Project description:In this study, we aimed to find out how the sperm tsRNA involved in paternal high-fat diet induced abnormal gluconeogenesis of F1 offspring, and explore the underlying molecular mechanism of its regulation.
Project description:Spermatozoa harbor a complex and environment sensitive pool of small non-coding RNAs (sncRNA)1, which influences offspring development and adult phenotypes1-7. Whether spermatozoa in the epididymis are directly susceptible to environmental cues is not fully understood8. We used two distinct paradigms of preconception acute high fat diet to dissect epididymal vs testicular contributions to the sperm sncRNA pool and offspring health. We show that epididymal spermatozoa, but not developing germ cells, are sensitive to the environment and identify mitochondrial tRNAs and their fragments (mt-tsRNA) as sperm-borne factors. In humans, mt-tsRNAs in spermatozoa correlate with BMI and paternal overweight at conception doubles offspring obesity risk and compromises metabolic health. Sperm sncRNA-seq of mice mutant for genes involved in mitochondrial function, and metabolic phenotyping of their wild-type offspring, suggest that alterations of mt-tsRNAs are downstream of mitochondrial dysfunction. Most importantly, single embryo transcriptomics of genetically hybrid two-cell embryos demonstrated sperm-to-oocyte transfer of mt-tRNAs at fertilisation and implied them in the control of early embryo transcription. Our study supports the importance of paternal health at conception for offspring metabolism, shows that mt-tRNAs are diet-induced and sperm-borne and demonstrates, for the first time in a physiological setting, father-to-offspring transfer of sperm mitochondrial RNAs at fertilization.
Project description:Sperm-derived tsRNAs could act as acquired epigenetic factors and contribute to offspring phenotypes. However, the roles of specific tsRNAs in early embryo development remain to be elucidated. Here, by using pigs as a research model, we probed the tsRNA dynamics during spermatogenesis and sperm maturation, and demonstrated the delivery of tsRNAs from semen-derived exosomes to spermatozoa. By microinjection of the antisense sequence into in vitro fertilized oocytes and subsequent single-cell RNA-sequencing of embryos, we identified a specific functional tsRNA group (Gln-TTGs) that participate in the early cleavage of porcine preimplantation embryos, probably by regulating cell cycle-associated genes. Thus, specific tsRNAs present in mature spermatozoa play significant roles during preimplantation embryo development.
Project description:Cadmium (Cd) is a toxic heavy metal and ubiquitous environmental endocrine disruptor. Previous studies on Cd-induced damage to male fertility mainly focus on the structure and function of testis, and semen quality. Nevertheless, to date, no studies have investigated the effects of Cd exposure on sperm epigenetic inheritance and intergenerational inheritance. In our study, we systematically revealed the changes in sperm tRNA-derived small RNAs (tsRNA) profiles and found that 14 tsRNAs (9 up-regulated and 5 down-regulated) were significantly altered after Cd exposure. Bioinformatics of tsRNA-mRNA-pathway interactions revealed that the altered biological functions mainly were related to ion transmembrane transport, lipid metabolism and cell membrane system. In addition, we focused on two stages of early embryo development and selected two organs to study the impact of these changes on cell membrane system, especially mitochondrion and lysosome, two typical membrane-enclosed organelles. Surprisingly, we found that the content of mitochondrion was significantly decreased in 2-cell stage, whereas remarkably increased in the morula stage. The contents of mitochondrion and lysosome were significantly increased in the testes of 6-days offspring and livers of adult offspring, whereas remarkably decreased in the testes of adult offspring. This provides a possible basis to further explore the effects of paternal Cd exposure on offspring health.
Project description:Increasing evidences indicate diet-induced metabolic disorder could be paternally inherited, but the exact sperm epigenetic carrier remains unclear. Here, in a paternal high-fat diet (HFD) mouse model, we revealed that a highly enriched subset of sperm small RNAs (30-34 nt) that derived from the 5â halves of tRNAs (tsRNAs), exhibit changes in both expression profiles and RNA modifications. Injection of sperm tsRNAs from HFD male but not synthetic tsRNAs lacking RNA modifications, into normal zygotes generated metabolic disorders in the F1 offspring. Injection of HFD sperm tsRNAs derails gene expression in both early embryos and islets of F1 offspring, enriched in metabolic pathways, but unrelated to DNA methylation at CpG-enriched region. Collectively, we uncover sperm tsRNAs as a type of âepigenetic carrierâ that mediate intergenerational inheritance of acquired traits. Mature sperm small-RNA profiles between High-fat-diet (HFD) and Normal-diet (ND) males; Transcriptional profiles of 8-cell embryos and balstocysts that developed from zygotes that injected with sperm RNAs from HFD vs ND males. Transcriptional profiles and RRBS profiles of islets of F1 offsrping that generated from zygotes that injected with sperm RNAs from HFD vs ND males.
Project description:Transcriptional profiling of adult mouse liver tissue comparing offspring derived from sperm and seminal plasma of normal protein diet fed males (controls, NN), sperm and seminal plasma from males fed a low protein diet fed males (LL), sperm from normal protein fed males and seminal plasma from low protein fed males (NL) or sperm from low protein diet fed males and seminal plasma from normal protein diet males (NL). The first letter denotes the diet of the sperm donor and the second letter the diet of the seminal plasma donor. Three-condition experiment: NN vs. LL, NN vs. NL, NN vs. LN. Adult offspring liver tissue. Biological replicates: 7 control (NN), 9 LL, 7 NL and 7 LN. One replicate per array chip.
