b-Carbonic Anhydrases in Fungi Figure 4. Localization of the carbonic anhydrase CAS2. (A) Fluorescence microscopic analysis of a S. macrospora wild type strain carrying plasmid pGFP-CAS2. Expression of full-length cas2-egfp leads to EGFP import into mitochondria, visible as tubular structures. CAS2-EGFP co-localizes to mitochondria stained with Mito-Tracker (Invitrogen, Germany) (B) Co-transformation of pGFP-CAS2 and pDsRED-SKL results in clearly distinguishable signals from green fluorescent mitochondria and red peroxisomes. (C) Fluorescence microscopic analysis of a S. macrospora wild type strain carrying either pMito-DsRED (N-terminal mitochondrial signal sequence of cas2 fused to DsRed) or pDMito-CAS-DsRED (cas2 gene without the signal sequence fused to DsRed). DIC: differential interference contrast. Scale bar indicates 20 mm. doi:10.1371/journal.pone.0005177.g004 PLoS ONE | www.plosone.org 5 April 2009 | Volume 4 | Issue 4 | e5177