Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
, 25 (1), 6-21

Tree of Motility - A Proposed History of Motility Systems in the Tree of Life


Tree of Motility - A Proposed History of Motility Systems in the Tree of Life

Makoto Miyata et al. Genes Cells.


Motility often plays a decisive role in the survival of species. Five systems of motility have been studied in depth: those propelled by bacterial flagella, eukaryotic actin polymerization and the eukaryotic motor proteins myosin, kinesin and dynein. However, many organisms exhibit surprisingly diverse motilities, and advances in genomics, molecular biology and imaging have showed that those motilities have inherently independent mechanisms. This makes defining the breadth of motility nontrivial, because novel motilities may be driven by unknown mechanisms. Here, we classify the known motilities based on the unique classes of movement-producing protein architectures. Based on this criterion, the current total of independent motility systems stands at 18 types. In this perspective, we discuss these modes of motility relative to the latest phylogenetic Tree of Life and propose a history of motility. During the ~4 billion years since the emergence of life, motility arose in Bacteria with flagella and pili, and in Archaea with archaella. Newer modes of motility became possible in Eukarya with changes to the cell envelope. Presence or absence of a peptidoglycan layer, the acquisition of robust membrane dynamics, the enlargement of cells and environmental opportunities likely provided the context for the (co)evolution of novel types of motility.

Keywords: Mollicutes; appendage; cytoskeleton; flagella; membrane remodeling; motor protein; peptidoglycan; three domains.

Conflict of interest statement

There are no conflicts of interest to declare.


Figure 1
Figure 1
Various types of motility systems. Cartoons of those systems are listed according to the order in the text and roughly assigned to the relative positions in Tree of Life (Hug et al. 2016; Castelle & Banfield 2018). (1a) bacterial flagellar swimming, (1b) spirochetes flagellar swimming, (1c) magnetotactic bacterial flagellar swimming, (1d) bacterial flagellar swarming, (1e) Leptospira crawling motility, (2) bacterial pili motility, (3) Myxococcus xanthus adventurous (A) motility, (4) Bacteroidetes gliding, (5) Chloroflexus aggregans surface motility, (6) Synechococcus nonflagellar swimming, (7) archaella swimming, (8a) amoeba motility based on actin polymerization, (9) heliozoa motility based on microtubule depolymerization, (10) myosin sliding, (11) kinesin sliding, (12) dynein sliding, (10a) amoeba motility driven by contraction of cortical actin–myosin. (10b) animal muscle contraction, (11a, 12a) flagellar surface motility (FSM), (12b) flagellar swimming, (13) haptonemal contraction, (14) spasmoneme contraction, (15) amoeboid motility of nematode sperm, (8b) actin‐based comet tail bacterial motility, (16) Mycoplasma mobile gliding, (17) Mycoplasma pneumoniae gliding, (18) Spiroplasma swimming, (i) bacterial sliding, (ii) gas vesicle, (iii) dandelion seed. Refer to Table 1 for more details. The three eukaryotic conventional motor proteins are shown in the dotted box

Similar articles

See all similar articles

Cited by 1 article


    1. Agrebi R., Wartel M., Brochier‐Armanet C., & Mignot T. (2015). An evolutionary link between capsular biogenesis and surface motility in bacteria. Nature Reviews Microbiology, 13, 318–326. 10.1038/nrmicro3431 - DOI - PubMed
    1. Akil C., & Robinson R. C. (2018). Genomes of Asgard archaea encode profilins that regulate actin. Nature, 562, 439–443. 10.1038/s41586-018-0548-6 - DOI - PubMed
    1. Alam M., & Oesterhelt D. (1984). Morphology, function and isolation of halobacterial flagella. Journal of Molecular Biology, 176, 459–475. 10.1016/0022-2836(84)90172-4 - DOI - PubMed
    1. Albers S. V., & Jarrell K. F. (2015). The archaellum: How Archaea swim. Frontiers in Microbiology, 6, 23 10.3389/fmicb.2015.00023 - DOI - PMC - PubMed
    1. Albers S. V., & Meyer B. H. (2011). The archaeal cell envelope. Nature Reviews Microbiology, 9, 414–426. 10.1038/nrmicro2576 - DOI - PubMed