During the course of this study, the role of Drosophila homologues of Golgi matrix proteins in the organisation of the early exocytic pathway (tER and Golgi) was investigated. dp115, dGM130 and dGRASP were depleted from Drosophila S₂ cells by RNA interference. Using electron and immunofluorescence microscopy, dp115 depletion was shown to result in Golgi stack breakdown and tER dispersion. The effect on tER organisation was specific for dp115, as depletion of the other Golgi matrix proteins did not have a similar effect. Although, dGRASP or dGM130 single depletion did not lead to a quantitative disruption of the Golgi morphology, dGM130/dp115 and dGM130/dGRASP double depletions pointed to genetic interactions for building and/or maintenance of the Golgi stacks. Considering the key role of the Golgi apparatus in protein transport along the exocytic pathway, anterograde transport of plasma membrane protein Delta, from its site of synthesis (ER) to its final destination, was monitored in cell depleted of the above mentioned Golgi matrix proteins. Surprisingly, none of the depletions, including dp115 that alters considerably the organisation of the exocytic pathway, led to a significant inhibition of intracellular transport. Anterograde intracellular transport in the absence of Golgi stacks exists physiologically during Drosophila development. In a morphological study performed in imaginal discs during the transition from early 3^rd instar larva to white pupa, the biogenesis of the Golgi stacks from vesicular-tubular larval clusters was described. These larval clusters were shown to contain several Golgi-specific markers and, therefore seem capable of carrying out proper Golgi functions.