In vivo dynamic 3D imaging of oocytes and embryos in the mouse oviduct

Developmental biologists have always relied on imaging to shed light on dynamic cellular events. However, processes such as mammalian fertilization and embryogenesis are generally inaccessible for direct imaging. In consequence, how the oviduct (fallopian tube) facilitates the transport of gametes and preimplantation embryos continues to be unanswered. Here we present a combination of intravital window and optical coherence tomography for dynamic, volumetric, in vivo imaging of oocytes and embryos as they are transported through the mouse oviduct. We observed location-dependent circling, oscillating, and long-distance bidirectional movements of oocytes and embryos that suggest regulatory mechanisms driving transport and question established views in the field. This in vivo imaging approach can be combined with a variety of genetic and pharmacological manipulations for live functional analysis, bringing the potential to investigate reproductive physiology in its native state.

Automated summary

Developmental biologists have used imaging techniques to study dynamic cellular events, but some processes like mammalian fertilization and embryogenesis are difficult to directly image. This study used intravital window and optical coherence tomography to observe the transport of oocytes and embryos through the mouse oviduct, revealing novel location-dependent movement patterns and questioning established views in the field. The in vivo imaging approach offers potential for investigating reproductive physiology with live functional analysis.