Attachment organelle ultrastructure correlates with phylogeny, not gliding motility properties, in Mycoplasma...

Area of Science:

• Microbiology
• Cell Biology
• Evolutionary Biology

Background:

• The Mycoplasma pneumoniae cluster comprises eight species known for cellular polarity.
• Their polar attachment organelle is crucial for cytadherence and gliding motility.
• The organelle's electron-dense core is vital for structural integrity, but its role in motility is unclear.

Purpose of the Study:

• To investigate and compare gliding motility and ultrastructural features of attachment organelles across seven species within the Mycoplasma pneumoniae cluster.
• To elucidate the mechanistic basis of attachment organelle functions, particularly gliding motility.
• To determine the role of the electron-dense core in gliding motility.

Main Methods:

• Comparative analysis of gliding motility and attachment organelle ultrastructure in seven Mycoplasma pneumoniae cluster species.
• Microscopic examination of cellular polarity and organelle morphology.
• Assessment of gliding speed and correlation with ultrastructural features.

Main Results:

• Gliding ability was identified in Mycoplasma imitans, Mycoplasma pirum, and Mycoplasma testudinis, species where it was not previously reported.
• Ultrastructural features of attachment organelles and their cores did not correlate with gliding speed across species.
• Morphological analysis suggests the electron-dense core plays a limited direct role in gliding motility.

Conclusions:

• The electron-dense core's role in gliding motility is likely less prominent than previously hypothesized.
• Mycoplasma pneumoniae exhibits unique cellular adaptations compared to its close relatives within the cluster.
• Comparative studies reveal diverse evolutionary strategies for motility and cell structure within the Mycoplasma pneumoniae cluster.