Two differing salmon GnRH precursor mRNAs are co-expressed in the brain of sockeye salmon.
The localization of two salmon-type gonadotropin-releasing hormone (sGnRH) precursors, pro-sGnRH-I (short type) and pro-sGnRH-II (long type), was investigated by using in situ hybridization techniques in the brain of the landlocked sockeye salmon, Oncorhynchus nerka. We used 30-mer oligonucleotide probes complementary to pro-sGnRH-I and pro-sGnRH-II cDNA. No significant differences were observed in the localization of sGnRH neurons expressing pro-sGnRH-I and pro-sGnRH-II mRNAs; both were expressed in the olfactory nerve, the olfactory bulbs, the regions between the olfactory bulb and telencephalon, the ventral telencephalon, the preoptic area, and the hypothalamus. Almost all sGnRH neurons examined co-expressed both precursors. The expression of two sGnRH precursors in the same neuron and the wide distribution of such neurons in the brain suggest that there are no functional differences between the two precursors.
Amano
M
M
Nikko Branch, National Research Institute of Aquaculture, Nikko, Tochigi 321-16, Japan. amanoma@nnettown.or.jp
Ashihara
M
M
Yoshiura
Y
Y
Kitamura
S
S
Ikuta
K
K
Aida
K
K
D000818:Animals; D001483:Base Sequence; D001921:Brain / Q000378:metabolism*; D005260:Female; D015870:Gene Expression; D007987:Gonadotropin-Releasing Hormone / Q000031:analogs & derivatives* / Q000096:biosynthesis; D015151:Immunoblotting; D017403:In Situ Hybridization; D008969:Molecular Sequence Data; D009474:Neurons / Q000378:metabolism; D015345:Oligonucleotide Probes; D011498:Protein Precursors / Q000096:biosynthesis*; D012333:RNA, Messenger / Q000032:analysis; D012474:Salmon / Q000378:metabolism*
D015345:Oligonucleotide Probes; D011498:Protein Precursors; D012333:RNA, Messenger; C091931:salmon gonadotropin-releasing hormone precursor; D007987:Gonadotropin-Releasing Hormone