Genetic Variation in Disease Resistance Against White Spot Syndrome Virus (WSSV) in Liptopenaeus vannamei

Abstract

White Spot Syndrome Virus (WSSV) is the most damaging pathogen in terms of production and economic losses for the shrimp sector world-wide. Estimation of heritability for WSSV resistance was made in this study to obtain necessary parameter inputs for broadening the breeding objectives of an ongoing selective breeding programme for Whiteleg shrimp ( Liptopenaeus vannamei ) that has focussed exclusively on improving growth performance since 2014. The present study involved a disease challenge test experiment using a total of 15,000 shrimps from 150 full- and half-sib families (100 individuals per family). Survival rates were recorded at six different experimental periods: 1–3 days (S1), 1–5 days (S2), 1–7 days (S3), 1–9 days (S4), 1–12 days (S5), and 1–15 days (S6) and were used as measures of WSSV resistance. There was significant variation in WSSV resistance among families studied. Quantitative-real time PCR (qPCR) analysis showed that the amount of viral titer (viral load) was significantly lower in high than low resistance families. Analyses of heritability were carried out using linear mixed model (LMM) and threshold logistic generalized model (TLGM). Both linear and threshold models used showed that the heritability (h 2 ) for WSSV resistance was moderate in the early infection phases (S1–S4), whilst a low h 2 value was observed for survival after 12 and 15 days of the challenge test (S5 and S6). The transformed heritabilities for WSSV resistance ranged from 1 to 31% which were somewhat lower than those estimated on the liability scale. Genetic correlations between survival rates measured over six different days post-infection were high and positive (0.82–0.99). The phenotypic correlations ranged from 0.31 ± 0.01 to 0.97 ± 0.01. The genetic correlations between body weights and WSSV resistance were negative. Our results on the heritability and genetic correlations show that improvement of WSSV resistance can be achieved through selective breeding in this population of Whiteleg shrimp.

The Complete Genome of an Endogenous Nimavirus (Nimav-1_LVa) From the Pacific Whiteleg Shrimp Penaeus (Litopenaeus) Vannamei

“…The data suggested Nimav-1_LVa virus might take a different strategy than WSSV, aiming at a long-term or benign relationship with the host. The genome of Nimav-1_LVa could facilitate a better understanding of evolution in virus family Nimaviridae and could also be applicable in the shrimp breeding, traceability of farmed shrimp, WSSV diagnosis, and treatment of WSD [26,87].…”

“…A recent study in Kuruma shrimp, Penaeus (Marsupenaeus) japonicus, illustrated that the entry of WSSV into the host cell is via the endocytosis pathway, triggered by the interaction of virion and a transmembrane immunoglobulin receptor, designated as MjpIgR [24]. So far, progress has been made in developing WSSV-resistant P. vannamei lines [25,26], but a lot more work remains ahead to achieve the stabilization of the resistance.…”

Salmonid Antibacterial Immunity: An Aquaculture Perspective

“…In some cases, heritability of disease resistance is observed without negatively influencing animal growth [ 187 ], such as has been observed in rainbow trout with resistance towards F. psychrophilum [ 188 ] or F. columnare [ 189 ]. However, it has also been shown that selecting for resistance to a single pathogen can sometimes result in increased susceptibility to another or in decreased growth [ 190 , 191 , 192 , 193 , 194 ]. In these studies, the gold standard for determining disease resistance is survival comparisons during live infection challenges (reviewed in [ 195 ]).…”

Resistance to Streptococcus iniae and its genetic associations with traits of economic importance in Asian seabass (Lates calcarifer)

“…Improved resistance to infectious diseases through selective breeding has been demonstrated in previous studies (Doan et al, 2017;Trang, Nguyen, Nguyen, Wayne, & Nguyen, 2019b). Across aquaculture species, heritabilities (h 2 ) for resistance to a range of diseases from parasites to bacteria and virus are low to moderate (Ødegård, Baranski, Gjerde, & Gjedrem, 2011), for instance, h 2 = 0.03 -0.18 for resistance to Aeromonas salmonicida bacteria in Atlantic salmon (Salmo salar) (Gjerde, Evensen, Bentsen, & Storset, 2009;Kjøglum, Henryon, Aasmundstad, & Korsgaard, 2008;Ødegård, Olesen, Gjerde, & Klemetsdal, 2006, 2007bOlesen, Hung, & Ødegård, 2007); h 2 = 0.05-0.25 for resistance to Yersinia ruckeri and Flavobacterium psychrophilum bacteria in rainbow trout (Oncorhynchus mykiss) (Evenhuis, Leeds, Marancik, Lapatra, & Wiens, 2015;Hastefnl, Guo'ding, & Eve-Risen, 2005;Leeds et al, 2010;Silverstein et al, 2009;Wiens et al, 2013); h 2 = 0.03 and 0.04 for resistance to Aeromonas hydrophila bacteria in Rohu carp (Labeo rohita) (Mahapatra et al, 2008) and in common carp (Cyprinus carpio) (Ødegård et al, 2010), respectively; or h 2 = 0.08 for resistance to Vibrio anguillarum in Atlantic cod (Kettunen, Serenius, & Fjalestad, 2007).…”

“…However, there has not been any selection programme for improved resistance to S. iniae in Asian seabass. Furthermore, genetic association between disease resistance and growth or survival is not consistently reported in aquaculture species, being either positive (Barría, Doeschl-Wilson, Lhorente, Houston, & Yáñez, 2019), negative (Yáñez et al, 2016) or not significant (Trang, Nguyen, et al, 2019b). There is also a paucity of scientific knowledge regarding genetic relationships between disease resistance and cannibalism in aquaculture species, especially in marine finfish including seabass.…”