Distribution and ontogeny of B cells in the garden lizard, Calotes versicolor

Abstract

Surface immunoglobulin bearing (sIg cells were identified in the lizard Calotes versicolor by immunofluorescence using a polyvalent antiserum to lizard immunoglobulins and class-specific antibodies to lizard IgM and IgY. 53.3±1.6% of spleen cells, 23.6±0.8% of peripheral blood monoclear cells, 21.5±1.8% of bone marrow mononuclear cells and less than 1% of thymus cells were found to bear immunoglobulin (Ig) on their surface. A similar proportion of cells in each tissue was stained with rabbit anti-lizard μ(specific for IgM) whereas only a small proportion of cells were stained with rabbit anti-lizard (θ) (specific for IgY). Adult thymectomy significantly increased the proportion of sIgM cells in spleen and blood whereas high dose cyclophosphamide (300mg/kg body weight)decreased the proportion of sIgM cells thus suggesting that sIg cells in the lizard are of B cell lineage as in higher vertebrates. Ontogenetic studies indicate that embryonic liver is an organ enriched for sIgM cells at certain stages of development and thus suggest liver to be a site for differentiation of sIg cells in lizard embryos.