The number and diversity of inhibitory neurons (INs) increased substantially during mammalian brain evolution. However, the generative mechanisms of the vast repertoire of human INs remain elusive. We performed spatial and single-cell transcriptomics of human medial ganglionic eminence (hMGE), a pivotal source of cortical and subpallial INs, and built the trajectories of hMGE-derived cells during brain development. We identified spatiotemporally and molecularly segregated progenitor cell populations fated to produce distinct IN types. We uncovered an evolutionarily distinct progenitor cell type in the hMGE subventricular zone that maintained the production of INs and glial cells throughout human brain development. Our findings reveal evolutionarily distinct features of IN generation and shed light on the distinct mechanisms underlying human brain development.
A critical first step in human evolutionary divergence from chimpanzees and other primates is the production of greatly increased numbers of cortical pyramidal neurons during development and over evolutionary time. This expansion underpins the enlarged human cerebral cortex and, consequently, higher-order cognition and consciousness. However, the cellular and molecular mechanisms driving this progressive increase in cortical neuron number remain incompletely understood. Here we show that elevated ERK signaling in human cortical radial glia (RGs), relative to mouse RGs, arises from evolutionary changes in the developmental expression of existing shared genes. Using the Emx1-Cre line to overexpress MEK1DD, a constitutively active mutant of rat MAP2K1, we found that enhanced ERK signaling in mouse cortical RGs upregulates cAMP-PKA signaling, along with promoting self-renewal, expanding the RG pool, and accelerating cell cycle progression. Conversely, overexpression of PKA signaling in mouse cortical RGs via in utero electroporation of constitutively active PRKACA mutants (L206R or W196G) reduces ERK activity, prolongs the cell cycle, suppresses SHH-SMO and YAP/TAZ pathway activity, and blocks ependymal gliogenesis. Together, our results demonstrate that ERK and PKA signaling in cortical RGs engage a dynamic balance of synergistic and antagonistic interactions. This interplay couples evolutionarily enhanced ERK and PKA activities to increased cortical RG numbers, prolonged cell cycle progression, and an extended neurogenic period, which collectively culminate in a marked increase in neuronal production. We conclude that heightened ERK pathway activity in cortical RGs serves as a central driver of progressive neocortical expansion across mammalian evolution.
Diffuse intrinsic pontine glioma (DIPG), a lethal pediatric cancer driven by H3K27M oncohistones, exhibits aberrant epigenetic regulation and stem-like cell states. Here, we uncover an axis involving H3.3K27M oncohistones, CREB5/ID1, which sustains the stem-like state of DIPG cells, promoting malignancy. We demonstrate that CREB5 mediates elevated ID1 levels in the H3.3K27M/ACVR1WT subtype, promoting tumor growth; while BMP signaling regulates this process in the H3.1K27M/ACVR1MUT subtype. Furthermore, we reveal that H3.3K27M directly enhances CREB5 expression by reshaping the H3K27me3 landscape at the CREB5 locus, particularly at super-enhancer regions. Additionally, we elucidate the collaboration between CREB5 and BRG1, the SWI/SNF chromatin remodeling complex catalytic subunit, in driving oncogenic transcriptional changes in H3.3K27M DIPG. Intriguingly, disrupting CREB5 super-enhancers with ABBV-075 significantly reduces its expression and inhibits H3.3K27M DIPG tumor growth. Combined treatment with ABBV-075 and a BRG1 inhibitor presents a promising therapeutic strategy for clinical translation in H3.3K27M DIPG treatment.
Neodon, a typical group of high-altitude rodents, originated in the high-altitude regions of the Tibet-Himalayan area. These rodents inhabit meadows, swampy grasslands, and shrublands at elevations ranging from 3,700 to 4,800 m in Qinghai-Tibet Plateau, where they experience environment stresses such as hypoxia, enhanced ultraviolet radiation, and low temperature. In this study, we assembled a high-quality chromosome-level genome of Neodon fuscus and use it to investigate the potential genetic bases of high-altitude adaptation. The genome of N. fuscus shows gene family expansion in genes related to immunity. Comparative genomics analysis revealed several positively selected genes and rapidly evolving genes associated with DNA damage repair (Atm and Pdia4) and male sperm quality (Idh3b and Atplb1) that aid in clarifying high-altitude adaptation of Neodon species. Additionally, we found that genes (Nrp2, Vav3, Cat and Adam8) associated with oxidative stress and cardiovascular regulation seem to have experienced convergent evolution among plateau species. Notably, we identified a Neodon-specific 24 bp deletion in Map3k6, which may regulate angiogenesis, aiding Neodon species adapt to hypoxic environments. These findings elucidate molecular mechanisms underlying high-altitude adaptation, emphasizing the integrative roles of immunity, stress response, and reproduction. The high-quality genome of N. fuscus offers new insights into how Neodon adapt to high-altitude environments and will facilitate future research on Neodon.
