Project description:To define what genes are predominantly or specifically expressed in either soma or germline in C. elegans adults, total RNA was extracted from germline-less glp-4 mutant animals or from dissected gonads, respectively. Total RNA sequencing was peformed in duplicates. Four samples in total.
Project description:To define what genes are predominantly or specifically expressed in either soma or germline in C. elegans adults, total RNA was extracted from germline-less glp-4 mutant animals or from dissected gonads, respectively.
Project description:In C. elegans, the H3K4me2 demethylase, SPR-5, and the H3K9 methyltransferase, MET-2, are maternally deposited into the oocyte where they reprogram histone methylation to prevent somatic expression of germline genes. Here, we show that the progeny of spr-5; met-2 mutants display a severe developmental delay that is associated with the ectopic expression of germline genes targeted by the H3K36me2/3 methyltransferase, MES-4. Maternally deposited MES-4 maintains H3K36me2/3 at a subset of germline genes (hereafter referred to as MES-4 germline genes) in a transcription-independent manner, and this is required for germline proliferation in the subsequent generation. By performing ChIP-seq on L1 progeny from spr-5; met-2 mutants, we find that MES-4 germline genes ectopically accumulate H3K36me3 in somatic tissues. Additionally, knocking down MES-4 suppresses the ectopic expression of MES-4 germline genes and rescues the developmental delay. These data suggest a model where SPR-5, MET-2 and MES-4 carefully balance the inheritance of histone methylation from the parental germline to ensure the proper specification of germline versus soma in the progeny. Without SPR-5; MET-2 maternal reprogramming, somatic cells struggle to specify their proper cell fate amongst the background noise of inappropriate germline gene transcription, leading to a severe developmental delay.
Project description:In C. elegans, the H3K4me2 demethylase, SPR-5, and the H3K9 methyltransferase, MET-2, are maternally deposited into the oocyte where they reprogram histone methylation to prevent somatic expression of germline genes. Here, we show that the progeny of spr-5; met-2 mutants display a severe developmental delay that is associated with the ectopic expression of germline genes targeted by the H3K36me2/3 methyltransferase, MES-4. Maternally deposited MES-4 maintains H3K36me2/3 at a subset of germline genes (hereafter referred to as MES-4 germline genes) in a transcription-independent manner, and this is required for germline proliferation in the subsequent generation. By performing ChIP-seq on L1 progeny from spr-5; met-2 mutants, we find that MES-4 germline genes ectopically accumulate H3K36me3 in somatic tissues. Additionally, knocking down MES-4 suppresses the ectopic expression of MES-4 germline genes and rescues the developmental delay. These data suggest a model where SPR-5, MET-2 and MES-4 carefully balance the inheritance of histone methylation from the parental germline to ensure the proper specification of germline versus soma in the progeny. Without SPR-5; MET-2 maternal reprogramming, somatic cells struggle to specify their proper cell fate amongst the background noise of inappropriate germline gene transcription, leading to a severe developmental delay.
Project description:At the onset of reproduction, oviparous animals synthesize large amounts of yolk in somatic tissues to provide lipids and other nutrients to their progeny. However, whether the yolk transports other types of molecules, such as RNAs with gene regulatory functions, remains largely unexplored. Here, we have biochemically purified the yolk in the nematode Caenorhabditis elegans and show it contains microRNAs (miRNAs). We provide evidence that the yolk transports such miRNAs from the mother’s intestine to the embryos via the lipoprotein yolk receptor RME-2. These yolk-enriched miRNAs inherited by the embryos regulate the transcriptomes of developing larvae. Moreover, environmental stresses and maternal age modulate the transfer of yolk-enriched miRNAs, providing stress resilience benefits to progeny. This discovery establishes a novel paradigm in intergenerational gene regulation, where the gut-germline axis orchestrates the transmission of environmental cues through yolk-enriched miRNAs. Our work reveals a new mechanism underlying the soma-to-germline transfer of epigenetic information in animals.