scholarly journals A Drosophila toolkit for defining gene function in spermatogenesis

Reproduction ◽  
2017 ◽  
Vol 153 (4) ◽  
pp. R121-R132 ◽  
Author(s):  
N A Siddall ◽  
G R Hime
Keyword(s):  
Germ Cells ◽  
Gene Function ◽  
Primordial Germ Cells ◽  
Rapid Assessment ◽  
Model Organism ◽  
Time Frame ◽  
Individual Organism ◽  
Expression Of Genes ◽  
X Irradiation ◽  
Human Spermatogenesis

Expression profiling and genomic sequencing methods enable the accumulation of vast quantities of data that relate to the expression of genes during the maturation of male germ cells from primordial germ cells to spermatozoa and potential mutations that underlie male infertility. However, the determination of gene function in specific aspects of spermatogenesis or linking abnormal gene function with infertility remain rate limiting, as even in an era of CRISPR analysis of gene function in mammalian models, this still requires considerable resources and time. Comparative developmental biology studies have shown the remarkable conservation of spermatogenic developmental processes from insects to vertebrates and provide an avenue of rapid assessment of gene function to inform the potential roles of specific genes in rodent and human spermatogenesis. The vinegar fly, Drosophila melanogaster, has been used as a model organism for developmental genetic studies for over one hundred years, and research with this organism produced seminal findings such as the association of genes with chromosomes, the chromosomal basis for sexual identity, the mutagenic properties of X-irradiation and the isolation of the first tumour suppressor mutations. Drosophila researchers have developed an impressive array of sophisticated genetic techniques for analysis of gene function and genetic interactions. This review focuses on how these techniques can be utilised to study spermatogenesis in an organism with a generation time of 9 days and the capacity to introduce multiple mutant alleles into an individual organism in a relatively short time frame.

Effects of ten–eleven translocation 1 (Tet1) on DNA methylation and gene expression in chicken primordial germ cells

2019 ◽  
Vol 31 (3) ◽  
pp. 509 ◽  
Author(s):  
Minli Yu ◽  
Dongfeng Li ◽  
Wanyan Cao ◽  
Xiaolu Chen ◽  
Wenxing Du
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Germ Cells ◽  
Dna Methyltransferase ◽  
Primordial Germ Cells ◽  
Dna Demethylation ◽  
Caveolin 1 ◽  
Expression Of Genes ◽  
Deleted In Azoospermia

Ten–eleven translocation 1 (Tet1) is involved in DNA demethylation in primordial germ cells (PGCs); however, the precise regulatory mechanism remains unclear. In the present study the dynamics of 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC) in developing PGCs and the role of Tet1 in PGC demethylation were analysed. Results show that 5mC levels dropped significantly after embryonic Day 4 (E4) and 5hmC levels increased reaching a peak at E5–E5.5. Interestingly, TET1 protein was highly expressed during E5 to E5.5, which showed a consistent trend with 5hmC. The expression of pluripotency-associated genes (Nanog, PouV and SRY-box 2 (Sox2)) and germ cell-specific genes (caveolin 1 (Cav1), piwi-like RNA-mediated gene silencing 1 (Piwi1) and deleted in azoospermia-like (Dazl)) was upregulated after E5, whereas the expression of genes from the DNA methyltransferase family was decreased. Moreover, the Dazl gene was highly methylated in early PGCs and then gradually hypomethylated. Knockdown of Tet1 showed impaired survival and proliferation of PGCs, as well as increased 5mC levels and reduced 5hmC levels. Further analysis showed that knockdown of Tet1 led to elevated DNA methylation levels of Dazl and downregulated gene expression including Dazl. Thus, this study reveals the dynamic epigenetic reprogramming of chicken PGCs invivo and the molecular mechanism of Tet1 in regulating genomic DNA demethylation and hypomethylation of Dazl during PGC development.

scholarly journals SWI/SNF chromatin remodeling complex is required for initiation of sex-dependent differentiation in mouse germline

