Grooming and touching behaviour in captive ring-tailed lemurs (Lemur catta L.)

The distribution of grooming and touching behaviours was recorded in a group of captive ring-tailed lemurs. Grooming was found to be performed chiefly by older, higher ranking animals; touching (i.e., “reach out and touch” behaviour) was directed primarily by younger, low ranking animals to older, high ranking individuals. It is suggested that such touching is a submissive gesture in this species.     

Nile crocodiles, Crocodylus niloticus, and estuarine crocodiles, Crocodylus porosus, show similar osmoregulatory responses on exposure to seawater

1. Nile crocodiles, reared in fresh water and exposed acutely to seawater, suffer marked dehydration and hypernatraemia. Cloacal urine osmolarity and potassium concentration increased markedly but urine sodium remains low. 2. Hypernatraemia is increased when secretion from the lingual salt glands is prevented. 3. C. niloticus appears not to drink seawater. 4. Similarities in osmoregulatory response between estuarine and Nile crocodiles suggest that the lingual salt glands of C. niloticus are functional in salt water, playing an important role in sodium balance. 5. Significant differences in the function of the renal/cloacal complex of Alligator and Crocodylus emphasize further the differences between these two groups of crocodilian and provide support for the postulated marine ancestry of many or all of the Crocodylidae.     

Effect of Light Quality (Red:Far-red Ratio) at the Apical Bud of the Main Stolon on Morphogenesis of Trifolium repens L.

A controlled environment experiment investigated whether thered:far-red (R:FR) ratio of light at the apical bud of the mainstolon could alter plant morphogenesis in clonal cuttings ofwhite clover (Trifolium repens L.) The apical bud included theapical meristem, five to six developing leaf primordia withassociated axillary bud primordia and stipules and the firstemerged folded leaf until development was greater than 0·3on the Carlson scale. Three light regimes were imposed on theapical bud by collimating light from R or FR light-emittingdiodes so that the R:FR ratio of light incident at the apicalbud was set at 0·25, 1·6 or 2·1, withoutsignificantly altering photosynthetically active radiation.The effect of these light regimes on white clover seedling growthwas also tested. At a low R:FR ratio seedling hypocotyl and cotyledon lengthswere significantly longer. However, with the cuttings, the lighttreatments did not alter node appearance rate or internode lengthof the main stolon, petiole length, area of leaves or totalshoot dry matter. There was one significant photomorphogeneticresponse in the cuttings, a delay of 0·5 of a phyllochronin the appearance of branches from axillary buds in the lowR:FR ratio treatment relative to the other treatments. Wherebranch appearance was delayed plants had fewer branches. Thisdifference could be ascribed solely to a delay in branch appearanceas there were no significant treatment effects on either theinitiation of axillary bud primordia within the apical bud,the probability of branching or on the rate of growth of branchesafter appearance. Because treatment of the apical bud inducedonly one of the many previously observed responses of whiteclover to a decrease in the R:FR ratio of light, we concludethat other plant organs must also sense the quality of incidentlight.Copyright 1994, 1999 Academic Press White clover, Trifolium repens, apical bud, light quality, red:far-red ratio, light-emitting diode, branching, axillary buds, photomorphogenesis     

Bacteriophage Ø105clz induces the GroEL-homologue protein inBacillus subtilis

Using two-dimensional polyacrylamide gel electrophoresis, the GroEL homologue ofBacillus subtilis was shown to be induced upon infection with Ø105clz, a clear plaque mutant of the temperate bacteriophage Ø105. Western blotting of one dimensional polyacrylamide gels also showed the induction of the GroEL homologue when cells were infected with Ø105clz.