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While a variety of evidence supports a prenatal component in schizophrenia, there are few data regarding the cell populations involved. We sought to identify cells of the human prenatal brain mediating genetic risk for schizophrenia by integrating cell-specific gene expression measures generated through single-nuclei RNA sequencing with recent large-scale genome-wide association study (GWAS) and exome sequencing data for the condition. Single-nuclei RNA sequencing was performed on 5 brain regions (frontal cortex, ganglionic eminence, hippocampus, thalamus, and cerebellum) from 3 fetuses from the second trimester of gestation. Enrichment of schizophrenia common variant genetic liability and rare damaging coding variation was assessed in relation to gene expression specificity within each identified cell population. Common risk variants were prominently enriched within genes with high expression specificity for developing neuron populations within the frontal cortex, ganglionic eminence, and hippocampus. Enrichments were largely independent of genes expressed in neuronal populations of the adult brain that have been implicated in schizophrenia through the same methods. Genes containing an excess of rare damaging variants in schizophrenia had higher expression specificity for developing glutamatergic neurons of the frontal cortex and hippocampus that were also enriched for common variant liability. We found evidence for a distinct contribution of prenatal neuronal development to genetic risk for schizophrenia, involving specific populations of developing neurons within the second-trimester fetal brain. Our study significantly advances the understanding of the neurodevelopmental origins of schizophrenia and provides a resource with which to investigate the prenatal antecedents of other psychiatric and neurologic disorders. [ABSTRACT FROM AUTHOR]

In the cerebral cortex, GABAergic interneurons have evolved as a highly heterogeneous collection of cell types that are characterized by their unique spatial and temporal capabilities to influence neuronal circuits. Current estimates suggest that up to 50 different types of GABAergic neurons may populate the cerebral cortex, all derived from progenitor cells in the subpallium, the ventral aspect of the embryonic telencephalon. In this review, we provide an overview of the mechanisms underlying the generation of the distinct types of interneurons and their integration in cortical circuits. Interneuron diversity seems to emerge through the implementation of cell-intrinsic genetic programs in progenitor cells, which unfold over a protracted period of time until interneurons acquire mature characteristics. The developmental trajectory of interneurons is also modulated by activity-dependent, non-cell-autonomous mechanisms that influence their ability to integrate in nascent circuits and sculpt their final distribution in the adult cerebral cortex. GABAergic interneurons are critical for information processing in the cerebral cortex. Here, Lim and colleagues review recent advances on the cellular and molecular mechanisms regulating the emergence of interneuron diversity during development and their integration in cortical circuits. [ABSTRACT FROM AUTHOR]

In the current work, a custom-made vibration injection molding device that can provide oscillatory pressure was utilized to create an injection-molded hierarchical structure. Growth competition among α, β, and γphases in the injection-molded structure can be studied because of the presence of this hierarchical structure, wherein shish-kebab and spherulite layers were arranged alternately along the thickness direction. The γcrystals only existed in layers subjected to high pressure and shear stress, whereas β crystals formed between the shear layers. The change in trend of the γfraction was similar to that of parent-to-daughter ratio. In addition, this hierarchical and alternating crystal structure can sharply increase the mechanical properties. [ABSTRACT FROM AUTHOR]

GABAergic interneurons (GABA, g-aminobutyric acid) regulate neural-circuit activity in the mammalian cerebral cortex. These cortical interneurons are structurally and functionally diverse. Here, we use single-cell transcriptomics to study the origins of this diversity in the mouse. We identify distinct types of progenitor cells and newborn neurons in the ganglionic eminences, the embryonic proliferative regions that give rise to cortical interneurons. These embryonic precursors show temporally and spatially restricted transcriptional patterns that lead to different classes of interneurons in the adult cerebral cortex. Our findings suggest that shortly after the interneurons become postmitotic, their diversity is already patent in their diverse transcriptional programs, which subsequently guide further differentiation in the developing cortex. [ABSTRACT FROM AUTHOR]

Summary: The mechanisms by which early spatiotemporal expression patterns of transcription factors such as Pax6 regulate cortical progenitors in a region-specific manner are poorly understood. Pax6 is expressed in a gradient across the developing cortex and is essential for normal corticogenesis. We found that constitutive or conditional loss of Pax6 increases cortical progenitor proliferation by amounts that vary regionally with normal Pax6 levels. We compared the gene expression profiles of equivalent Pax6-expressing progenitors isolated from Pax6 +/+ and Pax6 −/− cortices and identified many negatively regulated cell-cycle genes, including Cyclins and Cdks. Biochemical assays indicated that Pax6 directly represses Cdk6 expression. Cyclin/Cdk repression inhibits retinoblastoma protein (pRb) phosphorylation, thereby limiting the transcription of genes that directly promote the mechanics of the cell cycle, and we found that Pax6 inhibits pRb phosphorylation and represses genes involved in DNA replication. Our results indicate that Pax6’s modulation of cortical progenitor cell cycles is regional and direct. [Copyright &y& Elsevier]

