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Poultry Science Nov 2020The present research was conducted to assess Mn requirements of broiler breeder hens. One hundred and twenty Cobb 500 hens, 22 wk of age, were individually allocated in...
The present research was conducted to assess Mn requirements of broiler breeder hens. One hundred and twenty Cobb 500 hens, 22 wk of age, were individually allocated in cages. After fed a Mn-deficient diet (22.2 ppm), hens were randomly placed in treatments having 6 increments of 30-ppm Mn. All trace minerals were from laboratory grade sources being Mn from Mn sulfate (MnSOHO). Treatments were fed for 4 periods of 28 d. There were no interactions between dietary Mn and period for any evaluated response (P > 0.05). Requirements of Mn for hen day egg production and settable egg production were 115.8 and 56.6 ppm and 122.1 and 63.6 ppm (P < 0.05), respectively, using quadratic polynomial (QP) and broken line quadratic (BLQ) models, whereas total eggs and total settable eggs per hen had Mn requirements estimated at 115.7 and 56.6 and 121.8 and 61.7 ppm (P < 0.05), respectively. Number of cracked, defective, and contaminated eggs decreased, whereas hatchability, hatchability of fertile eggs, eggshell percentage, and eggshell palisade layer increased when hens were fed diets having 48.5 to 168.2-ppm Mn (P < 0.05). Maximum responses for egg weight and eggshell percentage were 117.7 and 63.6 ppm as well as 131.6 and 71.0 ppm (P < 0.05), respectively, using QP and BLQ models. Breaking strength and egg specific gravity had Mn requirements estimated at 140.2 and 112.7 ppm as well as 131.3 68.5 ppm (P < 0.05), whereas eggshell palisade layer and eggshell thickness were maximized with 128.8 and 68.8 ppm and 140.2 134.2 ppm, respectively, for QP and BLQ models (P < 0.05). Maximum yolk Mn content values were obtained using 118.0- and 118.4-ppm Mn by QP and BLQ models, respectively. The average Mn requirements estimated for QP and BLQ models is 128.4 and 92.3 ppm Mn (18.7 and 13.5 mg/hen/d), respectively, which is much lower than what has been currently recommended in commercial production.
Topics: Animal Feed; Animals; Chickens; Diet; Egg Shell; Female; Manganese; Random Allocation; Zygote
PubMed: 33142499
DOI: 10.1016/j.psj.2020.06.085 -
Advanced Science (Weinheim,... May 2024Epigenetic modifiers that accumulate in oocytes, play a crucial role in steering the developmental program of cleavage embryos and initiating life. However, the...
Epigenetic modifiers that accumulate in oocytes, play a crucial role in steering the developmental program of cleavage embryos and initiating life. However, the identification of key maternal epigenetic regulators remains elusive. In the findings, the essential role of maternal Ep400, a chaperone for H3.3, in oocyte quality and early embryo development in mice is highlighted. Depletion of Ep400 in oocytes resulted in a decline in oocyte quality and abnormalities in fertilization. Preimplantation embryos lacking maternal Ep400 exhibited reduced major zygotic genome activation (ZGA) and experienced developmental arrest at the 2-to-4-cell stage. The study shows that EP400 forms protein complex with NFYA, occupies promoters of major ZGA genes, modulates H3.3 distribution between euchromatin and heterochromatin, promotes transcription elongation, activates the expression of genes regulating mitochondrial functions, and facilitates the expression of rate-limiting enzymes of the TCA cycle. This intricate process driven by Ep400 ensures the proper execution of the developmental program, emphasizing its critical role in maternal-to-embryonic transition.
Topics: Animals; Mice; Oocytes; Zygote; Female; Embryonic Development; Chromatin; Gene Expression Regulation, Developmental; Molecular Chaperones; Epigenesis, Genetic; E1A-Associated p300 Protein
PubMed: 38493496
DOI: 10.1002/advs.202308018 -
Developmental Cell Apr 2022Targeted protein degradation methods offer a unique avenue to assess a protein's function in a variety of model systems. Recently, these approaches have been applied to...
