The Evolution of HD2 Proteins in Green Plants.

In eukaryotes, protein deacetylation is carried out by two well-conserved histone deacetylase (HDAC) families: RPD3/HDA1 and SIR2. Intriguingly, model plants such as Arabidopsis express an additional plant-specific HDAC family, termed type-2 HDACs (HD2s). Transcriptomic analyses from more than 1300 green plants generated by the 1000 plants (1KP) consortium showed that HD2s appeared early in green plant evolution, the first members being detected in several streptophyte green alga. The HD2 family has expanded via several rounds of successive duplication; members are expressed in all major green plant clades. Interestingly, angiosperm species express new HD2 genes devoid of a zinc-finger domain, one of the main structural features of HD2s. These variants may have been associated with the origin and/or the biology of the ovule/seed.

Frequent proviral integration of the human betaretrovirus in biliary epithelium of patients with autoimmune and idiopathic liver disease.

BACKGROUND: A human betaretrovirus (HBRV) has been linked with primary biliary cirrhosis (PBC) following the detection of viral particles in biliary epithelium by electron microscopy and cloning of the betaretrovirus genome from biliary epithelium and peri-hepatic lymph nodes. Evidence for viral infection was found in the majority of PBC patients' peri-hepatic lymph node samples. However, less than a third of the liver samples had detectable HBRV, whereas others were unable to detect betaretrovirus infection or noted the presence of virus in the liver of patients with other diagnoses. AIMS: To address the hypothesis that the betaretrovirus may be below the limits of detection in the liver, biliary epithelial cells (BEC) were investigated for the evidence of infection. METHODS: Ligation-mediated PCR and next generation sequencing were used to detect proviral integrations in liver, lymph nodes and BEC isolated from liver transplant recipients. Hybridisation-based assays were used to detect betaretroviral RNA in BEC. RESULTS: Unique HBRV integrations and betaretrovirus RNA were detected in the majority of biliary epithelia derived from patients with PBC, autoimmune hepatitis and cryptogenic liver disease but rarely in other liver transplant recipients with primary sclerosing cholangitis and other hepatic disorders. HBRV integrations were commonly found in PBC patients' lymph nodes but rarely in whole liver samples. CONCLUSIONS: Human betaretrovirus infection is frequently observed at the site of disease in patients with primary biliary cirrhosis and also in biliary epithelium of patients with autoimmune hepatitis and cryptogenic liver disease.

Genetic variation at the tumour virus B locus in commercial and laboratory chicken populations assessed by a medium-throughput or a high-throughput assay.

The tumour virus B (TVB) locus encodes cellular receptors mediating infection by three subgroups of avian leukosis virus (B, D, and E). Three major alleles, TVB*S1, TVB*S3, and TVB*R, have been described. TVB*S1 encodes a cellular receptor mediating infection of subgroups B, D, and E. TVB*S3 encodes the receptor for two subgroups, B and D, and TVB*R encodes a dysfunctional receptor that does not permit infection by any of the subgroups, B, D, or E. Genetic diversity at the TVB locus of chickens was investigated in both layer and broiler commercial pure lines and laboratory lines. Genotyping assays were developed for both medium-throughput and high-throughput analysis. Of the 36 broiler lines sampled, 14 were fixed for the susceptible allele TVB*S1. Across all broiler lines, 83% of chickens were typed as TVB*S1/*S1, 3% as TVB*R/*R, and 14% as TVB*S1/*R. In the egg-layer lines, five of the 16 tested were fixed for TVB*S1/*S1. About 44% of egg-layers were typed as TVB*S1/*S1, 15% as TVB*R/*R, with the rest segregating for two or three of the alleles. In the laboratory chickens, 60% were fixed for TVB*S1/*S1, 6% for TVB*S3/*S3, 14% for TVB*R/*R, and the rest were heterozygotes (TVB*S1/*S3 or TVB*S1/*R). All commercial pure lines examined in this study carry the TVB*S1 allele that sustains the susceptibility to avian leukosis viruses B, D, and E. More importantly, the TVB*R allele was identified in multiple populations, thus upholding the opportunities for genetic improvement through selection.