Molecular Characterization and Gene Expression Profiling ... - CUSAT

Chapter 5
quantifying an mRNA transcript. The method evaluates the product
accumulation during the exponential phase of the reaction, has a large
dynamic range and a high throughput capacity (Marone et al., 2001).
Generally the immunological parameters were at peak 48 hrs post-
challenge with WSSV via diet (Sajeevan et al., 2006; Pillai, 2007). Hence in the
present work, sampling was done at 48 th hr to assess the variation in the
expression of AMPs in response to varying stimuli. Chang et al., (2000)
evaluated the effectiveness of β-1,3-glucan derived from Schizophyllum
commune in enhancing shrimp survival as well as phagocytosis and
superoxide anion production in brooder P. monodon and showed that
immunostimulatory enhancement peaked at day 24 after starting the dietary
exposure and subsequently decreased to the pre-feeding level at the end of
40 days feeding trial. Itami et al (1994) reported that the dietary
administration of Schizophyllan, a water soluble β-1,3-glucan with some β-
1,6-glucoside side chains derived from the fungus S. commune, increased the
resistance of P. japonicus against vibriosis. Using β-1,3-1,6 glucan, extracted
from the yeast cell wall, Sung et al. (1994) and Song et al. (1997)
demonstrated enhanced resistance of P. monodon to vibriosis and WSSV
infection. But no works have been carried till date out analyzing the
expression pattern of important AMP families of shrimps in response to
immunostimulants and WSSV challenge. Immune genes differentially
expressed during WSSV infection are considered of special interest as they
could represent a potential target for the development of antiviral strategies.
Expression profile of three control genes viz. 18S rRNA, β-actin and
ELF were analyzed in the present study since these are routinely used as
internal controls in a variety of experimental conditions and are widely used
for semi-quantitative RT-PCR studies (Suzuki et al., 2000; Marone et al.,
2001). AMPs were found to be differentially expressed by various
immunostimulants used in the study. ALFs, first purified from the
Molecular Characterization and Gene Expression Profiling of Antimicrobial Peptides in Penaeid Shrimps
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