EXPERIMENTAL INJECTION OF α-INTERFERON (CHINESE HAMSTER OVARY DERIVED) RECOMBINANT PROTEIN TO RED-CLAW CRAYFISH (Cherax quadricarinatus): THE FIRST REPORT

Aims: Interferon (IFN) was recognized as a natural defense of vertebrates in response to viral infection. In later studies, IFN regulatory factor genes (IRF)s within Metazoan Kingdom was identified in Phylum Arthropoda, which are Chinese mitten crab (Ericheir sinensis) (ErS1, GenBank no. FG360214) and Pacific white shrimp (Litopenaeus vannamei) (PENVA, GenBank no. AOAOR6M5F1). This study aimed to confirm the existence of an IFN pathway in red claw crayfish (C. quadricarinatus), which also belong to Phylum Arthropoda.

Methodology: α-IFN, Chinese hamster ovary derived (CHO-Derived) recombinant protein was subcutaneously injected into adult red-claw crayfish at different dosages per body weight (BW), namely a.100 IU, b. 200IU, and c. 225IU. The right reflecting-time of the red-claw was counted. Polymerase chain reaction (PCR) was conducted using designed primers from Chinese mitten crab (E. sinensis).

Results: Basic Local Alignment Search Tool for nucleotides (BLASTn) showed somewhat similar characteristics between our sequences and other crustacean species. The highest matched value was 89% red-claw crayfish (C. quadricarinatus) microsatellite cqu.005 (GenBank no. AF156901)) and the lowest was 66% Noble crayfish (Astacus astacus) clone Aas8 microsatellite (GenBank no. EU692886). Two of our sequences matched 72 and 75% with a sequence of Chinese mitten crab (E. sinensis) microsatellite ES19 (GenBank no. DQ388785).

Conclusion: In conclusion, since the designed primers did not support the idea of an IRF as part of an IFN pathway existing in red-claw crayfish, our study tends to confirm that to date, no other IRF exists in Arthropoda, except perhaps in the Chinese mitten crab and Pacific white shrimp. This finding supports the rational consideration that IRFs within the Metazoan Kingdom, Phylum Arthropoda, might have diverged somewhat or been completely lost during evolution.