The mammalian brain contains diverse neuronal and immune cell types that exhibit dynamic motions in response to distinct extracellular environments. However, technical limitations make it difficult to investigate complex cellular motions in the developing brain in vivo. Here, we establish the intravital imaging of externally immobilized embryos (IMEE) method for long-term, large-field, and deep-depth imaging of mouse embryos, excelling in viewing angle flexibility, procedural simplicity, and functional applicability. Through combining IMEE with in utero retro-orbital injection and topological analysis of vector fields, we characterize distinct neuronal migration patterns and illustrate interactions among neurons, immune cells, and vasculature under physiological conditions and environmental stress during brain development. Our results suggest that neuronal migration guidance and immune surveillance depend on cellular adaptation to the local environment through distinct motion patterns of somata or processes. Our findings provide critical insight into the environmentally adaptive nature of neural cells in the developmental landscape.
Human cerebellum encompasses numerous neurons, exhibiting a distinct developmental paradigm from cerebrum. Here we conducted scRNA-seq, scATAC-seq and spatial transcriptomic analyses of fetal samples from gestational week (GW) 13 to 18 to explore the emergence of cellular diversity and developmental programs in the developing human cerebellum. We identified transitory granule cell progenitors that are conserved across species. Special patterns in both granule cells and Purkinje cells were dissected multidimensionally. Species-specific gene expression patterns of cerebellar lobes were characterized and we found that PARM1 exhibited inconsistent distribution in human and mouse granule cells. A novel cluster of potential neuroepithelium at the rhombic lip was identified. We also resolved various subtypes of Purkinje cells and unipolar brush cells and revealed gene regulatory networks controlling their diversification. Therefore, our study offers a valuable multi-omics landscape of human fetal cerebellum and advances our understanding of development and spatial organization of human cerebellum.
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.
Habitat degradation and loss of genetic diversity are common threats faced by almost all of today's wild cats. Big cats, such as tigers and lions, are of great concern and have received considerable conservation attention through policies and international actions. However, knowledge of and conservation actions for small wild cats are lagging considerably behind. The black-footed cat, Felis nigripes, one of the smallest felid species, is experiencing increasing threats with a rapid reduction in population size. However, there is a lack of genetic information to assist in developing effective conservation actions. A de novo assembly of a high-quality chromosome-level reference genome of the black-footed cat was made, and comparative genomics and population genomics analyses were carried out. These analyses revealed that the most significant genetic changes in the evolution of the black-footed cat are the rapid evolution of sensory and metabolic-related genes, reflecting genetic adaptations to its characteristic nocturnal hunting and a high metabolic rate. Genomes of the black-footed cat exhibit a high level of inbreeding, especially for signals of recent inbreeding events, which suggest that they may have experienced severe genetic isolation caused by habitat fragmentation. More importantly, inbreeding associated with two deleterious mutated genes may exacerbate the risk of amyloidosis, the dominant disease that causes mortality of about 70% of captive individuals. Our research provides comprehensive documentation of the evolutionary history of the black-footed cat and suggests that there is an urgent need to investigate genomic variations of small felids worldwide to support effective conservation actions.
Female sociosexual behaviors, essential for survival and reproduction, are adaptively modulated by ovarian hormones. However, the neural mechanisms integrating internal hormonal states with external social cues to guide these behaviors remain poorly understood. Here we identified primary estrous-sensitive Cacna1h-expressing medial prefrontal (mPFCCacna1h+) neurons that orchestrate adaptive sociosexual behaviors. Bidirectional manipulation of mPFCCacna1h+ neurons drives opposite-sex-directed behavioral shifts between estrus and diestrus females. In males, these neurons serve opposite functions compared to estrus females, mediating sexually dimorphic effects via anterior hypothalamic outputs. Miniscope imaging reveals mixed-representation of self-estrous states and social target sex in distinct mPFCCacna1h+ subpopulations, with biased-encoding of opposite-sex social cues in estrus females and males. Mechanistically, ovarian hormone-driven upregulation of Cacna1h-encoded T-type calcium channels underlies estrus-specific activity changes and sexual-dimorphic function of mPFCCacna1h+ neurons. These findings uncover a prefrontal circuit that integrates internal hormonal states and target-sex information to exert sexually bivalent top-down control over adaptive social behaviors. ### Competing Interest Statement The authors have declared no competing interest.
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.