Island endemic birds account for the majority of extinct vertebrates in the past few centuries. To date, the evolutionary characteristics of island endemic bird's is poorly known. In this research, we de novo assembled a high‐quality chromosome‐level reference genome for the Swinhoe's pheasant, which is a typical endemic island bird. Results of collinearity tests suggest rapid ancient chromosome rearrangement that may have contributed to the initial species radiation within Phasianidae, and a role for the insertions of CR1 transposable elements in rearranging chromosomes in Phasianidae. During the evolution of the Swinhoe's pheasant, natural selection positively selected genes involved in fecundity and body size functions, at both the species and population levels, which reflect genetic variation associated with island adaptation. We further tested for variation in population genomic traits between the Swinhoe's pheasant and its phylogenetically closely related mainland relative the silver pheasant, and found higher levels of genetic drift and inbreeding in the Swinhoe's pheasant genome. Divergent demographic histories of insular and mainland bird species during the last glacial period may reflect the differing impact of insular and continental climates on the evolution of species. Our research interprets the natural history and population genetic characteristics of the insular endemic bird the Swinhoe's pheasant, at a genome‐wide scale, provides a broader perspective on insular speciation, and adaptive evolution and contributes to the genetic conservation of island endemic birds. [ABSTRACT FROM AUTHOR]

Background: Gorals Naemorhedus resemble both goats and antelopes, which prompts much debate about the intragenus species delimitation and phylogenetic status of the genus Naemorhedus within the subfamily Caprinae. Their evolution is believed to be linked to the uplift of the Qinghai-Tibet Plateau (QTP). To better understand its phylogenetics, the genetic information is worth being resolved. Results : Based on a sample from the eastern margin of QTP, we constructed the first reference genome for Himalayan goral Naemorhedus goral, using PacBio long-read sequencing and Hi-C technology. The 2.59 Gb assembled genome had a contig N50 of 3.70 Mb and scaffold N50 of 106.66 Mb, which anchored onto 28 pseudo chromosomes. A total of 20,145 protein-coding genes were predicted in the assembled genome, of which 99.93% were functionally annotated. Phylogenetically, the goral was closely related to muskox on the mitochondrial genome level and nested into the takin-muskox clade on the genome tree, rather than other so-called goat-antelopes. The cladogenetic event among muskox, takin and goral occurred sequentially during the late Miocene (~ 11 − 5 Mya), when the QTP experienced a third dramatic uplift with consequent profound changes in climate and environment. Several chromosome fusions and translocations were observed between goral and takin/muskox. The expanded gene families in the goral genome were mainly related to the metabolism of drugs and diseases, so as the positive selected genes. The Ne of goral continued to decrease since ~ 1 Mya during the Pleistocene with active glaciations. Conclusion: The high-quality goral genome provides insights into the evolution and valuable information for the conservation of this threatened group. [ABSTRACT FROM AUTHOR]

The transcription factor Pax6 is a crucial regulator of eye and central nervous system development. Both the spatiotemporal patterns and the precise levels of Pax6 expression are subject to tight control, mediated by an extensive set of cis-regulatory elements. Previous studies have shown that a YAC reporter transgene containing 420Kb of genomic DNA spanning the human PAX6 locus drives expression of a tau-tagged GFP reporter in mice in a pattern that closely resembles that of endogenous Pax6. Here we have closely compared the pattern of tau-GFP reporter expression at the cellular level in the forebrains and eyes of transgenic mice carrying either complete or truncated versions of the YAC reporter transgene with endogenous Pax6 expression and found several areas where expression of tau-GFP and Pax6 diverge. Some discrepancies are due to differences between the intracellular localization or perdurance of tau-GFP and Pax6 proteins, while others are likely to be a consequence of transcriptional differences. We show that cis-regulatory elements that lie outside the 420kb fragment of PAX6 are required for correct expression around the pallial-subpallial boundary, in the amygdala and the prethalamus. Further, we found that the YAC reporter transgene effectively labels cells that contribute to the lateral cortical stream, including cells that arise from the pallium and subpallium, and therefore represents a useful tool for studying lateral cortical stream migration. [ABSTRACT FROM AUTHOR]

