“Detection of Nnv Persistent Infection in Greater Amberjack Broodstock Gonad Shows a Sex-dependent Immune Response (7074)” Written by diazoma on July 11, 2025. Posted in Abstracts. Abstract DETECTION OF NNV PERSISTENT INFECTION IN GREATER AMBERJACK BROODSTOCK GONAD SHOWS A SEX-DEPENDENT IMMUNE RESPONSE DETECTION OF NNV PERSISTENT INFECTION IN GREATER AMBERJACK BROODSTOCK GONAD SHOWS A SEX-DEPENDENT IMMUNE RESPONSE Laura Cervera1,2, Daniel Álvarez-Torres3, Julia Béjar3, Alberto Cuesta2, Virginia Martín4, Salvador Jérez4, Elena Chaves-Pozo1* 1 COMU-IEO, CSIC, Spain 2 University of Murcia, Spain 3 University of Málaga, Spain 4 COC-IEO, CSIC, Spain. *elena.chaves@ieo.csic.es Introduction The rapid growth of aquaculture in last years have derived in the necessity of diversifying marine species. In Spain, greater amberjack (Seriola dumerili) constitutes a serious candidate to be introduced in aquaculture (APROMAR, 2023). However, little is known about the susceptibility of greater amberjack to viral pathogens. Nodavirus (NNV) is a widely spread and causes mortalities up to 100% in larvae and juveniles while adults remain asymptomatic and are able to transmit the virus to their progeny. The aim of this work is to develop non-lethal NNV-diagnosis methods involving gonadal biopsies or blood to detect persistent infections and deepen in the gonadal immune response. Methodology Adults’ specimens of greater amberjack were submitted to gonadal biopsies and blood collection. NNV diagnosis was performed by qPCR detection of viral genes and by using RTG psaumx2-luc cells luciferase activity. According to the data obtained, fish were divided into non-infected or infected specimens for evaluating their immune response triggered in males and females using qPCR. Also, serum levels of sexual hormones 11-ketotestosterone and estradiol were evaluated. Results Gene expression analysis of viral markers in gonadal fluids and luciferase activity in blood analysis revealed that 11/14 males and 5/13 females were positive for NNV. Regarding the immune response, we observed a great up-regulation of interferon pathway, cell markers and AMPs in males, but no in females. In females, only the serum levels of estradiol were increased. Moreover, dmrt1, related to testicular functionality, was down-regulated in infected males. Conclusions qPCR is a sensitive tool to detect NNV in gonadal biopsies while luciferase method is an accurate method to detect viruses in blood samples. Thus, both techniques can be proposed as non-lethal diagnosis methods. The great differences in virus behavior once colonizing the gonad and the immune response triggered between males and females demonstrated a clearly sex biased. In fact, the great immune response triggered in males point to a persistent infection instead of the latent infection observed in females, probably favoring by the high levels of estradiol. Funding The MCIN/AEI/10.13039/501100011033 (grant RTI2018-096625-BC33 and PRE2020-093771) and the European Union NextGenerationEU/PRTR, MCIN/AEI10.13039/501100011033 and Fundación Séneca (ThinkInAzulprogramme: PRTR-C17.I1). Authors CHAVES-POZO, ELENA, COMU-IEO, CSIC, Presenter Cervera, Laura, University of Murcia, Author Álvarez-Torres, Daniel, University of Málaga, Author Béjar, Julia, University of Málaga, Author Cuesta, Alberto, University of Murcia, Author Martín, Virginia, COC-IEO, CSIC, Author Jeréz, Salvador, COC-IEO, CSIC, Author Previous Next