The critical role of transcription factor GATA1 in erythrocyte proliferation and morphology in blood clam Anadara granosa

The blood clam ( Anadara granosa ) exhibits innovative red blood compared to other molluscs, with erythrocytes constituting 79 % to 89 % of the total hemocyte count. Previously, we identified that GATA-binding protein 1 (designated as Ag GATA1) was significantly up-regulated in the transcriptomes of blood clam populations with high hemocyte counts. However, the function of Ag GATA1 in erythropoiesis remains unknown. In this study, we conducted GATA1 knockdown experiments in A. granosa , which resulted in a significant reduction of both erythrocytes and other cells during the S phase, as well as significantly decreased proliferative activity in the gill tissue. The cell proliferation assay demonstrated that overexpression of Ag GATA1 increased the DNA replication activity of K562 cells. Additionally, o-dianisidine staining revealed defects in erythropoiesis within the gill tissue following Ag GATA1 knockdown, while protein analyses confirmed a significant reduction in Ag GATA1 expression. Furthermore, decreased cytoskeletal fluorescence and morphological changes in erythrocytes suggest that Ag GATA1 influenced cytoskeletal protein expression, leading to changes in erythrocyte morphology. This study provides new insights into the role of Ag GATA1 in hemocyte formation and highlights its significance in understanding erythropoiesis within invertebrate developmental tissues.