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In mammals, male and female gonads initially develop from bipotential progenitor cells, which can differentiate into either testicular or ovarian cells. The decision to adopt a testicular or ovarian fate relies on robust genetic forces, i.e., activation of the testis-determining gene Sry , as well as a delicate balance of expression levels for pro-testis and pro-ovary factors. Recently, epigenetic regulation has been found to be a key element in activation of Sry . Nevertheless, the mechanism by which epigenetic regulation controls the expression balance of pro-testis and pro-ovary factors remains unclear. Chromodomain Y-like protein (CDYL) is a reader protein for repressive histone H3 methylation marks. We found that a subpopulation of Cdyl -deficient mice exhibited XY sex reversal. Gene expression analysis revealed that the testis-promoting gene Sox9 was downregulated in XY Cdyl -deficient gonads during the sex determination period without affecting Sry expression. Instead, we found that the ovary-promoting gene Wnt4 was derepressed in XY Cdyl -deficient gonads prior to and during the sex-determination period. Wnt4 heterozygous deficiency restored SOX9 expression in Cdyl -deficient XY gonads, indicating that derepressed Wnt4 is a cause of the repression of Sox9 . We found that CDYL directly bound to the Wnt4 promoter and maintained its H3K27me3 levels during the sex-determination period. These findings indicate that CDYL reinforces male gonadal sex determination by repressing the ovary-promoting pathway in mice.

Male penis is required to become erect during copulation. In the upper (dorsal) part of penis, the erectile tissue termed corpus cavernosum (CC) plays fundamental roles for erection by regulating the inner blood flow. When blood flows into the CC, the microvascular complex termed sinusoidal space is reported to expand during erection. A novel in vitro explant system to analyze the dynamic erectile responses during contraction/relaxation is established. The current data show regulatory contraction/relaxation processes induced by phenylephrine (PE) and nitric oxide (NO) donor mimicking dynamic erectile responses by in vitro CC explants. Two-photon excitation microscopy (TPEM) observation shows the synchronous movement of sinusoidal space and the entire CC. By taking advantages of the CC explant system, tadalafil (Cialis) was shown to increase sinusoidal relaxation. Histopathological changes have been generally reported associating with erection in several pathological conditions. Various stressed statuses have been suggested to occur in the erectile responses by previous studies. The current CC explant model enables to analyze such conditions through directly manipulating CC in the repeated contraction/relaxation processes. Expression of oxidative stress marker and contraction-related genes, Hypoxia-inducible factor 1-alpha (Hif1a), glutathione peroxidase 1 (Gpx1), Ras homolog family member A (RhoA), and Rho-associated protein kinase (Rock), was significantly increased in such repeated contraction/relaxation. Altogether, it is suggested that the system is valuable for analyzing structural changes and physiological responses to several regulators in the field of penile medicine.

Mammalian male sex differentiation is triggered during embryogenesis by the activation of the Y-linked testis-determining gene SRY. Since insufficient or delayed expression of SRY results in XY gonadal sex reversal, accurate regulation of SRY is critical for male development in XY animals. In humans, dysregulation of SRY may cause disorders of sex development. Mouse Sry is the most intensively studied mammalian model of sex determination. Sry expression is controlled in a spatially and temporally stringent manner. Several transcription factors play a key role in sex determination as trans-acting factors for Sry expression. In addition, recent studies have shown that several epigenetic modifications of Sry are involved in sex determination as cis-acting factors for Sry expression. Herein, we review the current understanding of transcription factor- and epigenetic modifier-mediated regulation of SRY/Sry expression.

Di- or tri-methylated H3K9 (H3K9me2/3) is an epigenetic mark of heterochromatin. Heterochromatin protein 1 (HP1) specifically recognizes H3K9me2/3, contributing to transcriptional suppression and spread of H3K9me2/3. Here, we demonstrate another role of HP1 in heterochromatin organization: regulation of protein stability of H3K9 methyltransferases (H3K9 MTs) and demethylases (H3K9 DMs). We show that HP1 interaction-defective mutants of H3K9 MTs, Suv39h1 and Setdb1, undergo protein degradation. We further establish mouse embryonic stem cell lines lacking all three HP1 paralogs. In the HP1-deficient cells, Suv39h1, Suv39h2, Setdb1, and G9a/GLP complex decrease at the protein level, and the enzymes are released from chromatin. HP1 mutants that cannot recognize H3K9me2/3 or form dimers cannot stabilize these enzymes, indicating that the tethering of H3K9 MTs to chromatin is critical for their protein stability. We show that HP1 also stabilizes H3K9 DMs, Jmjd1a and Jmjd1b. Our study indicates that mammalian HP1 forms a heterochromatin hub that governs protein stability of H3K9 MTs and H3K9 DMs.

