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Biomedical subjects

C Bordereau

Publications and source records attributed to C Bordereau.

6 recordsLinked to original sources
PubMed2001

(Z)-dodec-3-en-1-ol, a novel termite trail pheromone identified after solid phase microextraction from Macrotermes annandalei.

(Z)-dodec-3-en-1-ol was isolated and identified by GC-MS as the major component of the trail-following pheromone from whole body and sternal gland extracts of workers of the fungus-growing termite, Macrotermes annandalei (Silvestri) (Termitidae, Macrotermitinae). For the first time, this trail pheromone was also identified by using solid phase microextraction from the surface of the secretory sternal gland of workers. Bioassays showed that synthetic dodecenol induced both orientation and recruitment behavioral effects. The activity threshold of (Z)-dodec-3-en-1-ol in eliciting trail-following is similar to that of (3Z,6Z,8E)-dodeca-3,6,8-trien-1-ol in the Rhinotermitidae, but amounts of dodecenol secreted are 100 times higher than those of dodecatrienol. There is about 1 ng of (Z)-dodec-3-en-1-ol per worker. Artificial trails made of synthetic dodecenol are able to compete with natural trails in the field. The activity duration of synthetic (Z)-dodec-3-en-1-ol trails is shorter than that of trails made from whole sternal secretion of workers. Observations showed that (Z)-dodec-3-en-1-ol is probably the only major component of the trail-following pheromone of M. annandalei and that it could be associated with other compounds in a pheromonal blend providing specificity and/or stability to trails.

Journal Article↗
PubMed2000

Insect immunity. Constitutive expression of a cysteine-rich antifungal and a linear antibacterial peptide in a termite insect.

Two novel antimicrobial peptides, which we propose to name termicin and spinigerin, have been isolated from the fungus-growing termite Pseudacanthotermes spiniger (heterometabole insect, Isoptera). Termicin is a 36-amino acid residue antifungal peptide, with six cysteines arranged in a disulfide array similar to that of insect defensins. In contrast to most insect defensins, termicin is C-terminally amidated. Spinigerin consists of 25 amino acids and is devoid of cysteines. It is active against bacteria and fungi. Termicin and spinigerin show no obvious sequence similarities with other peptides. Termicin is constitutively present in hemocyte granules and in salivary glands. The presence of termicin and spinigerin in unchallenged termites contrasts with observations in evolutionary recent insects or insects undergoing complete metamorphosis, in which antimicrobial peptides are induced in the fat body and released into the hemolymph after septic injury.

Amino Acid Sequence↗
PubMed1984

Soldier formation regulated by a primer pheromone from the soldier frontal gland in a higher termite, Nasutitermes lujae.

In the nasute higher termite Nasutitermes lujae, the differentiation of new soldiers is suppressed or delayed by the soldiers themselves. Experimental data strongly suggest that this inhibitory effect results from the action of a primer pheromone secreted by the frontal gland of soldiers. The pheromone must be contacted directly. Thus, the frontal gland of termite soldiers assumes a new role in addition to alarm and defense, although this extension cannot be generalized to all termite species. The soldier inhibitory pheromone is evidently only one of multiple factors contributing soldier regulation in termite societies.

Journal Article↗
PubMed1982

Ultrastructure and formation of the physogastric termite queen cuticle.

The physogastric termite queen is the most striking example in insects of growth in size without cuticular moulting. This phenomenon has been studied with electron microscopy and histochemical tests in two species of higher termites, Cubitermes fungifaber and Macrotermes bellicosus. The abdominal hypertrophy (physogastry) is allowed by growth of the arthrodial membranes of the swarming imago. The growth is slow (over several years) but important: the cuticular dry weight is multiplied by 20 in C. fungifaber, by 100-150 in M. bellicosus. The termite queen cuticle arises from the transformation of the cuticle of the swarming imago or imaginal cuticle (unfolding and growing of the epicuticle, stretching of the endocuticle, resorption of the subcuticle) and from the secretion of a new endocuticle or royal endocuticle. The termite queen is the first example known in insects of epicuticular growth. In the physogastric queen, three cuticular types are observed: the rigid cuticle of the sclerites, the soft cuticle of the arthrodial membranes and the partially rigid cuticle of special structures, the neosclerites, which show both rigidity and growth. The fibrillar architecture varies according to the abdominal zones and the position within the cuticle. It appears to be determined by the forces arising from the musculature and the anisometric abdominal growth. The king does not become physogastric, although its cuticle is also modified.

Animals↗
PubMed1978

Structural cuticular proteins in termite queens.

The abdominal cuticle from queens of two termite species, Cubitermes fungifaber and Macrotermes bellicosus, has been investigated with respect to changes occurring during development of physogastry. The following properties have been determined: 1. Relative content of protein and chitin and the percentage of easily extracted protein. 2. Number of proteins separated by electrophoresis and their molecular weights. 3. Amino acid compositions of the intertergal and pleural membranes and of the neosclerites in M. bellicosus. The intertergal and pleural membranes appear to be typical "soft" cuticles, and the neosclerites must also be considered "soft" cuticles, although they are rather rigid.

Animals↗