Dual barrier system against xenomitochondrial contamination in mouse embryos.

Heteroplasmic mammalian embryos between genetically distant species fail to develop to term, preventing transmission of xenomitochondrial DNA to progeny. However, there is no direct evidence indicating the mechanisms by which species specificity of the mitochondrial genome is ensured during mammalian development. Here, we have uncovered a two-step strategy underlying the prevention of xenomitochondrial DNA transmission in mouse embryos harboring bovine mitochondria (mtB-M embryos). First, mtB-M embryos showed metabolic disorder by transient increase of reactive oxygen species at the 4-cell stage, resulting in repressed development. Second, trophoblasts of mtB-M embryos led to implantation failure. Therefore, we tested cell aggregation with tetraploid embryos to compensate for the placentation of mtB-M embryos. The 14 mtB-M embryos harboring bovine mtDNAs developed to term at embryonic day 19.5. Taken together, our results show that contamination of bovine mtDNA is prohibited by embryonic lethality due to metabolic disruption and failure of placentation, suggesting these represent xenomitochondrial elimination mechanisms in mammalian embryos.

Immune checkpoint inhibitor-induced asthma and chronic obstructive pulmonary disease overlap in patient with adenocarcinoma.

A 67-year-old current smoker Japanese man, with no history of asthma, was diagnosed with lung adenocarcinoma. He received first-line chemotherapy with carboplatin, pemetrexed, ipilimumab, and nivolumab in July 20XX-1, and subsequently a maintenance therapy with nivolumab. In October 20XX, he became aware of wheezy dyspnoea, and chest computed tomography demonstrated worsening bronchial wall thickenings. Eosinophilia was noted, and a pulmonary function test showed obstructive dysfunction insufficiently responding to beta-agonists, with 130 mL increase of forced expiratory volume in one second and high fractional exhaled nitric oxide level (85 ppb). He was clinically diagnosed with asthma and chronic obstructive pulmonary disease overlap, secondary to immune checkpoint inhibitors (ICIs). The inhibition of binding between programmed cell death-protein-1 (PD-1), expressed on T cells, and programmed cell death-ligand-2 (PD-L2), expressed on tumour and dendritic cells, can induce airway hyperresponsiveness. Physicians should be wary of asthmatic symptoms and chest image findings during ICIs therapy.

Pulmonary artery aneurysm induced by lung abscess.

Physicians should consider a pulmonary artery aneurysm complication in patients presenting with hemoptysis during treatment for a pulmonary abscess. Contrast-enhanced CT or angiography is recommended for diagnosis, followed by pulmonary embolization for treatment.

Cell-cycle dependent GATA2 subcellular localization in mouse 2-cell embryos.

GATA factors are essential transcription factors for embryonic development that broadly control the transcription of other genes. This study aimed to examine GATA2 protein localization in mouse embryos at the 2-cell stage, when drastic transformation in gene expression occurs for subsequent development in early embryos. We first analyzed GATA2 localization in 2-cell embryos at the interphase and mitotic phases by immunofluorescence analysis. In the interphase, GATA2 protein was localized in the nucleus, as a common transcription factor. In the mitotic phase, GATA2 protein was observed as a focally-aggregated spot around the nucleus of each blastomere. To explore the relationship between GATA2 protein localization and cell cycle progression in mouse 2-cell stage embryos, GFP-labeled GATA2 protein was overexpressed in the blastomere of 2-cell embryos. Overexpression of GFP-labeled GATA2 protein arrested cellular mitosis, focally aggregated GATA2 protein expression was not observed. This mitotic arrest by GATA2 overexpression was not accompanied with the upregulation of a 2-cell stage specific gene, murine endogenous retrovirus-L. These results suggest that GATA2 protein localization changes dynamically depending on cell cycle progression in mouse 2-cell embryos; in particular, focally aggregated localization of GATA2 in the mitotic phase requires appropriate cell cycle progression.

Trophectoderm regeneration to support full-term development in the inner cell mass isolated from bovine blastocyst.