Targeted protein degradation methods offer a unique avenue to assess a protein's function in a variety of model systems. Recently, these approaches have been applied to mammalian cell culture models, enabling unprecedented temporal control of protein function. However, the efficacy of these systems at the tissue and organismal levels in vivo is not well established. Here, we tested the functionality of the degradation tag (dTAG) degron system in mammalian development. We generated a homozygous knock-in mouse with a FKBP12 tag fused to negative elongation factor b (Nelfb) locus, a ubiquitously expressed regulator of transcription. In our validation of targeted endogenous protein degradation across mammalian development and adulthood, we demonstrate that irrespective of the route of administration the dTAG system is non-toxic, rapid, and efficient in embryos from the zygote-to-mid-gestation stages. Additionally, acute depletion of NELFB revealed a specific role in zygote-to-2-cell development and zygotic genome activation (ZGA).
Topics: Animals; Embryonic Development; Gene Expression Regulation, Developmental; Genome; Mammals; Mice; RNA Polymerase II; Zygote
PubMed: 35421370
DOI: 10.1016/j.devcel.2022.03.013 -
International Journal of Molecular... Jan 2024Mammalian fertilization initiates the reprogramming of oocytes and sperm, forming a totipotent zygote. During this intricate process, the zygotic genome undergoes a... (Review)
Review
Mammalian fertilization initiates the reprogramming of oocytes and sperm, forming a totipotent zygote. During this intricate process, the zygotic genome undergoes a maternal-to-zygotic transition (MZT) and subsequent zygotic genome activation (ZGA), marking the initiation of transcriptional control and gene expression post-fertilization. Histone modifications are pivotal in shaping cellular identity and gene expression in many mammals. Recent advances in chromatin analysis have enabled detailed explorations of histone modifications during ZGA. This review delves into conserved and unique regulatory strategies, providing essential insights into the dynamic changes in histone modifications and their variants during ZGA in mammals. The objective is to explore recent advancements in leading mechanisms related to histone modifications governing this embryonic development phase in depth. These considerations will be useful for informing future therapeutic approaches that target epigenetic regulation in diverse biological contexts. It will also contribute to the extensive areas of evolutionary and developmental biology and possibly lay the foundation for future research and discussion on this seminal topic.
Topics: Animals; Pregnancy; Female; Male; Zygote; Histone Code; Epigenesis, Genetic; Gene Expression Regulation, Developmental; Semen; Embryonic Development; Mammals
PubMed: 38338738
DOI: 10.3390/ijms25031459 -
Scientific Reports Nov 2020A battery of chromatin modifying enzymes play essential roles in remodeling the epigenome in the zygote and cleavage stage embryos, when the maternal genome is the sole...
A battery of chromatin modifying enzymes play essential roles in remodeling the epigenome in the zygote and cleavage stage embryos, when the maternal genome is the sole contributor. Here we identify an exemption. DOT1L methylates lysine 79 in the globular domain of histone H3 (H3K79). Dot1l is an essential gene, as homozygous null mutant mouse embryos exhibit multiple developmental abnormalities and die before 11.5 days of gestation. To test if maternally deposited DOT1L is required for embryo development, we carried out a conditional Dot1l knockout in growing oocytes using the Zona pellucida 3-Cre (Zp3-Cre) transgenic mice. We found that the resulting maternal mutant Dot1l offspring displayed normal development and fertility, suggesting that the expression of the paternally inherited copy of Dot1l in the embryo is sufficient to support development. In addition, Dot1l maternal deletion did not affect the parental allele-specific expression of imprinted genes, indicating that DOT1L is not needed for imprint establishment in the oocyte or imprint protection in the zygote. In summary, uniquely and as opposed to other histone methyltransferases and histone marks, maternal DOT1L deposition and H3K79 methylation in the zygote and in the preimplantation stage embryo is dispensable for mouse development.
