Meeting Abstract
P1.124 Tuesday, Jan. 4 Potential Egg Laying Role of Asymmetric White Cells of Armina californica KRUEGER, K; STAFSTROM, JA; MURRAY, JA*; U. Washington; U. Washington; Cal. State. U. East Bay, Friday Harbor Labs james.murray@csueastbay.edu
In Aplysia californica, a model egg laying neuroendocrine system has been documented, showing a distributed network comprised of several ganglia that control egg-laying behaviors through the use of proELH (egg laying prohormone). This system and its neuropeptides are highly conserved within all branches of gastropods. A conspicuous white cell cluster (WCC) located on the dorsal surface of the right pleural ganglion in the brain of the nudibranch Armina californica, for which there is no known function, shares similarities with cells associated with egg laying in Aplysia. The white coloration of neurons is indicative being peptidergic, and this cluster exhibits extreme asymmetry, being exclusively located on the right dorsolateral surface of the right pleural ganglia (similar to the right-dominant asymmetry present in the white cells of Aplysia, as well as in the asymmetrical alignment of the gonopore in Armina). White cell bodies from Armina were extracted and injected into intact Armina to test for a hormonal role. Non-white cells located in the right pleural ganglion were used as a control. Six Armina were injected with white cells, 6 were injected with non-white cells. After recording 2h of pre-treatment behavior, white cell/control injections were given. Following injection, 2h of behavior were recorded. Slugs were then placed into sea tables. The absence or presence of egg-laying was monitored for 4d following treatment. There were no differences in percentage of time spent moving or number of vertical climbs between experimental groups. No egg-laying behaviors were witnessed during the 4h of recorded behavior, yet egg-laying did occurr during the 4d following treatment. Four of the 6 individuals injected with a WCC laid eggs, whereas no individual injected with non-white cells laid eggs.
