TY - JOUR
T1 - 5α-Dihydrotestosterone is a potent androgen in the fathead minnow (Pimephales promelas)
AU - Margiotta-Casaluci, Luigi
AU - Sumpter, John P.
N1 - Funding Information:
We thank GlaxoSmithKline (GSK) for funding the Ph.D. of L.M-C.
PY - 2011/5/1
Y1 - 2011/5/1
N2 - Dihydrotestosterone (DHT) is one of the most physiologically important androgens in many male vertebrates, with the exception of teleost fish, in which 11-ketotestosterone (KT) is generally considered the major circulating male androgen. In the present study, we investigated the effects of KT and DHT on fathead minnow juveniles (Pimephales promelas), with the aim to compare the effects of the two androgens on critical physiological processes, such as somatic growth, male secondary sexual characteristics expression, and gonad maturation. Juvenile fish (60. days post-hatch) were exposed to 20 and 200. ng/L of KT and DHT for 45. days. Exposure to both androgens significantly stimulated somatic growth in both males (20 and 200. ng/L) and females (200. ng/L). Nuptial tubercle formation was induced by both KT and DHT, but only the latter, at 200. ng/L, caused the appearance of dorsal fin spot in 92% of males and 75% of females. Circulating plasma T concentrations showed a sex-specific response; a significant increase was recorded in exposed males and a decrease in females. Both androgens induced a significant advancement of the spermatogenic processes in males at 200. ng/L. In contrast, only DHT caused a severe disruption of ovarian physiology and morphology in females, inducing the development of spermatogenic tissue (intersex). These results show that in fathead minnow juveniles, DHT had in vivo androgenic potency comparable to KT in males, and higher than KT in females, suggesting a potential involvement of DHT in the mediation of fathead minnow androgenic responses.
AB - Dihydrotestosterone (DHT) is one of the most physiologically important androgens in many male vertebrates, with the exception of teleost fish, in which 11-ketotestosterone (KT) is generally considered the major circulating male androgen. In the present study, we investigated the effects of KT and DHT on fathead minnow juveniles (Pimephales promelas), with the aim to compare the effects of the two androgens on critical physiological processes, such as somatic growth, male secondary sexual characteristics expression, and gonad maturation. Juvenile fish (60. days post-hatch) were exposed to 20 and 200. ng/L of KT and DHT for 45. days. Exposure to both androgens significantly stimulated somatic growth in both males (20 and 200. ng/L) and females (200. ng/L). Nuptial tubercle formation was induced by both KT and DHT, but only the latter, at 200. ng/L, caused the appearance of dorsal fin spot in 92% of males and 75% of females. Circulating plasma T concentrations showed a sex-specific response; a significant increase was recorded in exposed males and a decrease in females. Both androgens induced a significant advancement of the spermatogenic processes in males at 200. ng/L. In contrast, only DHT caused a severe disruption of ovarian physiology and morphology in females, inducing the development of spermatogenic tissue (intersex). These results show that in fathead minnow juveniles, DHT had in vivo androgenic potency comparable to KT in males, and higher than KT in females, suggesting a potential involvement of DHT in the mediation of fathead minnow androgenic responses.
KW - 11-Ketotestosterone
KW - Androgens
KW - Dihydrotestosterone
KW - Fathead minnow
KW - Gonad maturation
KW - Intersex
UR - http://www.scopus.com/inward/record.url?scp=79953740245&partnerID=8YFLogxK
U2 - 10.1016/j.ygcen.2011.02.012
DO - 10.1016/j.ygcen.2011.02.012
M3 - Article
AN - SCOPUS:79953740245
SN - 0016-6480
VL - 171
SP - 309
EP - 318
JO - General and Comparative Endocrinology
JF - General and Comparative Endocrinology
IS - 3
ER -