• Melissa C. Keinath
  • Asya Davidian
  • Vladimir Timoshevskiy
  • Nataliya Timoshevskaya
  • Joseph G. Gall

The lampbrush chromosomes (LBCs) in oocytes of the Mexican axolotl (Ambystoma mexicanum) were identified some time ago by their relative lengths and predicted centromeres, but they have never been associated completely with the mitotic karyotype, linkage maps or genome assembly. We identified 9 of the axolotl LBCs using RNAseq to identify actively transcribed genes and 13 BAC (bacterial artificial clone) probes containing pieces of active genes. Using read coverage analysis to find candidate centromere sequences, we developed a centromere probe that localizes to all 14 centromeres. Measurements of relative LBC arm lengths and polymerase III localization patterns enabled us to identify all LBCs. This study presents a relatively simple and reliable way to identify each axolotl LBC cytologically and to anchor chromosome-length sequences (from the axolotl genome assembly) to the physical LBCs by immunostaining and fluorescence in situ hybridization. Our data will facilitate a more detailed transcription analysis of individual LBC loops.

Original languageEnglish
Article number112523
Number of pages6
JournalExperimental Cell Research
Volume401
Issue number2
DOIs
StatePublished - 15 Apr 2021

    Scopus subject areas

  • Cell Biology

    Research areas

  • Ambystoma mexicanum, Axolotl, BAC FISH, Centromere, Lampbrush chromosomes, Ambystoma mexicanum/genetics, In Situ Hybridization, Fluorescence, Chromosome Mapping, Chromosomes, Artificial, Bacterial/genetics, Animals, Oocytes/growth & development, Transcription, Genetic, Chromosomes/genetics, Centromere/genetics

ID: 75307563