Expression profiles of long and short RNA s in the cytoplasm and nuclei of growing chicken (Gallus gallus domesticus) oocytes

Abstract

Maternal rnas accumulated during oocyte maturation are required not only for zygote formation but also for su��orting the first embryonic cell divisions until embryo genome activation. Essential stages of transcri�tome analysis include ada�tation of rna extraction �rocedures and characterization of the rna ex�ression �rofile. ovaries of domestic birds re�resent an adequate model for ex�loration of rna accumulation during oogenesis. in the �resent study�� we o�timized methods of rna extraction from chic�en (Gallus gallus domesticus� oocyte cyto�lasm and nucleo�lasm and characterized changes in �rofiles of long and short rnas during oocyte growth. cyto�lasmic rna fractions contained 2�S and 1�S ribosomal rnas (rrnas��� small rnas�� and long rnas heterogeneous in size. The �rofiles of total rna from growing oocyte nuclei were dominated by low molecular weight rnas corres�onding in size to trans�ort rnas�� small nuclear rnas�� and short regulatory rnas. im�ortantly�� oocyte nuclei from chic�en egg-laying females demonstrated trace amounts or absence of 2�S and 1�S rrna�� which was due to inactivation of the only nucleolar organizer. Three grou�s of short rnas differing in size (from 20 to 40 nucleotides� were recognized in chic�en oocytes. They might corres�ond to short regulatory rna classes. furthermore�� we demonstrated that short rnas were accumulated in the cyto�lasm during oocyte growth. we suggest that short rnas accumulated in avian oocyte cyto�lasm are involved in the regulation of genome functions at early embryogenesis stages.Key words�� domestic chic�en; non-coding rna; short rna; maternal rna; oocyte; oogenesis; ribosomal rna. �атеринская РН���� накапливаемая в ооците во время созревания�� нео�ходима не тол��ко для формирования зиготы�� но и для поддержания определенного �исла клето�ных делений до активации генома зародыша. �� одним из существенных этапов исследования транскриптома ооцитов относятся адаптация методик экстракции РН�� и характеристика профиля экспрессии РН��. �декватной модел��� для исследования динамики накопления РН�� в ходе оогенеза представля�тся яи�ники доместицированных видов птиц. В настоящей ра�оте оптимизированы методы экстракции РН�� из цитоплазмы и нуклеоплазмы ооцитов домашней курицы (Gallus gallus domesticus� и охарактеризованы изменения в профиле длинных и коротких РН�� в ходе роста ооцита. Во фракциях РН�� из цитоплазмы ооцитов курицы выявлено нали�ие 2�S и 1�S ри�осомных РН�� (рРН����� малых РН�� и гетерогенных по размеру длинных РН��. В профиле тотал��ной РН�� из ядер растущих ооцитов присутству�т преимущественно пики низкомолекулярной РН���� соответству�щей по размеру транспортным�� малым ядерным и коротким регуляторным РН��. В ядрах растущих ооцитов самок курицы зарегистрированы следовые коли�ества или отсутствие 2�S и 1�S рРН���� �то о�условлено инактивацией единственного ядрышкового организатора. В ооцитах домашней курицы выявлены три отли�а�щиеся по размеру группы коротких (от 20 до 40 н.� РН���� которые могут соответствоват�� классам коротких регуляторных РН��. �ока...

Transcription of highly repetitive tandemly organized DNA in amphibians and birds: A historical overview and modern concepts

“…100 Additionally, short RNAs accumulate in chicken oocyte cytoplasm. 101 These short regulatory RNAs transferred to the embryo with the ooplasm can be potentially involved in transfer of epigenetic information through generations. 101 Parts of these short RNAs can originate from long processed transcripts of tandem DNA repeats (Fig.…”

“…101 These short regulatory RNAs transferred to the embryo with the ooplasm can be potentially involved in transfer of epigenetic information through generations. 101 Parts of these short RNAs can originate from long processed transcripts of tandem DNA repeats (Fig. 3B), 101 including the PO41 and CNM repeats, whose transcription from both strands occurs on the lampbrush chromosomes of Galliformes (Fig.…”

“…101 Parts of these short RNAs can originate from long processed transcripts of tandem DNA repeats (Fig. 3B), 101 including the PO41 and CNM repeats, whose transcription from both strands occurs on the lampbrush chromosomes of Galliformes (Fig. 3B).…”