Sperm cell (SC) lineage development from the haploid microspore to SCs represents a unique biological process where the microspore generates a larger vegetative cell (VC) and a smaller generative cell (GC) enclosed in the VC, then the GC further develops to functionally specified SCs in the VC for double fertilization. Understanding the mechanisms of SC lineage development remains a critical goal in plant biology. Tai Wang’ group shows that SC lineage development involves global repression of genes for pluripotency, somatic development and metabolism following microspore asymmetric division and coordinated upregulation of GC/SC preferential genes. This process is accompanied by progressive loss of the active marks H3K4me3 and H3K9ac, and accumulation of the repressive marks H3K9 methylation. The SC lineage has a higher ratio of lncRNAs to mRNAs and preferentially expresses a larger percentage of lncRNAs than does the non-SC lineage. A co-expression network showed that the largest set of lncRNAs in these nodes, with more than 100 links, are GC-preferential, and a small portion of lncRNAs co-express with their neighboring genes. Single molecular FISH showed that several candidate genes may be markers distinguishing the three cell types of the SC lineage. These results reveal the molecular programming and potential roles of lncRNAs for SC lineage development.
This study has been published in Plant Journal on July 26, 2018 and was supported by “973” project from the Ministry of Science and Technology.