Search

Recent large-scale cDNA cloning studies have shown that a significant proportion of the transcripts expressed from vertebrate genomes do not appear to encode protein. Moreover, it was reported in mammals (human and mice) that these non-coding transcripts are expressed and regulated by mechanisms similar to those involved in the control of protein-coding genes. We have produced a collection of cDNA sequences from immunologically active tissues with the aim of discovering chicken genes involved in immune mechanisms, and we decided to explore the non-coding component of these immune-related libraries. After finding known non-coding RNAs (miRNA, snRNA, snoRNA), we identified new putative mRNA-like non-coding RNAs. We characterised their expression profiles in immune-related samples. Some of them showed changes in expression following viral infections. As they exhibit patterns of expression that parallel the behaviour of protein-coding RNAs in immune tissues, our study suggests that they could play an active role in the immune response. [ABSTRACT FROM AUTHOR]

We have identified and characterised a cluster of sixTRIM-B30.2genes flanking the chickenBF/BLregion of theBcomplex. The TRIM-B30.2 proteins are a subgroup of the TRIM protein family containing the tripartite motif (TRIM), consisting of a RING domain, a B-box and a coiled coil region, and a B30.2-like domain. In humans, a cluster of sevenTRIM-B30.2genes has been characterised within the MHC on Chromosome 6p21.33. Among the six chickenTRIM-B30.2genes two are orthologous to those of the human MHC, and two (TRIM41andTRIM7) are orthologous to human genes located on Chromosome 5. In humans, these last two genes are adjacent toGNB2L1, a guanine nucleotide-binding protein gene, the ortholog of the chickenc12.3gene situated in the vicinity of theTRIM-B30.2genes. This suggests that breakpoints specific to mammals have occurred and led to the remodelling of their MHC structure. In terms of structure, like their mammalian counterparts, each chicken gene consists of five coding exons; exon 1 encodes the RING domain and the B-box, exons 2, 3 and 4 form the coiled-coil region, and the last exon represents the B30.2-like domain. Phylogenetic analysis led us to assume that this extendedBF/BLregion may be similar to the human extended class I region, because it contains a cluster ofBGgenes sharing an Ig-V like domain with theBTNgenes (Henry et al. 1997a) and sixTRIM-B30.2genes containing the B30.2-like domain, shared with theTRIM-B30.2members and theBTNgenes. [ABSTRACT FROM AUTHOR]