Safeguarding spermatogenesis from retrotransposon insertions by forming ecDNA.
#Transposons #Retrotransposons #ExtrachromosomalCircularDNA #ecDNA #Spermatogenesis #Drosophila #Preprint
Retrotransposon mobilization in germline cells enables the rewriting of genetic information to drive genome innovation, species evolution, and adaptation through the generation of de novo mutations. However, uncontrolled mobilization can cause DNA breaks and genome instability, often leading to sterility. How germ cells balance retrotransposon-induced genome innovation with the need for genomic integrity remains poorly understood. Here, we used Drosophila spermatogenesis as a model to investigate retrotransposon mobilization dynamics. Although many retrotransposon families are transcriptionally active, we found that the LTR-retrotransposon nomad completes the full mobilization cascade—including mRNA export, protein translation, and reverse transcription—to produce double-stranded DNA (dsDNA) the most efficiently. Strikingly, despite successfully generating dsDNA, nomad rarely achieves genomic reintegration. Instead, its newly synthesized DNA predominantly forms extrachromosomal circular DNA (ecDNA). These findings suggest that ecDNA formation acts as a protective mechanism to sequester retrotransposon-derived DNA and prevent widespread genomic integration during spermatogenesis, thereby preserving genome stability while allowing limited retrotransposon activity.
Abstract Arecoline hydrobromide has been demonstrated to regulate cellular survival and male reproduction. However, the specific roles and regulated genes of arecoline hydrobromide in spermatogenesis are poorly understood. This study aimed to investigate the effects of arecoline hydrobromide on spermatogenesis and associated transcriptome changes. The spermatogenic cell line GC-1 cells were treated with arecoline hydrobromide to determine the effects of proliferation and apoptosis for arecoline hydrobromide in vitro. The ICR mice were treated with arecoline hydrobromide by intragastric administration. The testes and epididymis were used for sperm count, HE staining, apoptosis detection and transcriptome analysis. Cellular morphology was significantly altered and the number of apoptotic cells increased with increasing concentration and duration of arecoline hydrobromide treatment, and cell proliferation was inhibited. Animal experiments showed that the spermatozoa in the experimental groups were significantly reduced compared with that in the control group. Transcriptome sequencing was executed for testes of four-week arecoline hydrobromide treated mice, which identified 181 significant up-regulated genes and 159 significant down-regulated genes which were then analyzed with gene ontology (GO) and revealed some testicular development and hormone-related pathways. The results verified that arecoline hydrobromide inhibited the proliferation and promoted the apoptosis of GC-1 cells, and caused a decrease in the number of spermatozoa and an increase in level of testosterone in mice.
28-Aug-2024
Shocking revelation: an electrically-activated protein regulates #spermatogenesis
Researchers from Osaka University find that a voltage-dependent phosphatase is crucial for translating electrical signals into chemical signals that promote proper #sperm maturation
Of course it takes a spark to make the love happen ...
https://www.eurekalert.org/news-releases/1056061 #science #physiology #proteins #nanoworld
Researchers from Osaka University found that voltage-sensing phosphatase (VSP) is activated by electrical signals during sperm maturation and is crucial for establishing the optimal phosphoinositide environment to generate functional spermatozoa. Modulating VSP function to promote appropriate sperm maturation could be used to develop clinical treatments for infertility in the future.
Understanding Spermatogenesis: The Journey of Male Germ Cells
#Gametogenesis, #HumanReproduciton, #MaleGamets, #Meiosis, #Spermatocytogenesis, #Spermatogenesis, #Sperms #CellBiology Introduction: Spermatogenesis, the process by which sperm cells are produced, is a marvel of biological intricacy fundamental to the continuation…. Medical Microbiology & Recombinant DNA Technology (RDT) Labs | Read More -
Understanding Spermatogenesis: The Journey of Male Germ Cells
#Gametogenesis, #HumanReproduciton, #MaleGamets, #Meiosis, #Spermatocytogenesis, #Spermatogenesis, #Sperms #CellBiology Introduction: Spermatogenesis, the process by which sperm cells are produced, is a marvel of biological intricacy fundamental to the continuation…. Medical Microbiology & RDT Labs | Read More -
Malfunction in #spermatogenesis: Researchers uncover contribution of #cylicin proteins to male fertility.
https://phys.org/news/2023-11-malfunction-spermatogenesis-uncover-contribution-cylicin.html
For successful fertilization, sperm should move forward rapidly and be shaped correctly. The unique structure of the sperm cells forms during spermiogenesis. Now, researchers from the University Hospital Bonn (UKB) and the Transdisciplinary Research Unit Life & Health at the University of Bonn have found that fertility problems in both mice and humans can be caused by loss of so-called cylicins. This causes defects in the head and tail structure of sperm. The results of the study have now been published in the journal eLife.
AMG-1/SLRP-1 is required for #spermatogenesis in #C_elegans: Study.
https://phys.org/news/2023-07-amg-1slrp-required-spermatogenesis-elegans.html
Summary: The 14th NYRA meeting covered a wide range of topics related to male germline research, including the impact of mutations in the male germline on future generations, the use of innovative sequencing tools for the study of male infertility, and the intricate germline epigenome.
#Sperm motility and anchoring of the #spore capsule in spreading #earthmoss.
#bryophytes #auxin #PINC #Physcomitrella #spermatogenesis
https://phys.org/news/2023-01-sperm-motility-anchoring-spore-capsule.html
As a component of moors, mosses are important for climate conservation. They are also gaining increasing significance in biotechnology and the manufacture of biopharmaceuticals. For the most varied of reasons, mosses are interesting research objects. One reason for this is that they are particularly similar to the first land plants. As a result, they provide insight into the original function of signaling molecules which regulate growth and development in all land plants today.
Reprobio, biology reproduction
Amelia Cervera 🧬
Cytology and Genetics
michael
micrordt
CellBioNews
Biology Open