Mitochondria are the site of iron utilization, wherein imported iron is incorporated into heme or iron-sulfur clusters. Previously, we showed that a cytosolic siderophore, which resembles a bacterial siderophore, facilitates mitochondrial iron import in eukaryotes, including zebrafish. An evolutionarily conserved 3-hydroxy butyrate dehydrogenase, 3-hydroxy butyrate dehydrogenase 2 (Bdh2), catalyzes a rate-limiting step in the biogenesis of the eukaryotic siderophore. We found that inactivation of bdh2 in developing zebrafish embryo results in heme deficiency and delays erythroid maturation. The basis for this erythroid maturation defect is not known. Here we show that bdh2 inactivation results in mitochondrial dysfunction and triggers their degradation by mitophagy. Thus, mitochondria are prematurely lost in bdh2-inactivated erythrocytes. Interestingly, bdh2-inactivated erythroid cells also exhibit genomic alterations as indicated by transcriptome analysis. Reestablishment of bdh2 restores mitochondrial function, prevents premature mitochondrial degradation, promotes erythroid development, and reverses altered gene expression. Thus, mitochondrial communication with the nucleus is critical for erythroid development. T he zebrafish (Danio rerio) is a well-established model system to study vertebrate hematopoiesis: zebrafish hematopoiesis is strikingly similar to mammalian hematopoiesis, and zebrafish have inherent experimental advantages (1). In the zebrafish embryo, hematopoiesis occurs in spatially distinct steps: the primitive or first wave of hematopoiesis occurs in two distinct anatomical locations, the posterior lateral mesoderm, which forms the intermediate cell mass (ICM) and is the site of erythroid development, and the anterior lateral mesoderm, which is the site of myeloid development. The definitive or second wave of hematopoiesis arises from self-renewing hematopoietic stem cells located in the wall of dorsal aorta (2, 3). These two waves of hematopoiesis are tightly controlled at the transcriptional level (4, 5).In erythropoiesis, pluripotent hematopoietic stem cells give rise to committed erythroid progenitor cells and to additional progenitors and precursors (6). The earliest committed erythroid progenitor is the burst-forming unit erythroid, which differentiates to produce CFU-erythroid (7). Terminal erythropoiesis begins at this stage and involves as many as six terminal divisions, differential regulation of erythroid-specific genes, nuclear changes, and extrusion of mitochondria (all species) and the nucleus (mammals) (6). Terminal erythropoiesis involves predominantly three cell types: proerythroblasts, basophilic erythroblasts, and polychromatophilic erythroblasts, which undergo morphologically distinguishable pattern of differentiation (8). In terminal erythropoiesis, polychromatophilic/orthochromatophilic erythroblasts give rise to reticulocytes. Reticulocytes lose all of their organelles, including mitochondria (8). The primary method used to eliminate mitochondria is mitophagy, a form of ...