Chlamydomonas rheinhartii is a unicellular green algae that has a pair of flagella to make it motile. It ’s now used by JGI as a benchmark for new sequencing technologies to detect low abundant mRNAs using 454 and Solexa sequencers.

Further reading:

Merchant, S.S. et al. The Chlamydomonas genome reveals the evolution of key animal and plant functions.Science 318, 245-50 (2007). [pubmed]