Project description:Maternal stress, anxiety, and depression increase the risk of psychiatric disorders in the progeny. These maternal effects can extend beyond the first generation and affect the grandchildren. In contrast to paternal, maternal effects can impact the offspring not only during gametogenesis, but also through fetal and early-postnatal life, increasing phenotypic complexity and the overall impact. To better understand its non-genetic structure, we dissected a complex maternally-transmitted phenotype to elementary behaviors and their corresponding transmission mechanisms. Chronic stress and depression are associated with reduced serotonin1A receptor (5-HT1AR) levels, and we reported that 5-HT1AR+/- dams transmit anxiety/stress-reactivity traits to their wild-type offspring. Here we show that the maternal effect is propagated to multiple generations, and that the behavioral traits are not transmitted in unison, but rather via parallel and segregated mechanisms, each with generation-dependent penetrance and gender specificity. The ârisk-avoidanceâ and âhypoactivityâ traits of anxiety were transmitted, via a neuro-immune pathway, consecutively from mother to the wild-type F1, F2, and occasionally F3 generation by iterative non-gametic-programming, while the âincreased stress-reactivityâ trait was transmitted to the F2 generation by gametic-programming. Iterative non-gametic-programming of anxiety was linked, via gene expression changes and clustered DNA hypo/hypermethylation at intragenic enhancers, to sphingolipid metabolism and GPCRs in the F1/F2 hippocampus, suggesting dysregulated lipid raft functioning/transmembrane signaling. Conversely, gametic-programming of behavior was predominantly associated with hypomethylation at different promoter-enhancing sequences within a set of genes with diverse neuronal functions. Since differential methylation appeared only postnatally in F2 neurons and was absent in F3 neurons, it is secondary to earlier F2 gametic changes that survive reprogramming in the early embryo, but are erased in F3 germ-cells. Our data introduce parallel and segregated non-genetic transmission of traits as a mechanism that may explain the propagation and pleiotropy of complex behavioral and psychiatric disease phenotypes across generations. Compared three generations of male offspring from wild-type and 5HT1A-R-/+ Swiss Webster mothers with two replicates per sample. Included as well is F2 embryo transfer from wild-type and het parents in wild-type surogates
Project description:Maternal 5-HT1A-receptor (R) is required for the timely development of the hippocampus and the establishment of emotional behaviors in Swiss-Webster (SW) mice. A partial and/or complete loss of maternal 5-HT1AR results in delayed ventral dentate granule cell (v-DGC) development and subsequent anxiety-like phenotype in the wild-type offspring by a non-genetic, presumably epigenetic mechanism. Here we tested v-DGCs for genome-wide DNA methylation changes elicited by the receptor deficient maternal environment. We identified a set of hypomethylated regions in the offspring of receptor deficient mothers. A significant fraction of these maternal-differentially methylated regions (m-DMRs) mapped to strong CpG islands, sequences that are typically not methylated or if methylated, resistant to environmental-induced changes. Many m-DMRs mapped to exons and some were associated with expression changes. Their hypomethylation was due to an arrest in de novo methylation and, to a lesser extent, to demethylation during postnatal life indicating that the perturbation in methylation coincides with the developmental delay in DGC maturation in the offspring of receptor deficient mothers. Inhibiting methylation in differentiating neurons impaired their maturation further suggesting a link between de novo methylation and neuronal differentiation. These data suggest that methylation at specific exonic CpG-islands may contribute to the mechanism through which maternal 5-HT1AR modulates hippocampal development and consecutively the level of anxiety in the SW offspring. Reduced 5-HT1AR-binding has been reported in individuals, particularly in association with anxiety/depression, including peri/postpartum depression. Therefore, maternal receptor deficit may contribute, via a non-genetic mechanism, to the high prevalence and heritability of anxiety disorders in human. Examined 4 samples: 5HT1A wild type offspring with 5HT1A wild type/heterozygous mother or 5HT1A KO offspring with 5HT1A of heterozygous/knock out mother
Project description:Spermatozoa deliver a complex and environment sensitive pool of small non-coding RNAs (sncRNA) to the oocyte at fertilisation, which influences offspring development and adult phenotypic trajectories. Whether mature spermatozoa in the epididymis can directly sense the environment is still not fully understood. Here, we used two distinct paradigms of preconception acute High Fat Diet challenge to dissect epididymal vs spermatogenic contributions to the sperm sncRNA pool and offspring health. We show that epididymal spermatozoa, but not developing germ cells, are sensitive to the environment and identify mitochondrial tRNA fragments as sperm-born sensors. In human spermatozoa, we found mt-tsRNAs in linear association with BMI and showed that paternal overweight at conception is sufficient to double offspring obesity risk and compromise metabolic health. Using mouse genetics and metabolic phenotypic data, we show that alterations of mt-tsRNAs are downstream of mitochondrial dysfunction in mice. Most importantly, single embryo transcriptomics of genetically hybrid two-cell embryos demonstrated sperm-to-oocyte transfer of mt-tsRNAs at fertilisation and implied them in the control of early embryo metabolism. Our study supports the importance of paternal health at conception for offspring metabolism, propose mt-tsRNAs as sperm-born environmental effectors of paternal inheritance and demonstrate, for the first time in a physiological and unperturbed setting, father-to-offspring transfer of sperm mt-tsRNAs at fertilisation.