Two rather than one For several decades, it has been believed that the mammalian sex-determining gene Sry contains a single exon. Miyawaki et al. have now identified a cryptic second exon of mouse Sry . Loss- and gain-of-function analyses revealed that the two-exon SRY (SRY-T), not the canonical single exon–encoded SRY (SRY-S), is the bona fide testis-determining factor. Sry exon2 is composed of retrotransposon-derived sequences. The SRY-S carboxyl terminus contains a degradation sequence (degron), whereas the SRY-T carboxyl terminus encoded in the Sry exon2 is degron free, thereby conferring protein stability on SRY-T. Science , this issue p. 121

Background/Aim: The entire mechanisms by which epigenetic modifiers contribute to the development of pancreatic cancer remain unknown. Although the histone methyltransferase G9a is a promising target in human cancers, its role in pancreatic carcinogenesis has been under-studied. The aim of the study was to examine the role of G9a in pancreatic carcinogenesis by a gene-targeting mouse model. Materials and Methods: We established pancreas-specific G9a(flox/flox )mice and crossed them with Ptf1a(Cre/); Kras(G12D/+ )(KC) mice, which spontaneously develop pancreatic cancer. The phenotypes of the resulting KC mice with G9a deletion were examined. We analyzed transcriptomic data by microarray and genome-wide chromatin accessibility by transposase-accessible chromatin using sequencing. We established pancreatic organoids from KC mice. Results: G9a deficiency impaired the progression of pancreatic intraepithelial neoplasia (PanIN) and prolonged the survival of KC mice. The number of phosphorylated Erk-positive cells and Dclk1-positive cells, which are reported to be essential for the progression of PanIN, were decreased by G9a deletion. UNC0638, an inhibitor of G9a, suppressed the growth of organoids and increased global chromatin accessibility, especially around the regions including the protein phosphatase 2A genes. Conclusion: Thus, our study suggested the functional interaction of G9a, Dclk1 and Mapk pathway in the Kras-driven pancreatic carcinogenesis. The inhibition of G9a may suppress the initiation of oncogenic Kras-driven pancreatic carcinogenesis.

We report thermal conductivity (κ) above 300 K for perovskite ferroelectrics BaTiO3 (T c ≈ 402 K) and PbTiO3 (763 K), as well as antiferroelectrics PbZrO3 (503 K) and PbHfO3 (476 and 433 K). BaTiO3 and PbTiO3 show similar κ in the paraelectric phase. In contrast, smaller and glasslike κ is found above T c for PbZrO3 and PbHfO3, signifying the presence of large anharmonic distortions in the paraelectric phase. Low-temperature heat capacity on PbZrO3 shows a lack of glasslike thermal behavior in the antiferroelectric phase.

Reconstituting the ovarian follicle Recent advances have enabled the generation of oocytes from pluripotent stem cells in vitro. However, these cells require a somatic environment to develop fully as reproductive cells. Yoshino et al. applied what is known about differentiation processes in vivo to determine a culture condition to differentiate embryonic stem cells into gonadal somatic cell–like cells (see the Perspective by Yang and Ng). When the embryonic stem cell–generated ovarian gonadal tissue was combined with early primordial germ cells or in vitro–derived primordial germ cell–like cells, germ cells developed into viable oocytes within the reconstituted follicles that could be fertilized and result in viable offspring. This system enables an alternative method for mouse gamete production and advances our understanding of mammalian reproduction and development. Science , abe0237, this issue p. eabe0237 ; see also abj8347, p. 282

Among caspase family members, Caspase-8 is unique, with associated critical activities to induce and suppress death receptor-mediated apoptosis and necroptosis, respectively. Caspase-8 inhibits necroptosis by suppressing the function of receptor-interacting protein kinase 1 (RIPK1 or RIP1) and RIPK3 to activate mixed lineage kinase domain-like (MLKL). Disruption ofCaspase-8expression causes embryonic lethality in mice, which is rescued by depletion of eitherRipk3orMlkl, indicating that the embryonic lethality is caused by activation of necroptosis. Here, we show that knockdown ofCaspase-8expression in embryoid bodies derived from ES cells markedly enhances retinoic acid (RA)-induced cell differentiation and necroptosis, both of which are dependent onRipk1andRipk3; however, the enhancement of RA-induced cell differentiation is independent ofMlkland necrosome formation. RA treatment obviously enhanced the expression of RA-specific target genes having the retinoic acid response element (RARE) in their promoter regions to induce cell differentiation, and induced marked expression of RIPK1, RIPK3, and MLKL to stimulate necroptosis.Caspase-8knockdown induced RIPK1 and RIPK3 to translocate into the nucleus and to form a complex with RA receptor (RAR), and RAR interacting with RIPK1 and RIPK3 showed much stronger binding activity toRAREthan RAR without RIPK1 or RIPK3. InCaspase-8-deficient as well asCaspase-8- andMlkl-deficient mouse embryos, the expression of RA-specific target genes was obviously enhanced. Thus, Caspase-8, RIPK1, and RIPK3 regulate RA-induced cell differentiation and necroptosis both in vitro and in vivo.

While the significance of acquired genetic abnormalities in the initiation of hepatocellular carcinoma (HCC) has been established, the role of epigenetic modification remains unknown. Here we identified the pivotal role of histone methyltransferase G9a in the DNA damage-triggered initiation of HCC. Using liver-specific G9a-deficient (G9aΔHep) mice, we revealed that loss of G9a significantly attenuated liver tumor initiation caused by diethylnitrosamine (DEN). In addition, pharmacological inhibition of G9a attenuated the DEN-induced initiation of HCC. After treatment with DEN, while the induction of γH2AX and p53 were comparable in the G9aΔHep and wild-type livers, more apoptotic hepatocytes were detected in the G9aΔHep liver. Transcriptome analysis identified Bcl-G, a pro-apoptotic Bcl-2 family member, to be markedly upregulated in the G9aΔHep liver. In human cultured hepatoma cells, a G9a inhibitor, UNC0638, upregulated BCL-G expression and enhanced the apoptotic response after treatment with hydrogen peroxide or irradiation, suggesting an essential role of the G9a-Bcl-G axis in DNA damage response in hepatocytes. The proposed mechanism was that DNA damage stimuli recruited G9a to the p53-responsive element of the Bcl-G gene, resulting in the impaired enrichment of p53 to the region and the attenuation of Bcl-G expression. G9a deletion allowed the recruitment of p53 and upregulated Bcl-G expression. These results demonstrate that G9a allows DNA-damaged hepatocytes to escape p53-induced apoptosis by silencing Bcl-G, which may contribute to the tumor initiation. Therefore, G9a inhibition can be a novel preventive strategy for HCC.

