The pattern of growth of the golgi complex during the fetal and postnatal development of the rat epididymis

Abstract

The growth of the Golgi complex was studied during the fetal and postnatal development of the rat epididymis. Prenatal and newborn animals had small Golgi complexes composed of a linear arrangement of 1–3 stacks of 4–6 highly flattened cisternae and several types of smooth vesicles. The most rapid growth of the Golgi apparatus occurred during the first 3 weeks after birth. Increases were observed in the number of stacks of cisternae, the number of cisternae per stack, and the size of individual cisternae, but the relative importance of these different modes of growth varied with the developmental stage. Initial changes observed in animals 10 days old were increased distention and fenestration of cisternae, accompanied by increase in the number of stacks of cisternae and their arrangement in a circular pattern. Growth between 10 and 21 days occurred mainly by increases in the lateral extent of the cisternae and in the number of cisternae per stack. Golgi vacuoles also appeared at this stage. After the first 3 weeks, growth was less rapid, but continued until the animals were 6 weeks old. Examples of close apposition between the endoplasmic reticulum and the Golgi apparatus were observed at all stages. Possible mechanisms of growth of the Golgi complex and the source of the new membrane are discussed.