bioRxiv Science⌕ Search

Biology subjects

Xu, Y.-H.

Publications and source records attributed to Xu, Y.-H..

4 recordsLinked to original sources

Single-cell spatial transcriptomics and snRNA-seq decoding the organizational principles of functional modules in the mouse amygdala

The amygdala is a functionally heterogeneous nuclear complex comprising multiple subnuclei that orchestrate diverse behaviors, making it essential for survival and reproduction. However, the precise neural mechanisms underlying these heterogeneous functions remain elusive, primarily due to limited knowledge of the amygdalas cellular heterogeneity, developmental origins, spatial organization, and gene expression profiles. Here, we integrate single-cell-resolution spatial transcriptomics with precise anatomical dissection and single-nucleus RNA sequencing to systematically map the subnuclear enrichment patterns of amygdalar cell types. We further demonstrate that developmental origin determines subnuclear positioning and propose a novel functional modular architecture based on cellular composition and gene expression signatures. Furthermore, we reveal that the central amygdala (CEA) exhibits developmental heterogeneity, with Isl1+ neurons in its medial subdivision (CEAm) predominantly originating from hypothalamic progenitors. Our findings establish a spatially resolved cellular and molecular framework for investigating amygdalar functions at cellular type resolution and understanding amygdala-related neuropsychiatric disorders.

neuroscience↗

Evolutionary modes of wtf meiotic driver genes in Schizosaccharomyces pombe

Killer meiotic drivers (KMDs) are a class of selfish genetic elements that defy Mendels law and bias transmission in their favor by destroying meiotic progeny that do not carry them. How KMDs evolve is not well understood. In the fission yeast Schizosaccharomyces pombe, the largest gene family, known as the wtf genes, is a KMD family that causes intraspecific hybrid sterility. Here, we investigate how wtf genes evolve using long-read-based genome assemblies of 31 distinct S. pombe natural isolates, which encompass the known genetic diversity of S. pombe. Our analysis, involving nearly 1,000 wtf genes in these isolates, yields a comprehensive portrayal of the intraspecific diversity of wtf genes. Leveraging single-nucleotide polymorphisms in adjacent unique sequences, we pinpoint wtf-gene-containing loci that have recently undergone gene conversion events and infer their pre-gene-conversion state. These events include the revival of wtf pseudogenes, lending support to the notion that gene conversion plays a role in preserving this gene family from extinction. Moreover, our investigation reveals that solo long terminal repeats (LTRs) of retrotransposons, frequently found near wtf genes, can act as recombination arms, influencing the upstream regulatory sequences of wtf genes. Additionally, our exploration of the outer boundaries of wtf genes uncovers a previously unrecognized type of directly oriented repeats flanking wtf genes. These repeats may have facilitated the early expansion of the wtf gene family in S. pombe. Our findings enhance the understanding of the mechanisms influencing the evolution of this KMD gene family.

evolutionary biology↗

The wtf meiotic driver gene family has unexpectedly persisted for over 100 million years

Meiotic drivers are selfish elements that bias their own transmission into more than half of the viable progeny produced by a driver+/driver- heterozygote. Meiotic drivers are thought to exist for relatively short evolutionary timespans because a driver gene or gene family is often found in a single species or in a group of very closely related species. Additionally, drivers are generally considered doomed to extinction when they spread to fixation or when suppressors arise. In this study, we examine the evolutionary history of the wtf meiotic drivers first discovered in the fission yeast Schizosaccharomyces pombe. We identify homologous genes in three other fission yeast species S. octosporus, S. osmophilus, and S. cryophilus, which are estimated to have diverged over 100 million years ago from the S. pombe lineage. Synteny evidence supports that wtf genes were present in the common ancestor of these four species. Moreover, the ancestral genes were likely drivers as wtf genes in S. octosporus cause meiotic drive. Our findings indicate that active meiotic drive systems can be maintained for long evolutionary timespans.

evolutionary biology↗

Harnessing the Cross-talk between Tumor Cells and Tumor-associated Macrophages with a Nano-drug for modulation of Glioblastoma Immune Microenvironment

