Molecular Characterization and Gene Expression Profiling ... - CUSAT

Chapter 2
Albores et al., 2004). Many full-length cDNA and several ESTs of crustins
have been described in a wide range of penaeid prawns.
2.1.2.7. Patterns of expression
Evidence of the role of crustins as direct antimicrobial defence
effectors has been sought from studies of their expression in different tissues
and following experimental infection. Certainly most crustins seem to be
constitutively expressed by the blood cells (Soderhall and Cerenius 1998; Relf
et al., 1999; Vargas-Albores et al., 2004; Hauton et al., 2006; Brockton et al.,
2007; Amparyup et al., 2008; Supungul et al., 2008) often at very high levels
(Hauton et al., 2006). The proteins seem to be synthesised in the granular
haemocytes, at least from the few studies on haemocyte populations (Relf et
al., 1999; Brockton et al., 2007). Transcripts of crustin-encoding genes have
also been observed in gills, heart and intestine (Zhang et al., 2007; Supungul
et al., 2008), but as these tissues are highly vascularised, it is not clear if the
signal from these organs is due primarily to the haemocytes. Patterns of
expression during development are also very poorly understood, as most
studies of crustins have been performed only on late-stage postlarvae or
adults. Larvae of the shrimp, P. monodon, have been reported to express a
crustin transcript at high levels at all stages of development from nauplii
stage IV through to juveniles (Jiravanichpaisal et al., 2007).
2.1.3. Penaeidins
2.1.3.1. Structural features
The penaeidins, a unique antimicrobial peptide family, were first
purified from haemocytes of the shrimp, L. vannamei, and their encoding
genes were cloned from shrimp haemocyte cDNA (Destoumieux et al., 1997).
Penaeidins are the well-characterized AMP family at the level of gene
expression and biological activities. Penaeidins were the subjects of two
review articles (Bachere et al., 2000a; Destoumieux et al., 2000a) soon after
Molecular Characterization and Gene Expression Profiling of Antimicrobial Peptides in Penaeid Shrimps
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