What a couple of dimensions can do for you: Comparative developmental studies using 4D microscopy--examples from...

Area of Science:

• Developmental biology
• Evolutionary biology
• Microscopy

Background:

• Analyzing 4-dimensional (space and time) organismal development requires specialized methods.
• Traditional fluorescent labeling techniques are insufficient for observing cell lineage in certain small embryos.

Purpose of the Study:

• To present and validate a 4D microscopy method for analyzing embryogenesis.
• To demonstrate the applicability of 4D microscopy beyond Caenorhabditis elegans for studying diverse small embryos.

Main Methods:

• Developed a 4D microscopy system comprising a motorized microscope, trigger software, and a database.
• Applied the system to record and analyze the complete embryonic development of various organisms, including tardigrades.
• Utilized the technique to identify new developmental characters and assess existing ones.

Main Results:

• The 4D microscopy system successfully recorded detailed embryonic development, including cleavage, cell migration, apoptosis, and differentiation.
• The method enabled cell lineage analysis in small embryos not amenable to fluorescent labeling.
• Analysis of tardigrade development revealed new characters and provided insights into phylogenetic relationships.

Conclusions:

• 4D microscopy is a powerful tool for studying the development of diverse small organisms.
• This technique offers novel insights into evolutionary developmental processes and phylogenetic relationships.
• The findings contribute to understanding the evolution of Ecdysozoa, including Arthropoda and Cycloneuralia.