The leaf beetle Chelymorpha alternans propagates a plant pathogen in exchange for pupal protection.

Many insects rely on microbial protection in the early stages of their development. However, in contrast to symbiont-mediated defense of eggs and young instars, the role of microbes in safeguarding pupae remains relatively unexplored, despite the susceptibility of the immobile stage to antagonistic challenges. Here, we outline the importance of symbiosis in ensuring pupal protection by describing a mutualistic partnership between the ascomycete Fusarium oxysporum and Chelymorpha alternans, a leaf beetle. The symbiont rapidly proliferates at the onset of pupation, extensively and conspicuously coating C. alternans during metamorphosis. The fungus confers defense against predation as symbiont elimination results in reduced pupal survivorship. In exchange, eclosing beetles vector F. oxysporum to their host plants, resulting in a systemic infection. By causing wilt disease, the fungus retained its phytopathogenic capacity in light of its symbiosis with C. alternans. Despite possessing a relatively reduced genome, F. oxysporum encodes metabolic pathways that reflect its dual lifestyle as a plant pathogen and a defensive insect symbiont. These include virulence factors underlying plant colonization, along with mycotoxins that may contribute to the defensive biochemistry of the insect host. Collectively, our findings shed light on a mutualism predicated on pupal protection of an herbivorous beetle in exchange for symbiont dissemination and propagation.

CRISPR/Cas9-mediated ELANE knockout enables neutrophilic maturation of primary hematopoietic stem and progenitor cells and induced pluripotent stem cells of severe congenital neutropenia patients.

A Autosomal-dominant ELANE mutations are the most common cause of severe congenital neutropenia. Although the majority of congenital neutropenia patients respond to daily granulocyte colony stimulating factor, approximately 15 % do not respond to this cytokine at doses up to 50 µg/kg/day and approximately 15 % of patients will develop myelodysplasia or acute myeloid leukemia. "Maturation arrest," the failure of the marrow myeloid progenitors to form mature neutrophils, is a consistent feature of ELANE associated congenital neutropenia. As mutant neutrophil elastase is the cause of this abnormality, we hypothesized that ELANE associated neutropenia could be treated and "maturation arrest" corrected by a CRISPR/Cas9-sgRNA ribonucleoprotein mediated ELANE knockout. To examine this hypothesis, we used induced pluripotent stem cells from two congenital neutropenia patients and primary hematopoietic stem and progenitor cells from four congenital neutropenia patients harboring ELANE mutations as well as HL60 cells expressing mutant ELANE We observed that granulocytic differentiation of ELANE knockout induced pluripotent stem cells and primary hematopoietic stem and progenitor cells were comparable to healthy individuals. Phagocytic functions, ROS production, and chemotaxis of the ELANE KO (knockout) neutrophils were also normal. Knockdown of ELANE in the mutant ELANE expressing HL60 cells also allowed full maturation and formation of abundant neutrophils. These observations suggest that ex vivo CRISPR/Cas9 RNP based ELANE knockout of patients' primary hematopoietic stem and progenitor cells followed by autologous transplantation may be an alternative therapy for congenital neutropenia.