SummaryDuring spermatogenesis, meiosis is accompanied by robust alteration in gene expression and chromatin status. However, it remained elusive how meiotic transcriptional program is established to ensure completion of meiotic prophase. Here, we identified a novel protein complex consisting of germ-cell-specific zinc-finger protein ZFP541 and its interactor KCTD19 as the key transcriptional regulator for meiotic prophase exit. Our genetic study showed that ZFP541 and KCTD19 are co-expressed from pachytene onward and play an essential role in the completion of meiotic prophase program in the testis. Furthermore, our ChIP-seq and transcriptome analyses revealed that ZFP541 binds to and suppresses a broad range of genes whose function is associated with biological processes of transcriptional regulation and covalent chromatin modification. The present study demonstrated that germ-cell specific ZFP541-KCTD19 containing complex promotes meiotic prophase exit in males, and triggers reconstruction of the transcription network and chromatin organization leading to post-meiotic development.

During spermatogenesis, meiosis is accompanied by a robust alteration in gene expression and chromatin status. However, it remains elusive how the meiotic transcriptional program is established to ensure completion of meiotic prophase. Here, we identify a protein complex that consists of germ-cell-specific zinc-finger protein ZFP541 and its interactor KCTD19 as the key transcriptional regulators in mouse meiotic prophase progression. Our genetic study shows that ZFP541 and KCTD19 are co-expressed from pachytene onward and play an essential role in the completion of the meiotic prophase program in the testis. Furthermore, our ChIP-seq and transcriptome analyses identify that ZFP541 binds to and suppresses a broad range of genes whose function is associated with biological processes of transcriptional regulation and covalent chromatin modification. The present study demonstrates that a germ-cell specific complex that contains ZFP541 and KCTD19 promotes the progression of meiotic prophase towards completion in male mice, and triggers the reconstruction of the transcriptional network and chromatin organization leading to post-meiotic development., The authors add to our knowledge of the transcriptional regulation of the meiotic program in mice spermatocytes, showing ZFP541 regulates meiotic prophase and transition to the division phase by being the target for upstream factors MEIOSIN/STRA8.

We report on the development of a capacitance measuring system which allows measurements of capacitance in pulsed magnetic fields up to 61~T. By using this system, magnetic-field responses of various physical quantities such magnetostriction, magnetic-field-induced change in complex dielectric constant, and magneto-caloric effect can be investigated in pulsed-magnetic-field conditions. Here, we examine the validity of our system for investigations of these magnetic-field-induced phenomena in pulse magnets. For the magnetostriction measurement, magnetostriction of a specimen can be measured through a change in the capacitance between two aligned electrodes glued on the specimen and a dilatometer. We demonstrate a precise detection of valley polarization in semimetallic bismuth through a magnetostriction signal with a resolution better than 10$^{-6}$ of the relative length change. For the magnetic-field-induced change in complex dielectric constant, we successfully observed clear dielectric anomalies accompanied by magnetic/magnetoelectric phase transitions in multiferroic Pb(TiO)Cu$_4$(PO$_4$)$_4$. For the measurement of magneto-caloric effect, a magnetic-field-induced change in sample temperature was verified for Gd$_3$Ga$_5$O$_{12}$ with a capacitance thermometer made of a non-magnetic ferroelectric compound KTa$_{1-x}$Nb$_x$O$_3$ ($x$ = 0.02) whose capacitance is nearly field-independent. These results show that our capacitance measuring system is a promising tool to study various magnetic-field-induced phenomena which have been difficult to detect in pulsed magnetic fields., 10 pages, 5 figures, submitted to Review of Scientific Instruments

The mammalian sex-determining gene

Regulation of gene expression without changing the DNA sequence is governed by epigenetic mechanisms. Epigenetic regulation is important for changing chromatin structure in response to environmental cues as well as maintaining chromatin structure after cell division. The epigenetic machinery can reversibly change chromatin function, allowing a wide variety of biological processes in multicellular organisms to be controlled. Epigenetic regulation ensures spatial and temporal accuracy of the expression of developmentally regulated genes. So far, few studies have focused on the relationship between epigenetic regulation and mammalian sex development, despite this being an interesting area of research. Sex development consists of three sequential stages: the undifferentiated stage, gonadal differentiation into testes or ovaries, and differentiation of internal and external genitalia. Some genetic studies have revealed that epigenetic regulation is required for proper gonadal differentiation in mice. Particularly, the epigenetic machinery plays an integral part in sex determination, which is the first step of gonadal differentiation. Mammalian sex determination is triggered by activation of the mammalian sex-determining gene, Sry, in a spatially and temporally accurate manner. Several studies have demonstrated that expression of Sry is controlled not only by specific transcription factors but also by the epigenetic machinery. Here, we focus on the epigenetic regulation of Sry expression.

