RESUMO
In many species, older males are often preferred mates because they carry 'good' genes that account for their viability. How females discern a male's age is a matter of question. However, for animals that rely heavily on chemical communication there is some indication that an animal's age can be determined by its scent. To investigate whether there are changes in body odours with age, and if so their composition, mice were trained in a Y-maze to discriminate urine odours of donor mice of different ages: Adult (3-10 months old) and Aged (more than 17 months old). Trained mice could discriminate between these two age groups by odour alone. To determine the chemical basis for these discriminations, studies were performed using gas chromatography and mass spectrometry. These analyses demonstrated differences in the ratio of urinary volatiles with age. The most prominent differences involved significantly greater amounts of 2-phenylacetamide and significantly lower amounts of methylbutyric acids in Aged animals relative to Adult animals. Fractionating and manipulating the levels of these compounds in the urine demonstrated that the mice can distinguish age based on variation in amounts of these specific compounds in the combined urine.
Assuntos
Acetamidas/urina , Envelhecimento/fisiologia , Benzenoacetamidas , Butiratos/urina , Indóis/urina , Odorantes , Acetamidas/isolamento & purificação , Envelhecimento/urina , Animais , Butiratos/isolamento & purificação , Discriminação Psicológica , Feminino , Cromatografia Gasosa-Espectrometria de Massas/veterinária , Masculino , Aprendizagem em Labirinto , Camundongos , Camundongos Endogâmicos C57BL , Odorantes/análise , VolatilizaçãoRESUMO
It has long been recognized that various genetic and metabolic human disorders alter body odor, which is not surprising because they may alter body chemistry. Thus, it has been suggested that some human diseases may be diagnosed by odor alone. In that regard, the mouse mammary tumor virus (MMTV) and its tumors of mice, which may have human counterparts, are of special interest because of the need for basic research possible only in inbred and genetically defined animals. Accordingly, we now show that the mouse MMTV, whether obtained environmentally or genetically transmitted, alters the body odor of mice in both males and females, and regardless of the presence or absence of tumors. These observations, together with the prospect of artificial human odor discrimination, may aid in the search for early human diagnostics.