Divergent organelle allocation in the evolution of sperm gigantism revealed from subcellular quantification of nematode sperm with electron microscopy

The purpose of the study this data is associated with is to explore differences between sperm cell composition in Caenorhabditis nematode species with giant vs. standard sized sperm. To accomplish this, mated females with sperm in their uteri of the species C. nouraguensis (standard-sized sperm) and C. macrosperma (giant sperm) were chemically fixed, embedded, thin-sectioned, stained, and TEM imaged. This allows us to view cross-sections of sperm cells inside the uterus and, using ImageJ software, measure the area of the total sperm cell, pseudopod, and organelles such as mitochondria, membranous organelles (MOs), and in some cases nuclei. Additionally, we can compare relative area of a sperm cell allocated to an organelle type as a proxy for certain investment into that organelle and its function in the sperm cell.