Journal of Biology最新文献

Taste cells regularly generate action potentials, but their functional significance in taste signaling is unclear. A paper in BMC Neuroscience reveals the identity of the voltage-gated Na+ channels underlying action potentials, providing the foundation for insights into their function.

Parasites are accomplished evaders of host immunity. Their evasion strategies have shaped every facet of the immune system, driving diversity within gene families and immune gene polymorphisms within populations. New studies published recently in BMC Biology and Journal of Experimental Medicine document parasite-associated immunosuppression in natural populations and suggest that host genetic variants favoring resistance to parasites may be detrimental in the absence of infection.

Expressed sequence tag analyses of the annelid Pomatoceros lamarckii, recently published in BMC Evolutionary Biology, are consistent with less extensive gene loss in the Lophotrochozoa than in the Ecdysozoa, but it would be premature to generalize about patterns of gene loss on the basis of the limited data available.

Detailed analysis of T cell dynamics in humans is challenging and mouse models can be important tools for characterizing T cell dynamic processes. In a paper just published in Journal of Biology, Marques et al. suggest that a mouse model with its activated CD4(+) T cells are deleted has relevance for HIV infection.

The regulation of gene expression in trypanosomes is unique. In the absence of transcriptional control at the level of initiation, a subset of Trypanosoma brucei genes form post-transcriptional regulons in which mRNAs are co-regulated in response to differentiation signals. See research articles http://www.biomedcentral.com/1471-2164/10/427, http://www.biomedcentral.com/1471-2164/10/482 and http://www.biomedcentral.com/1471-2164/10/495.

Sperm from Drosophila simulans that carry a sex-ratio distorter is preferentially lost from females' sperm-storage organs. This suggests that sperm dumping is a major factor affecting sperm competition in this species, and may have evolved in response to sex-ratio distorters.

The complete genome sequence of the crenarchaeon Ignicoccus hospitalis published recently in Genome Biology provides a great leap forward in the dissection of its unique association with another hyperthermophilic archaeon, Nanoarchaeum equitans.

The obligate intracellular bacterial endosymbionts of insects are a paradigm for reductive genome evolution. A study published recently in BMC Biology demonstrates that similar evolutionary forces shaping genome structure may also apply to extracellular endosymbionts.

Reconstruction of transcriptional regulatory networks of uncharacterized bacteria is a main challenge for the post-genomic era. Recent studies, including one in BMC Systems Biology, address this problem in the relatively underexplored actinobacteria clade, which includes major pathogenic and economically relevant taxa.

Background: Vertebrates share the same general body plan and organs, possess related sets of genes, and rely on similar physiological mechanisms, yet show great diversity in morphology, habitat and behavior. Alteration of gene regulation is thought to be a major mechanism in phenotypic variation and evolution, but relatively little is known about the broad patterns of conservation in gene expression in non-mammalian vertebrates.

Results: We measured expression of all known and predicted genes across twenty tissues in chicken, frog and pufferfish. By combining the results with human and mouse data and considering only ten common tissues, we have found evidence of conserved expression for more than a third of unique orthologous genes. We find that, on average, transcription factor gene expression is neither more nor less conserved than that of other genes. Strikingly, conservation of expression correlates poorly with the amount of conserved nonexonic sequence, even using a sequence alignment technique that accounts for non-collinearity in conserved elements. Many genes show conserved human/fish expression despite having almost no nonexonic conserved primary sequence.

Conclusions: There are clearly strong evolutionary constraints on tissue-specific gene expression. A major challenge will be to understand the precise mechanisms by which many gene expression patterns remain similar despite extensive cis-regulatory restructuring.