Meeting Abstract
14.2 Tuesday, Jan. 4 Interaction between hCG and arginine vasotocin in the induction of sexual behavior in an anuran amphibian MIRANDA, R.A.*; KRUEGER, A.J.; NATKIN, L.D.; OWOLABI, A.A.; PROPPER, C.R.; Northern Arizona Univ.; Northern Arizona Univ.; Northern Arizona Univ.; Northern Arizona Univ.; Northern Arizona Univ. ram257@nau.edu
The neurohormones arginine vasotocin (AVT) and arginine vasopressin (AVP) mediate a variety of social and sexual behaviors such as vocalizations in vertebrates. To develop Xenopus tropicalis as a neuroendocrine model for endocrine disruption of behavior, we investigated the dose response effect of human chorionic gonadotropin (hCG) on male sexual behavior. Next, we evaluated the effect of AVT on hCG-induced male sexual behavior. In both experiments hormonal treatments were injected into the dorsal lymph sac in 50 ul amphibian Ringers, and males were placed in individual tanks with six liters of salt-conditioned RO water and an untreated adult female. Vocalizations were recorded using a hydrophone and male clasping behavior was documented using focal observations (20 min/hr) over the course of five hours. In the hCG dose response study male frogs received 0, 5, 10 or 20 IU hCG (n=6). Results show hCG induces male calling and clasping behavior. In the second experiment males (n=12) received one of three treatments: hCG only, hCG with 20 ug AVT or hCG with 40 ug Manning compound, an AVP receptor antagonist. There is a significant difference among treatments in clasp attempts (Kruskal-Wallis test, p= 0.029) and time calling (Kruskal-Wallis test, p=0.025). Furthermore, males receiving hCG/AVT clasp (Mann-Whitney U test, p<0.01) and call (Mann-Whitney U test, p=0.012) significantly more than males receiving hCG only. Males receiving hCG/Manning compound did not differ in behavior compared to hCG-only treated animals, but show significantly less behavior than those treated with hCG/AVT (G-test, p=0.031). Our results demonstrate that male sexual behavior in X. tropicalis is influenced by the interaction between gonadotropins and neurohormones.