Topics: Animals; Blastocyst; Cell Proliferation; Embryo, Mammalian; Embryonic Development; Histone Methyltransferases; Histone-Lysine N-Methyltransferase; Histones; Lysine; Methylation; Mice; Mice, Knockout; Mice, Transgenic; Models, Animal; Oocytes; Zygote
PubMed: 33244015
DOI: 10.1038/s41598-020-77545-6 -
International Journal of Molecular... Feb 2022The double homeobox ) gene, encoding a double homeobox transcription factor, is one of the key drivers of totipotency in mice. Recent studies showed Dux was temporally... (Review)
Review
The double homeobox ) gene, encoding a double homeobox transcription factor, is one of the key drivers of totipotency in mice. Recent studies showed Dux was temporally expressed at the 2-cell stage and acted as a transcriptional activator during zygotic genome activation (ZGA) in embryos. A similar activation occurs in mouse embryonic stem cells, giving rise to 2-cell-like cells (2CLCs). Though the molecular mechanism underlying this expanded 2CLC potency caused by Dux activation has been partially revealed, the regulation mechanisms controlling Dux expression remain elusive. Here, we discuss the latest advancements in the multiple levels of regulation of Dux expression, as well as Dux function in 2CLCs transition, aiming to provide a theoretical framework for understanding the mechanisms that regulate totipotency.
Topics: Animals; Embryonic Development; Gene Expression Regulation, Developmental; Genes, Homeobox; Genome; Homeodomain Proteins; Humans; Transcription Factors; Zygote
PubMed: 35216182
DOI: 10.3390/ijms23042067 -
Cell Research Sep 2022Chromatin remodeling is essential for epigenome reprogramming after fertilization. However, the underlying mechanisms of chromatin remodeling remain to be explored....
Chromatin remodeling is essential for epigenome reprogramming after fertilization. However, the underlying mechanisms of chromatin remodeling remain to be explored. Here, we investigated the dynamic changes in nucleosome occupancy and positioning in pronucleus-stage zygotes using ultra low-input MNase-seq. We observed distinct features of inheritance and reconstruction of nucleosome positioning in both paternal and maternal genomes. Genome-wide de novo nucleosome occupancy in the paternal genome was observed as early as 1 h after the injection of sperm into ooplasm. The nucleosome positioning pattern was continually rebuilt to form nucleosome-depleted regions (NDRs) at promoters and transcription factor (TF) binding sites with differential dynamics in paternal and maternal genomes. NDRs formed more quickly on the promoters of genes involved in zygotic genome activation (ZGA), and this formation is closely linked to histone acetylation, but not transcription elongation or DNA replication. Importantly, we found that NDR establishment on the binding motifs of specific TFs might be associated with their potential pioneer functions in ZGA. Further investigations suggested that the predicted factors MLX and RFX1 played important roles in regulating minor and major ZGA, respectively. Our data not only elucidate the nucleosome positioning dynamics in both male and female pronuclei following fertilization, but also provide an efficient method for identifying key transcription regulators during development.
Topics: Animals; Chromatin Assembly and Disassembly; Female; Fertilization; Male; Mice; Nucleosomes; Regulatory Factor X1; Semen; Zygote
PubMed: 35428874
DOI: 10.1038/s41422-022-00652-8 -
PLoS Biology Jan 2021To ensure genome stability, sexually reproducing organisms require that mating brings together exactly 2 haploid gametes and that meiosis occurs only in diploid zygotes....
To ensure genome stability, sexually reproducing organisms require that mating brings together exactly 2 haploid gametes and that meiosis occurs only in diploid zygotes. In the fission yeast Schizosaccharomyces pombe, fertilization triggers the Mei3-Pat1-Mei2 signaling cascade, which represses subsequent mating and initiates meiosis. Here, we establish a degron system to specifically degrade proteins postfusion and demonstrate that mating blocks not only safeguard zygote ploidy but also prevent lysis caused by aberrant fusion attempts. Using long-term imaging and flow-cytometry approaches, we identify previously unrecognized and independent roles for Mei3 and Mei2 in zygotes. We show that Mei3 promotes premeiotic S-phase independently of Mei2 and that cell cycle progression is both necessary and sufficient to reduce zygotic mating behaviors. Mei2 not only imposes the meiotic program and promotes the meiotic cycle, but also blocks mating behaviors independently of Mei3 and cell cycle progression. Thus, we find that fungi preserve zygote ploidy and survival by at least 2 mechanisms where the zygotic fate imposed by Mei2 and the cell cycle reentry triggered by Mei3 synergize to prevent zygotic mating.
