Fish Immunology (1+1)

Unit 6- Ontogeny of Fish Immune System

6.3. Ontogeny of T and B Cells in Lymphoid Organ Development
The sIg+ cells (cells bearing Ig on their surface) could be detected in the thymus and pronephros from day 14 after fertilization, and in the mesonephros and spleen from day 28. Cytoplasmic Ig+ cells (cells bearing Ig in their cytoplasm) were first seen in the pronephros at day 21. The percentage of sIg' cells increased gradually to the age of 16 months, with 15.8-48.1% for blood, pronephros 9.7-21.6%, mesonephros 7.2-16.8% , spleen 15.9-21.6% , and thymus 1.5-3.7%. but in the case of cIg+ cells, the percentage was very low or even absent in spleen, thymus, and blood. Plasma cells were not found in the kidney of the fishes of the age below 1 month old and 0.17% can be seen in the fishes of 1 month old followed by increase in plasma cells, and increased to 1% at the age of 8 months.