Differentially Expressed Genes in Hepatopancreas of Acute Hepatopancreatic Necrosis Disease Tolerant and Susceptible Shrimp (Penaeus vannamei)

Abstract

Acute hepatopancreatic necrosis disease (AHPND) is a lethal disease in marine shrimp that has caused large-scale mortalities in shrimp aquaculture in Asia and the Americas. The etiologic agent is a pathogenic Vibrio sp. carrying binary toxin genes, pirA and pirB in plasmid DNA. Developing AHPND tolerant shrimp lines is one of the prophylactic approaches to combat this disease. A selected genetic line of Penaeus vannamei was found to be tolerant to AHPND during screening for disease resistance. The mRNA expression of twelve immune and metabolic genes known to be involved in bacterial pathogenesis were measured by quantitative RT-PCR in two populations of shrimp, namely P1 that showed susceptibility to AHPND, and P2 that showed tolerance to AHPND. Among these genes, the mRNA expression of chymotrypsin A (ChyA) and serine protease (SP), genes that are involved in metabolism, and crustin-P (CRSTP) and prophenol oxidase activation system 2 (PPAE2), genes involved in bacterial pathogenesis in shrimp, showed differential expression between the two populations. The differential expression of these genes shed light on the mechanism of tolerance against AHPND and these genes can potentially serve as candidate markers for tolerance/susceptibility to AHPND in P. vannamei. This is the first report of a comparison of the mRNA expression profiles of AHPND tolerant and susceptible lines of P. vannamei.

Comparison of Gene Expression Between Resistant and Susceptible Families Against VPAHPND and Identification of Biomarkers Used for Resistance Evaluation in Litopenaeus vannamei

“…Meanwhile, the top 10 gene sets enriched in resistant families in the GSEA were all involved in energy metabolism process. The finding was consistent with the previous report that SP and ChyB had a significantly higher expression level in resistant shrimp line during the AHPND infection (Mai et al, 2021). Several studies have indicated that metabolic processes such as lipid metabolism and carbohydrate metabolic process in shrimp were greatly affected during AHPND infection (Velazquez-Lizarraga et al, 2019;Kumar et al, 2021).…”

“…In this study, several genes in proPO activation system showed a higher expression level in the susceptible families. A previous report showed that PPAE2 presented a higher expression level in the susceptible line of L. vannamei after AHPND challenge in comparison with the resistant line (Mai et al, 2021). This system is important for fighting against bacteria pathogens in penaeid shrimp (Amparyup, et al, 2013), and the increased activity of proPO system against Vibrio has been reported in Fenneropenaeus indicus (Sarathi et al, 2007), L. vannamei (Boonchuen et al, 2021), and Macrobrachium rosenbergii (Rao et al, 2015).…”

“…The C-type lectin was also upregulated in the susceptible families of shrimp; the C-type lectin plays an important role in phagocytosis, melanization, respiratory burst, and coagulation; and it can also activate the proPO system (Junkunlo et al, 2012). Interestingly, C-type lectin 1-like and Crustin-P had significant higher expression levels in the AHPND-susceptible line of L. vannamei than resistant line at 24 h post-infection (Mai et al, 2021). In Litopenaeus stylirostris, the basal expression level of antimicrobial peptide was significantly higher in Vibrio-susceptible shrimp line (Lorgeril et al, 2008).…”

Transcriptome Analysis on Hepatopancreas Reveals the Metabolic Dysregulation Caused by Vibrio parahaemolyticus Infection in Litopenaeus vannamei

“…Recently, studies have shown that the interaction between immunity and metabolism seems to participate in shrimp’s response to AHPND [ 29 ]. However, transcriptome studies of shrimp responses to AHPND have mainly focused on immune-related genes and pathways, and little is known about metabolism-related changes [ 16 , 30 , 31 , 32 ]. Here, the comparative transcriptome study mainly focused on the metabolic processes in shrimp hepatopancreas at different time points post V. parahaemolyticus infection.…”

Two Independently Comparative Transcriptome Analyses of Hemocytes Provide New Insights into Understanding the Disease-Resistant Characteristics of Shrimp against Vibrio Infection

“…The variation of disease-resistant ability could be reflected by differential expression of genes at the background level. In P. vannamei, several genes including chymotrypsin A, serine protease, crustin-P and prophenol oxidase activation system 2 showed differential expression levels between VpAHPND tolerant and susceptible populations [9]. A transcriptomic comparison between three VpAHPND resistant and three susceptible families identified 489 differentially expressed genes (DEGs) in L. vannamei and 19 tested genes also showed different expression in their offspring [10].…”