1−/Y mice to examine the role of Dax-1 in SF-1-dependent steroidogenesis in vivo. While the SF-1 expression was impaired in SF-1+/− mice, there was no change in Dax-1 expression in SF-1+/− mice and no change in SF-1 expression in Dax-1−/Y mice. SF-1+/− mice had small adrenal glands with adrenal hypoplasia and cellular hypertrophy. The loss of Dax-1 in SF-1+/−: Dax-1−/Y mice reversed the decreased adrenal weight and histological abnormalities observed in SF-1+/− mice. SF-1+/− mice had elevated ACTH and the lowest corticosterone following restraint stress. In contrast, Dax-1−/Y mice had elevated corticosterone and decreased ACTH. Adrenal responsiveness (ACTH/corticosterone) was highest in Dax-1−/Y mice, intermediate in WT and SF-1+/−: Dax-1−/Y mice, and lowest in SF-1+/− mice. In accordance with these findings, ACTH stimulation testing resulted in the highest levels of corticosterone in the Dax-1−/Y mice. Protein levels of P450c21 and the ACTH receptor were increased in Dax-1−/Y mice and intermediate in SF-1+/−: Dax-1−/Y mice following chronic food deprivation. These results are consistent with a model in which Dax-1 functions to inhibit SF-1-mediated steroidogenesis in vivo.

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