title: Gonadotrope-specific expression and regulation of ovine follicle stimulating hormone Beta: transgenic and adenoviral approaches using primary murine gonadotropes.
abstract: The beta subunit of follicle stimulating hormone (FSHB) is expressed specifically in pituitary gonadotropes in vertebrates. Transgenic mouse studies have shown that enhancers in the proximal promoter between -172/-1 bp of the ovine FSHB gene are required for gonadotrope expression of ovine FSHB. These enhancers are associated with regulation by activins and gonadotropin releasing hormone (GnRH). Additional distal promoter sequence between -4741/-750 bp is also required for expression. New transgenic studies presented here focus on this distal region and narrow it to 1116 bp between -1866/-750 bp. In addition, adenoviral constructs were produced to identify these critical distal sequences using purified primary mouse gonadotropes as an in vitro model system. The adenoviral constructs contained -2871 bp, -750 bp or -232 bp of the ovine FSHB promoter. They all showed gonadotrope-specific regulation since they were induced only in purified primary gonadotropes by activin A (50 ng/ml) and inhibited by GnRH (100 nM) in the presence of activin (except -232FSHBLuc). However, basal expression of all three viral constructs (in the presence of follistatin to block cellular induction by activin) was relatively high in pituitary non-gonadotropes as well as gonadotropes. Thus, gonadotrope-specific regulation associated with the proximal promoter was observed as expected, but the model was blind to distal promoter elements between -2871/-750 necessary for gonadotrope-specific expression of ovine FSHB in vivo. The new adenoviral-based in vitro technique did detect, however, a novel GnRH response element between -750 bp and -232 bp of the ovine FSHB promoter. We conclude that adenoviral-based studies in primary gonadotropes can adequately recognize regulatory elements on the ovine FSHB promoter associated with gonadotrope-specific regulation/expression, but that more physiologically based techniques, such as transgenic studies, will be needed to identify sequences between -1866/-750 bp of the ovine FSHB promoter that are also required for tissue/cell specific expression in vivo.
authors.affiliation: Mount Sinai School of Medicine, Department of Neurology, New York City, New York, USA.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Jia
authors.forename: Farideh
authors.initials: F
authors.lastname: Shafiee-Kermani
authors.forename: William L
authors.initials: WL
authors.lastname: Miller
mesh_terms: D000256:Adenoviridae; D000704:Analysis of Variance; D000818:Animals; D017931:DNA Primers / Q000235:genetics; D004742:Enhancer Elements, Genetic / Q000235:genetics; D037201:Follicle Stimulating Hormone, beta Subunit / Q000235:genetics* / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000502:physiology*; D052681:Gonadotrophs / Q000378:metabolism*; D008156:Luciferases; D051379:Mice; D008822:Mice, Transgenic; D011401:Promoter Regions, Genetic / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D012756:Sheep / Q000235:genetics* / Q000502:physiology
chemical_list: D017931:DNA Primers; D037201:Follicle Stimulating Hormone, beta Subunit; D008156:Luciferases