3D organization of chicken genome demonstrates evolutionary conservation of topologically associated domains and highlights unique architecture of erythrocytes' chromatin.

How chromosomes are folded, spatially organized and regulated in three dimensions inside the cell nucleus are among the longest standing questions in cell biology. Genome-wide chromosome conformation capture (Hi-C) technique allowed identifying and characterizing spatial chromatin compartments in several mammalian species. Here, we present the first genome-wide analysis of chromatin interactions in chicken embryonic fibroblasts (CEF) and adult erythrocytes.

Giant poly(A)-rich RNP aggregates form at terminal regions of avian lampbrush chromosomes.

The cell nucleus comprises a number of chromatin-associated domains. Certain chromatin-associated domains are nucleated by nascent RNA and accumulate non-nascent transcripts in the form of ribonucleoprotein (RNP) aggregates. In the transcriptionally active nucleus of the growing avian oocyte, RNP-rich structures, here termed giant terminal RNP aggregates (GITERA), form at the termini of lampbrush chromosomes.

Transcription of subtelomere tandemly repetitive DNA in chicken embryogenesis.

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).

Structure of RecX protein complex with the presynaptic RecA filament: Molecular dynamics simulations and small angle neutron scattering.

Using molecular modeling techniques we have built the full atomic structure and performed molecular dynamics simulations for the complexes formed by Escherichia coli RecX protein with a single-stranded oligonucleotide and with RecA presynaptic filament. Based on the modeling and SANS experimental data a sandwich-like filament structure formed two chains of RecX monomers bound to the opposite sides of the single stranded DNA is proposed for RecX::ssDNA complex. The model for RecX::RecA::ssDNA include RecX binding into the grove of RecA::ssDNA filament that occurs mainly via Coulomb interactions between RecX and ssDNA.

Two RecA protein types that mediate different modes of hyperrecombination.

RecAX53 is a chimeric variant of the Escherichia coli RecA protein (RecAEc) that contains a part of the central domain of Pseudomonas aeruginosa RecA (RecAPa), encompassing a region that differs from RecAEc at 12 amino acid positions. Like RecAPa, this chimera exhibits hyperrecombination activity in E. coli cells, increasing the frequency of recombination exchanges per DNA unit length (FRE).