Biology subjects

Tanwar, D. K.

Publications and source records attributed to Tanwar, D. K..

3 recordsLinked to original sources

bioRxiv2021

Early life stress affects the miRNA cargo in epididymal extracellular vesicles in mouse

Sperm RNA can be modified by environmental factors and has been implicated in communicating signals about changes in a fathers environment to the offspring. The RNA composition of sperm is influenced during its final stage of maturation in the epididymis by extracellular vesicles released by epididymal cells. We studied the effect of exposure to stress in postnatal life on the transcriptome of epididymal extracellular vesicles using a mouse model of transgenerational transmission. We found that the small RNA signature of epididymal extracellular vesicles, particularly miRNAs, is altered in adult males exposed to postnatal stress. miRNAs changes correlate with differences in the expression of their target genes in sperm and zygotes generated from that sperm. These results suggest that stressful experiences in early life can have persistent biological effects on the male reproductive tract that may in part be responsible for the transmission of the effects of exposure to the offspring. Summary SentencemiRNA cargo of extracellular vesicles in cauda epididymis is changed by paternal exposure to early life stress, which correlates with differences in the expression of their target genes in sperm and zygotes generated from that sperm

molecular biology↗

bioRxiv2020

Transcriptome and epigenome characterization of mouse spermatogonial cells reveals distinct chromatin regulatory landscapes in postnatal and adult testis

In mammals, spermatogonial cells (SPGs) are undifferentiated male germ cells in testis that are quiescent until birth and then self-renew and differentiate to produce spermatogenic cells and functional sperm from early postnatal life throughout adulthood. The transcriptome of SPGs is highly dynamic and timely regulated during postnatal development. We examined if such dynamics involves changes in chromatin organization by profiling the transcriptome and chromatin accessibility of SPGs from early postnatal stages to adulthood in mice using deep RNA-seq, ATAC-seq and computational deconvolution analyses. By integrating transcriptomic and epigenomic features, we show that SPGs undergo massive chromatin remodeling during postnatal development that partially correlates with distinct gene expression profiles and transcription factors (TF) motif enrichment. We identify genomic regions with significantly different chromatin accessibility in adult SPGs that are marked by histone modifications associated with enhancers and promoters. Some of the regions with increased accessibility correspond to transposable element subtypes enriched in multiple TFs motifs and close to differentially expressed genes. Our results underscore the dynamics of chromatin organization in developing germ cells and complement existing datasets on SPGs by providing maps of the regulatory genome at high resolution from the same cell populations at early postnatal, late postnatal and adult stages collected from single individuals.

developmental biology↗

bioRxiv2019

A novel mode of communication between blood and the germline for the inheritance of paternal experiences

In many species, environmental stimuli can affect the germline and contribute to phenotypic changes in the offspring, without altering the genetic code1-5. So far, little is known about which biological signals can link exposure to germ cells. Using a mouse model of postnatal trauma with transgenerational effects, we show that exposure alters lipid-based metabolites in blood of males and their non-exposed offspring. Comparable alterations are validated in serum and saliva of orphan children exposed to trauma. Peroxisome proliferator-activated receptor (PPAR) is identified as mediating the effects of metabolites alterations. Mimicking PPAR activation with a dual PPAR/{gamma} agonist in vivo induces changes in the sperm transcriptome similarly to trauma, and reproduces metabolic phenotypes in the offspring. Injecting serum collected from adult males exposed to postnatal trauma into controls recapitulates metabolic phenotypes in the offspring. These results suggest conserved effects of early life adversity on blood metabolites, and causally involve paternal blood factors and PPAR nuclear receptor in phenotype heritability.

molecular biology↗