Two approaches to using optical floating zone (OFZ) technique for single crystal growth of the perovskite Pr1−xLaxAlO3 are discussed, along with the influence on the physical properties of the resulting single crystals due to oxidizing and reducing post anneals. In method one (M1) we used pre-reduced Pr2O3 powder starting material, while in the other method, M2, we employed an argon 5% hydrogen reducing environment during the floating zone single crystal growth. Magnetic susceptibility of the low temperature monoclinic phase of Pr0.2La0.8AlO3 is shown to be sensitive to the precise annealing protocol followed. For the post-growth reduced single crystal the magnetic susceptibility is flat across the R-3c to C2/m structural transition, whereas the oxidized and as-grown samples display a sharp upturn and downturn, respectively. We attribute the low temperature susceptibility differences to relative proportions of Pr3+ and Pr4+.

We report the thermal conductivity (κ) of perovskite Sr1−x (La0.5Na0.5) x TiO3 (0 ≤ x ≤ 1) and the thermoelectric properties of Nb-doped samples for x = 0.1 and 0.2. The κ of the solid solution shows a distinct minimum near the cubic-tetragonal phase boundary at x = 0.2, where the value becomes close to the minimum theoretical κ. Nb doping to x = 0.2 retains the high power factor found in Nb-doped SrTiO3, but also raises the κ to result in a thermoelectric figure of merit of 0.24 at 773 K.

We present the distribution coefficient for the entire series of rare-earth dopants (RE = La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) in flux-grown Y3Al5O12 garnet crystals. When the distribution coefficient is plotted in a logarithmic scale as a function of dopant radius, it shows a smooth parabolic drop from the smallest dopant (Lu3+) at 1.5 to the largest dopant (La3+) at 0.004. This behavior can be interpreted by the lattice strain model, with Lu3+ having close to the ideal radius for the 8-fold coordination site of the aluminum garnet structure.

Summary Primordial germ cells (PGCs) are specified from epiblast cells in mice. Genes associated with naive pluripotency are repressed in the transition from inner cell mass to epiblast cells, followed by upregulation after PGC specification. However, the molecular mechanisms underlying the reactivation of pluripotency genes are poorly characterized. Here, we exploited the in vitro differentiation of epiblast-like cells (EpiLCs) from embryonic stem cells (ESCs) to elucidate the molecular and epigenetic functions of PR domain-containing 14 (PRDM14). We found that Prdm14 overexpression in EpiLCs induced their conversion to ESC-like cells even in the absence of leukemia inhibitory factor in adherent culture. This was impaired by the loss of Kruppel-like factor 2 and ten-eleven translocation (TET) proteins. Furthermore, PRDM14 recruited OCT3/4 to the enhancer regions of naive pluripotency genes via TET-base excision repair-mediated demethylation. Our results provide evidence that PRDM14 establishes a transcriptional network for naive pluripotency via active DNA demethylation., Graphical Abstract, Highlights • PRDM14 converts from EpiLCs to ESCs in adherent culture • EpiLC to ESC conversion by PRMD14 depends on KLF2 and TET-base excision repair pathway • PRDM14 enhances the recruitments of OCT3/4 at pluripotent genes, In this article, Seki and colleagues exploit an in vitro differentiation system of epiblast-like cells (EpiLCs) from embryonic stem cells (ESCs) to investigate the function of PRDM14. Overexpression of PRDM14 in EpiLCs induces the conversion from EpiLCs to ESCs through active DNA demethylation-mediated OCT3/4 recruitment at pluripotent genes in adherent culture.

Mammalian sex determination is triggered by activation of the mammalian sex-determining gene, Sry, in a spatially and temporally controlled manner. Because reduced or delayed Sry expression results in male-to-female sex reversal, male development is highly dependent on the accurate transcription of Sry. SRY dysregulation is a potential cause of human disorders of sex development (DSD). In addition to changes in DNA sequences, gene expression is regulated by epigenetic mechanisms. Epigenetic regulation ensures spatial and temporal accuracy of the expression of developmentally regulated genes. Epigenetic regulation such as histone tail modification, DNA methylation, chromatin remodeling, and non-coding RNA regulation engages several biological processes in multicellular organisms. In recent years, it has been revealed that various types of epigenetic regulation are involved in accurate gonadal differentiation in mammals. In particular, histone modification plays an integral part in sex determination, which is the first step of gonadal differentiation. Here, we focus on the findings on the epigenetic modifications that regulate Sry expression. Finally, we discuss the role of metabolism that potentially alters the epigenetic state in response to environmental cues.

Epigenetic information (epigenome) on chromatin is crucial for the determination of cellular identity and for the expression of cell type-specific biological functions. The cell type-specific epigenome is maintained beyond replication and cell division. Nucleosomes of chromatin just after DNA replication are a mixture of old histones with the parental epigenome and newly synthesized histones without such information. The diluted epigenome is mostly restored within one cell cycle using the epigenome on the parental DNA and nucleosomes as replication templates. However, many important questions about the epigenome replication process remain to be clarified. In this study, we investigated the model system comprising of dimethylated histone H3 lysine 9 (H3K9me2) and its regulation by the lysine methyltransferase G9a. Using this epigenome model system, we addressed whether H3K9me2 can be induced in specific cell cycle stages, especially G1. Using cell cycle-specific degrons, we achieved G1 or late G1-to M phases specific accumulation of exogenous G9a in G9a deficient cells. Importantly, global levels of H3K9me2 were significantly recovered by both cell types. These data indicate that H3K9me2 may be plastic and inducible, even in the long-living, terminally-differentiated, post-mitotic, G0-G1 cell population in vivo. This knowledge is valuable in designing epigenome-manipulation-based treatments for diseases.

