Tandem 41-bp repeats in chicken and Japanese quail genomes: FISH mapping and transcription analysis on lampbrush chromosomes

Chromosoma. 2007 Dec;116(6):519-30. doi: 10.1007/s00412-007-0117-5. Epub 2007 Jul 10.

Abstract

The chromosomal distribution of 41-bp repeats, known as CNM and PO41 repeats in the chicken genome and BglII repeats in the Japanese quail, was analyzed precisely using giant lampbrush chromosomes (LBC) from chicken, Japanese quail, and turkey growing oocytes. The PO41 repeat is conserved in all galliform species, whereas the other repeats are species specific. In chicken and quail, the centromere and subtelomere regions share homologous satellite sequences. RNA polymerase II transcribes the 41-bp repeats in both centromere and subtelomere regions. Ongoing transcription of these repeats was demonstrated by incorporation of BrUTP injected into oocytes at the lampbrush stage. RNA complementary to both strands of CNM and PO41 repeats is present on chicken LBC loops, whereas strand-specific G-rich transcripts are characteristic of BglII repeats in the Japanese quail. The RNA from 41-bp repeats does not undergo cotranscriptional U snRNP-dependent splicing. At the same time, the ribonucleoprotein matrix of transcription units with C-rich RNA of CNM and PO41 repeats was enriched with hnRNP protein K. Potential promoters for satellite transcription are discussed.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Chickens / genetics*
  • Chromosome Mapping*
  • Coturnix / genetics*
  • Female
  • Genome / genetics*
  • In Situ Hybridization, Fluorescence*
  • Oocytes
  • Tandem Repeat Sequences / genetics*
  • Transcription, Genetic / genetics*
  • Turkeys / genetics