Editing Magnetoreception (section)

=== Passive alignment in bacteria ===

[[File:Magnetite magnetosomes in Gammaproteobacteria.png|thumb|upright=1.7|[[Magnetite]] magnetosomes in [[Gammaproteobacteria]] strain SS-5. (A) Chain of highly elongated magnetosomes. (B) Part of a chain. (C) The magnetosome in the lower right in (B), viewed along the <math>\scriptstyle [1\overline{1}0]</math> direction, with its [[Fourier transform]] in the lower right.<ref>{{cite journal |last1=Pósfai |first1=Mihály |last2=Lefèvre |first2=Christopher T. |last3=Trubitsyn |first3=Denis |last4=Bazylinski |first4=Dennis A. |last5=Frankel |first5=Richard B. |title=Phylogenetic significance of composition and crystal morphology of magnetosome minerals |journal=[[Frontiers in Microbiology]] |date=2013 |volume=4 |page=344 |doi=10.3389/fmicb.2013.00344 |pmc=3840360 |pmid=24324461|doi-access=free }}</ref>]]

[[Magnetotactic bacteria]] of multiple taxa contain sufficient magnetic material in the form of [[magnetosome]]s, nanometer-sized particles of [[magnetite]],<ref>{{cite journal |last=Blakemore |first=Richard |year=1975 |title=Magnetotactic Bacteria |journal=[[Science (journal)|Science]] |volume=190 |issue=4212 |pages=377–379 |doi=10.1126/science.170679 |pmid=170679 |bibcode=1975Sci...190..377B |s2cid=5139699 }}</ref> that the Earth's magnetic field passively aligns them, just as it does with a compass needle. The bacteria are thus not actually sensing the magnetic field.<ref>{{cite journal |last=Bellini |first=Salvatore |title=On a unique behavior of freshwater bacteria |journal=Chinese Journal of Oceanology and Limnology |date=27 March 2009 |volume=27 |issue=1 |pages=3–5 |doi=10.1007/s00343-009-0003-5 |bibcode=2009ChJOL..27....3B |s2cid=86828549 }}</ref><ref>{{cite journal |last1=Bellini |first1=Salvatore |title=Further studies on "magnetosensitive bacteria" |journal=Chinese Journal of Oceanology and Limnology |date=27 March 2009 |volume=27 |issue=1 |pages=6–12 |doi=10.1007/s00343-009-0006-2 |bibcode=2009ChJOL..27....6B |s2cid=86147382 }}</ref>

A possible but unexplored mechanism of magnetoreception in animals is through [[endosymbiosis]] with magnetotactic bacteria, whose DNA is widespread in animals. This would involve having these bacteria living inside an animal, and their magnetic alignment being used as part of a magnetoreceptive system.<ref>{{cite journal |last1=Natan |first1=Eviatar |last2=Fitak |first2=Robert Rodgers |last3=Werber |first3=Yuval |last4=Vortman |first4=Yoni |date=28 September 2020 |title=Symbiotic magnetic sensing: raising evidence and beyond |journal=[[Philosophical Transactions of the Royal Society B]] |volume=375 |issue=1808 |pages=20190595 |doi=10.1098/rstb.2019.0595 |pmid=32772668 |pmc=7435164 |doi-access=free }}</ref>