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Toshiaki Ito ◽  
Atsuki Osada ◽  
Masami Ohta ◽  
Kana Yokota ◽  
Akira Nishiyama ◽  
...  
Keyword(s):  
Chromatin Remodeling ◽  
Germ Cells ◽  
De Novo ◽  
Primordial Germ Cells ◽  
Strand Break ◽  
Conditional Knockout ◽  
Dna Hypomethylation ◽  
Aberrant Expression ◽  
Chromatin Remodeling Complex ◽  
Expression Of Genes

AbstractSexual reproduction involves the creation of sex-dependent gametes, oocytes and sperm. In mammals, sexually dimorphic differentiation commences in the primordial germ cells (PGCs) in embryonic gonads; PGCs in ovaries and testes differentiate into meiotic primary oocytes and mitotically quiescent prospermatogonia, respectively. Here, we show that the transition from PGCs to sex-specific germ cells was abrogated in conditional knockout mice carrying a null mutation of Smarcb1 (also known as Snf5) gene, which encodes a core subunit of the SWI/SNF chromatin remodeling complex. In female mutant mice, failure to upregulate meiosis-related genes resulted in impaired meiotic entry and progression, including defects in synapsis formation and DNA double strand break repair. Mutant male mice exhibited delayed mitotic arrest and DNA hypomethylation in retrotransposons and imprinted genes, resulting from aberrant expression of genes related to growth and de novo DNA methylation. Collectively, our results demonstrate that the SWI/SNF complex is required for transcriptional reprogramming in the initiation of sex-dependent differentiation of germ cells.

scholarly journals X-irradiation Removes Endogenous Primordial Germ Cells (PGCs) and Increases Germline Transmission of Donor PGCs in Chimeric Chickens

2012 ◽  
Vol 58 (4) ◽  
pp. 432-437 ◽  
Author(s):  
Yoshiaki NAKAMURA ◽  
Fumitake USUI ◽  
Daichi MIYAHARA ◽  
Takafumi MORI ◽  
Tamao ONO ◽  
...  
Keyword(s):  
Germ Cells ◽  
Primordial Germ Cells ◽  
Germline Transmission ◽  
X Irradiation

scholarly journals Stage-specific transcriptomes and DNA methylomes indicate an early and transient loss of transposon control in Arabidopsis shoot stem cells

2018 ◽  
Author(s):  
Ruben Gutzat ◽  
Klaus Rembart ◽  
Thomas Nussbaumer ◽  
Rahul Pisupati ◽  
Falko Hofmann ◽  
...  
Keyword(s):  
Stem Cells ◽  
Germ Cells ◽  
Early Stage ◽  
Primordial Germ Cells ◽  
Postembryonic Development ◽  
Specific Gene ◽  
Germline Development ◽  
Expression Of Genes ◽  
Deep Embedding ◽  
Cell Expression

In contrast to animals, postembryonic development in plants is modular, and aerial organs originate from stem cells in the center of the shoot apical meristem (SAM) throughout life. Descendants of SAM stem cells in the subepidermal layer (L2) give also rise to male and female gametes (reviewed in 1) and are therefore considered primordial germ cells. In these cells, transmission of somatic mutations including virus and TE insertions must be avoided. Despite their essential role for plant development and intergenerational continuity, no comprehensive molecular analysis of SAM stem cells exists, due to their low number, deep embedding among non-stem cells, and difficult isolation. Here we present a comprehensive analysis of stage-specific gene expression and DNA methylation dynamics in Arabidopsis SAM stem cells. Stem cell expression signatures are mostly defined by development, but we also identified a core set of differentially expressed stemness genes. Surprisingly, vegetative SAM stem cells showed increased expression of transposable elements (TEs) relative to surrounding cells, despite high expression of genes connected to epigenetic silencing. We also find increasing methylation at CHG and a drop in CHH methylation at TEs before stem cells enter the reproductive lineage, indicating an onset of epigenetic reprogramming at an early stage. Transiently elevated TE expression is reminiscent of that in animal primordial germ cells (PGCs) 2 and demonstrates commonality of transposon biology. Our results connect SAM stem cells with germline development and transposon evolution and will allow future experiments to determine the degree of epigenetic heritability between generations.

