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Maternally provided LSD1/KDM1A enables the maternal-to-zygotic transition and prevents defects that manifest postnatally.

Wasson JA, Simon AK, Myrick DA, Wolf G, Driscoll S, Pfaff SL, Macfarlan TS, Katz DJ - Elife (2016)

Bottom Line: Moreover, partial loss of maternal LSD1/KDM1A results in striking phenotypes weeks after fertilization; including perinatal lethality and abnormal behavior in surviving adults.These maternal effect hypomorphic phenotypes are associated with alterations in DNA methylation and expression at imprinted genes.These results establish a novel mammalian paradigm where defects in early epigenetic reprogramming can lead to defects that manifest later in development.

View Article: PubMed Central - PubMed

Affiliation: Department of Cell Biology, Emory University School of Medicine, Atlanta, United States.

ABSTRACT
Somatic cell nuclear transfer has established that the oocyte contains maternal factors with epigenetic reprogramming capacity. Yet the identity and function of these maternal factors during the gamete to embryo transition remains poorly understood. In C. elegans, LSD1/KDM1A enables this transition by removing H3K4me2 and preventing the transgenerational inheritance of transcription patterns. Here we show that loss of maternal LSD1/KDM1A in mice results in embryonic arrest at the 1-2 cell stage, with arrested embryos failing to undergo the maternal-to-zygotic transition. This suggests that LSD1/KDM1A maternal reprogramming is conserved. Moreover, partial loss of maternal LSD1/KDM1A results in striking phenotypes weeks after fertilization; including perinatal lethality and abnormal behavior in surviving adults. These maternal effect hypomorphic phenotypes are associated with alterations in DNA methylation and expression at imprinted genes. These results establish a novel mammalian paradigm where defects in early epigenetic reprogramming can lead to defects that manifest later in development.

No MeSH data available.


Related in: MedlinePlus

Expression of epigenetic regulators in Kdm1aZp3 2C embryos.Sequenced RNA-seq reads showing relative expression from Kdm1afl/fl M+Z+ 2C embryos and Kdm1aZp3 M-Z+ 2C embryos aligned to the genome for Lsd1/Kdm1a (A), Tet1 (B), Trim28 (C), Zfp57 (D), Dppa3/stella (E), Dnmt1 (F) and Uhrf1 (G). Gene tracks visualized using Integrative Genomics Viewer.DOI:http://dx.doi.org/10.7554/eLife.08848.015
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fig3s3: Expression of epigenetic regulators in Kdm1aZp3 2C embryos.Sequenced RNA-seq reads showing relative expression from Kdm1afl/fl M+Z+ 2C embryos and Kdm1aZp3 M-Z+ 2C embryos aligned to the genome for Lsd1/Kdm1a (A), Tet1 (B), Trim28 (C), Zfp57 (D), Dppa3/stella (E), Dnmt1 (F) and Uhrf1 (G). Gene tracks visualized using Integrative Genomics Viewer.DOI:http://dx.doi.org/10.7554/eLife.08848.015

Mentions: The perinatal lethality and behavioral defects observed in Kdm1aVasaM-Z+ progeny are remarkable because these animals have a normal Kdm1a allele. Thus the defects that we observe in Kdm1aVasaM-Z+ progeny must be due to a heritable effect originating from the low level of maternal KDM1A. As a result, we sought to determine the nature of this heritable defect. The Kdm1a homolog Kdm1b is expressed maternally in mice, and loss of Kdm1b results in a heritable embryonic lethality defect associated with a failure to maternally acquire DNA methylation at imprinted genes (Ciccone et al., 2009; Stewart et al., 2015). Therefore, we considered the possibility that the heritable defects could be due to DNA methylation defects at these loci, or in maternally methylated imprinted loci unaffected by the loss of KDM1B. In addition, in our RNA-seq data, we observe the misregulation of multiple genes that could potentially affect DNA methylation at imprinted loci. For example, four genes that are known to maternally affect DNA methylation at imprinted loci, Tet1, Trim28, Zfp57 and Dppa3/Stella (Dawlaty et al., 2013; Li et al., 2008; Messerschmidt et al., 2012; Nakamura et al., 2007; Yamaguchi et al., 2013), are all misregulated in Kdm1aZp3M-Z+mutants (Tet1: -3.8 fold, Trim28: -3.3 fold, Zfp57: +3.2 fold and Dppa3/Stella: +.58 fold, Figure 3—figure supplement 3; Figure 3—source data 1B, quantitative RT-PCR validation of Trim28, Zfp57 and Dppa3/Stella in Figure 3—figure supplement 4). Additionally, the DNA methyltransferase DNMT1 is overexpressed in Kdm1aZp3M-Z+ mutants (Dnmt1: +2.1 fold, Figure 3—figure supplement 3; Figure 3—source data 1B). DNMT1 is thought to primarily act as the maintenance DNA methyltransferase (Li et al., 1992; Pradhan et al., 1999), but when overexpressed, DNMT1 has been shown to have de novo DNA methyltransferase activity (Vertino et al., 1996). Taken together, these observations raise the possibility that DNA methylation and monoallelic expression at imprinted genes could be altered in Kdm1aVasaM-Z+ progeny, either directly or indirectly. Interestingly, despite the clear loss of KDM1A in Kdm1aZp3mutant oocytes, the regulatory proteins that are affected by the loss of KDM1A are either not expressed in oocytes (Tet1) or not affected until after fertilization (Trim28, Zfp57, Dppa3/Stella and Dnmt1,Figure 3—figure supplements 4,5). This is consistent with our previous observations that KDM1A primarily affects the MZT.