Mammalian sex determination is triggered by activation of the mammalian sex-determining gene, Sry, in a spatially and temporally controlled manner. Because reduced or delayed Sry expression results in male-to-female sex reversal, male development is highly dependent on the accurate transcription of Sry. SRY dysregulation is a potential cause of human disorders of sex development (DSD). In addition to changes in DNA sequences, gene expression is regulated by epigenetic mechanisms. Epigenetic regulation ensures spatial and temporal accuracy of the expression of developmentally regulated genes. Epigenetic regulation such as histone tail modification, DNA methylation, chromatin remodeling, and non-coding RNA regulation engages several biological processes in multicellular organisms. In recent years, it has been revealed that various types of epigenetic regulation are involved in accurate gonadal differentiation in mammals. In particular, histone modification plays an integral part in sex determination, which is the first step of gonadal differentiation. Here, we focus on the findings on the epigenetic modifications that regulate Sry expression. Finally, we discuss the role of metabolism that potentially alters the epigenetic state in response to environmental cues.

This paper reports a systematic study of distribution coefficient in YVO4 for the entire series of trivalent rare-earth dopants (RE = La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Sc). For this aim, single crystals for each RE dopant were flux-grown under a fixed condition, with the starting ratio of Y0.9RE0.1. The compositions of the grown crystals were then determined using inductively coupled plasma emission spectroscopy. The distribution coefficient is close to 1 when the size mismatch between the dopant ion and the host Y3+ ion is within about ±3%, and drops off in a similar manner for both larger and smaller dopants. The distribution coefficients for the largest (La3+) and smallest (Sc3+) dopants are 0.2 and 0.07, respectively.

The XY pyrochlore Yb$_2$Ti$_2$O$_7$, with pseudo spin 1/2 at the Yb$^{3+}$ site, has been celebrated as potential host for the quantum spin ice state. The substitution of non-magnetic Ti with Pt gives Yb$_2$Pt$_2$O$_7$, a system with remarkably similar magnetic properties. The large nuclear gyromagnetic ratio ($\gamma_{n}/2 \pi = 9.15$~MHz/T) of $^{195}$Pt makes Yb$_2$Pt$_2$O$_7$ an ideal material for NMR investigation of its unconventional magnetic properties. Based on the $^{195}$Pt nuclear spin-lattice relaxation rate $1/T_1$ and the magnetic specific heat $C_{p}$ measured in a broad range of magnetic field $B_{ext}$, we demonstrate that the field-induced magnon gap linearly decreases with $B_{ext}$ but additional low energy mode of spin excitations emerge below $\sim 0.5$~T.

The single ion physics of Ho$_2$Ti$_2$O$_7$ is well-understood to produce strong Ising anisotropy, which is an essential ingredient to its low-temperature spin ice state. We present inelastic neutron scattering measurements on Ho$_2$Ti$_2$O$_7$ that reveal a clear inconsistency with its established single ion Hamiltonian. Specifically, we show that a crystal field doublet near 60~meV is split by approximately 3~meV. Furthermore, this crystal field splitting is not isolated to Ho$_2$Ti$_2$O$_7$ but can also be found in its chemical pressure analogs, Ho$_2$Ge$_2$O$_7$ and Ho$_2$Sn$_2$O$_7$. We demonstrate that the origin of this effect is a vibronic bound state, resulting from the entanglement of a phonon and crystal field excitation. We derive the microscopic Hamiltonian that describes the magneto-elastic coupling and provides a quantitative description of the inelastic neutron spectra.

Epigenetics is the study of changes in gene function that cannot be explained by changes in DNA sequence. A mammalian body contains more than two hundred types of cells. Since all of them are derived from a single fertilized egg, their genotypes are identical. However, the gene expression patterns are different between the cell types, indicating that each cell type has unique own “epigenotype”. Epigenetic gene regulation mechanisms essentially contribute to various processes of mammalian development. The essence of epigenetic regulation is the structural change of chromatin to modulate gene activity in a spatiotemporal manner. DNA methylation and histone modifications are the major epigenetic mechanisms. Sex determination is the process for gender establishment. There are two types of sex‐determining mechanisms in animals, environmental sex determination (ESD) and genotypic sex determination (GSD). Recent studies have provided some evidence that epigenetic mechanisms play indispensable roles in ESD and GSD. Some fishes undergo ESD, in which DNA methylation is essentially involved. GSD is employed in therian mammals, where Sry (sex‐determining region on the Y chromosome) triggers testis differentiation from undifferentiated gonads. Sry expression is tightly regulated in a spatiotemporal manner. A recent study demonstrated that histone modification is involved in Sry regulation. In this review, we discuss the role of epigenetic mechanisms for sex determination in mammals and other vertebrates.

A mammalian body is composed of more than 200 different types of cells. The purification of a certain cell type from tissues/organs enables a wide variety of studies. One popular cell purification method is immunological isolation, using antibodies against specific cell surface antigens. However, this is not a general-purpose method, since suitable antigens have not been found in certain cell types, including embryonic gonadal somatic cells and Sertoli cells. To address this issue, we established a knock-in mouse line, named R26 KI, designed to express the human cell surface antigen hCD271 through Cre/loxP-mediated recombination. First, we used the R26 Kl mouse line to purify embryonic gonadal somatic cells. Gonadal somatic cells were purified from the R26 KI; Nr5a1-Cre-transgenic (tg) embryos almost equally as efficiently as from Nr5a1-hCD271-tg embryos. Second, we used the R26 KI mouse line to purify Sertoli cells successfully from R26 KI; Amh-Cre-tg testes. In summary, we propose that the R26 KI mouse line is a powerful tool for the purification of various cell types.

