Genetic Susceptibility of Cultured Shrimp (Penaeus vannamei) to Infectious Hypodermal and Hematopoietic Necrosis Virus andBaculovirus penaei:Possible Relationship with Growth Status and Metabolic Gene Expression

Abstract

Offspring of four crosses (I, II, III, and IV) of Penaeus vannamei from known high-and low-growth families were challenged with infectious hypodermal and hematopoietic necrosis virus (IHHNV) and Baculovirus penaei (BP) to compare their susceptibility to these viral agents and examine the genetic component involved in disease resistance or susceptibility. Family crosses were made using broodstock from five families developed by the U.S. Marine Shrimp Farming Program. The prevalence of IHHNV infection was highest in cross I and lowest in cross III. Cross I was developed using male and female broodstock from the low-growth family 1.6, and cross III was developed using a female from the high-growth family 1.3 and a male from the low-growth family 1.6. The prevalence of BP infection at Day 4 was highest (100%) in cross IV, which was developed using a female from the low-growth family 1.4 and a male from the high-growth family 1.5. The reciprocal cross, cross III, had the lowest (68%) prevalence at Day 4 postexposure. Both crosses I and II had 88% prevalence2 of infection at Day 4. Despite 100% prevalence of BP infection in cross IV at 4 days, animals from this cross and cross II exhibited high survival by Day 18 (85 and 77%). On the other hand, crosses I and III (with 88 and 68% prevalence at Day 4, respectively) showed low survival at Day 18 (19 and 24%). On the basis of prevalence of infection and mortality rates, it was concluded that the susceptibility to BP in penaeid shrimp is governed by the genetic background of the parental crosses. The random amplified polymorphic DNA polymorphisms for crosses I, II, III, and IV, were 43, 45, 53, and 51%, respectively, showing no clear relationship between IHHNV and BP prevalence of infection and levels of nuclear genetic diversity. Though the mtDNA haplotypes in offspring from the different crosses were the same, major differences were observed in both steady-state levels and patterns of expression of the mitochondrial 12s rRNA in offspring obtained at various early developmental stages from each of the four crosses. The possible relationship among disease susceptibility, growth status, and expression of mitochondrial 12s rRNA is discussed in the context of a complex nuclearcytoplasmic genetic system involved in the regulation of gene expression.

Susceptibility to an inoculum of infectious hypodermal and haematopoietic necrosis virus (IHHNV) in three batches of whiteleg shrimp Litopenaeus vannamei (Boone, 1931)

“…The latter species soon became the main cultured species since the late 1980s ( Lotz 1997 ). This virus has affected other penaeid species in the Pacific ( Alcivar-Warren et al 1997 ) and various countries in America, Asia and Oceania ( Lightner 1996 ).…”

Impact of Vaccination and Pathogen Exposure Dosage on Shedding Kinetics of Infectious Hematopoietic Necrosis Virus (IHNV) in Rainbow Trout

“…It has been observed that selective breeding results in reduced antibody diversity in fish (Sommer 2005;Spielman et al 2007), and could therefore reduce vaccine competence. Host immunity to one pathogen can also have tradeoffs with susceptibility to another (Ehlinger 1977;Alcivar-Warren et al 1997). There was some indication of this here because the ARS-Fp-R line, which has been bred for resistance to bacterial coldwater disease, suffered more mortality than the IHNV.R line.…”

Host–Symbiont Relationships: Understanding the Change from Guest to Pest

“…Genetics Offspring of male and female crosses of high-growth and low-growth "families" of a well-defined population at GCRL Consortium at OI, Hawaii, were fed BP as 15-day-old postlarvae (PL15s) (Alcivar-Warren et al 1997). The high  high-growth and low  high-growth (female  male) postlarvae, respectively, had a 77 and 85 % survival rate at 18 days postexposure compared with 19 and 24 % survival for the low  low-growth and high  low-growth offspring.…”