Acronym NA
Category
Aquaculture
Title Function of Anti-Müllerian hormone in fish testis development and maturation to puberty Programme National Programme
Instrument (FP6)
Contact Type (FP7)
Strand (Interreg)
NA
Theme (FP7)
Activity Area (FP6)
Regional Area (Interreg)
Action (COST)
NA
Specific Programme (FP7)
NA
Funding source National Coordinator Rune Male Coordinator email rune.male@mbi.uib.no
Coordinator institution
UiB - University of Bergen (Norway)
Institutions involved
NA
Start year 2004 End year 2010 Funding (€) € 1,117,706 Website https://prosjektbanken.forskningsradet.no/project/FORISS/159045?Kilde=FORISS&distribution=Ar&chart=bar&calcType=funding&Sprak=no&sortBy=date&sortOrder=desc&resultCount=30&offset=6840&TemaEmne.1=LTP2+Fagmilj%C3%B8er+og+talenter&source=FORISS&projectId=315066 Summary This project aims to determine the function of Anti-Müllerian hormone (AMH) in fish as a factor in testis determination, development, and maturation at puberty. AMH, also named Müllerian inhibiting substance or spermatogenesis preventing substance, belongs to the transforming growth factor-beta family. In mammals, AMH is secreted from testicular Sertoli cells. In the foetus it directs Müllerian duct regression and controls spermatogenesis by suppression of Leydig cells until puberty and may be associated with precocious puberty . AMH is present in fish, where it has been shown to block spermatogenesis at a very early stage by preventing the differentiation of rapidly proliferating spermatogonia. We hypothesise that AMH suppresses the expression and/or activity of the receptor responsible for mediating the effects of 11-ketotestosterone. Development of tools included genes and cDNAs cloned and characterized from salmon, Atlantic cod an zebrafish. These include several markers for germ and somatic tissues of gonads. A transgenic line of zebrafish was produced with a inducible copy of amh. Several antibodies have been produced, as well as cell line expressing recombinant Amh. Testis tissue organ cultures were developed. Amh was characterized from salmon, Atlantic cod and zebrafish, included pattern of expression, cell types of origin, identification of receptor, and regulation during sex differentiation. Studies of zebrafish Amh as recombinant protein showed site specific proteolyttic processing but not dimerization or glycosylation of the bio-active protein. Overexpression of Amh during sex differentiation of zebrafish increased the tendency of becoming a male. Heat treatment gives similar result, probably by driving early oocytes in to apoptosis. The effect of Amh overexpression is additive to heat effect. Amh treatment of testis from adult animals revealed that Amh seem to block early proliferation of germ cells and arrest germ in early differentiation, suppress Leydig cell steroidogenesis. The effect could not be overcome by 11-kT supplementation.
Goals:
(1) Determine the function of AMH in the regulation of spermatogenesis, and hence in the establishment of male puberty in fish; (2) To start exploring in a descriptive way the possibility that AMH is involved in sex differentiation in fish: (i) Clone and characterize AMH, its key regulators and downstream genes in salmon, cod and zebrafish; (ii) To determine quantitatively and qualitatively the expression profile of AMH, its regulation in testis, and a physiological regulation through the brain-pituitary-testis axis during sex differentiation and puberty; (iii) To determine the effect of AMH in fish testis during maturation and puberty by mutagenesis knock-out and over-expressing in a zebrafish transgenic model; (iv) Study effect of AMH in Sertoli cell cultures and in primary testis tissue cultures; (v) A molecular and physiological characterization of sex differentiation and puberty in fish.
Keywords
Fish biology;
Fish;
Salmon;
Engineering;
Cod;
Genetic;
Marine Region
42
Barents Sea (27.I)
14
Skagerrak, Kattegat (27.IIIa)
41
Norwegian Sea (27.IIa)
13
Northern North Sea (27.IVa)
4
Marine Region Map
