Cystocyte and lymphocyte derived fusomes/spectrosomes: analogies and differences: a mini-review

Structures analogous to Drosophila spectrosomes were found in mammalian lymphocytes. Repasky and colleagues discovered an intracellular spectrin-rich structure in lymphoid cells, which had far-reaching parallels with the fusome/spectrosome of D. melanogaster germ cells. This fact implies that spectrosomes may be characteristic not only of insect germ cells, but also that an analogous structure may play an important role in other cell types. The term "spectrosome" was first used by Lin and Spradling in 1995 to describe a large sphere of fusomal material in D. melanogaster germline stem cells and their differentiated daughter cells - cytoblasts. In the D. melanogaster ovary, membrane skeletal proteins such as ankyrin, alpha/beta spectrin as well as adducin-like Hts protein(s) were found in this specific organelle - spectrosome/fusome. These orgalelles are involved in the creation of mitotic spindles and D. melanogaster cyst formation and oocyte differentiation, but the role of analogous spectrin-based aggregates found in nucleated cells still remains unclear.