Epigenetics is the study of changes in gene function that cannot be explained by changes in DNA sequence. A mammalian body contains more than two-hundred different types of cells, all derived from a single fertilized egg. Epigenetic gene regulation mechanisms essentially contribute to various processes of mammalian development. The essence of epigenetic regulation is the modulation of gene activity through changes in chromatin structure. DNA methylation and histone modifications are the major epigenetic mechanisms. Sex determination is the process of establishing a gender. Sry, the sex-determining gene in therian mammals, initiates testis differentiation. Recent studies have provided evidence that epigenetic mechanisms contribute to Sry regulation.

Thermal conductivity data between 1.8 and 300 K are reported for K 1− x Li x TaO 3 (0≤ x ≤0.03) and KTa 1− x Nb x O 3 (0≤ x ≤0.16) single crystals. Whereas lightly Li- and Nb-doped crystals exhibit relaxor-like behavior in dielectric susceptibility, they do not show the glasslike thermal transport found in conventional relaxors such as PbMg 1/3 Nb 2/3 O 3 and Na 1/2 Bi 1/2 TiO 3 . The lack of glasslike behavior in K 1− x Li x TaO 3 and KTa 1− x Nb x O 3 is confirmed by the absence of temperature-linear contribution in heat capacity.

We report neutron scattering measurements on ${\mathrm{Er}}_{2}{\mathrm{Pt}}_{2}{\mathrm{O}}_{7}$, a new addition to the $XY$ family of frustrated pyrochlore magnets. Symmetry analysis of our elastic scattering data shows that ${\mathrm{Er}}_{2}{\mathrm{Pt}}_{2}{\mathrm{O}}_{7}$ orders into the $k=0$, ${\mathrm{\ensuremath{\Gamma}}}_{7}$ magnetic structure (the Palmer-Chalker state), at ${T}_{N}=0.38\text{ }\text{ }\mathrm{K}$. This contrasts with its sister $XY$ pyrochlore antiferromagnets ${\mathrm{Er}}_{2}{\mathrm{Ti}}_{2}{\mathrm{O}}_{7}$ and ${\mathrm{Er}}_{2}{\mathrm{Ge}}_{2}{\mathrm{O}}_{7}$, both of which order into ${\mathrm{\ensuremath{\Gamma}}}_{5}$ magnetic structures at much higher temperatures, ${T}_{N}=1.2$ and 1.4 K, respectively. In this temperature range, the magnetic heat capacity of ${\mathrm{Er}}_{2}{\mathrm{Pt}}_{2}{\mathrm{O}}_{7}$ contains a broad anomaly centered at ${T}^{*}=1.5\text{ }\text{ }\mathrm{K}$. Our inelastic neutron scattering measurements reveal that this broad heat capacity anomaly sets the temperature scale for strong short-range spin fluctuations. Below ${T}_{N}=0.38\text{ }\text{ }\mathrm{K}$, ${\mathrm{Er}}_{2}{\mathrm{Pt}}_{2}{\mathrm{O}}_{7}$ displays a gapped spin-wave spectrum with an intense, flat band of excitations at lower energy and a weak, diffusive band of excitations at higher energy. The flat band is well described by classical spin-wave calculations, but these calculations also predict sharp dispersive branches at higher energy, a striking discrepancy with the experimental data. This, in concert with the strong suppression of ${T}_{N}$, is attributable to enhanced quantum fluctuations due to phase competition between the ${\mathrm{\ensuremath{\Gamma}}}_{7}$ and ${\mathrm{\ensuremath{\Gamma}}}_{5}$ states that border each other within a classically predicted phase diagram.

Multiferroic orthorhombic $o\ensuremath{-}{\mathrm{LuMnO}}_{3}$ exhibits large ferroelectric polarization induced by an $E$-type magnetic order. Recently, the $E$-type magnetic phase in ${\mathrm{LuMnO}}_{3}$ was proposed to feature magnetic moments tilted away from the collinear ordering. We employed neutron diffraction to determine the symmetry of the magnetic order in $o\ensuremath{-}{\mathrm{LuMnO}}_{3}$. We observed that below ${T}_{N}=39$ K, the ${\mathrm{Mn}}^{3+}$ spins order into an incommensurate amplitude-modulated phase that obeys the Pbnm crystal symmetry and is paraelectric. The incommensurate phase locks into a commensurate phase at ${T}_{C}=35.5$ K described by a fully antiferromagnetic and noncollinear $E$-type order. This noncollinear $E$-type ordering breaks the spatial inversion symmetry and induces a spontaneous polarization at ${T}_{C}$. At $T=2$ K, an appreciably large electric polarization was observed similar to that of other orthorhombic manganites featuring $E$-type magnetic order. We also present a Pbnm symmetry-allowed Dzyaloshinskii-Moriya interaction that explains the noncollinear $E$-type order in the commensurate phase. These results are in qualitative agreement with the type of distortions from collinear $E$-type antiferromagnetic order found using Monte Carlo simulation for rare-earth manganites [M. Mochizuki et al., Phys. Rev. B 84, 144409 (2011)].

