Early life stage mortality in fish is one of the problems faced by loach aquaculture. However, our understanding of immune system in early life stage fish is still incomplete, and the information available is restricted to a few fish species. In the present work, we investigated the expression of immune-related transcripts in loach during early development. In fishes, recombination-activating gene 1 (RAG-1) and sacsin (SACS) have been considered as immunological function. In this study, the expression of the both genes was assessed throughout the early developmental stages of loach using real-time PCR method. maRAG-1 mRNA was first detected in 0 dph, observed the increased mostly until 40 dph. Significant expression of maRAG-1 was detected in 0 to 40 dph. These patterns of expression may suggest that the loach start to develop its function after hatching. On the other hand, maSACS was detected in unfertilized oocyte to molura stages and 0 to 40 dph. maSACS mRNA transcripts were detected in unfertilized oocytes, suggesting that they are maternally transferred.

INTRODUCTION
MATERIAL & METHODS
RESULTS
DISCUSSION
ACKNOWLEDGEMENT
REFERENCES

• Jang Wook Lee(Inland Aquaculture Research Center, National Fisheries Research & Development Institute)
• Jung Eun Kim(Inland Aquaculture Research Center, National Fisheries Research & Development Institute)
• In Bon Goo(Inland Aquaculture Research Center, National Fisheries Research & Development Institute)
• Ju-Ae Hwang(Inland Aquaculture Research Center, National Fisheries Research & Development Institute)
• Jea Hyun Im(Inland Aquaculture Research Center, National Fisheries Research & Development Institute)
• Hye-Sung Choi(Inland Aquaculture Research Center, National Fisheries Research & Development Institute)
• Jeong-Ho Lee(Inland Aquaculture Research Center, National Fisheries Research & Development Institute) Corresponding author