scholarly journals A zebrafish nanos-related gene is essential for the development of primordial germ cells

2001 ◽  
Vol 15 (21) ◽  
pp. 2877-2885
Author(s):  
Marion Köprunner ◽  
Christine Thisse ◽  
Bernard Thisse ◽  
Erez Raz
Keyword(s):  
Germ Cells ◽  
Essential Role ◽  
Germ Plasm ◽  
Primordial Germ Cells ◽  
Model Organism ◽  
Vertebrate Model ◽  
The Stability ◽  
And Control ◽  
Asymmetrically Distributed ◽  
Cytoplasmic Determinants

Asymmetrically distributed cytoplasmic determinants collectively termed germ plasm have been shown to play an essential role in the development of primordial germ cells (PGCs). Here, we report the identification of a nanos-like (nanos1) gene, which is expressed in the germ plasm and in the PGCs of the zebrafish. We find that several mechanisms act in concert to restrict the activity of Nanos1 to the germ cells including RNA localization and control over the stability and translatability of the RNA. Reducing the level of Nanos1 in zebrafish embryos revealed an essential role for the protein in ensuring proper migration and survival of PGCs in this vertebrate model organism.

scholarly journals Depletion of Primordial Germ Cells (PGCs) by X-irradiation to Extraembryonic Region of Chicken Embryos and Expression of Xenotransplanted Quail PGCs

2009 ◽  
Vol 46 (2) ◽  
pp. 136-143 ◽  
Author(s):  
Yusuke Atsumi ◽  
Shigenobu Yazawa ◽  
Fumitake Usui ◽  
Yoshiaki Nakamura ◽  
Yasuhiro Yamamoto ◽  
...  
Keyword(s):  
Germ Cells ◽  
Primordial Germ Cells ◽  
Chicken Embryos ◽  
X Irradiation

Analysis of expression of genes specific for pluripotent and primordial germ cells in human and mouse embryonic stem cell lines

2006 ◽  
Vol 406 (1-6) ◽  
pp. 115-118 ◽  
Author(s):  
O. F. Gordeeva ◽  
N. Yu. Krasnikova ◽  
A. V. Larionova ◽  
T. A. Krylova ◽  
G. G. Polyanskaya ◽  
...  
Keyword(s):  
Stem Cell ◽  
Embryonic Stem Cell ◽  
Cell Lines ◽  
Germ Cells ◽  
Primordial Germ Cells ◽  
Embryonic Stem ◽  
Mouse Embryonic Stem Cell ◽  
Expression Of Genes ◽  
Stem Cell Lines ◽  
Human And Mouse

scholarly journals Transcriptional states of retroelement-inserted regions and KRAB zinc finger protein association regulate DNA methylation of retroelements in human male germ cells

2021 ◽  
Author(s):  
Kei Fukuda ◽  
Yoshinori Makino ◽  
Satoru Kaneko ◽  
Yuki Okada ◽  
Kenji Ichiyanagi ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Zinc Finger ◽  
Germ Cells ◽  
Molecular Mechanisms ◽  
Zinc Finger Protein ◽  
De Novo ◽  
Primordial Germ Cells ◽  
Male Germ Cells ◽  
Human Male ◽  
Human Spermatogenesis

DNA methylation, repressive histone modifications, and PIWI-interacting RNAs are essential for controlling retroelement silencing in mammalian germ lines. Dysregulation of retroelement silencing is associated with male sterility. Although retroelement silencing mechanisms have been extensively studied in mouse germ cells, little progress has been made in humans. Here, we show that the Krüppel-associated box domain zinc finger proteins (KRAB-ZFPs) are associated with DNA methylation of retroelements in human primordial germ cells (hPGCs), and hominoid-specific retroelement SINE-VNTR-Alus (SVA) is subjected to transcription-directed de novo DNA methylation during human spermatogenesis. Furthermore, we show that the degree of de novo DNA methylation in SVAs varies among human individuals, which confers a significant inter-individual epigenetic variation in sperm. Collectively, our results provide potential molecular mechanisms for the regulation of retroelements in human male germ cells.

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