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Meng, T.-G.

Publications and source records attributed to Meng, T.-G..

4 recordsLinked to original sources

Spatiotemporal and single-cell atlas to dissect cell lineage differentiation and regional specific cell types in mouse ovary morphogenesis

Characterization of cell heterogeneity and molecular diversity using single-cell RNA sequencing has greatly enhanced our understanding of the ovarys dynamic differentiation processes. However, regional specification of ovarian cells for certain physiological functions remains largely unexplored in the physical space. Here, we combine spatial transcriptomics with single-cell RNA sequencing technologies to build a spatiotemporal and single-cell atlas of ovaries from fetal to adult stages. We construct the pseudotime trajectories of female germ cells and bipotential pregranulosa cells and define key regulatory transcription factors responsible for their differentiation processes. Specifically, we dissect the relationships between two waves of meiosis initiation, oogenesis processes and folliculogenesis. Moreover, we characterize the region-specific subtypes of granulosa cells and luteal cells and construct pseudo-space-time trajectories from granulosa cells to luteal cells. Notably, we identify small luteal cells, a novel cell type, which highly express Onecut2 and exclusively locate at the corpus luteum. Altogether, this study comprehensively delineates ovary development and regional specific ovarian cell types.

developmental biology↗

SRSF2 is required for mRNA splicing and spermatogenesis

RNA splicing plays significant roles in fundamental biological activities. However, our knowledge about the roles of alternative splicing and underlying mechanisms during spermatogenesis is limited. Here, we report that Serine/arginine-rich splicing factor 2 (SRSF2), also known as SC35, plays critical roles in alternative splicing and male reproduction. Male germ cell-specific deletion of Srsf2 by Stra8-Cre caused complete infertility and defective spermatogenesis. Further analyses revealed that deletion of Srsf2 disrupted differentiation and meiosis initiation of spermatogonia. Mechanistically, by combining RNA-seq data with LACE-seq data, we showed that SRSF2 regulatory networks play critical roles in several major events including reproductive development, spermatogenesis, meiotic cell cycle, synapse organization, DNA recombination, chromosome segregation, and male sex differentiation. Furthermore, SRSF2 affected expression and alternative splicing of Stra8, Stag3 and Atr encoding critical factors for spermatogenesis in a direct manner. Taken together, our results demonstrate that SRSF2 has important functions in spermatogenesis and male fertility by regulating alternative splicing.

developmental biology↗

Single cell RNA sequencing reveals regulation of fetal ovary development in the monkey (Macaca fascicularis)

Germ cells are vital for reproduction and heredity. However, the mechanisms underlying female germ cell development in primates, especially in late embryonic stages, remain elusive. Here, we performed single-cell RNA sequencing of 12471 cells from whole fetal ovaries, and explored the communications between germ cells and niche cells. We depicted the two waves of oogenesis at single cell resolution and demonstrated that progenitor theca cells exhibit similar characteristics to Leydig cells in fetal monkey ovaries. Notably, we found that ZGLP1 displays differentially expressed patterns between mouse and monkey, which is not overlapped with NANOG in monkey germ cells, suggesting its role in meiosis entry but not in activating oogenic program in primates. Furthermore, the majority of germ cell clusters that highly expressed PRDM9 and SPO11 might undergo apoptosis after cyst breakdown, leading to germ cell attrition. Overall, our work provides new insights into the molecular and cellular basis of primate fetal ovary development at single-cell resolution.

developmental biology↗

Single cell RNA sequencing reveals the landscape of early female germ cell development

Female germ cell development consists of complex events including sex determination, meiosis initiation, retardation and resumption. During early oogenesis, the asynchrony of the transition from mitosis to meiosis results in heterogeneity in the female germ cell populations at a certain embryonic stage, which limits the studies of meiosis initiation and progression at a higher resolution level. Here, we investigated the transcriptional profiles of 19363 single germ cells collected from E12.5, E14.5 and E16.5 mouse fetal ovaries. Clustering analysis identified seven groups and defined dozens of corresponding transcription factors, providing a global view of cellular differentiation from primordial germ cells towards meiocytes. Further, we explored the dynamics of gene expression within the developmental trajectory with special focus on the mechanisms underlying meiotic initiation. We found that Dpy30 may be involved in the regulation of meiosis initiation at the epigenetic level. Our data provide key insights into the transcriptome features of peri-meiotic female germ cells, which offers new information not only on meiosis initiation and progression but also on screening pathogenic mutations in meiosis-associated diseases.

developmental biology↗