Ten-eleven translocation (TET) proteins oxidize 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC) and 5-carboxylcytosine (5caC). 5fC and 5caC can be excised and ...repaired by the base excision repair (BER) pathway, implicating 5mC oxidation in active DNA demethylation. Genome-wide DNA methylation is erased in the transition from metastable states to the ground state of embryonic stem cells (ESCs) and in migrating primordial germ cells (PGCs), although some resistant regions become demethylated only in gonadal PGCs. Understanding the mechanisms underlying global hypomethylation in naive ESCs and developing PGCs will be useful for realizing cellular pluripotency and totipotency. In this study, we found that PRDM14, the PR domain-containing transcriptional regulator, accelerates the TET-BER cycle, resulting in the promotion of active DNA demethylation in ESCs. Induction of Prdm14 expression transiently elevated 5hmC, followed by the reduction of 5mC at pluripotency-associated genes, germline-specific genes and imprinted loci, but not across the entire genome, which resembles the second wave of DNA demethylation observed in gonadal PGCs. PRDM14 physically interacts with TET1 and TET2 and enhances the recruitment of TET1 and TET2 at target loci. Knockdown of TET1 and TET2 impaired transcriptional regulation and DNA demethylation by PRDM14. The repression of the BER pathway by administration of pharmacological inhibitors of APE1 and PARP1 and the knockdown of thymine DNA glycosylase (TDG) also impaired DNA demethylation by PRDM14. Furthermore, DNA demethylation induced by PRDM14 takes place normally in the presence of aphidicolin, which is an inhibitor of G1/S progression. Together, our analysis provides mechanistic insight into DNA demethylation in naive pluripotent stem cells and developing PGCs.
Germline cells reprogramme extensive epigenetic modifications to ensure the cellular totipotency of subsequent generations and to prevent the accumulation of epimutations. Notably, primordial germ ...cells (PGCs) erase genome-wide DNA methylation and H3K9 dimethylation marks in a stepwise manner during migration and gonadal periods. In this study, we profiled DNA and histone methylation on transposable elements during PGC development, and examined the role of DNA replication in DNA demethylation in gonadal PGCs. CpGs in short interspersed nuclear elements (SINEs) B1 and B2 were substantially demethylated in migrating PGCs, whereas CpGs in long interspersed nuclear elements (LINEs), such as LINE-1, were resistant to early demethylation. By contrast, CpGs in both LINE-1 and SINEs were rapidly demethylated in gonadal PGCs. Four major modifiers of DNA and histone methylation, Dnmt3a, Dnmt3b, Glp and Uhrf1, were actively repressed at distinct stages of PGC development. DNMT1 was localised at replication foci in nascent PGCs, whereas the efficiency of recruitment of DNMT1 into replication foci was severely impaired in gonadal PGCs. Hairpin bisulphite sequencing analysis showed that strand-specific hemi-methylated CpGs on LINE-1 were predominant in gonadal PGCs. Furthermore, DNA demethylation in SINEs and LINE-1 was impaired in Cbx3-deficient PGCs, indicating abnormalities in G1 to S phase progression. We propose that PGCs employ active and passive mechanisms for efficient and widespread erasure of genomic DNA methylation.
Most social Hymenoptera are characterized by simple haploid sex determination and environment-based caste differentiation. This appears to be strikingly different in the queen-polymorphic ant ...Vollenhovia emeryi. Almost all long- and short-winged queens from a population in Central Japan were homozygous at three microsatellite loci, whereas workers were mostly heterozygous, suggesting either a complex system of genetic caste determination or, more likely, the production of female sexuals from unfertilized eggs by thelytokous parthenogenesis and of workers from fertilized eggs. Furthermore, male genotypes were not compatible with those of the queens and had exclusively the paternal allele found in the sterile, heterozygous workers, probably because males are produced from fertilized eggs after the exclusion of maternal nuclear DNA as recently reported for Wasmannia auropunctata. The genus Vollenhovia might provide an interesting model system to trace the evolution of unusual caste and sex determination systems.
Bioactive compounds are sensitive to many factors, and they can alter the sensory characteristics of foods. Microencapsulation could be a tool to provide protection and allow the addition of ...bioactives in new matrices, such as sugarcane juice. This study focused on producing and evaluating the potential function of probiotics and proanthocyanidin-rich cinnamon extract (PRCE), both in free and encapsulated forms when added to sugarcane juice. The pure sugarcane juice treatment T1 was compared with other sugarcane juices to which bioactive compounds had been added; T2, a non-encapsulated
Bifidobacterium animalis
subsp.
lactis
(BLC1); T3, a non-encapsulated BLC1 and PRCE; T4, BLC1 microcapsules; and T5, with BLC1 and PRCE microcapsules. The samples were morphologically, physicochemically, rheologically, and sensorially characterized. Samples were also evaluated regarding the viability of BLC1 during the juice’s storage at 4 °C. It was possible to produce probiotic sugarcane juice with non-encapsulated BLC1, but not with the addition of free PRCE, which in its free form reduced the viability of this microorganism to < 1 log CFU/mL after 7 days. The microcapsules were effective to protect BLC1 during juice storage and to maintain high contents of phenolic and proanthocyanidin compounds, although the products containing these had their viscosity altered and were less accepted than either the control or those with non-encapsulated BLC1.
