Figure 6. MTM-1 is expressed in engulfing cells and localizes to the plasma membrane. DIC and fluorescent confocal images of wild-type animals carrying an integrated array of Pmtm-1MTM-1::GFP are shown. MTM-1 is expressed in several known engulfing cell types including pharyngeal muscle cells (i, ii), hypodermal cells (iii, iv), body wall muscle cells (v, vi) and sheath cells (vii, viii) as indicated by arrows and is mainly localized to cell membranes. MTM-1::GFP also clusters around apoptotic cells (ix, x). Bars: 10 um. (B) DIC (i), GFP (ii), mCHERRY (iii) images and the merged image of GFP and mCHERRY (iv) of a wild-type embryo co-expressing MTM-1::GFP driven by
mtm-1 promoter (Pmtm-1mtm-1::gfp) and myri::mCHERRY controlled by heat-shock promoters (Phspmyri::mcherry) are shown. MTM-1::GFP co-localized with myri::mCHERRY to plasma membranes. Bars: 5 um. (C) The PH-GRAM and PTP domains of MTM-1 are required for membrane localization of MTM-1. DIC and fluorescent confocal images of full-length (i, ii) and truncated GFP::MTM-1 (iiiviii) controlled by the
ced-1 promoter in wild-type embryos are shown. Membrane localization was clearly seen with full-length MTM-1 (i, ii) and MTM-1(DeltaCC) (vii, viii), but not in embryos expressing GFP::MTM-1 lacking either the PTP domain (iii, iv) or the PH-GRAM domain (v, vi). Bars: 5 um.