Relationships among Dscam expression and diversity and pathogen tolerance in white shrimp

Abstract

Arthropod Dscam belongs to the Ig superfamily The protein plays a variety of roles in the immune system and also participates in neural guidance The typical structure of Dscam consists of 10 Ig domains six fibronectin type III (FN) repeats a transmembrane (TM) domain and a cytoplasmic tail A unique tail-less Dscam (lacking either a TM domain or a cytoplasmic tail) has also been identified in crustaceans Hypervariability in the Dscam extracellular region (due to alternative splicing in the Ig2 Ig3 and Ig7 regions) appears to enable the recognition of numerous pathogens The objective of this study was to identify relationships among Dscam expression the resulting diversity of Dscam isoforms and their ability to fight pathogens Individual shrimp were tagged and divided into two groups: those injected with PBS (control) and those injected with white spot syndrome virus (WSSV) Hemocyte samples were collected pre-infection and at 48 hpi Real-time PCR was used to detect the expression of Dscam and WSSV VP28 whereupon Dscam Ig2 and Ig3 regions were amplified Based on the Dscam response in individual shrimp (sampled before and after viral infection) we concluded that a decrease in Dscam variability may render shrimp less susceptible to infection with WSSV In addition we identified specific Dscam isoforms seem to show an ability against WSSV

Date of Award	2014 Sept 5
Original language	English
Supervisor	Han-Ching Wang (Supervisor)