secondary spermatocyte

A haploid immature germ cell which forms in the gonad by the division of a diploid primary spermatocyte. It undergoes a second meiotic division to complete meiosis, at which time the daughter cells detach from the residual body to become spermatids.

dorsal ganglion

ganglion that lies beside the nerve ring in the head. It contains neuron cell bodies that send their neuronal processes into the ring and longitudinal nerves, but form no local neuropil separate from the nerve ring. The dorsal ganglion is in close contact with the dorsal hypodermal cord.

dorso-rectal ganglion

the ganglion that lies above and behind the rectum in the tail, in close continuity with the anal hypodermal ridge. It contains 3 neuron cell bodies (DVA, DVB and DVC) that send their neuronal processes into the ventral nerve cord via dorso-rectal commissures that encircle the anus. The ganglion contains no local neuropil in the hermaphrodite. In the adult male tail, this ganglion gains additional neurons and some local neuropil.

ventral ganglion

ganglion lies beside the nerve ring in the head, just anterior of the retrovesicular ganglion. It contains about 20 interneuron and motorneuron cell bodies that all send their neuronal processes into the ring. The cell bodies are divided into two groups by the intrusion of the excretory duct and canal. The cells are bounded by a basal lamina which physically separates them from the lateral ganglion even though they are adjacent to one another.

retrovesicular ganglion

Ganglion that lies at the anterior limit of the ventral nerve cord, near the ventral ganglion and nerve ring in the head posterior to the excretory pore. It is open and continuous with the region containing the motoneurons of the ventral cord. In the early L1 this ganglion holds 12 neuron cell bodies plus one neuroblast (Sulston and Horvitz, 1977; White et al., 1986). In the adult animal, the ganglion holds 20 neuron cell bodies.