Modulation of Transcriptional and Inflammatory Responses in Murine Macrophages by the Mycobacterium tuberculosis Mammalian Cell Entry (Mce) 1 Complex

The outcome of many infections depends on the initial interactions between agent and host. Aiming at elucidating the effect of the M. tuberculosis Mce1 protein complex on host transcriptional and immunological responses to infection with M. tuberculosis, RNA from murine macrophages at 15, 30, 60 min, 4 and 10 hrs post-infection with M. tuberculosis H37Rv or Δ-mce1 H37Rv was analyzed by whole-genome microarrays and RT-QPCR. Immunological responses were measured using a 23-plex cytokine assay. Compared to uninfected controls, 524 versus 64 genes were up-regulated by 15 min post H37Rv- and Δ-mce1 H37Rv-infection, respectively. By 15 min post-H37Rv infection, a decline of 17 cytokines combined with up-regulation of Ccl24 (26.5-fold), Clec4a2 (23.2-fold) and Pparγ (10.5-fold) indicated an anti-inflammatory response initiated by IL-13. Down-regulation of Il13ra1 combined with up-regulation of Il12b (30.2-fold), suggested switch to a pro-inflammatory response by 4 hrs post H37Rv-infection. Whereas no significant change in cytokine concentration or transcription was observed during the first hour post Δ-mce1 H37Rv-infection, a significant decline of IL-1b, IL-9, IL-13, Eotaxin and GM-CSF combined with increased transcription of Il12b (25.1-fold) and Inb1 (17.9-fold) by 4 hrs, indicated a pro-inflammatory response. The balance between pro-and anti-inflammatory responses during the early stages of infection may have significant bearing on outcome

Biogéographie de Madagascar = Biogeography of Madagascar

Les coelacanthes, apparus au Dévonien, ont peuplé de nombreux milieux aquatiques à toutes les époques jusqu'au Crétacé supérieur. Ces diverses paléogéographies sont maintenant réduites à un seul biotope, l'Archipel des Comores au N.E. du Canal de Mozambique, biotopoe où vit le seul représentant actuel #Latimeria chalumnae. Au N.NW de Madagascar, dans le Bassin de Diego, des formations triasiques appartenant au Karoo, et de faciès peu profond, ont livré des coelacanthes de 20 cm de long en moyenne, et semblant être issus de parturitions de grands spécimens. Il est à noter que ce paléobiotope n'est qu'à 800 km du biotope de #Latimeria, qui dérive probablement d'un des coelacanthes triasiques malgaches. Si l'anatomie de #Latimeria$ est bien connue, en revanche on ignore les lieux de reproduction de ce poisson ovovivipare. La parturition a problablement lieu en eau peu profonde, dans les anfractuosités des récifs coralliens, ou les excavations des pentes volcaniques des Iles Comores, en zone euphotiques. N'y a-t-il pas là un pôle de recherche ? (Résumé d'auteur

Sensory lines and rostral skull bones in lungfish of the family Neoceratodontidae (Osteichthyes: Dipnoi)

Skull bones in early lungfish contain permanent insignia of the sensory lines of the head, but osteological evidence of sensory lines in derived lungfish is reduced to foramina for nerves to neuromasts, superficial grooves, or elevated ridges on some bones. This is particularly evident in anterior bones, making definition of these bones difficult, and creating problems for phylogenetic analyses. Despite a close association of the sensory lines with the bones of the developing skull in the Australian lungfish, Neoceratodus forsteri, few traces of the lines remain in the bones of the adult animal. Among derived dipnoans, Mioceratodus, a genus of neoceratodont fossil lungfish from Tertiary deposits in central and northern Australia, is unusual because traces of the supraorbital sensory line are retained in the anterior skull roofing bones of large specimens. Equivalent traces are absent from the rostral bones of N. forsteri, and from small specimens of Mioceratodus. The supraorbital sensory line grooves in Mioceratodus bones pass over the posterior surface of the rostral bone, and not the anterior process as in Neoceratodus. The rostral bones of Mioceratodus may be formed from the fusion of different bones in the primitive dipnoan skull compared with those that formed the rostral (EQ) bone of N. forsteri. Alternatively, the association between sensory lines and skull bones may not be constant