---
OA_place: publisher
_id: '22399'
abstract:
- lang: eng
  text: "Gaining an understanding of how biological regulation evolves is a fundamental
    research \r\nquestion in both evolutionary biology and molecular genetics. In
    order to gain more insight \r\ninto this topic, we focus on studying the simple
    gene regulatory system of the lac operon in \r\nE. coli. We show that simple population
    genetic models can shed light on evolution \r\nexperiments and that this combined
    approach of modelling the experimental system gives \r\ninsight to better understand
    the causes of evolutionary change in the experiment. We also \r\nstudy the natural
    diversity in the lac operon from 308 publicly available E. coli genomes that \r\ncome
    from various host species and different regions of the world. Evidence that selection
    is \r\ngenerally maintaining the function of the lac operon across the sample
    regardless of host \r\nspecies is provided and we show that different protein
    coding genes in the operon are under \r\ndifferent selective constraints on protein
    sequence preservation. A similar frameshift \r\nmutation found in experimental
    evolution studies is shown to be present in the sample we \r\nanalyzed, indicating
    that selectively relevant variants in evolution experiments are also \r\npresent
    in natural populations. We show that there is no simple phylogenetic relationship
    \r\nbetween host species, geographical location and the lac operon sequence. Finally,
    we argue \r\nthat a combined approach of comparative genomics, experimental evolution
    and theoretical \r\nmodelling contributes to a more complete understanding of
    molecular evolution. "
alternative_title:
- ISTA Master’s Thesis
article_processing_charge: No
author:
- first_name: Aleksa
  full_name: Spasić, Aleksa
  id: ecee9d38-4040-11ef-8843-b941efb445d6
  last_name: Spasić
citation:
  ama: Spasić A. Studying the evolutionary systems biology of the lac operon. 2026.
    doi:<a href="https://doi.org/10.15479/AT-ISTA-22399">10.15479/AT-ISTA-22399</a>
  apa: Spasić, A. (2026). <i>Studying the evolutionary systems biology of the lac
    operon</i>. Institute of Science and Technology Austria. <a href="https://doi.org/10.15479/AT-ISTA-22399">https://doi.org/10.15479/AT-ISTA-22399</a>
  chicago: Spasić, Aleksa. “Studying the Evolutionary Systems Biology of the Lac Operon.”
    Institute of Science and Technology Austria, 2026. <a href="https://doi.org/10.15479/AT-ISTA-22399">https://doi.org/10.15479/AT-ISTA-22399</a>.
  ieee: A. Spasić, “Studying the evolutionary systems biology of the lac operon,”
    Institute of Science and Technology Austria, 2026.
  ista: Spasić A. 2026. Studying the evolutionary systems biology of the lac operon.
    Institute of Science and Technology Austria.
  mla: Spasić, Aleksa. <i>Studying the Evolutionary Systems Biology of the Lac Operon</i>.
    Institute of Science and Technology Austria, 2026, doi:<a href="https://doi.org/10.15479/AT-ISTA-22399">10.15479/AT-ISTA-22399</a>.
  short: A. Spasić, Studying the Evolutionary Systems Biology of the Lac Operon, Institute
    of Science and Technology Austria, 2026.
corr_author: '1'
das_tickbox: '0'
date_created: 2026-07-25T13:08:32Z
date_published: 2026-07-27T00:00:00Z
date_updated: 2026-07-31T10:52:08Z
day: '27'
ddc:
- '576'
degree_awarded: MS
department:
- _id: GradSch
- _id: GaTk
- _id: CaGu
doi: 10.15479/AT-ISTA-22399
doi_confirm: '1'
file:
- access_level: open_access
  checksum: c29880dd71fcc37f23ac6e2843066ede
  content_type: application/pdf
  creator: aspasic
  date_created: 2026-07-27T13:00:07Z
  date_updated: 2026-07-27T13:00:07Z
  file_id: '22588'
  file_name: Aleksa_Spasic_Thesis_final.pdf
  file_size: 1986078
  relation: main_file
  success: 1
- access_level: closed
  checksum: 4ebe3bd2d833d913c0756343cca5e5f0
  content_type: application/vnd.openxmlformats-officedocument.wordprocessingml.document
  creator: aspasic
  date_created: 2026-07-27T13:00:22Z
  date_updated: 2026-07-27T13:07:23Z
  file_id: '22589'
  file_name: Thesis_final.docx
  file_size: 1868853
  relation: source_file
file_date_updated: 2026-07-27T13:07:23Z
has_accepted_license: '1'
language:
- iso: eng
month: '07'
oa: 1
oa_version: Published Version
page: '32'
publication_identifier:
  issn:
  - 2791-4585
publication_status: published
publisher: Institute of Science and Technology Austria
status: public
supervisor:
- first_name: Calin C
  full_name: Guet, Calin C
  id: 47F8433E-F248-11E8-B48F-1D18A9856A87
  last_name: Guet
  orcid: 0000-0001-6220-2052
- first_name: Gašper
  full_name: Tkačik, Gašper
  id: 3D494DCA-F248-11E8-B48F-1D18A9856A87
  last_name: Tkačik
  orcid: 0000-0002-6699-1455
title: Studying the evolutionary systems biology of the lac operon
type: dissertation
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
year: '2026'
...