ABSTRACT A simple dual band-notched antenna is proposed for ultra-wideband (UWB) applications. The basic UWB antenna, which consists of a half ring-shaped patch and a trapezoidal ground, occupies a compact area of 25 × 25 mm2. By introducing a single U-shaped resonator on the patch, dual band-notched function is realized without increasing the antenna size. An additional resonance near 3 GHz can be excited by the U-shaped resonator combined with the half ring-shaped radiator. And the antenna impedance at 3.5 GHz is also affected which leads to a notched band. Besides, reverse currents can be produced along the resonator to produce the other notched band at 5.5 GHz. Experimental results show that the designed antenna has a wide impedance bandwidth (return loss ≤10 dB) ranging from 2.97 to 12 GHz with two rejection bands operating at 3.5 and 5.5 GHz. Meanwhile, the antenna also exhibits moderate gains and omnidirectional radiation patterns over the operating bands except at the undesired frequencies, which make it a suitable candidate for UWB applications. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2129-2134, 2015 [ABSTRACT FROM AUTHOR]

The mammalian cerebral cortex contains an extraordinary diversity of cell types that emerge by implementing different developmental programs. Delineating when and how cellular diversification occurs is particularly challenging for cortical inhibitory neurons because they represent a small proportion of all cortical cells and have a protracted development. Here, we combine single-cell RNA sequencing and spatial transcriptomics to characterize the emergence of neuronal diversity among somatostatin-expressing (SST+) cells in mice. We found that SST+ inhibitory neurons segregate during embryonic stages into long-range projection (LRP) neurons and two types of interneurons, Martinotti cells and non-Martinotti cells, following distinct developmental trajectories. Two main subtypes of LRP neurons and several subtypes of interneurons are readily distinguishable in the embryo, although interneuron diversity is likely refined during early postnatal life. Our results suggest that the timing for cellular diversification is unique for different subtypes of SST+ neurons and particularly divergent for LRP neurons and interneurons. [Display omitted] • Diversity among cortical inhibitory SST+ neurons emerges early in development • The timing of interneuron diversification varies among different SST+ neurons • Long-range GABAergic neurons implement unique molecular programs of development Fisher et al. reveal that cortical GABAergic neurons expressing somatostatin are highly diverse during embryonic development. However, the timing of cell fate acquisition among these cells varies depending on their identity. Fisher and colleagues also identify distinct molecular programs governing the diversification of GABAergic long-range projection neurons and interneurons. [ABSTRACT FROM AUTHOR]

The crystallization behavior, rheological behavior, mechanical properties and microstructures of injection molded isotactic polypropylene ( iPP), polypropylene random copolymer ( co-PP) and iPP/ co-PP blends were investigated. Differential scanning calorimetry (DSC) and dynamic rheological analysis illustrated that iPP and co-PP were compatible in the blends and co-PP uniformly dispersed in the iPP phase. Polarizing optical microscope (POM) was adopted to observe the crystal size and morphology evolution. The results of mechanical properties and scanning electron microscopy (SEM) indicated that the crystal size of iPP in iPP/ co-PP blends (10 wt% co-PP + 90 wt% iPP and 30 wt% co-PP + 70 wt% iPP) radically decreased after the incorporation of co-PP. During crystallization, the molecular chain segments of co-PP could penetrate iPP spherulites and form a network-like crystalline structure. The network-like crystal structure could effectively transmit stress and consume more energy to overcome intermolecular forces to resist stretching. In this way, the strength would improve to a certain degree. The impact fracture mechanism of iPP/ co-PP blends is quasi ductile fracture by multiple crazes. Our work discovered that the blends containing 10 wt% and 30 wt% of co-PP exhibited prominent toughness and reinforcement. [ABSTRACT FROM AUTHOR]

Isotactic polypropylene ( iPP) samples obtained by pressure vibration injection molding (PVIM) and conventional injection molding (CIM) were studied by polarized-light microscopy (PLM), respectively. It was found that the alternating bright and dark banded spherulites were generated in the transitional region of PVIM parts. It is the first time that the banded spherulites of isotactic polypropylene were observed in polymer processing. What's more, the banded spherulites were proved to be constituted of α-form crystal by hot stage polarized-light microscopy (HT-PLM) and wide angle X-ray diffraction (WAXD). Morphology of the banded spherulites was also studied by scaning electronical microscopy (SEM). [ABSTRACT FROM AUTHOR]