Morpho-physiological analysis of the insect fat body: a review.

The insect fat body is the main organ of the intermediate metabolism of insects. The majority of proteins of the haemolymph is synthesized in this tissue, which also presents the functions of lipids, carbohydrates and proteins storage. This tissue is also responsible for the synthesis of vitellogenins, proteins with an important role in the reproduction of the insects, being incorporated into the oocytes during vitellogenesis. The fat body consists of thin layers or strings, generally one or two cells thick, or small nodules suspended in the hemocele through connective tissues and trachea. Within a species, the structure of this tissue is more or less constant, but can have considerable differences between insects of different orders. In this way, this article makes a review about the main morpho-physiological features of the fat body cells of the insects, as well as a phylogenetic study of the fat body between basal and derived species of the Attini tribe ants.