PUBLICATION

Loss of Fshr prevents testicular maturation in Atlantic salmon (Salmo salar L.)

Authors
Andersson, E., Schulz, R.W., Almeida, F., Kleppe, L., Skaftnesmo, K.O., Kjærner-Semb, E., Crespo, D., Fjelldal, P.G., Hansen, T.J., Norberg, B., Edvardsen, R.B., Wargelius, A.
ID
ZDB-PUB-240201-6
Date
2024
Source
Endocrinology   165(4): (Journal)
Registered Authors
Schulz, Rüdiger W.
Keywords
CRISPR-Cas9, FSH receptor, aquaculture, puberty, sterility
MeSH Terms
  • Animals
  • Follicle Stimulating Hormone/metabolism
  • Male
  • Mice
  • Receptors, FSH*/genetics
  • Receptors, FSH*/metabolism
  • Salmo salar*/genetics
  • Salmo salar*/metabolism
  • Sexual Maturation/genetics
  • Testis/metabolism
  • Zebrafish/genetics
PubMed
38298132 Full text @ Endocrinology
Abstract
Early puberty poses a significant challenge for male Atlantic salmon in aquaculture due to its negative impact on growth and welfare. The regulation of puberty in vertebrates involves two key reproductive hormones: follicle-stimulating hormone (FSH) and luteinizing hormone (LH) and their gonadal receptors. In male mice lacking FSH receptor, testes size is reduced, but fertility is maintained, while medaka and zebrafish with a disrupted fshr gene exhibit near normal testis size and fertility. In these fishes both Fsh and Lh are present during puberty and Lh may rescue fertility, while in salmonid fish only Fsh is present in the circulation during puberty. Using CRISPR-Cas9, we produced crispants with a high prevalence of fshr mutations at the target site, which remained fertile, although more than half showed a testis development deviating from wild-type (wt) males. Crossing out these F0 crispants to each other produced a viable F1 generation showing frameshift (fshr-/-) or in-frame mutations (fshrif/if). Nearly all wt males matured while all fshr-/- males remained immature with small testes containing A spermatogonia as the furthest developed germ cell type and prepubertal plasma androgen levels. Also, the pituitary transcript levels of gnrhr2bba and lhb, but not for fshb, were reduced in the fshr-/- males compared to maturing males. More than half of the fshrif/if mutant males showed no, or a delayed maturation. In conclusion, Atlantic salmon show the unique characteristic that loss of Fshr function alone results in male infertility, offering new opportunities to control precocious puberty or fertility in salmon.
Genes / Markers
Figures
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Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping