58 research outputs found

    White-gutted soldiers: simplification of the digestive tube for a non-particulate diet in higher Old World termites (Isoptera: Termitidae)

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    Previous observations have noted that in some species of higher termites the soldier caste lacks pigmented particles in its gut and, instead, is fed worker saliva that imparts a whitish coloration to the abdomen. In order to investigate the occurrence of this trait more thoroughly, we surveyed a broad diversity of termite specimens and taxonomic descriptions from the Old World subfamilies Apicotermitinae, Cubitermitinae, Foraminitermitinae, Macrotermitinae, and Termitinae. We identified 38 genera that have this “white-gutted” soldier (WGS) trait. No termite soldiers from the New World were found to possess a WGS caste. Externally, the WGS is characterized by a uniformly pale abdomen, hyaline gut, and proportionally smaller body-to-head volume ratio compared with their “dark-gutted” soldier (DGS) counterparts found in most termitid genera. The WGS is a fully formed soldier that, unlike soldiers in other higher termite taxa, has a small, narrow, and decompartmentalized digestive tube that lacks particulate food contents. The presumed saliva-nourished WGS have various forms of simplified gut morphologies that have evolved at least six times within the higher termites

    The Cyst-Dividing Bacterium Ramlibacter tataouinensis TTB310 Genome Reveals a Well-Stocked Toolbox for Adaptation to a Desert Environment

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    Ramlibacter tataouinensis TTB310T (strain TTB310), a betaproteobacterium isolated from a semi-arid region of South Tunisia (Tataouine), is characterized by the presence of both spherical and rod-shaped cells in pure culture. Cell division of strain TTB310 occurs by the binary fission of spherical “cyst-like” cells (“cyst-cyst” division). The rod-shaped cells formed at the periphery of a colony (consisting mainly of cysts) are highly motile and colonize a new environment, where they form a new colony by reversion to cyst-like cells. This unique cell cycle of strain TTB310, with desiccation tolerant cyst-like cells capable of division and desiccation sensitive motile rods capable of dissemination, appears to be a novel adaptation for life in a hot and dry desert environment. In order to gain insights into strain TTB310's underlying genetic repertoire and possible mechanisms responsible for its unusual lifestyle, the genome of strain TTB310 was completely sequenced and subsequently annotated. The complete genome consists of a single circular chromosome of 4,070,194 bp with an average G+C content of 70.0%, the highest among the Betaproteobacteria sequenced to date, with total of 3,899 predicted coding sequences covering 92% of the genome. We found that strain TTB310 has developed a highly complex network of two-component systems, which may utilize responses to light and perhaps a rudimentary circadian hourglass to anticipate water availability at the dew time in the middle/end of the desert winter nights and thus direct the growth window to cyclic water availability times. Other interesting features of the strain TTB310 genome that appear to be important for desiccation tolerance, including intermediary metabolism compounds such as trehalose or polyhydroxyalkanoate, and signal transduction pathways, are presented and discussed

    Pesson, P. (Ed.). La vie dans les sols : aspects nouveaux, études expérimentales. Paris, Gauthier-Villars, 1971

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    Noirot Ch. Pesson, P. (Ed.). La vie dans les sols : aspects nouveaux, études expérimentales. Paris, Gauthier-Villars, 1971. In: La Terre et La Vie, Revue d'Histoire naturelle, tome 26, n°4, 1972. pp. 598-599

    XVI. - Orientation et routes chez les Termites. Le "balisage" des pistes

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    Grassé Pierre Paul, Noirot Ch. XVI. - Orientation et routes chez les Termites. Le "balisage" des pistes. In: L'année psychologique. 1949 vol. 50. pp. 273-280

    Soldier head morphology of the Neotropical termites: Embiratermes festivellus Silvestri and Spinitermes brevicornutus (Desneux) (Isoptera, Termitidae)

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    Heads of soldier termites belonging to the species Embiratermes festivellus (Silvestri, 1901) (Termitidae, Nasutitermitinae) and Spinitermes brevicornutus (Desneux, 1904) (Termitidae, Termitinae) were examined using scanning electron microscopy. Individual glandular openings are present in the upper part of E. festivellus head and correspond to class 3 glandular cells. Campaniform sensillae occur in both termite heads, but this sensorial structure was not observed in the nasus extremity of E. festivellus soldier
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