Which comes first: tissue structure or cell differentiation? Although different cell types establish distinct structures delineating the inside and outside of an embryo, they progressively become specified by the blastocyst stage, when two types of cell lineages are formed: the inner cell mass (ICM) and the trophectoderm (TE). This inside-outside aspect can be experimentally converted by the isolation of the ICM from a blastocyst, leading to a posteriori externalization of the blastomeres composing the outermost layer of the ICM. Here, we investigated the totipotency of isolated mouse and bovine ICMs to determine whether they are competent for TE regeneration. Surprisingly, a calf was generated from the bovine isolated ICM with re-formed blastocoel (re-iICM), but no mouse re-iICMs developed to term. To further explore the cause of difference in developmental competency between the mouse and bovine re-iICMs, we investigated the SOX17 protein expression that is a representative molecular marker of primitive endoderm. The localization pattern of SOX17 was totally different between mouse and bovine embryos. Particularly, the ectopic SOX17 localization in the TE might be associated with lethality of mouse re-iICMs. Meanwhile, transcriptome sequencing revealed that some of the bovine re-iICMs showed transcriptional patterns of TE-specific genes similar to those of whole blastocysts. Our findings suggest that TE regeneration competency is maintained longer in bovine ICMs than in mouse ICMs and provide evidence that the ICM/TE cell fate decision is influenced by structural determinants, including positional information of each blastomere in mammalian embryos.

Overgrowth of mice generated from postovulatory-aged oocyte spindles.

Oocyte spindle transfer (OST) is a potent reproductive technology used for mammals that enables the spindle in a deteriorated oocyte at the metaphase of the second meiotic division (MII) to serve as the genetic material for producing descendants. However, whether postnatal growth is achieved via OST using developmentally deteriorated MII oocytes remains unclear. At 16 h after human chorionic gonadotropin administration, denuded MII oocytes immediately after retrieval from oviducts (0 h-oocytes) were used for in vitro fertilization (IVF) as controls. For IVF using postovulatory-aged oocytes, the 0 h-oocytes were further incubated for 12 h and 24 h (12 h- and 24 h-oocytes). These mouse oocytes served as a model for assessing the postnatal growth of individuals produced via OST from developmentally deteriorated oocytes. The embryos from 12 h- and 24 h-oocyte spindles exhibited high rates of development up to the neonatal stage as good as the non-manipulated controls. However, the mice derived from the 24 h-oocyte spindles displayed heavier body weights and greater feed consumption than both controls and mice derived from 12 h-oocyte spindles. Our results demonstrate the feasibility of OST as a potent reproductive technology and its limitation in the use of excessively aged postovulatory oocytes in mammalian reproduction.

Nanoscale Color Sorting of Surface Plasmons in a Double-Nanogap Structure with Multipolar Plasmon Excitation.

We demonstrated a new plasmonic nanodevice that spatially sorts photons according to their colors on the nanoscale while maintaining their nanoconcentration. The properties of this nanoscale color sorting based on constructive and destructive interferences between different multipolar plasmon modes are controlled by tuning the incidence angle of the incoming photons. The added ability of color sorting and its manipulation could significantly influence the development of possible photonic applications, including nanoscale spectroscopy and sensing.

High-pressure synthesis and structural characterization of the type II clathrate compound Na(30.5)Si(136) encapsulating two sodium atoms in the same silicon polyhedral cages.

Single crystals of sodium containing silicon clathrate compounds Na8Si46 (type I) and NaxSi136 (type II) were prepared from the mixtures of NaSi and Si under high-pressure and high-temperature conditions of 5 GPa at 600-1000 °C. The type II crystals were obtained at relatively low-temperature conditions of 700-800 °C, which were found to have a Na excess composition Na30.5Si136 in comparison with the compounds NaxSi136 (x ≤ 24) obtained by a thermal decomposition of NaSi under vacuum. The single crystal study revealed that the Na excess type II compound crystallizes in space group Fd3̅m with a lattice parameter of a = 14.796(1) Å, slightly larger than that of the ambient phase (Na24Si136), and the large silicon hexakaidecahedral cages (@Si28) are occupied by two sodium atoms disordered in the two 32e sites around the center of the @Si28 cages. At temperatures <90 K, the crystal symmetry of the compound changes from the face-centered to the primitive cell with space group P213, and the Na atoms in the @Si28 cages are aligned as Na2 pairs. The temperature dependence of the magnetic susceptibility of Na30.5Si136 suggests that the two Na ions (2 Na(+)) in the cage are changed to a Na2 molecule. The Na atoms of Na30.5Si136 can be deintercalated from the cages topochemically by evacuation at elevated temperatures. The single crystal study of the deintercalated phases NaxSi136 (x = 25.5 and 5.5) revealed that only excess Na atoms have disordered arrangements.