The most fundamental process for the perpetuation of a species is the transfer of information from parent to offspring. Although genomic DNA contributes to the majority of the inheritance, it is now ...clear that epigenetic information −information beyond the underlying DNA sequence − is also passed on to future generations. However, the mechanism and extent of such inheritance are not well-understood. Here, I review some of the concepts, evidence, and mechanisms of intergenerational epigenetic inheritance via sperm small RNAs. Recent studies provide evidence that mature sperm are highly abundant in small non-coding RNAs. These RNAs are modulated by paternal environmental conditions and potentially delivered to the zygote at fertilization, where they can regulate early embryonic development. Intriguingly, sperm small RNA payload undergoes dramatic changes during testicular and post-testicular maturation, making the mature sperm epigenome highly unique and distinct from testicular germ cells. I explore the mechanism of sperm small RNA remodeling during post-testicular maturation in the epididymis, and the potential role of this reprograming in intergenerational epigenetic inheritance.
In this paper, a systematic literature review was conducted to synthesize understanding on farmers’ perception on climate change. Farmers’ perception of climate change is conceptualized as comprising ...of three dimensions—first, as farmers’ “awareness”; second, “conceptual understanding”; and third, the “experience” of climate change. The review included 162 papers published during the period January 2000 to July 2019. The highest number of studies was conducted in Africa, followed by Asia. A large majority of farmers report being aware of climate change. However, only a few studies elicit the difference between climate variability and climate change from farmers. A negligible number of studies attempt to identify the role of agricultural activities in greenhouse gas emissions and climate change. Furthermore, authors compare farmers’ perception with meteorological evidence, which is more aligned in terms of change in “temperature” rather than “precipitation.” The insights from the review provide guidance on conceptualization and operationalization of the variable “farmers’ perception of climate change” for future studies.
There is mounting evidence that ancestral life experiences and environment can influence phenotypes in descendants. The parental environment regulates offspring phenotypes potentially via modulating ...epigenetic marks in the gametes. Here, we review examples of across-generational inheritance of paternal environmental effects and the current understanding of the role of small RNAs in such inheritance. We discuss recent advances in revealing the small RNA payload of sperm and how environmental conditions modulate sperm small RNAs. Further, we discuss the potential mechanism of inheritance of paternal environmental effects by focusing on sperm small RNA-mediated regulation of early embryonic gene expression and its role in influencing offspring phenotypes.
Following testicular spermatogenesis, mammalian sperm continue to mature in a long epithelial tube known as the epididymis, which plays key roles in remodeling sperm protein, lipid, and RNA ...composition. To understand the roles for the epididymis in reproductive biology, we generated a single-cell atlas of the murine epididymis and vas deferens. We recovered key epithelial cell types including principal cells, clear cells, and basal cells, along with associated support cells that include fibroblasts, smooth muscle, macrophages and other immune cells. Moreover, our data illuminate extensive regional specialization of principal cell populations across the length of the epididymis. In addition to region-specific specialization of principal cells, we find evidence for functionally specialized subpopulations of stromal cells, and, most notably, two distinct populations of clear cells. Our dataset extends on existing knowledge of epididymal biology, and provides a wealth of information on potential regulatory and signaling factors that bear future investigation.
Several recent studies link parental environments to phenotypes in subsequent generations. In this work, we investigate the mechanism by which paternal diet affects offspring metabolism. Protein ...restriction in mice affects small RNA (sRNA) levels in mature sperm, with decreased let-7 levels and increased amounts of 5’ fragments of glycine transfer RNAs (tRNAs). In testicular sperm, tRNA fragments are scarce but increase in abundance as sperm mature in the epididymis. Epididymosomes (vesicles that fuse with sperm during epididymal transit) carry RNA payloads matching those of mature sperm and can deliver RNAs to immature sperm in vitro. Functionally, tRNA-glycine-GCC fragments repress genes associated with the endogenous retroelement MERVL, in both embryonic stem cells and embryos. Our results shed light on sRNA biogenesis and its dietary regulation during posttesticular sperm maturation, and they also link tRNA fragments to regulation of endogenous retroelements active in the preimplantation embryo.
Pashmina, the world's finest natural fiber is derived from secondary hair follicles of Changthangi goats which are domesticated in Ladakh region of Jammu and Kashmir by nomadic pastoralists. Complex ...epithelial-mesenchymal interactions involving numerous signal molecules and signaling pathways govern hair follicle morphogenesis and mitosis across different species. The present study involved transcriptome profiling of skin from fiber type Changthangi goats and meat type Barbari goats to unravel gene networks and metabolic pathways that might contribute to Pashmina development. In Changthangi goats, 525 genes were expressed at significantly higher levels and 54 at significantly lower levels with fold change >2 (p
< 0.05). Functional annotation and enrichment analysis identified significantly enriched pathways to be formation of the cornified envelope, keratinization and developmental biology. Expression of genes for keratins (KRTs) and keratin-associated proteins (KRTAPs) was observed to be much higher in Changthangi goats. A host of transcriptional regulator genes for hair follicle keratin synthesis such as GPRC5D, PADI3, HOXC13, FOXN1, LEF1 and ELF5 showed higher transcript abundance in Pashmina producing goats. Positive regulation of Wnt signaling pathway and negative regulation of Oncostatin M signaling pathway may be speculated to be important contributors to hair follicle development and hair shaft differentiation in Changthangi goats.
