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R Ikan

Publications and source records attributed to R Ikan.

16 recordsLinked to original sources

Differential olfactory perception of enantiomeric compounds by blind subterranean mole rats (Spalax ehrenbergi).

The behavior of mole rats (Spalax ehrenbergi) near pairs of enantiomeric compounds was examined in 901 two-choice experimental tests. Positioning of the nest and food store and the preferred location of the tested animal were used to assess attraction or aversion to the tested odorants. The results indicated that mole rats respond differentially to odors of stereoisomers (enantiomers of carvone, citronellol, and fechone). They responded to one enantiomer of each tested pair but were indifferent to or did not smell the other. Both sexes were attracted to the odor of R-(-)-carvone and repelled by the odor of (+)-citronellol. Females were attracted to the odor of (-)-fenchone while males had no preference. By contrast, all animals were indifferent to or did not smell the odor of S-(+)-carvone, (-)-citronellol, and (+)-fenchone. Further research to distinguish between these alternatives (indifference vs hyposmia/anosmia) is suggested.

Acyclic Monoterpenes↗

Sexual pheromones in lipids and other fractions from urine of the male mole rat, Spalax ehrenbergi.

Spalax ehrenbergi mole rats are blind, solitary, territorial, aggressive, subterranean rodents with a yearly breeding season that peaks in December and January. We confirm here an earlier report that estrous females are attracted to substances present in the urine of homospecific as compared to heterospecific adult males. We have also found that nonestrous female mole rats show avoidance behavior to the same homospecific urine. Our objective was to ascertain the nature of the pheromone(s) and gain insight as to its possible role in reproductive isolation and speciation. An active principle, detected in either two- or three-choice behavior tests, was found to be extractable from urine by methylene chloride (CH2Cl2) and mainly found in the neutral lipid fraction. Total lipids were chromatographed by thin layer chromatography on silica gel G60 plates. Most of the activity was found in a zone bounded by Rfs 0.2 and 0.7. Cholesterol, other sterols, and ethyl esters of fatty acids chromatographed in this zone as determined by standards and staining. Ethyl esters of fatty acids were also detected in this fraction by GC/MS analysis. Although a large amount of activity was found in lipids, it only accounted for about 1% of that found in urine. Some activity may have been destroyed or lost during the extraction procedure and some may remain in a lipid insoluble form. Preliminary tests of lipid extracts of various portions of the male urogenital tract revealed pheromonal activity present, particularly in tissues associated with testes, epididymis, prostate, and bladder.

Animals↗