Replication of non-defective reticuloendotheliosis viruses in the avian embryo assayed by PCR and immunofluorescence.

Congenital transmission of reticuloendotheliosis virus (REV) is known to occur when one of the parents in either tolerantly infected or viraemic; however little attention has been paid to replication of the virus within the embryo itself. In this study five non-defective and one replication-defective strain of REV were inoculated into the yolk sac of 6-day-old embryonated eggs. With the exception of one non-defective strain, the others induced embryonic deformation or lesions that were apparent on the day of hatching.

Functional domains of the yeast chromatin protein Sin1p/Spt2p can bind four-way junction and crossing DNA structures.

Sin1p/Spt2p is a yeast chromatin protein that, when mutated or deleted, alters the transcription of a family of genes presumably by modulating local chromatin structure. In this study, we investigated the ability of different domains of this protein to bind four-way junction DNA (4WJDNA) since 4WJDNA can serve as a model for bent double helical DNA and for the crossed structure formed at the exit and entry of DNA to the nucleosomes. Sequence alignment of Sin1p/Spt2p homologues from 11 different yeast species showed conservation of several domains.

[Circular dichroism of the complexes between poly-L-lysine and DNA with different GC contents].

Studies were carried out of circular dichroism spectra of the complexes between poly-l-lysine (PL) and calf thymus DNA, E. coli DNA, T2--and T7--phage DNA, Modiolus sp. DNA.

[Distribution of large ligands on DNA macromolecules of different GC-content].

The complexes of calf thymus DNA, E-coli DNA, phage T2 and T7 DNA with protamine and poli-lysine (mol. wt. 52 000 and 20 000) were studied by thermal denaturation method.

[Structure of polylysine-DNA complexes].

By the methods of nuclease digestion and electron microscopy the complexes of poly-I-lysine with phage T2 DNA were studied. At micrococcal nuclease digestion of complexes polylysine--phage T2 DNA structures resistant to nuclease and containing fragments of DNA with lengths of about 300, 600, 1200 base pairs were revealed. On the electron micrographs structures superficially resembling nucleosomes were detected.