Generation of microalga Chlamydomonas reinhardtii expressing shrimp antiviral dsRNA without supplementation of antibiotics

TY - JOUR

T1 - Generation of microalga Chlamydomonas reinhardtii expressing shrimp antiviral dsRNA without supplementation of antibiotics

AU - Charoonnart, Patai

AU - Worakajit, Nichakorn

AU - Zedler, Julie A.Z.

AU - Meetam, Metha

AU - Robinson, Colin

AU - Saksmerprome, Vanvimon

PY - 2019

Y1 - 2019

N2 - RNA interference (RNAi) is an effective way of combating shrimp viruses by using sequence-specific double-stranded (dsRNA) designed to knock down key viral genes. The aim of this study was to use microalgae expressing antiviral dsRNA as a sustainable feed supplement for shrimp offering viral protection. In this proof of concept, we engineered the chloroplast genome of the green microalga Chlamydomonas reinhardtii for the expression of a dsRNA cassette targeting a shrimp yellow head viral gene. We used a previously described chloroplast transformation approach that allows for the generation of stable, marker-free C. reinhardtii transformants without the supplementation of antibiotics. The generated dsRNA-expressing microalgal strain was then used in a shrimp feeding trial to evaluate the efficiency of the algal RNAi-based vaccine against the virus. Shrimps treated with dsRNA-expressed algal cells prior to YHV infection had 50% survival at 8 day-post infection (dpi), whereas 84.1% mortality was observed in control groups exposed to the YHV virus. RT-PCR using viral specific primers revealed a lower infection rate in dsRNA-expressing algae treated shrimp (55.6 ± 11.1%) compared to control groups (88.9 ± 11.1% and 100.0 ± 0.0%, respectively). Our results are promising for using microalgae as a novel, sustainable alternative as a nutritious, anti-viral protective feedstock in shrimp aquaculture.

AB - RNA interference (RNAi) is an effective way of combating shrimp viruses by using sequence-specific double-stranded (dsRNA) designed to knock down key viral genes. The aim of this study was to use microalgae expressing antiviral dsRNA as a sustainable feed supplement for shrimp offering viral protection. In this proof of concept, we engineered the chloroplast genome of the green microalga Chlamydomonas reinhardtii for the expression of a dsRNA cassette targeting a shrimp yellow head viral gene. We used a previously described chloroplast transformation approach that allows for the generation of stable, marker-free C. reinhardtii transformants without the supplementation of antibiotics. The generated dsRNA-expressing microalgal strain was then used in a shrimp feeding trial to evaluate the efficiency of the algal RNAi-based vaccine against the virus. Shrimps treated with dsRNA-expressed algal cells prior to YHV infection had 50% survival at 8 day-post infection (dpi), whereas 84.1% mortality was observed in control groups exposed to the YHV virus. RT-PCR using viral specific primers revealed a lower infection rate in dsRNA-expressing algae treated shrimp (55.6 ± 11.1%) compared to control groups (88.9 ± 11.1% and 100.0 ± 0.0%, respectively). Our results are promising for using microalgae as a novel, sustainable alternative as a nutritious, anti-viral protective feedstock in shrimp aquaculture.

UR - http://www.scopus.com/inward/record.url?scp=85062325748&partnerID=8YFLogxK

U2 - 10.1038/s41598-019-39539-x

DO - 10.1038/s41598-019-39539-x

M3 - Journal article

C2 - 30816201

AN - SCOPUS:85062325748

SN - 2045-2322

VL - 9

SP - 1

EP - 8

JO - Scientific Reports

JF - Scientific Reports

M1 - 3164

ER -