Bird sex chromosomes play a unique role in sex-determination, and affect the sexual morphology and behavior of bird species. Core waterbirds, a major clade of birds, share the common characteristics of being sexually monomorphic and having lower levels of inter-sexual conflict, yet their sex chromosome evolution remains poorly understood. Here, by we analyse of a chromosome-level assembly of a female crested ibis (Nipponia nippon), a typical core waterbird. We identify neo-sex chromosomes resulting from fusion of microchromosomes with ancient sex chromosomes. These fusion events likely occurred following the divergence of Threskiornithidae and Ardeidae. The neo-W chromosome of the crested ibis exhibits the characteristics of slow degradation, which is reflected in its retention of abundant gametologous genes. Neo-W chromosome genes display an apparent ovary-biased gene expression, which is largely driven by genes that are retained on the crested ibis W chromosome but lost in other bird species. These results provide new insights into the evolutionary history and expression patterns for the sex chromosomes of bird species.
BACKGROUND: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. METHODS: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. RESULTS: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. CONCLUSIONS: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.
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.
Interneurons are fundamental cells for maintaining the excitation-inhibition balance in the brain in health and disease. While interneurons have been shown to play a key role in the pathophysiology of autism spectrum disorder (ASD) in adult mice, little is known about how their maturation is altered in the developing striatum in ASD. Here, we aimed to track striatal developing interneurons and elucidate the molecular and physiological alterations in the Cntnap2 knockout mouse model. Using Stereo-seq and single-cell RNA sequencing data, we first characterized the pattern of expression of Cntnap2 in the adult brain and at embryonic stages in the medial ganglionic eminence (MGE), a transitory structure producing most cortical and striatal interneurons. We found that Cntnap2 is enriched in the striatum, compared to the cortex, particularly in the developing striatal cholinergic interneurons. We then revealed enhanced MGE-derived cell proliferation, followed by increased cell loss during the canonical window of developmental cell death in the Cntnap2 knockout mice. We uncovered specific cellular and molecular alterations in the developing Lhx6-expressing cholinergic interneurons of the striatum, which impacts interneuron firing properties during the first postnatal week. Overall, our work unveils some of the mechanisms underlying the shift in the developmental trajectory of striatal interneurons which greatly contribute to the ASD pathogenesis.
The granular dorsolateral prefrontal cortex (dlPFC) is an evolutionary specialization of primates that is centrally involved in cognition. We assessed more than 600,000 single-nucleus transcriptomes from adult human, chimpanzee, macaque, and marmoset dlPFC. Although most cell subtypes defined transcriptomically are conserved, we detected several that exist only in a subset of species as well as substantial species-specific molecular differences across homologous neuronal, glial, and non-neural subtypes. The latter are exemplified by human-specific switching between expression of the neuropeptide somatostatin and tyrosine hydroxylase, the rate-limiting enzyme in dopamine production in certain interneurons. The above molecular differences are also illustrated by expression of the neuropsychiatric risk gene FOXP2 , which is human-specific in microglia and primate-specific in layer 4 granular neurons. We generated a comprehensive survey of the dlPFC cellular repertoire and its shared and divergent features in anthropoid primates.
Abstract Background: The emergence and spread of antibiotic resistance are a significant threat to global health. Silage is a major forage feed for ruminants, and its safety is an important guarantee that high-quality ruminant products will remain available to humans. However, little attention has been given to the silage resistome. To define the antibiotic resistome and its potential risk to silage from different climate zones and in response to the ensiling process, this study used metagenomics to investigate bacterial communities and the type and amount of antibiotic resistance gene (ARG) in corn silage harvested from six climate zones (Cfa, BWk, Dwc, Dwa, BSk, and Aw based on Köppen-Geiger climate classification) in China. Results: The composition and succession of silage bacterial communities varied significantly between different climate zones. Lactobacillus was the predominant bacteria during corn ensiling. A total of 134 ARGs were observed in corn silage, with the dominant classes being beta-lactamase and multidrug resistance and the primary mechanisms being efflux pump, inactivation, and target protection. Differences in the resistome were mainly attributed to disparities in microbial composition, which was indirectly affected by climatic factors and fermentation pH. ARG abundance was lower in 90-day silages than 5-day silages except in Hainan silage. The diversity and relative abundance (0.65-0.4% based on total gene number) of ARGs was lower in silage microbiota from Tibet than other climate zones. The dominant ARGs were tetM, oqxB, lmrD, lnuA, ermB, and tetS, and Enterobacter, Klebsiella, Staphylococcus, Lactobacillus and Lactococcus were the primary ARG hosts. Eleven high-risk ARGs were chosen to evaluate the pollution level of silages harvested from different climate zones. The highest relative abundance of high-risk ARGs belonging to Lactobacillus occurred in corn silages from Cfa, Dwa and BWk climate zones. Conclusions: The ensiling process decreased ARG abundance. While resistome contamination of silage from Tibet was relatively low, ARGs with high risk were abundant in silages from Cfa, Dwa and BWk climate zones.
