Gonadotropins in the Russian Sturgeon: Their Role in Steroid Secretion and the Effect of Hormonal Treatment on Their Secretion.
In the reproduction process of male and female fish, pituitary derived gonadotropins (GTHs) play a key role. To be able to specifically investigate certain functions of Luteinizing (LH) and Follicle stimulating hormone (FSH) in Russian sturgeon (Acipenser gueldenstaedtii; st), we produced recombinant variants of the hormones using the yeast Pichia pastoris as a protein production system. We accomplished to create in vitro biologically active heterodimeric glycoproteins consisting of two associated α- and β-subunits in sufficient quantities. Three dimensional modelling of both GTHs was conducted in order to study the differences between the two GTHs. Antibodies were produced against the unique β-subunit of each of the GTHs, in order to be used for immunohistochemical analysis and to develop an ELISA for blood and pituitary hormone quantification. This detection technique revealed the specific localization of the LH and FSH cells in the sturgeon pituitary and pointed out that both cell types are present in substantially higher numbers in mature males and females, compared to immature fish. With the newly attained option to prevent cross-contamination when investigating on the effects of GTH administration, we compared the steroidogeneic response (estradiol and 11-Keto testosterone (11-KT) in female and males, respectively) of recombinant stLH, stFSH, and carp pituitary extract in male and female sturgeon gonads at different developmental stages. Finally, we injected commercially available gonadotropin releasing hormones analog (GnRH) to mature females, and found a moderate effect on the development of ovarian follicles. Application of only testosterone (T) resulted in a significant increase in circulating levels of 11-KT whereas the combination of GnRH + T did not affect steroid levels at all. The response pattern for estradiol demonstrated a similar situation. FSH levels showed significant increases when GnRH + T was administered, while no changes were present in LH levels.
Department of Animal Sciences, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, 76100, Israel.
Svetlana
S
Yom-Din
Department of Animal Sciences, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, 76100, Israel.
Lian
L
Hollander-Cohen
Department of Animal Sciences, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, 76100, Israel.
Joseph
J
Aizen
Department of Animal Sciences, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, 76100, Israel.
Benjamin
B
Boehm
Department of Animal Sciences, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, 76100, Israel.
Michal
M
Shpilman
Department of Animal Sciences, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, 76100, Israel.
Matan
M
Golan
MIGAL Galilee Technology Center, PO Box 831, Kiryat Shmona, 10200, Israel.
Avshalom
A
Hurvitz
MIGAL Galilee Technology Center, PO Box 831, Kiryat Shmona, 10200, Israel.
Gad
G
Degani
Department of Animal Sciences, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, 76100, Israel.
Berta
B
Levavi-Sivan
D000818:Animals; D004797:Enzyme-Linked Immunosorbent Assay; D004958:Estradiol / Q000378:metabolism; D005260:Female; D005399:Fishes / Q000502:physiology*; D005640:Follicle Stimulating Hormone / Q000737:chemistry / Q000494:pharmacology; D007987:Gonadotropin-Releasing Hormone / Q000031:analogs & derivatives / Q000494:pharmacology; D006065:Gonadotropins, Pituitary / Q000737:chemistry / Q000502:physiology*; D007986:Luteinizing Hormone / Q000737:chemistry / Q000494:pharmacology; D008297:Male; D008958:Models, Molecular; D006080:Ovarian Follicle / Q000187:drug effects / Q000502:physiology; D010902:Pituitary Gland / Q000187:drug effects / Q000502:physiology; D021122:Protein Subunits; D011994:Recombinant Proteins / Q000737:chemistry / Q000494:pharmacology; D013256:Steroids / Q000502:physiology*; D013737:Testis / Q000187:drug effects / Q000502:physiology; D013739:Testosterone / Q000031:analogs & derivatives / Q000378:metabolism / Q000494:pharmacology
D006065:Gonadotropins, Pituitary; D021122:Protein Subunits; D011994:Recombinant Proteins; D013256:Steroids; D007987:Gonadotropin-Releasing Hormone; D013739:Testosterone; D004958:Estradiol; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; C003600:11-ketotestosterone