Chicken thrombocytes express the CD51/CD61 integrin

A panel of commercially available anti-human mab was screened for cross-reactivity on chicken cells. All mab were screened at least twice on PBL collected from two different chicken lines. Out of the 377 mab tested, only two consistently reacted with subpopulations of PBL. The mab HUH73A reactive with CD11a was detected on all lymphocytes. In contrast, the mab 23C6 obtained from Serotec and reactive with an epitope formed by humanVβ3 integrin chains (CD51/CD61) reacted with all thrombocytes, but not with other cells. In double immunofluorescence analyses, the 23C6+ cells were found to coexpress the CD45 antigen and the chicken thrombocyte marker K1. The chicken genes encoding CD51 and CD61 were analyzed by database mining. The CD51 gene is encoded by a 43 kb region containing 30 exons on chicken chromosome 7, whereas the 16 kb CD61 gene consisted of 15 exons and was localized to chromosome 27. In conclusion, the mab 23C6 is a useful reagent to identify chicken thrombocytes.