TY - JOUR
T1 - The effect of injection and topical application of hCG and GnRH agonist to induce sperm-release in the roseate frog, Geocrinia rosea
AU - Silla, Aimee J.
AU - Roberts, J. Dale
AU - Byrne, Phillip G.
PY - 2020/12/4
Y1 - 2020/12/4
N2 - Reproductive technologies may assist amphibian conservation breeding programs (CBPs) to achieve propagation targets and genetic management goals. However, a trial-and-error approach to protocol refinement has led to few amphibian CBPs routinely employing reproductive technologies with predictable outcomes. Additionally, while injections can be safely administered to amphibians, perceived animal welfare risks, such as injury and disease transmission, warrant the development of alternative hormone administration protocols. The present study investigated the spermiation response of roseate frogs, Geocrinia rosea, administered various doses of human chorionic gonadotropin (hCG) and gonadotropin-releasing hormone agonist (GnRH-a) via subcutaneous injection. This study also quantified the spermiation response of frogs administered both hormones via topical application. Total sperm, sperm concentration and sperm viability were assessed over a 12-h period post hormone administration. Males released sperm in response to the injection of hCG (88-100% response; 5, 10 or 20 IU), but all samples collected from males administered hCG topically (100, 100 + DMSO or 200 IU hCG) were aspermic. In contrast, males consistently released sperm in response to both the injection (100% response; 1, 5 or 10 mu g), or topical application (80-100% response; 50, 50 + DMSO or 100 mu g) of GnRH-a. Overall, the administration of GnRH-a was more effective at inducing spermiation than hCG. Mean total sperm and sperm concentration were highest in response to the optimal topically applied dose of 100 mu g GnRH-a (mean total sperm= 2.44x10(3), sperm concentration= 1.48x10(5) sperm/ml). We provide novel evidence that topical application provides a viable alternative to injection for the administration of GnRH-a to induce spermiation in amphibians.
AB - Reproductive technologies may assist amphibian conservation breeding programs (CBPs) to achieve propagation targets and genetic management goals. However, a trial-and-error approach to protocol refinement has led to few amphibian CBPs routinely employing reproductive technologies with predictable outcomes. Additionally, while injections can be safely administered to amphibians, perceived animal welfare risks, such as injury and disease transmission, warrant the development of alternative hormone administration protocols. The present study investigated the spermiation response of roseate frogs, Geocrinia rosea, administered various doses of human chorionic gonadotropin (hCG) and gonadotropin-releasing hormone agonist (GnRH-a) via subcutaneous injection. This study also quantified the spermiation response of frogs administered both hormones via topical application. Total sperm, sperm concentration and sperm viability were assessed over a 12-h period post hormone administration. Males released sperm in response to the injection of hCG (88-100% response; 5, 10 or 20 IU), but all samples collected from males administered hCG topically (100, 100 + DMSO or 200 IU hCG) were aspermic. In contrast, males consistently released sperm in response to both the injection (100% response; 1, 5 or 10 mu g), or topical application (80-100% response; 50, 50 + DMSO or 100 mu g) of GnRH-a. Overall, the administration of GnRH-a was more effective at inducing spermiation than hCG. Mean total sperm and sperm concentration were highest in response to the optimal topically applied dose of 100 mu g GnRH-a (mean total sperm= 2.44x10(3), sperm concentration= 1.48x10(5) sperm/ml). We provide novel evidence that topical application provides a viable alternative to injection for the administration of GnRH-a to induce spermiation in amphibians.
KW - amphibian
KW - animal welfare
KW - assisted reproductive technologies
KW - captive breeding
KW - hormone
KW - percutaneous absorption
KW - sperm
KW - spermiation
KW - ARTIFICIAL FERTILIZATION
KW - SPERMIATION
KW - HORMONE
U2 - 10.1093/conphys/coaa104
DO - 10.1093/conphys/coaa104
M3 - Article
C2 - 33304589
SN - 2051-1434
VL - 8
JO - Conservation Physiology
JF - Conservation Physiology
IS - 1
M1 - coaa104
ER -