Fig. 1. Deletion of scpA and scpB leads to abnormal, decondensed nucleoid structure and formation of anucleate cells. Fluorescence microscopy of exponentially growing cells from strains (A) PY79 (wild type), (B) JM11 (scpA::tet), (C) PG32 (scpB::tet), (D) JM12 (scpA-B::tet), (E) PG37 (scpA::tet, spoIIIE::spec), (F) PG43 (scpB::tet, pspac-smc at amy locus, smc::kan) growing in the absence of IPTG (inducer) and (G) PG39 (scpB::tet, spo0J::spec). DNA was stained with DAPI, membranes with FM4-64 and outlines of cells by Nomarski digital interference contrast (DIC). Arrows indicate anucleate cells and white lines show chromosomes dissected (‘guilloutined’) by prematurely formed septa. (B), (D) and (E) are direct captures of DAPI fluorescence and Nomarski DIC. White rectangles indicate 2 µm.