Topics: Cell Cycle; Cell Cycle Proteins; Fungal Proteins; Genes, Fungal; Mating Factor; Meiosis; Organisms, Genetically Modified; Ploidies; RNA-Binding Proteins; Recombination, Genetic; Schizosaccharomyces; Schizosaccharomyces pombe Proteins; Zygote
PubMed: 33406066
DOI: 10.1371/journal.pbio.3001067 -
Cell Reports Jun 2020After fertilization, sperm and oocyte nuclei are rapidly remodeled to form swollen pronuclei (PN) in mammalian zygotes, and the proper formation and function of PN are...
After fertilization, sperm and oocyte nuclei are rapidly remodeled to form swollen pronuclei (PN) in mammalian zygotes, and the proper formation and function of PN are key to producing totipotent zygotes. However, how mature PN are formed has been unclear. We find that filamentous actin (F-actin) assembles in the PN of mouse zygotes and is required for fully functional PN. The perturbation of nuclear actin dynamics in zygotes results in the misregulation of genes related to genome integrity and abnormal development of mouse embryos. We show that nuclear F-actin ensures DNA damage repair, thus preventing the activation of a zygotic checkpoint. Furthermore, optogenetic control of cofilin nuclear localization reveals the dynamically regulated F-actin nucleoskeleton in zygotes, and its timely disassembly is needed for developmental progression. Nuclear F-actin is a hallmark of totipotent zygotic PN, and the temporal regulation of its polymerized state is necessary for normal embryonic development.
Topics: Actin Cytoskeleton; Actin Depolymerizing Factors; Actins; Animals; Cell Cycle Checkpoints; Cell Nucleus; Cell Survival; Checkpoint Kinase 1; DNA Damage; Embryo, Mammalian; Embryonic Development; Gene Expression Regulation, Developmental; Imaging, Three-Dimensional; Light; Mice, Inbred ICR; Mitosis; Polymerization; Up-Regulation; Zygote
PubMed: 32610125
DOI: 10.1016/j.celrep.2020.107824 -
Molecular Plant Sep 2021Fertilization constitutes a critical step in the plant life cycle during which the gamete genomes undergo chromatin dynamics in preparation for embryogenesis. In...
Fertilization constitutes a critical step in the plant life cycle during which the gamete genomes undergo chromatin dynamics in preparation for embryogenesis. In mammals, parental chromatin is extensively reprogrammed through the global erasure of DNA methylation. However, in flowering plants it remains unclear whether and how DNA methylation is remodeled in gametes and after fertilization in the zygote. In this study, we characterize DNA methylation patterns and investigate the function of DNA glycosylases in rice eggs, sperm, and unicellular zygotes and during embryogenesis. We found that DNA methylation is locally reconfigured after fertilization and is intensified during embryogenesis. Genetic, epigenomic, and transcriptomic analysis revealed that three rice DNA glycosylases, DNG702, DNG701, and DNG704, demethylate DNA at distinct genomic regions in the gametes and the zygote, and are required for zygotic gene expression and development. Collectively, these results indicate that active DNA demethylation takes place in the gametes and the zygote to locally remodel DNA methylation, which is critical for egg and zygote gene expression and reproduction in rice.
Topics: Arabidopsis; Chromatin; DNA Methylation; DNA, Plant; Germ Cells, Plant; Oryza; Plant Development; Zygote
PubMed: 34116223
DOI: 10.1016/j.molp.2021.06.006