| 1. |
- Paloviita, P, et al.
(författare)
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Small RNA expression and miRNA modification dynamics in human oocytes and early embryos
- 2021
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Ingår i: Genome research. - : Cold Spring Harbor Laboratory. - 1549-5469 .- 1088-9051. ; 31:8, s. 1474-
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Tidskriftsartikel (refereegranskat)abstract
- Small noncoding RNAs (sRNAs) play important roles during the oocyte-to-embryo transition (OET), when the maternal phenotype is reprogrammed and the embryo genome is gradually activated. The transcriptional program driving early human development has been studied with the focus mainly on protein-coding RNAs, and expression dynamics of sRNAs remain largely unexplored. We profiled sRNAs in human oocytes and early embryos using an RNA-sequencing (RNA-seq) method suitable for low inputs of material. We show that OET in humans is temporally coupled with the transition from predominant expression of oocyte short piRNAs (os-piRNAs) in oocytes, to activation of microRNA (miRNA) expression in cleavage stage embryos. Additionally, 3′ mono- and oligoadenylation of miRNAs is markedly increased in zygotes. We hypothesize that this may modulate the function or stability of maternal miRNAs, some of which are retained throughout the first cell divisions in embryos. This study is the first of its kind elucidating the dynamics of sRNA expression and miRNA modification along a continuous trajectory of early human development and provides a valuable data set for in-depth interpretative analyses.
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| 3. |
- Sepponen, K., et al.
(författare)
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Steroidogenic factor 1 (NR5A1) induces multiple transcriptional changes during differentiation of human gonadal-like cells
- 2022
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Ingår i: Differentiation. - : Elsevier BV. - 0301-4681. ; 128:Nov-Dec, s. 83-100
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Tidskriftsartikel (refereegranskat)abstract
- Nuclear receptor subfamily 5 group A member 1 (NR5A1) encodes steroidogenic factor 1 (SF1), a key regulatory factor that determines gonadal development and coordinates endocrine functions. Here, we have established a stem cell-based model of human gonadal development and applied it to evaluate the effects of NR5A1 during the transition from bipotential gonad to testicular cells. We combined directed differentiation of human induced pluripotent stem cells (46,XY) with activation of endogenous NR5A1 expression by conditionally-inducible CRISPR activation. The resulting male gonadal-like cells expressed several Sertoli cell transcripts, secreted anti-Müllerian hormone and responded to follicle-stimulating hormone by producing sex steroid intermediates. These characteristics were not induced without NR5A1 activation. A total of 2691 differentially expressed genetic elements, including both coding and non-coding RNAs, were detected immediately following activation of NR5A1 expression. Of those, we identified novel gonad-related putative NR5A1 targets, such as SCARA5, which we validated also by immunocytochemistry. In addition, NR5A1 activation was associated with dynamic expression of multiple gonad- and infertility-related differentially expressed genes. In conclusion, by combining targeted differentiation and endogenous activation of NR5A1 we have for the first time, been able to examine in detail the effects of NR5A1 in early human gonadal cells. The model and results obtained provide a useful resource for future investigations exploring the causative reasons for gonadal dysgenesis and infertility in humans. © 2022 The Authors
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