Genetic variation confers susceptibility to neurodevelopmental disorders by affecting the development of specific cell types. Changes in cortical and striatal γ-aminobutyric acid–expressing (GABAergic) neurons are common in autism and schizophrenia. In this study, we used single-cell RNA sequencing to characterize the emergence of cell diversity in the human ganglionic eminences, the transitory structures of the human fetal brain where striatal and cortical GABAergic neurons are generated. We identified regional and temporal diversity among progenitor cells underlying the generation of a variety of projection neurons and interneurons. We found that these cells are specified within the human ganglionic eminences by transcriptional programs similar to those previously identified in rodents. Our findings reveal an evolutionarily conserved regulatory logic controlling the specification, migration, and differentiation of GABAergic neurons in the human telencephalon.
Summary Multi‐omics approach was adopted to investigate the modulation of bacterial microbiota and metabolome as well as their interactions in whole crop corn ensiling systems by inoculating homofermentative Lactobacillus plantarum or heterofermentative Lactobacillus buchneri. Inoculations of the two different inoculants resulted in substantial differences in microbial community and metabolic composition as well as their dynamics in ensiled corn. Inoculants also altered the correlations of microbiota in different manners, and various keystone species were identified in corn silages with different treatments. Many metabolites with biofunctional activities like bacteriostatic, antioxidant, central nervous system inhibitory and anti‐inflammatory were found in the present silage. A constitutive difference in microbiota dynamics was found for several pathways, which were upregulated by specific taxa in middle stage of fermentation, and widespread associations between metabolites with biofunctions and the species of lactic acid bacteria dominated in silage were observed. Multiple microbial and metabolic structures and dynamics were correlated and affected the fermentation process of the corn ensiling systems. Results of the current study improve our understanding of the complicated biological process underlying silage fermentation and provide a framework to re‐evaluate silages with biofunctions, which may contribute to target‐based regulation methods to produce functional silage for animal production.
Mylabris aulica is a widely distributed blister beetle of the Meloidae family. It has the ability to synthesize a potent defensive secretion that includes cantharidin, a toxic compound used to treat many major illnesses. However, owing to the lack of genetic studies on cantharidin biosynthesis in M. aulica, the commercial use of this species is less extensive than that of other blister beetle species in China. This study reports a draft assembly and possible genes and pathways related to cantharidin biosynthesis for the M. aulica blister beetle using nanopore sequencing data. The draft genome assembly size was 288.5 Mb with a 467.8 Kb N50, and a repeat content of 50.62%. An integrated gene finding pipeline performed for assembly obtained 16 500 protein coding genes. Benchmarking universal single-copy orthologs assessment showed that this gene set included 94.4% complete Insecta universal single-copy orthologs. Over 99% of these genes were assigned functional annotations in the gene ontology, Kyoto Encyclopedia of Genes and Genomes, or Genbank non-redundant databases. Comparative genomic analysis showed that the completeness and continuity of our assembly was better than those of Hycleus cichorii and Hycleus phaleratus blister beetle genomes. The analysis of homologous orthologous genes and inference from evolutionary history imply that the Mylabris and Hycleus genera are genetically close, have a similar genetic background, and have differentiated within one million years. This M. aulica genome assembly provides a valuable resource for future blister beetle studies and will contribute to cantharidin biosynthesis.
The Asian Buffalo leech, Hirudinaria manillensis, is an aquatic sanguivorous species distributed widely in Southeast Asia. H. manillensis has long been used clinically for bloodletting and other medical purposes. Recent studies have focused on artificial culturing, strain optimization, and the identification and development new drugs based on the anticoagulant effects of H. manillensis bites; however, data regarding its genome remain unclear. This study aimed to determine the genome sequence of an adult Asian Buffalo leech. We generated a draft assembly of 151.8 Mb and a N50 scaffold of 2.28 Mb. Predictions indicated that the assembled genome contained 21,005 protein-coding genes. Up to 17,865 genes were annotated in multiple databases including Gene Ontology. Sixteen anticoagulant proteins with a Hirudin or Antistasin domain were identified. This study is the first to report the whole-genome sequence of the Asian Buffalo leech, an important sanguivorous leech of clinical significance. The quality of the assembly is comparable to those of other annelids. These data will help further the current understanding of the biological mechanisms and genetic characteristics of leeches and serve as a valuable resource for future studies.