Phenotypic and cytologic studies of lymphoid cells and monocytes in primary culture of porcine bone marrow during infection of African swine fever virus.

We have modeled in vitro infection of African swine fever virus (ASFV) in primary unstimulated cells of the porcine bone marrow and have studied the phenotypical changes in the population of porcine lymphoid cells by cytophotometry. Monocytes and large-sized lymphocytes completely vanished in 72 h of infection which is result of high sensitivity of those cells to ASFV. We describe DNA synthesis in monocytes at 24 h post infection. Cytophotometry of the uninfected cells revealed the few number of atypical lymphocytes and lymphoblasts after 72 h of cultivation; whereas in viral infected cultures, atypical cells appeared in large quantity (about 14%) with 24 h. Most of atypical lymphocytes and lymphoblasts had altered nucleus, and only a small number of atypical cells had additional nucleus. The cytophotometry of main and additional nuclei showed that DNA content didn't exceed diploid standard which indicates that the additional nuclei were consequence of fragmentation of nuclei in lymphocytes.

Long-distance charge transport in duplex DNA: the phonon-assisted polaron-like hopping mechanism.

An anthraquinone-linked duplex DNA oligomer containing 60 base pairs was synthesized by PCR. The strand complementary to the quinone-containing strand has four isolated GG steps, which serve as traps for a migrating radical cation. Irradiation of the quinone leads to electron transfer from the DNA to the quinone forming the anthraquinone radical anion and a base radical cation. The radical cation migrates through the DNA, causing reaction at GG steps revealed as strand breaks. The efficiency of strand cleavage falls off exponentially with distance from the quinone (slope = -0.02 A(-1)). This finding necessitates reinterpretation of mechanisms proposed for radical cation migration in DNA. We propose that radical cations form self-trapped polarons that migrate by thermally activated hopping.

Effect on embryos of injection of phosphorothioate-modified oligonucleotides into pregnant mice.

Phosphorothioate-modified oligonucleotides were injected into pregnant female mice to assess the effect on developing embryos. Injections were carried out during two different time periods, one when embryos were in preimplantation stages of development (about 3.5 days of development) and the other after implantation, when both a fetus and placenta are present (from days 9.5 to 11.5 of development). Three different phosphorothioate-modified oligonucleotides were injected. One, which had a sequence not present in the mouse genome, was used to ask whether nonspecific toxic or teratogenic effects on embryos result from treatment of the mother. A second was complementary to the mRNA of the testis-determining factor gene Sry and was used to ask whether a specific developmental pathway (i.e., sex determination) could be disrupted in embryos in vivo. The third was the complement of the anti-Sry sequence. None of these oligonucleotides reduced the frequency of successful pregnancy after mating or the average litter size from that observed in controls animals. Furthermore, examination of 291 pups or fetuses from all oligonucleotide-injected pregnant females revealed no developmental defects regardless of which sequence was used. It is concluded that injection of phosphorothioate-modified oligonucleotides into pregnant females according to the protocols described here is not toxic or teratogenic to embryos in a nonspecific way. Also, anti-Sry oligonucleotides did not influence sex determination in embryos, although there are several possible explanations for this.

Evolution of sex determination and the Y chromosome: SRY-related sequences in marsupials.

In mammals, testis determination is under the control of the testis-determining factor borne by the Y chromosome. SRY, a gene cloned from the sex-determining region of the human Y chromosome, has been equated with the testis-determining factor in man and mouse. We have used a human SRY probe to identify and clone related genes from the Y chromosome of two marsupial species. Comparisons of eutherian and metatherian Y-located SRY sequences suggest rapid evolution of these genes, especially outside the region encoding the DNA-binding HMG box. The SRY homologues, together with the mouse Ube1y homologues, are the first genes to be identified on the marsupial Y chromosome.

Complete amino acid sequence of chicken cartilage link protein deduced from cDNA clones.

cDNA clones coding for chicken cartilage link protein were isolated and sequenced. The DNA sequence for the entire core polypeptide of the mature link protein and the predicted signal peptide consists of 1065 nucleotides. The deduced primary translation product (355 amino acids) has a molecular mass of 40.7 kDa; the calculated molecular mass of the mature link protein core polypeptide (340 amino acids) is 39.06 kDa. The DNA sequence contains two tandemly arranged repeat sequences that may code for repeated functional domains of link protein involved in binding to hyaluronic acid. The mRNAs for chicken link protein are 6.0, 5.8, and 3.0 kilobase pairs, and the difference between the sizes of the RNA species lies in the 3' untranslated region.