Maternally provided LSD1/KDM1A enables the maternal-to-zygotic transition and prevents defects that manifest postnatally.

Wasson JA, Simon AK, Myrick DA, Wolf G, Driscoll S, Pfaff SL, Macfarlan TS, Katz DJ - Elife (2016)

Expression of epigenetic regulators in Kdm1aZp3 2C embryos.Sequenced RNA-seq reads showing relative expression from Kdm1afl/fl M+Z+ 2C embryos and Kdm1aZp3 M-Z+ 2C embryos aligned to the genome for Lsd1/Kdm1a (A), Tet1 (B), Trim28 (C), Zfp57 (D), Dppa3/stella (E), Dnmt1 (F) and Uhrf1 (G). Gene tracks visualized using Integrative Genomics Viewer.DOI:http://dx.doi.org/10.7554/eLife.08848.015
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Related In: Results  -  Collection

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fig3s3: Expression of epigenetic regulators in Kdm1aZp3 2C embryos.Sequenced RNA-seq reads showing relative expression from Kdm1afl/fl M+Z+ 2C embryos and Kdm1aZp3 M-Z+ 2C embryos aligned to the genome for Lsd1/Kdm1a (A), Tet1 (B), Trim28 (C), Zfp57 (D), Dppa3/stella (E), Dnmt1 (F) and Uhrf1 (G). Gene tracks visualized using Integrative Genomics Viewer.DOI:http://dx.doi.org/10.7554/eLife.08848.015
Mentions: The perinatal lethality and behavioral defects observed in Kdm1aVasaM-Z+ progeny are remarkable because these animals have a normal Kdm1a allele. Thus the defects that we observe in Kdm1aVasaM-Z+ progeny must be due to a heritable effect originating from the low level of maternal KDM1A. As a result, we sought to determine the nature of this heritable defect. The Kdm1a homolog Kdm1b is expressed maternally in mice, and loss of Kdm1b results in a heritable embryonic lethality defect associated with a failure to maternally acquire DNA methylation at imprinted genes (Ciccone et al., 2009; Stewart et al., 2015). Therefore, we considered the possibility that the heritable defects could be due to DNA methylation defects at these loci, or in maternally methylated imprinted loci unaffected by the loss of KDM1B. In addition, in our RNA-seq data, we observe the misregulation of multiple genes that could potentially affect DNA methylation at imprinted loci. For example, four genes that are known to maternally affect DNA methylation at imprinted loci, Tet1, Trim28, Zfp57 and Dppa3/Stella (Dawlaty et al., 2013; Li et al., 2008; Messerschmidt et al., 2012; Nakamura et al., 2007; Yamaguchi et al., 2013), are all misregulated in Kdm1aZp3M-Z+mutants (Tet1: -3.8 fold, Trim28: -3.3 fold, Zfp57: +3.2 fold and Dppa3/Stella: +.58 fold, Figure 3—figure supplement 3; Figure 3—source data 1B, quantitative RT-PCR validation of Trim28, Zfp57 and Dppa3/Stella in Figure 3—figure supplement 4). Additionally, the DNA methyltransferase DNMT1 is overexpressed in Kdm1aZp3M-Z+ mutants (Dnmt1: +2.1 fold, Figure 3—figure supplement 3; Figure 3—source data 1B). DNMT1 is thought to primarily act as the maintenance DNA methyltransferase (Li et al., 1992; Pradhan et al., 1999), but when overexpressed, DNMT1 has been shown to have de novo DNA methyltransferase activity (Vertino et al., 1996). Taken together, these observations raise the possibility that DNA methylation and monoallelic expression at imprinted genes could be altered in Kdm1aVasaM-Z+ progeny, either directly or indirectly. Interestingly, despite the clear loss of KDM1A in Kdm1aZp3mutant oocytes, the regulatory proteins that are affected by the loss of KDM1A are either not expressed in oocytes (Tet1) or not affected until after fertilization (Trim28, Zfp57, Dppa3/Stella and Dnmt1,Figure 3—figure supplements 4,5). This is consistent with our previous observations that KDM1A primarily affects the MZT.

Bottom Line: Moreover, partial loss of maternal LSD1/KDM1A results in striking phenotypes weeks after fertilization; including perinatal lethality and abnormal behavior in surviving adults.These maternal effect hypomorphic phenotypes are associated with alterations in DNA methylation and expression at imprinted genes.These results establish a novel mammalian paradigm where defects in early epigenetic reprogramming can lead to defects that manifest later in development.

View Article: PubMed Central - PubMed

Affiliation: Department of Cell Biology, Emory University School of Medicine, Atlanta, United States.

ABSTRACT
Somatic cell nuclear transfer has established that the oocyte contains maternal factors with epigenetic reprogramming capacity. Yet the identity and function of these maternal factors during the gamete to embryo transition remains poorly understood. In C. elegans, LSD1/KDM1A enables this transition by removing H3K4me2 and preventing the transgenerational inheritance of transcription patterns. Here we show that loss of maternal LSD1/KDM1A in mice results in embryonic arrest at the 1-2 cell stage, with arrested embryos failing to undergo the maternal-to-zygotic transition. This suggests that LSD1/KDM1A maternal reprogramming is conserved. Moreover, partial loss of maternal LSD1/KDM1A results in striking phenotypes weeks after fertilization; including perinatal lethality and abnormal behavior in surviving adults. These maternal effect hypomorphic phenotypes are associated with alterations in DNA methylation and expression at imprinted genes. These results establish a novel mammalian paradigm where defects in early epigenetic reprogramming can lead to defects that manifest later in development.

No MeSH data available.


Related in: MedlinePlus