Although the understanding on the theories of crystal growth is not an absolute requirement to obtain single crystals, the techniques can be better applied if basic aspects of the theories are known. This chapter begins with a discussion on crystal morphology, starting with a question of why single crystals of perovskite compounds have a cubic shape, spinel compounds an octahedral shape, and garnet compounds a dodecahedral shape. The chapter then moves on to the mechanisms of flux growth. The concepts of solubility and supersaturation are introduced, and the three main steps of crystal growth—the attainment of supersaturation, the formation of nuclei of the crystalline phase, and subsequent crystal growth on the nuclei—are described. The discussion gives the answer to why some crystals have flat faces whereas others show hopper or dendritic morphologies. The chapter ends with descriptions on various imperfections sometimes found in flux-grown crystals.

Although phase diagrams provide valuable information on proper growth conditions, they cannot be used to predict the size and quality of the crystals that will result from flux growth. While these features of crystals depend on the combination of various factors, the limits of what can be achieved in size and quality are often determined by the properties of the flux, and how the flux interacts with the solute compound at high temperatures. This chapter lists the 10 properties of an ideal flux, and discusses why these properties are important for successful flux growth. It is shown that as an ideal flux does not exist in most cases, a compromise is frequently made and a suitable flux is chosen based on the most important requirements. Also, a combination of compounds is often used to optimize properties. This chapter then discusses the typical fluxes used for growth of oxide compounds, using tables to show their basic properties and some of the crystals grown from these fluxes. Similar discussion then follows on growth of intermetallic compounds, where metallic elements are often used as a flux.

Because phase transformation is always involved in flux growth, phase diagrams provide valuable information on the proper techniques and procedures for growing the desired crystals. This chapter starts with discussions on the features of a binary eutectic phase diagram that are relevant to flux growth, and then moves on to describe the various examples of eutectic systems, incongruently melting compounds, solid solutions, and effects of oxygen partial pressure on oxidation state. Instead of delving into the thermodynamic foundations of phase diagrams, an intuitive approach is used throughout the chapter to discuss the phase diagrams most frequently encountered by flux growers. The chapter ends with discussions on various techniques of determining phase diagrams, which are sometimes used by the flux grower to define the optimum growth conditions for new systems.

The previous chapters have focused on the growth of single crystals, and very little discussion was made on their interesting physical properties. To give better ideas on the variety of crystals grown with the flux method, this chapter presents 12 examples of flux-grown crystals that are well-known to many researchers. The types of compounds presented include a high-temperature superconductor, low-dimensional quantum magnet, geometrically frustrated magnet, non-linear optical material, colossal magnetoresistive compound, relaxor ferroelectric, topological Kondo insulator, multiferroic, and metal-insulator transition compound. The examples are chosen mainly because the growth conditions for high-quality crystal are well documented. This chapter presents the photographs of the crystals and the recipes used to grow the crystals. Each photograph is accompanied by comments on the compound and its place in solid-state research.

The first half of this chapter discusses the furnaces, crucibles, and starting materials that are used in flux growth experiments. Although flux growth does not require special equipment, choosing a proper set of equipment is essential in growing high-quality crystals. The discussion on furnaces includes the comparison between the vertical tube furnace and box furnace, as well as between the various heating elements that are used for electrical resistive furnaces. Descriptions on the various materials used for crucibles are then given, which are followed by discussions on various features of starting materials that are used in flux growth. The second half of this chapter describes the basic procedures of flux growth experiments, one section covering the growth in air and another in a protective atmosphere. The final section provides some suggestions on the handling and assessment of the grown crystals.

The ferromagnetic phase of spinel compound CdCr2S4 was investigated by measuring the heat capacity and magnetic properties. The low-temperature heat capacity data indicate the existence of an unusual excitation besides the ferromagnetic spin wave and phonon excitations. The additional excitation with a T-linear contribution would relate to a continuous excitation such appeared in the glass-like state. The magnetic properties also showed spin-glass-like behaviors. These results suggest that the short-range magnetic clusters of the Cr3+ ions grow to larger spin clusters at low temperature.

Disorders of sex development in the human population range in severity from mild genital defects to gonadal sex reversal. XY female development has been associated with heterozygous mutations in several genes, including SOX9, WT1 and MAP3K1. In contrast, XY sex reversal in mice usually requires complete absence of testis-determining gene products. One exception to this involves T-associated sex reversal (Tas), a phenomenon characterized by the formation of ovotestes or ovaries in XY mice hemizygous for the hairpin-tail (T(hp)) or T-Orleans (T(Orl)) deletions on proximal mouse chromosome 17. We recently reported that mice heterozygous for a null allele of Map3k4, which resides in the T(hp) deletion, exhibit XY ovotestis development and occasional gonadal sex reversal on the sensitized C57BL/6J-Y(AKR) (B6-Y(AKR)) genetic background, reminiscent of the Tas phenotype. However, these experiments did not exclude the possibility that loss of other loci in the T(hp) deletion, or other effects of the deletion itself, might contribute to Tas. Here, we show that disruption to Sry expression underlies XY gonadal defects in B6-Y(AKR) embryos harbouring the T(hp) deletion and that a functional Map3k4 bacterial artificial chromosome rescues these abnormalities by re-establishing a normal Sry expression profile. These data demonstrate that Map3k4 haploinsufficiency is the cause of T-associated sex reversal and that levels of this signalling molecule are a major determinant of the expression profile of Sry.

The movement in Mongolia after the 1911 Revolution is often written within the context of the Mongolian Declaration of Independence, but this article analyzes various reactions from pro-independenc...