We developed a method for predicting the total cadmium (Cd) concentration Cd
T
in soil solution. Disregarding minor ion pairs, Cd
T
was approximated by
. We assumed that Cd
2+
activity (Cd
2+
) is ...dominated by the adsorption-desorption equilibrium, expressed stoichiometrically as
. From this, we derived the balance equation
We calculated (CdCl
+
) as the product of (Cd
2+
), chloride activity (Cl
-
), and a production constant. Our proposed prediction model was
We conducted an experiment using six types of soil and manipulated the Cd content, pH, and chloride concentration Cl
−
to determine the effect on Cd concentration in the soil solution. The soil solution measurements produced rectilinear regression relationships between log(Cd
2+
) and log Q
Cd
- 0.6pH with slopes of 1.0 in all soil types, which validated the proposed Cd adsorption-desorption stoichiometry; the y-intercept of the regression lines represented log(K
Cd
/C
Cd
) and depended on the soil type. Furthermore, we were able to predict log(K
Cd
/C
Cd
) as a function of cation exchange capacity (CEC), and the activity coefficient (f
Cd
) as a function of electrical conductivity (EC) alone. Substituting these functions into the proposed prediction model, we obtained Cd
T
= 0.288Q
Cd
10
−0.6pH
CEC
−2.37
{1 + 2.23EC
0.490
+ 95.5Cl
−
}. The model provided a high goodness-of-fit (r
2
= 0.956) between the predicted and measured values over a concentration range of more than five-orders of magnitude. This prediction equation therefore appears to have wide applicability, suggesting that Cd concentration in soil solution can be reliably predicted from measurements of Cd content, pH, CEC, EC, and Cl
−
.
When the model core curriculum for pharmacy education was revised in 2013, there were eight major diseases specified that should be managed continuously and extensively by students during their ...hospital training. The status of this student management during training was examined at Kitasato University East Hospital before the implementation of the revised model core curriculum. The mean number of diseases managed by each student during their ward training was 3.3, and ranging from one to six diseases. The diseases most frequently managed by students were cancer and hypertension. Diseases other than the specified eight were also frequently managed. The results revealed the difficulty in providing sufficient opportunities for students to continuously and extensively manage all eight diseases through only ward training. Therefore, special measures may be needed to clarify the diseases individual students managed during their hospital training, and to preferentially allocate them to relevant wards to experience the management of the remaining diseases.
A facile method for the fabrication of a highly sensitive surface relief is demonstrated, which operates on the principle of spatially patterned photopolymerization-induced mass transport in the ...amorphous films of a series of bisanthracene compounds. The stability of the resultant colorless transparent relief structure is dramatically improved owing to the polymerization of the bisanthracene.
Many studies have established that peptides containing RFamide at the carboxyl terminal are present in the nervous and endocrine systems, and act as neurotransmitters andlor hormones. Most of the ...studies about the RFamide family, however, were canied out in invertebrates and lower vertebrates. Few studies dealt with the distribution and imction of RFamide in higher vertebrates above amphibian. Recently, a new member of RFamide, C-RFamide, was isolated from the crucian carp, Carassius. The present study was designed to elucidate the localization the C-RFamide in the brain and endocrine systems of Xenopus laevis by immunohistochemistry. C-RFamide-like immunoreactivity was demonstrated extensively in various regions of Xenopus laevis brain, with the highest density in the diencephalon. Immunoreactive neuronal perikarya were located in the preoptic area and the hypothalamic paraventricular region. Most of the immunoreactive cells in the hypothalamus were bipolar in shape and located close to the ventricles. These bipolar neurons extended an apical process to reach the third ventricle, while projected the axon towards the median eminence, where the axon terminals gathered around the primary capillary plexus of the hypophyseal portal system. The bipolar neurons in the hypothalamus may receive information from the cerebrospinal fluid with their apical process and transmit it to the median eminence and other areas of the brain. It is also suggested that in Xenopus laevis, a C-RFamide-like substance functions as a neurohormone to regulate the secretion of pituitary hormones.
Because it is expected to induce cross-reactive serum and mucosal antibody responses, mucosal vaccination against highly pathogenic avian influenza (HPAI) is potentially superior to conventional ...parenteral vaccination. Here, we tested whether intraocular vaccination with an inactivated AI virus induced protective antibody responses in chickens. Chickens were inoculated intraocularly twice with 104 hemagglutination units of an inactivated H5N1 HPAI virus. Four weeks after the second vaccination, the chickens were challenged with a lethal dose of the homologous H5N1 HPAI virus. Results showed that most of the vaccinated chickens mounted positive antibody responses. The median serum hemagglutination inhibition titer was 1:80. Addition of CpG oligodeoxynucleotide 2006 or cholera toxin to the vaccine did not enhance serum antibody titers. Cross-reactive anti-hemagglutinin IgG, but not IgA, was detected in oropharyngeal secretions. In accordance with these antibody results, most vaccinated chickens survived a lethal challenge with the H5N1 HPAI virus and did not shed the challenge virus in respiratory or digestive tract secretions. Our results show that intraocular vaccination with an inactivated AI virus induces not only systemic but also mucosal antibody responses and confers protection against HPAI in chickens.
Societal Impact Statement
Parasitic witchweeds (
Striga
species) pose a serious threat to food security in Africa, attacking cereal grains and legumes. Chemicals released from the host roots that ...initiate the life cycle of
Striga
are known as germination stimulants, predominantly strigolactones (SLs). Strigol, the first identified SL, was isolated from the root exudates of cotton (
Gossypium hirsutum
), a false host of
Striga
, over 50 years ago. The identification of strigol synthase in cotton establishes the complete biosynthesis pathway of this emblematic SL. This discovery has the potential to advance our understanding of SL‐mediated rhizosphere interactions and enhance cotton's effectiveness as a trap crop.
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