Gonads directly regulate growth in teleosts.
In general, there is a relationship between growth and reproduction, and gonads are known to be important organs for growth, but direct evidence for their role is lacking. Here, using a fish model, we report direct evidence that gonads are endocrine organs equal to the pituitary in controlling body growth. Gonadal loss of function, gain of function, and rescue of growth were investigated in tilapia. Gonadectomy experiments were carried out in juvenile males and females. Gonadectomy significantly retarded growth compared with controls; however, this retardation was rescued by the implantation of extirpated gonads. Because gonads express growth hormone, it is possible that gonads control body growth through the secretion of growth hormone and/or other endocrine factors. We propose that gonads are integral players in the dynamic regulation of growth in teleosts.
Research Group for Fish Reproductive Physiology, South Ehime Fisheries Research Center,  Ehime University, Ehime 798-4292,  Japan.
Sandip
S
Bhatta
Toshiharu
T
Iwai
Chiemi
C
Miura
Masato
M
Higuchi
Sonoko
S
Shimizu-Yamaguchi
Haruhisa
H
Fukada
Takeshi
T
Miura
D000818:Animals; D049628:Body Size; D001835:Body Weight; D004703:Endocrine System; D005260:Female; D005399:Fishes / Q000502:physiology*; D006066:Gonads / Q000378:metabolism / Q000502:physiology*; D013006:Growth Hormone / Q000378:metabolism; D006728:Hormones / Q000378:metabolism; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D008954:Models, Biological; D012333:RNA, Messenger / Q000378:metabolism; D017210:Tilapia / Q000502:physiology; D014018:Tissue Distribution
D006728:Hormones; D012333:RNA, Messenger; D013006:Growth Hormone