---
OA_place: publisher
_id: '22804'
abstract:
- lang: eng
  text: 'Embryo cleavage — a series of rapid, reductive cell divisions — is the first
    morphogenetic movement following fertilisation. It lays the foundation for subsequent
    developmental events, including gastrulation, germ layer specification, organogenesis,
    and the establishment of the overall body plan. Two major modes of cleavage exist
    in the animal kingdom: holoblastic (complete) and meroblastic (incomplete) cleavage.
    Because holoblastic cleavage resembles canonical cytokinesis, its biochemical
    and mechanical basis has been extensively studied — an annular contractile ring
    forms at the equator and constricts in a purse-string-like manner, leading to
    the complete separation of two daughter cells. In contrast, although meroblastic
    cleavage occurs widely across the animal kingdom (e.g. in fish, reptiles, birds,
    and cephalopod molluscs), its mechanical basis remains largely unclear. During
    meroblastic cleavage, the cytokinetic furrow forms only at one pole and does not
    traverse the entire embryo, raising the question of how cytokinesis proceeds in
    the absence of a closed contractile ring. Moreover, the resulting daughter cells
    are not fully separated from the underlying yolk compartment, and how these blastomeres
    are subsequently cellularised remains unknown. This thesis takes the zebrafish
    as a model organism to address both questions. The first part characterises the
    biochemical and mechanical mechanisms underlying non-canonical meroblastic cleavage,
    revealing a two-phase process in which actomyosin cable contraction and cadherin-mediated
    membrane adhesion act sequentially to drive furrow ingression and invagination.
    The second part sheds light on the spatiotemporal dynamics by which individual
    blastomeres become cellularised, and uncovers a previously unrecognised contribution
    of central blastomeres to the yolk syncytial layer.'
acknowledged_ssus:
- _id: Bio
- _id: LifeSc
acknowledgement: "I gratefully acknowledge the NOMIS Stiftung (Project ID 5061.844,
  Cytoplasmic\r\nself-organization into cell-like compartments as a common guiding
  principle in\r\nearly animal development) for funding my doctoral studies."
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Xin
  full_name: Tong, Xin
  id: 50F65CDC-AA30-11E9-A72B-8A12E6697425
  last_name: Tong
citation:
  ama: Tong X. Towards a deeper understanding of meroblastic cleavage. 2026. doi:<a
    href="https://doi.org/10.15479/AT-ISTA-22804">10.15479/AT-ISTA-22804</a>
  apa: Tong, X. (2026). <i>Towards a deeper understanding of meroblastic cleavage</i>.
    Institute of Science and Technology Austria. <a href="https://doi.org/10.15479/AT-ISTA-22804">https://doi.org/10.15479/AT-ISTA-22804</a>
  chicago: Tong, Xin. “Towards a Deeper Understanding of Meroblastic Cleavage.” Institute
    of Science and Technology Austria, 2026. <a href="https://doi.org/10.15479/AT-ISTA-22804">https://doi.org/10.15479/AT-ISTA-22804</a>.
  ieee: X. Tong, “Towards a deeper understanding of meroblastic cleavage,” Institute
    of Science and Technology Austria, 2026.
  ista: Tong X. 2026. Towards a deeper understanding of meroblastic cleavage. Institute
    of Science and Technology Austria.
  mla: Tong, Xin. <i>Towards a Deeper Understanding of Meroblastic Cleavage</i>. Institute
    of Science and Technology Austria, 2026, doi:<a href="https://doi.org/10.15479/AT-ISTA-22804">10.15479/AT-ISTA-22804</a>.
  short: X. Tong, Towards a Deeper Understanding of Meroblastic Cleavage, Institute
    of Science and Technology Austria, 2026.
corr_author: '1'
date_created: 2026-09-04T11:54:20Z
date_published: 2026-07-12T00:00:00Z
date_updated: 2026-10-05T08:56:10Z
day: '12'
ddc:
- '596'
- '532'
- '572'
degree_awarded: PhD
department:
- _id: GradSch
- _id: CaHe
doi: 10.15479/AT-ISTA-22804
doi_confirm: '1'
file:
- access_level: closed
  checksum: fdcc187a5a92e785da0eff8936fb127e
  content_type: application/zip
  creator: xtong
  date_created: 2026-09-11T13:04:37Z
  date_updated: 2026-09-14T08:28:06Z
  file_id: '22909'
  file_name: 2026_TONG_Xin_Thesis.zip
  file_size: 126983933
  relation: source_file
- access_level: open_access
  checksum: 23ee39b3f08bccd46acfd332e67f5232
  content_type: application/pdf
  creator: xtong
  date_created: 2026-09-14T12:30:07Z
  date_updated: 2026-09-14T12:48:53Z
  file_id: '22930'
  file_name: 2026_TONG_Xin_Thesis.pdf
  file_size: 46855054
  relation: main_file
file_date_updated: 2026-09-14T12:48:53Z
fulldoi: https://doi.org/10.15479/AT-ISTA-22804
has_accepted_license: '1'
keyword:
- meroblastic cleavage
- cytokinesis
- active gel theory
- embryogenesis
- zebrafish
- adhesion
language:
- iso: eng
license: https://creativecommons.org/licenses/by-nc/4.0/
month: '07'
oa: 1
oa_version: Published Version
page: '121'
project:
- _id: 917c023a-16d5-11f0-9cad-eb5cafc52090
  name: Cytoplasmic self-organization into cell-like compartments as a common guiding
    principle in early animal development
publication_identifier:
  isbn:
  - 978-3-99078-080-0
  issn:
  - 2663-337X
publication_status: published
publisher: Institute of Science and Technology Austria
related_material:
  record:
  - id: '22777'
    relation: research_data
    status: public
  - id: '22807'
    relation: part_of_dissertation
    status: public
researchdata_availability: upon request
status: public
supervisor:
- first_name: Carl-Philipp J
  full_name: Heisenberg, Carl-Philipp J
  id: 39427864-F248-11E8-B48F-1D18A9856A87
  last_name: Heisenberg
  orcid: 0000-0002-0912-4566
title: Towards a deeper understanding of meroblastic cleavage
tmp:
  image: /images/cc_by_nc.png
  legal_code_url: https://creativecommons.org/licenses/by-nc/4.0/legalcode
  name: Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)
  short: CC BY-NC (4.0)
type: dissertation
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
year: '2026'
...