Editing Golgi apparatus (section)

===Model 3: Cisternal progression/maturation with heterotypic tubular transport===
* This model is an extension of the cisternal progression/maturation model. It incorporates the existence of tubular connections among the cisternae that form the Golgi ribbon, in which cisternae within a stack are linked. This model posits that the tubules are important for bidirectional traffic in the ER-Golgi system: they allow for fast anterograde traffic of small cargo and/or the retrograde traffic of native Golgi proteins.<ref name="Glick-2011"/><ref name="Wei-2010">{{cite journal |vauthors=Wei JH, Seemann J |title=Unraveling the Golgi ribbon |journal=Traffic |volume=11 |issue=11 |pages=1391–400 |date=November 2010 |pmid=21040294 |pmc=4221251 |doi=10.1111/j.1600-0854.2010.01114.x |url=}}</ref>
** '''Strengths:''' This model encompasses the strengths of the cisternal progression/maturation model that also explains rapid trafficking of cargo, and how native Golgi proteins can recycle independently of COPI vesicles.<ref name="Glick-2011"/>
** '''Weaknesses:''' This model cannot explain the transport kinetics of large protein cargo, such as [[collagen]]. Additionally, tubular connections are not prevalent in plant cells. The roles that these connections have can be attributed to a cell-specific specialization rather than a universal trait. If the membranes are continuous, that suggests the existence of mechanisms that preserve the unique biochemical gradients observed throughout the Golgi apparatus.<ref name="Glick-2011"/>