|ZFIN ID: ZDB-PUB-141115-3|
Genetic Analysis of Zebrafish Gonadotropin (FSH and LH) Functions by TALEN-mediated Gene Disruption
Zhang, Z., Zhu, B., Ge, W.
|Source:||Molecular endocrinology (Baltimore, Md.) 29(1): 76-98 (Journal)|
|Registered Authors:||Ge, Wei, Zhang, Zhiwei, Zhu, Bo|
|PubMed:||25396299 Full text @ Mol. Endocrinol.|
Zhang, Z., Zhu, B., Ge, W. (2015) Genetic Analysis of Zebrafish Gonadotropin (FSH and LH) Functions by TALEN-mediated Gene Disruption. Molecular endocrinology (Baltimore, Md.). 29(1):76-98.
ABSTRACTVertebrate reproduction is controlled by two gonadotropins (FSH and LH) from the pituitary. Despite numerous studies on FSH and LH in fish species, their functions in reproduction still remain poorly defined. This is partly due to the lack of powerful genetic approaches for functional studies in adult fish. This situation is now changing with the emergence of genome-editing technologies, especially TALEN and CRISPR/Cas9. In this study, we deleted the hormone-specific β genes of both FSH and LH in the zebrafish using TALEN. This was followed by phenotype analysis for key reproductive events, including gonadal differentiation, puberty onset, gametogenesis, final maturation, and fertility. FSH-deficient zebrafish (fshb(-/-)) were surprisingly fertile in both sexes; however, the development of both ovary and testis was significantly delayed. In contrast, LH-deficient zebrafish (lhb(-/-)) showed normal gonadal growth, but the females failed to spawn and were therefore infertile. Using previtellogenic (PV) follicles as the marker, we observed a significant delay of puberty onset in fshb mutant but not lhb mutant females. Interestingly, FSH seemed to play a role in maintaining female status as we repeatedly observed sexual reversal in fshb mutant. Neither fshb nor lhb mutation alone seemed to affect gonadal differentiation; however, double mutation of the two genes led to all males although the development of the testis was significantly delayed. In summary, our data confirmed some well-known functions of FSH and LH in fish while also providing evidence for novel functions, which would be difficult to reveal using traditional biochemical and physiological approaches.