Nonalcoholic fatty liver disease (NAFLD) is a serious public health concern, which calls for appropriate diet/nutrition intervention. Fish oil (FO) has several benefits in reducing obesity, but its ...intergenerational role in reducing the effects of paternal obesity has not been established. Hence, we hypothesized that FO supplementation to an obese father during the pre-conceptional period could improve the metabolic health of the offspring, specifically in the liver. Three groups of male mice were fed with a low-fat (LF), high-fat (HF), or high-fat diet supplemented with FO (HF-FO) for 10 weeks and were then allowed to mate with female mice fed a chow diet. Offspring were sacrificed at 16 weeks. The liver tissue was harvested for genomic and histological analyses. The offspring of HF and HF-FO fathers were heavier compared to that of the LF mice during 9-16 weeks. The glucose tolerance of the offspring of HF-FO fathers were significantly improved as compared to the offspring of HF fathers. Paternal FO supplementation significantly lowered inflammation and fatty acid synthesis biomarkers and increased fatty acid oxidation biomarkers in the offspring liver. In summary, FO supplementation in fathers shows the potential to reduce metabolic and cardiovascular diseases through genetic means in offspring.
The expression of genes and their regulation during lactation in buffaloes remains less understood. To understand the interplay of various genes and pathways, the milk transcriptome from three ...lactation stages of Murrah buffalo was analyzed by RNA sequencing. The filtered reads were mapped to the Bubalus bubalis as well as Bos taurus reference assemblies. The average mapping rate to water buffalo and Btau 4.6 reference sequence, was 75.5% and 75.7% respectively. Highly expressed genes (RPKM > 3000), throughout lactation included CSN2, CSN1S1, CSN3, LALBA, SPP1 and TPT1. A total of 12833 transcripts were common across all the stages, while 271, 205 and 418 were unique to early, mid and late lactation respectively. Majority of the genes throughout lactation were linked to biological functions like protein metabolism, transport and immune response. A discernible shift from metabolism in early stage to metabolism and immune response in mid stage, and an increase in immune response functions in late lactation was observed. The results provide information of candidate genes and pathways involved in the different stages of lactation in buffalo. The study also identified 14 differentially expressed and highly connected genes across the three lactation stages, which can be used as candidates for future research.
Sudden cardiac arrest has a high incidence and often leads to death. A treatment option that might improve the outcomes in refractory cardiac arrest is Extracorporeal Cardiopulmonary Resuscitation ...(ECPR).
This study investigates the number of in-hospital cardiac arrest (IHCA) and out-of-hospital cardiac arrest (OHCA) patients eligible to ECPR and identifies clinical characteristics that may help to identify which patients benefit the most from ECPR.
A retrospective two-centre study was conducted in Rotterdam, the Netherlands. All IHCA and OHCA patients between 1 January 2017 and 1 January 2020 were screened for eligibility to ECPR. The primary outcome was the percentage of patients eligible to ECPR and patients treated with ECPR. The secondary outcome was the comparison of the clinical characteristics and outcomes of patients eligible to ECPR treated with conventional Cardiopulmonary Resuscitation (CCPR) vs. those of patients treated with ECPR.
Out of 1246 included patients, 412 were IHCA patients and 834 were OHCA patients. Of the IHCA patients, 41 (10.0%) were eligible to ECPR, of whom 20 (48.8%) patients were actually treated with ECPR. Of the OHCA patients, 83 (9.6%) were eligible to ECPR, of whom 23 (27.7%) were actually treated with ECPR. In the group IHCA patients eligible to ECPR, no statistically significant difference in survival was found between patients treated with CCPR and patients treated with ECPR (hospital survival 19.0% vs. 15.0% respectively, 4.0% survival difference 95% confidence interval -21.3 to 28.7%). In the group OHCA patients eligible to ECPR, no statistically significant difference in-hospital survival was found between patients treated with CCPR and patients treated with ECPR (13.3% vs. 21.7% respectively, 8.4% survival difference 95% confidence interval -30.3 to 10.2%).
This retrospective study shows that around 10% of cardiac arrest patients are eligible to ECPR. Less than half of these patients eligible to ECPR were actually treated with ECPR in both IHCA and OHCA.
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