Short-Term Stored Sperm Alters DNA Methylation in Carp Embryos

Greg Howard
21st May, 2024

Short-Term Stored Sperm Alters DNA Methylation in Carp Embryos

Image Source: Natural Science News, 2024

Key Findings

  • The study from the University of South Bohemia examined the effects of short-term sperm storage on DNA methylation in common carp embryos
  • Short-term sperm storage reduced sperm motility, viability, and DNA integrity but did not change global DNA methylation levels in sperm and embryos
  • Despite no global changes, specific DNA methylation alterations were found in key genes, potentially affecting embryonic development
The University of South Bohemia recently conducted a study investigating the effects of short-term sperm storage on DNA methylation in the offspring of common carp (Cyprinus carpio)[1]. This research addresses a significant gap in our understanding of how short-term storage impacts embryonic development at a molecular level, particularly focusing on DNA methylation—a key epigenetic mechanism regulating gene expression. DNA methylation involves the addition of a methyl group to DNA, typically acting to suppress gene expression when occurring in gene promoter regions. However, recent research has shown that methylation in other regions, such as the first intron, can also significantly impact gene expression[2]. This study aimed to explore how short-term storage of sperm affects DNA methylation patterns in embryos, providing insights that could inform genetic management practices in aquaculture. In this study, sperm from common carp were stored in artificial seminal plasma on ice at 0–2°C for 0, 3, and 6 days. Fertilizations were performed using oocytes from a single female, and embryos were collected at the mid-blastula stage. The researchers then extracted DNA from both sperm and embryos, analyzing it through liquid chromatography with tandem mass spectrometry (LC–MS/MS) and whole genome bisulfite sequencing (WGBS). The results revealed that sperm storage negatively affected sperm motility, viability, and DNA integrity. However, it did not influence the global DNA methylation levels of spermatozoa and the resulting embryos. This aligns with previous findings that DNA methylation patterns can be highly dynamic and context-specific[3]. Despite the lack of global changes, the WGBS analysis identified 3313 differentially methylated regions (DMRs) in embryos fertilized with sperm stored for 6 days. These DMRs were primarily associated with genes involved in cell adhesion, calcium signaling, mitogen-activated protein kinase (MAPK) signaling, adrenergic signaling, melanogenesis, metabolism, and RNA transport. These findings suggest that while short-term storage does not alter overall DNA methylation levels, it does induce specific changes in methylation patterns that could impact embryonic development. This is particularly significant given that DNA methylation in the first intron has been shown to have a consistent inverse relationship with gene expression across various tissues and species[2]. The identification of DMRs in critical signaling and metabolic pathways indicates that prolonged storage time may disrupt normal embryonic development processes, potentially leading to adverse outcomes. The implications of this study are far-reaching for the field of aquaculture, where artificial fertilization using stored sperm is common. Understanding the specific methylation changes induced by storage can help in developing better storage practices to minimize negative impacts on offspring. Furthermore, this research contributes to the broader understanding of how epigenetic modifications during gametogenesis and early embryonic development affect reproductive outcomes, echoing findings from studies on the dynamic nature of DNA methylation during sperm development[3] and the importance of the sperm epigenome in reproductive success[4]. In conclusion, this study from the University of South Bohemia provides valuable insights into the epigenetic consequences of short-term sperm storage in common carp. While global DNA methylation levels remain unchanged, specific methylation alterations in key genes highlight the need for careful consideration of storage practices in aquaculture. Future research should continue to explore these epigenetic mechanisms to optimize reproductive success and genetic management in aquatic species.

GeneticsBiochemAnimal Science


Main Study

1) Fertilization by short-term stored sperm alters DNA methylation patterns at single-base resolution in common carp (Cyprinus carpio) embryos

Published 20th May, 2024

Related Studies

2) Consistent inverse correlation between DNA methylation of the first intron and gene expression across tissues and species.

3) Developmental alterations in DNA methylation during gametogenesis from primordial germ cells to sperm.

4) Epigenetics Role in Spermatozoa Function: Implications in Health and Evolution-An Overview.

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