TY - JOUR
T1 - Quantitative in situ hybridization of three gonadotropin-releasing hormone-encoding mRNAs in castrated and progesterone-treated male tilapia
AU - Parhar, Ishwar S.
AU - Soga, Tomoko
AU - Sakuma, Yasuo
N1 - Funding Information:
We thank Professor I. Wakabayashi (Nippon Medical School, Japan) for use of the image analyzing system. We also thank Professors K. Yamauchi and S. Adachi (Hokkaido University, Hako-date, Japan) for their help in progesterone hormone assay. This work was supported by the Japanese Ministry of Education, Science and Culture, Mombusho Grant 09680801 (I.S.P.).
Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 1998/12
Y1 - 1998/12
N2 - We investigated the effects of castration and progesterone administration on the three gonadotropin-releasing hormone (GnRH)-encoding mRNAs in sexually mature male tilapia Oreochromis niloticus. In situ hybridization histochemistry was performed using 35S-labeled antisense oligonucleotide probes complementary to salmon-, seabream-, and chicken II- GnRH cDNAs to quantify cellular GnRH mRNA expression in the terminal nerve ganglia (nucleus olfactoretinalis), preoptic area, and midbrain tegmentum of animals castrated for 2 weeks and injected intraperitoneally with sesame oil or progesterone. Castration significantly elevated salmon-GnRH mRNA but not seabream- or chicken II-GnRH mRNA levels. Progesterone treatment had no effect on salmon-, seabream-, or chicken II-GnRH mRNA levels. Comparisons between intact, castrated, and progesterone-treated animals showed no change in the total volume of nucleus olfactoretinalis, cell sizes, and total numbers of cells expressing GnRH mRNA within the midbrain and preoptic area. These results demonstrate that salmon-GnRH but not seabream- or chicken II- GnRH-synthesizing neurons are under a gonadal steroid negative feedback control and that progesterone might not be the main hormone regulating the three GnRH-encoding mRNAs in the male tilapia.
AB - We investigated the effects of castration and progesterone administration on the three gonadotropin-releasing hormone (GnRH)-encoding mRNAs in sexually mature male tilapia Oreochromis niloticus. In situ hybridization histochemistry was performed using 35S-labeled antisense oligonucleotide probes complementary to salmon-, seabream-, and chicken II- GnRH cDNAs to quantify cellular GnRH mRNA expression in the terminal nerve ganglia (nucleus olfactoretinalis), preoptic area, and midbrain tegmentum of animals castrated for 2 weeks and injected intraperitoneally with sesame oil or progesterone. Castration significantly elevated salmon-GnRH mRNA but not seabream- or chicken II-GnRH mRNA levels. Progesterone treatment had no effect on salmon-, seabream-, or chicken II-GnRH mRNA levels. Comparisons between intact, castrated, and progesterone-treated animals showed no change in the total volume of nucleus olfactoretinalis, cell sizes, and total numbers of cells expressing GnRH mRNA within the midbrain and preoptic area. These results demonstrate that salmon-GnRH but not seabream- or chicken II- GnRH-synthesizing neurons are under a gonadal steroid negative feedback control and that progesterone might not be the main hormone regulating the three GnRH-encoding mRNAs in the male tilapia.
KW - Chicken II-GnRH
KW - In situ hybridization
KW - LHRH
KW - Midbrain tegmentum
KW - Nucleus olfactoretinalis
KW - Preoptic area
KW - Salmon-GnRH
KW - Seabream- GnRH
UR - http://www.scopus.com/inward/record.url?scp=0032409998&partnerID=8YFLogxK
U2 - 10.1006/gcen.1998.7143
DO - 10.1006/gcen.1998.7143
M3 - Article
C2 - 9843646
AN - SCOPUS:0032409998
SN - 0016-6480
VL - 112
SP - 406
EP - 414
JO - General and Comparative Endocrinology
JF - General and Comparative Endocrinology
IS - 3
ER -