Epigenetic gene regulation linked to oncogenic pathways is an important focus of cancer research. KDM3A, a histone H3 lysine 9 (H3K9) demethylase, is known to have a pro-tumorigenic function. Here, we showed that KDM3A contributes to liver tumor formation through the phosphatidylinositol 3-kinase (PI3K) pathway, which is often activated in hepatocellular carcinoma. Loss of Kdm3a attenuated tumor formation in Pik3ca transgenic (Tg) mouse livers. Transcriptome analysis of pre-cancerous liver tissues revealed that the expression of activator protein 1 (AP-1) target genes was induced by PI3K activation, but blunted upon Kdm3a ablation. Particularly, the expression of Cd44, a liver cancer stem marker, was regulated by AP-1 in a Kdm3a-dependent manner. We identified Cd44-positive hepatocytes with epithelial-mesenchymal transition-related expression profiles in the Pik3ca Tg liver and confirmed their in vivo tumorigenic capacity. Notably, the number and tumor-initiating capacity of Cd44-positive hepatocytes were governed by Kdm3a. As a mechanism in Kdm3a-dependent AP-1 transcription, Kdm3a recruited c-Jun to the AP-1 binding sites of Cd44, Mmp7 and Pdgfrb without affecting c-Jun expression. Moreover, Brg1, a component of the SWI/SNF chromatin remodeling complex, interacted with c-Jun in a Kdm3a-dependent manner and was bound to the AP-1 binding site of these genes. Finally, KDM3A and c-JUN were co-expressed in 33% of human premalignant lesions with PI3K activation. Our data suggest a critical role for KDM3A in the PI3K/AP-1 oncogenic axis and propose a novel strategy for inhibition of KDM3A against liver tumor development under PI3K pathway activation.

The hemochorial placenta develops from the coordinated multilineage differentiation of trophoblast stem (TS) cells. An invasive trophoblast cell lineage remodels uterine spiral arteries, facilitating nutrient flow, failure of which is associated with pathological conditions such as preeclampsia, intrauterine growth restriction, and preterm birth. Hypoxia plays an instructive role in influencing trophoblast cell differentiation and regulating placental organization. Key downstream hypoxia-activated events were delineated using rat TS cells and tested in vivo, using trophoblast-specific lentiviral gene delivery and genome editing. DNA microarray analyses performed on rat TS cells exposed to ambient or low oxygen and pregnant rats exposed to ambient or hypoxic conditions showed up-regulation of genes characteristic of an invasive/vascular remodeling/inflammatory phenotype. Among the shared up-regulated genes was matrix metallopeptidase 12 (MMP12). To explore the functional importance of MMP12 in trophoblast cell-directed spiral artery remodeling, we generated an Mmp12 mutant rat model using transcription activator-like nucleases-mediated genome editing. Homozygous mutant placentation sites showed decreased hypoxia-dependent endovascular trophoblast invasion and impaired trophoblast-directed spiral artery remodeling. A link was established between hypoxia/HIF and MMP12; however, evidence did not support Mmp12 as a direct target of HIF action. Lysine demethylase 3A (KDM3A) was identified as mediator of hypoxia/HIF regulation of Mmp12 Knockdown of KDM3A in rat TS cells inhibited the expression of a subset of the hypoxia-hypoxia inducible factor (HIF)-dependent transcripts, including Mmp12, altered H3K9 methylation status, and decreased hypoxia-induced trophoblast cell invasion in vitro and in vivo. The hypoxia-HIF-KDM3A-MMP12 regulatory circuit is conserved and facilitates placental adaptations to environmental challenges.

Timing of cell differentiation is strictly controlled and is crucial for normal development and stem cell differentiation. However, underlying mechanisms regulating differentiation timing are fully unknown. Here, we show a molecular mechanism determining differentiation timing from mouse embryonic stem cells (ESCs). Activation of protein kinase A (PKA) modulates differentiation timing to accelerate the appearance of mesoderm and other germ layer cells, reciprocally correlated with the earlier disappearance of pluripotent markers after ESC differentiation. PKA activation increases protein expression of G9a, an H3K9 methyltransferase, along with earlier H3K9 dimethylation and DNA methylation in Oct3/4 and Nanog gene promoters. Deletion of G9a completely abolishes PKA-elicited acceleration of differentiation and epigenetic modification. Furthermore, G9a knockout mice show prolonged expressions of Oct3/4 and Nanog at embryonic day 7.5 and delayed development. In this study, we demonstrate molecular machinery that regulates timing of multilineage differentiation by linking signaling with epigenetics.

Lysine methylation of the histone tail is involved in a variety of biological events. G9a and GLP are known as major H3-K9 methyltransferases and contribute to transcriptional silencing. The functions of these genes in organogenesis remain largely unknown. Here, we analyzed the phenotypes of cardiomyocyte specific GLP knockout and G9a knockdown (GLP-KO/G9a-KD) mice. The H3-K9 di-methylation level decreased markedly in the nuclei of the cardiomyocytes of GLP-KO/G9a-KD mice, but not single G9a or GLP knockout mice. In addition, GLP-KO/G9a-KD mice showed neonatal lethality and severe cardiac defects (atrioventricular septal defects, AVSD). We also showed that hypoplasia in the atrioventricular cushion, which is a main part of the atrioventricular septum, caused AVSD. Expression analysis revealed downregulation of 2 AVSD related genes and upregulation of several non-cardiac specific genes in the hearts of GLP-KO/G9a-KD mice. These data indicate that G9a and GLP are required for sufficient H3-K9 di-methylation in cardiomyocytes and regulation of expression levels in multiple genes. Moreover, our findings show that G9a and GLP have an essential role in normal morphogenesis of the atrioventricular septum through regulation of the size of the atrioventricular cushion.