  Axes of polarity (and primary morphogenetic gradients) are established in the
oocyte - early embryo through active transport and localization of maternal
factors. It is the oocyte - syncytial embryo of Drosophila (D. melanogaster)
that is a model object for studying the molecular machinery of such transport
systems. The attention of researchers is focused on the processes of formation,
maintenance, and functioning of active transport systems of maternal mRNAs and
proteins that are key for early Drosophila embryogenesis. Here we develop an
approach for agent-based 3D modeling of the key components of transport by
molecular motors (by elements of the cytoskeleton) of the Drosophila
oocyte-syncytial embryo. The models were developed using Skeledyne software
developed by Odell and Foe [Odell and Foe, 2008]. We start with the results of
modeling transport along oriented microtubule (MT) bundles in the oocyte. This
is a model of transport systems in the Drosophila oocyte, where three maternal
mRNAs (bicoid (bcd), oskar, and gurken) that are key to embryonic polarity are
transported along their oriented MT bundles. Then we consider models of
oriented MT networks in the volume of a cell (oocyte) generated by a single
microtubule organization center (or a pair of the centers). This model
reproduces the formation of bcd mRNA intrusions deep into the cytoplasm in the
head half of the early syncytial embryo. Finally, we consider models for the
active transport of bcd mRNA in a syncytial embryo along a randomized network
of many short MT strands. In conclusion, we consider the prospects for the
implementation of cytoplasmic fountain flows in the active transport model.
