In insect spermiogenesis, mitochondrial cristae disappear and a proteinaceous material is deposited in filaments that become closely packed paracrystalline arrays. In this micrograph, crystals are pr...

The image shows a developing Drosophila spermatid immunostained for caspase activity (green). TRITC-phalloidin is used to label actin (red). Caspase is required in spermiogenesis for the elimination ...

Figure 236 from Chapter 7 (Mitochondria) of 'The Cell, 2nd Ed.' by Don W. Fawcett M.D. Fusion of mitochondria during insect spermiogenesis results in the formation of a structure called the nebenkern...

Time lapse movie of meiosis II in spermatocytes of the Locust Psophus stridulus showing two sequences that include metaphase and anaphase. This is a historic movie made in the early 40s by Kurt Mich...

Time lapse movie of the prophase stage during meiosis I in spermatocytes of the Locust Psophus stridulus. This is a historic movie made in the early 40s by Kurt Michel of the Zeiss company in Jena u...

Cross section through a seminiferous tubule showing the developing sperm with their tails pointing into the lumen of the tubule. The nuclei are stained blue with DAPI and mitochondria red with mitotra...

Time lapse movie of meiosis in spermatocytes of the Locust Psophus stridulus showing telophase of meiosis I, cytokinesis, interphase, and prophase of meiosis II. This is a historic movie made in the...

Time lapse movie of meiosis II in spermatocytes of the Locust Psophus stridulus showing telophase and the early spermatid stage. This is a historic movie made in the early 40s by Kurt Michel of the ...

During the differentiation of sperm most cellular proteins and organelles are degraded as they are no longer needed. Actin filaments in the cell help to collect and move cytoplasmic material in maturi...

Time lapse movie of meiotic metaphase and anaphase in spermatocytes of the Locust Psophus stridulus. Two sequences are shown, each continuing through telophase to the start of cytokinesis. In addition...