engleski

Transcription of satellite DNAs in insects

The very complex life cycle and extreme diversity of insect life forms require a carefully regulated network of biological processes to switch on and off the right genes at the right time. Chromatin condensation is an important regulatory mechanism of gene silencing as well as gene activation for the hundreds of functional protein genes harboured in heterochromatic regions of different insect species. Being the major heterochromatin constituents, satellite DNAs serve important roles in heterochromatin regulation in insects in general. Their expression occurs in all developmental stages, being the highest during embryogenesis. Satellite DNA transcripts range from small RNAs, corresponding in size to siRNAs and piwiRNAs, to large, a few kb long RNAs. The long transcripts are preferentially non-polyadenylated and remain in the nucleus. The actively regulated expression of satellite DNAs by cis or trans elements as well as by environmental stress, rather than constitutive transcription, speaks in favour of their involvement in differentiation, development and environmental response.

satellite DNA, non-coding RNA, heterochromatin

nije evidentirano