Fig. 8. Loss of SG1 and SG2 affects the quality and quantity of lumenal secretory content. (A-C) TEM analysis of wild-type (Oregon R) and Df(3R)Exel6216 salivary glands revealed differences in both the volume and morphology of apical secretions. (A-A''') Thin sections of wild-type salivary gland cells revealed uniform apical cell surfaces surrounding a relatively large lumenal space filled with fibrillar matrix material (asterisks). (B-B''') Thin sections of Df(3R)Exel6216 salivary glands revealed irregular and small lumenal spaces containing matrix of increased density (asterisks) and large regions where the apical cell surfaces appear to meet. (C,C') New adherens junctions (AJs) appear to have formed at the contact site of cells arising from opposite sides of the lumen of Df(3R)Exel6216 salivary glands (arrowheads indicate AJs). Secretory vesicle number and morphology were similar in wild-type and Df(3R)Exel6216 salivary glands, as were other aspects of salivary gland cell morphology. A-A''', B-B''' and C-C' are images from the same gland showing increased magnification from left to right; in some cases the angle of the image is changed slightly from panel to panel. Boxed regions in A'', B'' and C correspond to magnified images shown in A''', B''' and C', respectively. Df(3R)Exel6216 was balanced over TM3, twi-GFP, allowing us to select homozygous deficiency embryos prior to fixation.