title: Transcription of subtelomere tandemly repetitive DNA in chicken embryogenesis.
abstract: Transcription of tandemly repetitive DNA in embryogenesis seems to be of special interest due to a crucial role of non-coding RNAs in many aspects of development. However, only a few data are available on tandem repeats transcription at subtelomere regions of chromosomes during vertebrate embryogenesis. To reduce this gap, we examined stage and tissue-specific pattern of subtelomeric PO41 (pattern of 41 bp) tandem repeat transcription during embryogenesis of chicken (Gallus gallus domesticus). Using whole-mount RNA fluorescent in situ hybridization and reverse transcription PCR with specific primers, we demonstrated that both strands of PO41 repeat are transcribed at each of the studied stages of chicken embryo development: from 7-8 HH to 20 HH stages. Subtelomere-derived transcripts localize in the nuclei of all cell types and throughout the all embryonic bodies: head, somites, tail, wings and buds. In embryo-dividing cells and cultured embryonic fibroblasts, PO41 RNAs envelop terminal regions of chromosomes. PO41-containing RNAs are predominantly single-stranded and can be polyadenylated, indicating appearance of non-nascent form of subtelomeric transcripts. PO41 repeat RNAs represent a rare example of ubiquitously transcribed non-coding RNAs, such as Xist/XIST RNA or telomere repeat-containing RNA. Distribution of PO41 repeat transcripts at different stages of embryo development and among cell types has extremely uniform pattern, indicating on possible universal functions of PO41 non-coding RNAs.
authors.affiliation: Saint-Petersburg State University, 7-9, Universitetskaya nab., 199034, Saint-Petersburg, Russia.
authors.forename: Irina
authors.initials: I
authors.lastname: Trofimova
authors.affiliation: Saint-Petersburg State University, 7-9, Universitetskaya nab., 199034, Saint-Petersburg, Russia.
authors.forename: Darya
authors.initials: D
authors.lastname: Chervyakova
authors.affiliation: Saint-Petersburg State University, 7-9, Universitetskaya nab., 199034, Saint-Petersburg, Russia. alla.krasikova@gmail.com.
authors.forename: Alla
authors.initials: A
authors.lastname: Krasikova
mesh_terms: D000818:Animals; D002455:Cell Division / Q000235:genetics; D002642:Chick Embryo; D002645:Chickens / Q000235:genetics*; D047108:Embryonic Development / Q000235:genetics*; D005347:Fibroblasts / Q000378:metabolism; D015870:Gene Expression; D018507:Gene Expression Regulation, Developmental; D017403:In Situ Hybridization; D020133:Reverse Transcriptase Polymerase Chain Reaction; D020080:Tandem Repeat Sequences; D016615:Telomere / Q000235:genetics*; D014158:Transcription, Genetic
keywords: Chicken; Embryogenesis; Mitosis; Non-coding RNA; Subtelomere; Tandem repeat; Transcription; Whole-mount in situ hybridization