L. Alexander et al., Localization of somatostatin mRNAs in the brain and pancreas of rainbow trout (Oncorhynchus mykiss), COMP BIOC B, 129(2-3), 2001, pp. 221-228
Citations number
21
Categorie Soggetti
Biochemistry & Biophysics
Journal title
COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY B-BIOCHEMISTRY & MOLECULAR BIOLOGY
Rainbow trout possess three distinct mRNAs, each encoding a separate precur
sor: PPSS I, which contains a 14-amino acid sequence at its C-terminus (som
atostatin-lit) that is highly conserved among vertebrates, as well as two o
thers, PPSS II ' and PPSS II ", both containing [Tyr(7), Gly (10)]-somatost
atin-14 at their C-terminus. In this study, we used RNA template-specific P
CR and in situ hybridization to determine the distribution and cellular loc
alization of PPSS mRNAs in the brain and Brockmann body of rainbow trout. P
PSS I, PPSS II ' and PPSS II " were expressed in the Brockmann body and pit
uitary; the expression of PPSS mRNAs in the brain was region specific. PPSS
I mRNA was expressed in the Brockmann body predominantly by cells other th
an those that expressed PPSS IIs; however, there were several instances whe
re PPSS I and PPSS IIs were co-expressed within the same cell. Of the PPSS
II-expressing cells, many were observed to express both PPSS II ' and PPSS
II " mRNA; however, some cells expressed only PPSS II ' mRNA, while other c
ells expressed only PPSS II " mRNA. In the brain, PPSS I mRNA was expressed
in the optic tectum (OT) and in many hypothalamic nuclei, including the nu
cleus rotundus (NR), nucleus anterioris hypothalami (NAH), nucleus anterior
tuberis (NAT), nucleus lateral tuberis (NLT), as well as in the pituitary
(adenohypophysis). PPSS II " mRNA was present in the same regions as PPSS I
mRNA; however, PPSS II ' mRNA was present primarily in OT, NAT, NLT and ad
enohypohysis. These results indicate that PPSS mRNAs are expressed differen
tly by different cells, suggesting that cell-specific mechanisms are involv
ed with the control of PPSS expression and that particular biological respo
nses may be associated with a specific SS isoform. (C) 2001 Elsevier Scienc
e Inc. All rights reserved.