Abstract: | Flow cytometric analysis of forward angle versus 90 degree scatter patterns of hagfish peripheral blood revealed two distinct leucocyte populations with size characteristics analogous to mammalian monocytes/granulocytes (hagfish large leucocytes) and small lymphocytes (hagfish small leucocytes). A cell population enhanced for the small leucocytes was obtained by density gradient centrifugation. Over 70% of the small leucocyte population consistently stained with a rabbit antiserum directed against polypeptide determinants on hagfish immunoglobulin, while staining of the large cell population was greatly reduced (less than 10%). A panel of monoclonal antibodies raised against a crude hagfish leucocyte preparation distinguished the two cell populations and revealed the existence of subpopulations of both small and large leucocytes. |