Project description:We used transcriptome analysis to identify genes transcriptionally disregulated in feto-placental endothelial cells from mutants with conditional deletion of Igf2 gene driven by the Meox2Cre.
Project description:We used transcriptome analysis to identify genes transcriptionally disregulated in feto-placental endothelial cells from mutants with conditional deletion of Igf2 gene driven by the Tek-cre.
Project description:We used microarrays to identify genes that are transcriptionally dysregulated between Igf2EpiKO mutants and littermates controls at E19
Project description:The placenta acts as an interface between the mother and fetus, regulating nutrient transport and secreting hormones which impact maternal metabolism. Complications during pregnancy, such as placental endocrine malfunction, programme offspring to develop metabolic disease during adulthood, in part via changes in gene expression in critical metabolic organs, such as the liver, during fetal development. Placental endocrine malfunction was induced via the misexpression of two imprinted genes (Igf2 and H19) exclusively in the endocrine zone of the mouse placenta, to study the consequences this has on fetal hepatic gene expression.
Project description:Insulin-like growth factor 2 (Igf2) is the major fetal growth hormone in mammals. Here we identify the Kruppel-associated-box (KRAB) zinc finger protein 568 (ZFP568) as a direct repressor of a placental specific Igf2 transcript (designated Igf2-P0) in early mouse development. Loss of Zfp568, which leads to gastrulation failure, causes inappropriate Igf2-P0 activation. Strikingly, deletion of paternal Igf2 can completely rescue Zfp568 knockout-induced gastrulation phenotypes. Mechanistically, ZFP568 and its binding site are required to maintain H3K9me3 and CpG methylation of the Igf2-P0 region. The ZFP568 binding site upstream of the Igf2-P0 transcript is highly conserved throughout Eutheria, along with the DNA binding domain of ZFP568 orthologs, with the exception of human, whose three Znf568 alleles previously linked to human head size at birth have rapidly evolved and mostly lost the ability to bind and suppress Igf2, coincident with the loss of Igf2-P0 transcript activity. We speculate that the Igf2-P0 transcript and its repressor ZFP568 appeared in a common ancestor of placental mammals as a critical adaptation to boost Igf2 expression specifically in the placenta to regulate maternal supply and fetal demand for nutrients. These data also highlight the exquisite specificity and selectivity by which KRAB-ZFPs have been naturally selected to recognize their genomic targets for pinpoint heterochromatin establishment during mammalian evolution.
Project description:Abstract: Dysregulation of the imprinted H19/IGF2 locus can lead to Silver-Russell Syndrome (SRS) in humans. However, the mechanism of how abnormal H19/IGF2 expression contributes to various SRS phenotypes remains unclear, largely due to incomplete understanding of the developmental functions of these two genes. We previously generated a mouse model with humanized H19/IGF2 ICR (hIC1) on the paternal allele that exhibited H19/Igf2 dysregulation together with SRS-like growth restriction and perinatal lethality. Here we dissect the role of H19 and Igf2 in cardiac and placental development utilizing multiple mouse models with varying levels of H19 and Igf2. We report severe cardiac defects such as ventricular septal defects (VSDs) and thinned myocardium, placental anomalies including thrombosis and vascular malformations, together with growth restriction in mouse embryos that correlated with the extent of H19/Igf2 dysregulation. Transcriptomic analysis using cardiac endothelial cells of these mouse models shows that H19/Igf2 dysregulation disrupts pathways related to extracellular matrix (ECM) and proliferation of endothelial cells. Our work links the heart and placenta through regulation by H19 and Igf2, demonstrating that accurate dosage of both H19 and Igf2 is critical for normal embryonic development, especially related to the cardiac-placental axis. Methods: E12.5 hearts were lysed with Collagenase, Dispase II, and DNase I. Cardiac endothelial cells were collected using MACS CD31 microbeads and RNA was isolated using RNeasy Micro kit. After confirming RNA integrity using Bioanalyzer, mRNA library was generated from 25ng RNA using NEBNext Poly(A) mRNA Magnetic Isolation Module and Ultra II RNA Library Prep Kit. Library quality was assessed by Bioanalyzer and TapeStation. Sequencing was performed on NovaSeq 6000. Quality of raw fastq reads was assessed using FastQC version 0.11.5. Reads were aligned to the GRCm38/mm10 reference using STAR version 2.4.0i with default parameters and maximum fragment size of 2000 bp. Properly paired primary alignments were retained for downstream analysis using Samtools version 1.9. Count matrices were generated using FeatureCounts version 1.6.2 against RefSeq gene annotation and read into DESeq2 to perform normalization and statistical analysis.