Rheotaxis in Planaria Alpina

Rheotaxis in Planaria Alpina

Population Growth in Planaria

Planaria reproduce by transverse fission. Isolated worms increase in number exponentially, while social animals at the same density are inhibited in terms of numerical increase, but over a 25 day period undergo a larger increase in mass. Isolated posterior fission products reproduce faster than isolated anterior fission products. Regulation of population growth is independent of density over a ...

Regeneration in Planaria

Inmetazoans, regeneration of lost body parts requiring the formation of a blastema is known as epimorphic regeneration. A blastema is composed primarily of two cell populations: an outer cell layer or ectoderm, derived from the epidermis that covers the wound surface after amputation/fission; and mesenchymal cells that proliferate and accumulate beneath this wound epidermis, eventually differen...

Artificial rheotaxis

Motility is a basic feature of living microorganisms, and how it works is often determined by environmental cues. Recent efforts have focused on developing artificial systems that can mimic microorganisms, in particular their self-propulsion. We report on the design and characterization of synthetic self-propelled particles that migrate upstream, known as positive rheotaxis. This phenomenon res...

Bacterial rheotaxis.

The motility of organisms is often directed in response to environmental stimuli. Rheotaxis is the directed movement resulting from fluid velocity gradients, long studied in fish, aquatic invertebrates, and spermatozoa. Using carefully controlled microfluidic flows, we show that rheotaxis also occurs in bacteria. Excellent quantitative agreement between experiments with Bacillus subtilis and a ...