Anti-Mullerian hormone (Amh/amh) plays dual roles in maintaining gonadal homeostasis and gametogenesis in zebrafish
MOLECULAR AND CELLULAR ENDOCRINOLOGY
Authors: Zhang, Zhiwei; Zhu, Bo; Chen, Weiting; Ge, Wei
Abstract
Anti-Miillerian hormone (AMH/Amh) plays a role in gonadal differentiation and function across vertebrates. In zebrafish we demonstrated that Amh deficiency caused severe gonadal dysgenesis and dysfunction. The mutant gonads showed extreme hypertrophy with accumulation of early germ cells in both sexes, namely spermatogonia in the testis and primary growth oocytes in the ovary. In amh mutant females, the folliculogenesis was normal in young fish but receded progressively in adults, which was accompanied by progressive decrease in follicle-stimulating hormone (fshb) expression. Interestingly the expression of fshb increased in the pituitary of juvenile amh mutant males but decreased in adults. The upregulation offshb in mutant male juveniles was likely one of the mechanisms for triggering gonadal hypergmwth, whereas the downregulation of fshb in adults might involve a negative feedback by gonadal inhibin. Further analysis using mutants offshb and growth differentiation factor 9 (gdf9) provided evidence for a role of FSH in triggering ovarian hypertrophy in young female amh mutant as well. In summary, the present study provided comprehensive genetic evidence for dual roles of Amh in controlling zebrafish gonadal homeostasis and gametogenesis in both sexes. Amh suppresses proliferation or accumulation of early germ cells (spermatogonia in testis and primary growth oocytes in ovary) while promoting their exit to advanced stages, and its action may involve both endocrine and paracrine pathways.
Transcriptome Profiling Identifies Differentially Expressed Genes in Postnatal Developing Pituitary Gland of Miniature Pig
DNA RESEARCH
Authors: Shan, Lei; Wu, Qi; Li, Yuli; Shang, Haitao; Guo, Kenan; Wu, Jiayan; Wei, Hong; Zhao, Jianguo; Yu, Jun; Li, Meng-Hua
Abstract
In recent years, Tibetan pig and Bama pig are popularly used as animal models for medical researches. However, little genomic information is available for the two breeds, particularly regarding gene expression pattern at the whole-transcriptome level. In this study, we characterized the pituitary transcriptome profile along their postnatal developmental stages within and between the two breeds in order to illustrate the differential dynamics and functions of differentially expressed genes. We obtained a total of similar to 300 million 80-bp paired-end reads, detected 15 715 previously annotated genes. Most of the genes (90.33%) were shared between the two breeds with the main functions in metabolic process. Four hormone genes (GH, PRL, LHB, and FSHB) were detected in all samples with extremely high levels of expression. Functional differences between the three developmental stages (infancy, puberty and adulthood) in each breed were dominantly presented by the gene expressions at the first stage. That is, Bama pig was over-represented in the genes involved in the cellular process, while Tibetan pig was over-represented in the genes represented by the reproductive process. The identified SNPs indicated that the divergence between the miniature pig breeds and the large pig (Duroc) were greater than that between the two miniature pig breeds. This study substantially expands our knowledge concerning the genes transcribed in the pig pituitary gland and provides an overview of pituitary transcriptome dynamics throughout the period of postnatal development.