MN•CS•IO System: Cross‐Species Study for HBB Function in High‐Altitude Hypoxia Adaptation

ABSTRACT The genetic basis of high‐altitude hypoxia adaptation remains largely elusive, particularly the role of HBB. Here, we developed an integrative mesh‐nanorod (MN) cell sorting, chitosan nanoparticle (CS) delivery, and in vivo intraosseous (IO) injection (MN•CS•IO) system to functionally investigate HBB in cross‐species high‐altitude hypoxia adaptation. Using this MN•CS•IO platform, we transplanted high/low‐altitude species HBB‐modified lineage‐negative (Lin − ) cells into murine models, achieving 95.59% transfection efficiency and 8.15% HBB relative expression, and subjected them to simulated and natural Qinghai‐Tibet hypoxia conditions. High‐altitude HBB recipients exhibited downregulated Rragd expression, activated oxygen transport and hematopoietic lineage pathways, improved behavioral performance, and neuroprotection against hypoxia‐induced damage, compared with low‐altitude animals. MN•CS•IO system data demonstrate that HBB determines high‐altitude hypoxia adaptation. For validation, we generated bone marrow chimeras using CD45.1 hematopoietic cells with Pika‐HBB integrated at the Rosa26 locus. The reconstituted mice exhibited consistent hypoxic behavioral and phenotypic alterations with those observed via the MN•CS•IO system, validating the reliability and stability of HBB‐mediated high‐altitude hypoxia adaptation. Together, our findings demonstrate that HBB is a key genetic determinant of high‐altitude hypoxia adaptation, and also introduce a versatile gene‐function validation tool for evolutionary and biomedical research.