Microneedle manipulation of the mammalian spindle reveals specialized, short-lived reinforcement near chromosomes

  1. Pooja Suresh
  2. Alexandra F Long
  3. Sophie Dumont  Is a corresponding author
  1. University of California, San Francisco, United States

Abstract

The spindle generates force to segregate chromosomes at cell division. In mammalian cells, kinetochore-fibers connect chromosomes to the spindle. The dynamic spindle anchors kinetochore-fibers in space and time to move chromosomes. Yet, how it does so remains poorly understood as we lack tools to directly challenge this anchorage. Here, we adapt microneedle manipulation to exert local forces on the spindle with spatiotemporal control. Pulling on kinetochore-fibers reveals the preservation of local architecture in the spindle-center over seconds. Sister, but not neighbor, kinetochore-fibers remain tightly coupled, restricting chromosome stretching. Further, pulled kinetochore-fibers pivot around poles but not chromosomes, retaining their orientation within 3 μm of chromosomes. This local reinforcement has a 20 s lifetime, and requires the microtubule crosslinker PRC1. Together, these observations indicate short-lived, specialized reinforcement in the spindle center. This could help protect chromosome attachments from transient forces while allowing spindle remodeling, and chromosome movements, over longer timescales.

Data availability

Source data for all main and supplementary figures have been provided

Article and author information

Author details

  1. Pooja Suresh

    Biophysics Graduate Program, University of California, San Francisco, San Francisco, United States
    Competing interests
    The authors declare that no competing interests exist.
  2. Alexandra F Long

    Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, United States
    Competing interests
    The authors declare that no competing interests exist.
  3. Sophie Dumont

    Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, United States
    For correspondence
    sophie.dumont@ucsf.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-8283-1523

Funding

National Institute of General Medical Sciences (DP2GM119177)

  • Sophie Dumont

National Institute of General Medical Sciences (1R01GM134132)

  • Sophie Dumont

National Science Foundation (1554139 CAREER)

  • Sophie Dumont

National Science Foundation (1548297 Center for Cellular Construction)

  • Sophie Dumont

Rita Allen Foundation

  • Sophie Dumont

Chicago Community Trust (Searle Scholars' Program)

  • Sophie Dumont

National Science Foundation (Graduate Research Fellowship)

  • Pooja Suresh
  • Alexandra F Long

University of California, San Francisco (UCSF Kozloff Fellowship)

  • Alexandra F Long

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Copyright

© 2020, Suresh et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

Metrics

  • 1,989
    views
  • 340
    downloads
  • 32
    citations

Views, downloads and citations are aggregated across all versions of this paper published by eLife.

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Open citations (links to open the citations from this article in various online reference manager services)

Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)

  1. Pooja Suresh
  2. Alexandra F Long
  3. Sophie Dumont
(2020)
Microneedle manipulation of the mammalian spindle reveals specialized, short-lived reinforcement near chromosomes
eLife 9:e53807.
https://doi.org/10.7554/eLife.53807

Share this article

https://doi.org/10.7554/eLife.53807

Further reading

    1. Cell Biology
    Ryan M Finnerty, Daniel J Carulli ... Wipawee Winuthayanon
    Research Article

    The oviduct is the site of fertilization and preimplantation embryo development in mammals. Evidence suggests that gametes alter oviductal gene expression. To delineate the adaptive interactions between the oviduct and gamete/embryo, we performed a multi-omics characterization of oviductal tissues utilizing bulk RNA-sequencing (RNA-seq), single-cell RNA-sequencing (scRNA-seq), and proteomics collected from distal and proximal at various stages after mating in mice. We observed robust region-specific transcriptional signatures. Specifically, the presence of sperm induces genes involved in pro-inflammatory responses in the proximal region at 0.5 days post-coitus (dpc). Genes involved in inflammatory responses were produced specifically by secretory epithelial cells in the oviduct. At 1.5 and 2.5 dpc, genes involved in pyruvate and glycolysis were enriched in the proximal region, potentially providing metabolic support for developing embryos. Abundant proteins in the oviductal fluid were differentially observed between naturally fertilized and superovulated samples. RNA-seq data were used to identify transcription factors predicted to influence protein abundance in the proteomic data via a novel machine learning model based on transformers of integrating transcriptomics and proteomics data. The transformers identified influential transcription factors and correlated predictive protein expressions in alignment with the in vivo-derived data. Lastly, we found some differences between inflammatory responses in sperm-exposed mouse oviducts compared to hydrosalpinx Fallopian tubes from patients. In conclusion, our multi-omics characterization and subsequent in vivo confirmation of proteins/RNAs indicate that the oviduct is adaptive and responsive to the presence of sperm and embryos in a spatiotemporal manner.

    1. Cell Biology
    Weihua Wang, Junqiao Xing ... Zhangfeng Hu
    Research Article

    Existence of cilia in the last eukaryotic common ancestor raises a fundamental question in biology: how the transcriptional regulation of ciliogenesis has evolved? One conceptual answer to this question is by an ancient transcription factor regulating ciliary gene expression in both uni- and multicellular organisms, but examples of such transcription factors in eukaryotes are lacking. Previously, we showed that an ancient transcription factor X chromosome-associated protein 5 (Xap5) is required for flagellar assembly in Chlamydomonas. Here, we show that Xap5 and Xap5-like (Xap5l) are two conserved pairs of antagonistic transcription regulators that control ciliary transcriptional programs during spermatogenesis. Male mice lacking either Xap5 or Xap5l display infertility, as a result of meiotic prophase arrest and sperm flagella malformation, respectively. Mechanistically, Xap5 positively regulates the ciliary gene expression by activating the key regulators including Foxj1 and Rfx families during the early stage of spermatogenesis. In contrast, Xap5l negatively regulates the expression of ciliary genes via repressing these ciliary transcription factors during the spermiogenesis stage. Our results provide new insights into the mechanisms by which temporal and spatial transcription regulators are coordinated to control ciliary transcriptional programs during spermatogenesis.