Glioblastoma (GBM) is the most frequent and malignant brain tumor with a high mortality rate. The presence of a large population of macrophages (M{varphi}) in the tumor microenvironment is a prominent feature of GBM and these so-called tumor-associated M{varphi} (TAM) closely interact with the GBM cells to promote the survival, progression and therapy resistance of the GBM. Various therapeutic strategies have been devised either targeting the GBM cells or the TAM but few have addressed the cross-talks between the two cell populations. The present study was carried out to explore the possibility of exploiting the cross-talks between the GBM cells (GC) and TAM for modulation of the GBM microenvironment through using Nano-DOX, a drug composite based on nanodiamonds bearing doxorubicin. In the in vitro work on human cell models, Nano-DOX-loaded TAM were first shown to be viable and able to infiltrate three-dimensional GC spheroids and release cargo drug therein. GC were then demonstrated to encourage Nano-DOX-loaded TAM to unload Nano-DOX back into GC which consequently emitted damage-associated molecular patterns (DAMPs) that are powerful immunostimulatory agents as well as indicators of cell damage. Nano-DOX was next proven to be a more potent inducer of GC DAMPs emission than doxorubicin. As a result, Nano-DOX-damaged GC exhibited an enhanced ability to attract both TAM and Nano-DOX-loaded TAM. Most remarkably, Nano-DOX-damaged GC reprogrammed the TAM from a pro-GBM phenotype to an anti-GBM phenotype that suppressed GC growth. Finally, the in vivo relevance of the in vitro findings was tested in animal study. Mice bearing orthotopic human GBM xenografts were intravenously injected with Nano-DOX-loaded mouse TAM which were found releasing drug in the GBM xenografts 24 h after injection. GC damage was evidenced by the induction of DAMPs emission within the xenografts and a shift of TAM phenotype was detected as well. Taken together, our results demonstrate a novel way with therapeutic potential to harness the cross-talk between GBM cells and TAM for modulation of the tumor immune microenvironment.\n\nAbbreviationsATP, adenosine triphosphate; BBB, blood-brain barrier; BCA, bicinchoninic acid; BMDM, bone marrow derived macrophages; CD, cluster of differentiation; CFSE, 5(6)-carboxyfluorescein diacetate, succinimidyl ester; CM, conditioned culture medium; CNS, central nervous system; CRT, calreticulin; DAMPs, damage-associated molecular patterns; DAB, diaminobenzidine; DOX, doxorubicin; ECL, enhanced chemiluminescence; ELISA, enzyme-linked immunosorbent assay; HMGB1, high mobility group protein B1; HSP90, heat shock protein 90; FACS, flow cytometry; GBM, glioblastoma; Guanylate Binding Protein 5 (GBP5); GC, glioblastoma cells; IHC, immunohistochemical; IL, interleukin; M{varphi}, macrophages; mBMDM, mouse BMDM; mBMDM2, Type-2 mBMDM; M1, Type-1 Mo; M2, Type-2 Mo; Nano-DOX, ND-PG-RGD-DOX; ND, nanodiamonds; Nano-DOX-mBMDM, Nano-DOX-loaded mouse BMDM; NGCM, Nano-DOX-treated-GC-conditioned medium; PBS, phosphate buffered saline; PG, polyglycerol; PMA, phorbol 12-myristate 13-acetate; PVDF, polyvinylidene fluoride; RGD, tripeptide of L-arginine, glycine and L-aspartic acid; RM, regular culture medium; SD, standard deviation; TAM, tumor-associated M{varphi}; TBST, Tris Buffered Saline with Tween(R) 20.\n\nGraphic abstract\n\nO_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=153 SRC=\"FIGDIR/small/170282_ufig1.gif\" ALT=\"Figure 1\">\nView larger version (111K):\norg.highwire.dtl.DTLVardef@180aea2org.highwire.dtl.DTLVardef@14922f7org.highwire.dtl.DTLVardef@96a696org.highwire.dtl.DTLVardef@92f050_HPS_FORMAT_FIGEXP M_FIG C_FIG

pharmacology and toxicology↗