Ultra-high static magnetic fields altered the embryonic division and development in Caenorhabditis elegans via multipolar spindles.

Introduction: Ultra-high static magnetic fields (SMFs) have unique advantages in improving medical and academic research. However, the research on the early embryo exposure of ultra-high SMFs is minimal, extensive exploration is indispensable in living organisms.

Objectives: The present study was aimed to study the effects of ultra-high SMFs on the early embryonic division and development of Caenorhabditis elegans (C. elegans).

Methods: Early adult parents containing fertilized eggs in vivo were exposed to SMFs at intensities ranging from 4 T to 27 T. The number of mitotic cells in the reproductive glands of the P0 worms, early embryonic cell spindle localization, embryo hatching and the reproductive as well as developmental indicators of F1 and F2 nematodes were examined as endpoints.

Results: Our results indicated that ultra-high SMFs has no obvious effect on the germ cell cycle, while 14 T and 27 T SMFs significantly increased the proportion of multi-polar spindle formation in early embryonic cells, and reduced the developmental rate and lifespan of C. elegans exposed at the embryonic stage. Spindle abnormalities of early embryonic cells, as well as the down-regulation of genes related to asymmetric embryonic division and the abnormal expression of the non-muscle myosin NMY-2 in the division grooves played a critical role in the slowing down of embryonic development induced by ultra-high SMFs.

Conclusions: This study provided novel information and a new sight for evaluating the biosafety assessment by exposure to ultra-high SMFs at the early embryonic stage in vivo.