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.
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.
Project description:Spermatozoa deliver a complex and environment sensitive pool of small non-coding RNAs (sncRNA) to the oocyte at fertilisation [ref], which influences offspring development and adult phenotypic trajectories [refs]. Whether mature spermatozoa in the epididymis can directly sense the environment is still not fully understood [ref]. 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.
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.
Project description:Although it is increasingly accepted that some paternal environmental conditions can influence phenotypes in future generations, it remains unclear whether phenotypes induced in offspring represent specific responses to particular aspects of the paternal exposure history, or whether they represent a more generic response to paternal “quality of life”. To establish a paternal effect model based on a specific ligand-receptor interaction and thereby enable pharmacological interrogation of the offspring phenotype, we explored the effects of paternal nicotine administration on offspring phenotype in mouse. We show that paternal exposure to chronic nicotine induced a broad protective response to xenobiotic exposure in the next generation. This effect manifested as increased survival following an injection of toxic levels of nicotine, was specific to male offspring, and was only observed after these offspring were first acclimated to low levels of nicotine for a week. Importantly, offspring xenobiotic resistance was documented not only for toxic nicotine challenge, but also for toxic cocaine challenge, indicating that paternal nicotine exposure reprograms offspring to become broadly resistant to environmental toxins. Mechanistically, the reprogrammed state was characterized by enhanced clearance of nicotine in drug-acclimated animals, and we found that isolated hepatocytes displayed upregulation of enzymes that metabolize xenobiotics. Taken together, our data show that paternal nicotine exposure induces a protective phenotype in offspring by enhancing metabolic tolerance to xenobiotics in the environment.
Project description:<p>The gut microbiota operates at the interface of host-environment interactions to influence human homeostasis and metabolic networks. Environmental factors that unbalance gut microbial ecosystems can therefore elicit physiological and disease-associated responses across somatic tissues. However, the systemic impact of the gut microbiome on the germline - and consequently on the F1 offspring it gives rise to - is unexplored. Here we show that the gut microbiota act as a key interface between paternal preconception environment and intergenerational health in mice. Perturbations to the gut microbiota of prospective fathers increase the probability of their offspring presenting with low birth weight, severe growth restriction and premature mortality. Transmission of disease risk occurs via the germline and is provoked by pervasive gut microbiome perturbations, including non-absorbable antibiotics or osmotic laxatives, but is rescued by restoring the paternal microbiota before conception. This effect is linked with a dynamic response to induced dysbiosis in the male reproductive system, including impaired leptin signalling, altered testicular metabolite profiles and remapped small RNA payloads in sperm. As a result, dysbiotic fathers trigger an elevated risk of in utero placental insufficiency, revealing a placental origin of mammalian intergenerational effects. Our study defines a regulatory ‘gut-germline axis’ in males, which is sensitive to environmental exposures and programs offspring fitness through impacting placental function.</p>
Project description:This SuperSeries is composed of the following subset Series: GSE29454: Effect of Advanced Paternal Age on Copy Number Variation in Offspring (custom array) GSE29455: Effect of Advanced Paternal Age on Copy Number Variation in Offspring (commercial array) Refer to individual Series