Accepted_test

Transcriptional activity of chicken W-linked genes at the lampbrush chromosome stage based on RNA-seq and RNA-FISH data

Authors:
Plotnikov Vladimir, Saint-Petersburg State University, Saint-Petersburg, Russia
Kulikova Tatiana, Saint-Petersburg State University, Saint-Petersburg, Russia
Fedorov Anton, Saint-Petersburg State University, Saint-Petersburg, Russia
Schelkunov Mikhail, Genomics Core Facility, Skolkovo Institute of Science and Technology, Moscow, Russia; Institute for Information Transmission Problems, Moscow, Russia
Fedotova Anna, Genomics Core Facility, Skolkovo Institute of Science and Technology, Moscow, Russia; Lomonosov Moscow State University, Moscow, Russia
Krasikova Alla, Saint-Petersburg State University, Saint-Petersburg, Russia

Abstract ID: 603

Event: BGRS-abstracts

Sections: [Sym 1] Section “Genome-wide transcriptomics (differential gene expression)”

The aim of this study is to investigate whether the expression of W chromosome genes persists in growing oocytes during the diplotene stage of prophase I of meiosis. The nuclear and cytoplasmic RNA-seq profiles were visually inspected in the Integrative Genome Viewer to assess the transcriptional activity of Z-W gene pairs. Nuclear RNA-seq profile along exons and introns allows differentiation of transcripts originating from W-linked genes from their homologues on chromosome Z. The transcription of several genes on chicken lampbrush chromosome W was confirmed by RNA-FISH. A novel approach has been developed to synthesise a set of PCR-derived probes, eliminating the need for BAC clone-based probes. Finally, we analysed the transcriptome of embryos at an early developmental stage (EGK.III) and revealed the inheritance of spliced mRNA from the Z-W gene pairs. Remarkably, despite the extensive expansion of repetitive sequences in over 85% of the W chromosome and enrichment of heterochromatin markers such as DNA hypermethylation, a number of W-linked genes are transcribed at the lampbrush chromosome stage of oogenesis.