[Untitled]
- Resource Type
- Authors
- Laura M. Daniels; Mary E. Delany
- Source
- Chromosome Research. 11:305-317
- Subject
- Genetics
5S ribosomal RNA
Regulatory sequence
Sequence analysis
Large ribosomal subunit
Ribosomal RNA
Biology
Gene
Ribosomal DNA
Homology (biology)
- Language
- ISSN
- 0967-3849
The 5S ribosomal (r) RNA genes encode a small (∼120-bp) highly-conserved component of the large ribosomal subunit. The objective of the present research was to study the molecular and cytogenetic organization of the chicken 5S rDNA. A predominant 2.2-kb gene (5Sα) consisting of a coding and intergenic spacer (IGS) region was identified in ten research and commercial populations. A variant gene repeat of 0.6 kb (5Sβ) was observed in some of the populations. Genetic linkage analysis and cytogenetic localization by fluorescence in-situ hybridization assigned the 5S rDNA to chromosome 9. The 5S rDNA array was determined to be 80.2 ± 7.0 kb upon electrophoretic sizing following EcoRV digestion. Sequence analysis of 5Sα IGS regions revealed considerable conservation between chicken subspecies (98.4% identity) as well as homology with vertebrate Pol III promoter and regulatory sequence motifs. Minor intraindividual sequence variation within 1000 bp of IGS was observed in four cloned Red Jungle Fowl (Gallus gallus gallus) 5Sα repeats (95.5% identity in this region). Sequence comparisons between IGS regions of 5Sα and 5Sβ genes indicated two short continuous (>20 bp) and many short non-continuous homologous regions as well as other conserved features such as promoter and termination motifs.