Towards understanding multimodal traits of female reproduction in chimpanzees

Although primates have long been regarded as microsmatic, recent studies indicatethat olfaction is an important sensory mode of primate communication, for example, inthe context of reproduction. However, large gaps remain in understanding primateolfactory traits, especially in great apes. Female chimpanzees (Pan troglodytes)possess an exaggerated sexual swelling which is an imprecise signal of fertility toconfuse paternity. Even so, some high-ranking males copulating most frequently atfertile days of females seem to have more precise information on the timing ofovulation, suggesting the existence of an olfactory fertility trait. In order to provideevidence of fertility-related information in female chimpanzees, we used gaschromatography – mass spectrometry to analyze the chemical composition of femalebody odor collected across the menstrual cycle from various swelling stages (97samples of six females). We found that the chemical composition was significantlyaffected by swelling stages and detected nine substances that were strongly related toswelling stages. The existence of an additional olfactory fertility trait could either helpmales to fine-tune their sexual behavior or allow females to strengthen concealment ofthe exact timing of ovulation, which needs to be further investigated in follow-upstudies. The results of our study add much-needed evidence about the existence of anolfactory cue related to reproduction in chimpanzees and form a basis for futurestudies on the interplay between visual and olfactory information of female fertility

Quantitative metabolomics based on gas chromatography mass spectrometry: status and perspectives

Metabolomics involves the unbiased quantitative and qualitative analysis of the complete set of metabolites present in cells, body fluids and tissues (the metabolome). By analyzing differences between metabolomes using biostatistics (multivariate data analysis; pattern recognition), metabolites relevant to a specific phenotypic characteristic can be identified. However, the reliability of the analytical data is a prerequisite for correct biological interpretation in metabolomics analysis. In this review the challenges in quantitative metabolomics analysis with regards to analytical as well as data preprocessing steps are discussed. Recommendations are given on how to optimize and validate comprehensive silylation-based methods from sample extraction and derivatization up to data preprocessing and how to perform quality control during metabolomics studies. The current state of method validation and data preprocessing methods used in published literature are discussed and a perspective on the future research necessary to obtain accurate quantitative data from comprehensive GC-MS data is provided

Advances in structure elucidation of small molecules using mass spectrometry

The structural elucidation of small molecules using mass spectrometry plays an important role in modern life sciences and bioanalytical approaches. This review covers different soft and hard ionization techniques and figures of merit for modern mass spectrometers, such as mass resolving power, mass accuracy, isotopic abundance accuracy, accurate mass multiple-stage MS(n) capability, as well as hybrid mass spectrometric and orthogonal chromatographic approaches. The latter part discusses mass spectral data handling strategies, which includes background and noise subtraction, adduct formation and detection, charge state determination, accurate mass measurements, elemental composition determinations, and complex data-dependent setups with ion maps and ion trees. The importance of mass spectral library search algorithms for tandem mass spectra and multiple-stage MS(n) mass spectra as well as mass spectral tree libraries that combine multiple-stage mass spectra are outlined. The successive chapter discusses mass spectral fragmentation pathways, biotransformation reactions and drug metabolism studies, the mass spectral simulation and generation of in silico mass spectra, expert systems for mass spectral interpretation, and the use of computational chemistry to explain gas-phase phenomena. A single chapter discusses data handling for hyphenated approaches including mass spectral deconvolution for clean mass spectra, cheminformatics approaches and structure retention relationships, and retention index predictions for gas and liquid chromatography. The last section reviews the current state of electronic data sharing of mass spectra and discusses the importance of software development for the advancement of structure elucidation of small molecules

Comprehensive chemical derivatization for gas chromatography-mass spectrometry-based multi-targeted profiling of the major phytohormones

In the present investigation we report selection of the N-methyl-N-(tert.-butyldimethylsilyl)trifluoroacetamide (MTBSTFA) reagent as the most comprehensive derivatization protocol among 17 tested reactions covering trifluoroacetylation, pentafluorobenzylation, methylations, and trimethylsilylations. MTBSTFA allowed easy and robust tert.-butyldimethylsilyl derivatization of 1-aminocyclopropane-1-carboxylic acid, indole-3-acetic acid, (+/-)-jasmonic acid, salicylic acid, (+/-)-abscisic acid, meta-topolin, and trans-zeatin. Detection limits as analysed by selected ion monitoring quadrupole GC-MS were 0.2, 0.01, 1.0, 0.02, 0.3, 0.3, and 0.9 pmol of injected substance, respectively. Analysis of gibberellic acid A3, trans-zeatin riboside and (+/-)-abscisic acid-beta-D-glucopyranosyl ester was best when coupled by splitting extracts and trimethysilylation. The MTBSTFA derivatization protocol was optimised, and validated. The preparation was insensitive to 2% residual water and to :51 day storage at room temperature. The final scheme was highly reproducible and successfully applied to extracts from similar to300 mg (fresh mass) of tobacco (Nicotiana tabacum) root and Arabidopsis thaliana seedling. (C) 2003 Elsevier Science B.V. All rights reserved. [References: 37] 3

Comparative chemical analysis of body odor in great apes

Olfaction is important across the animal kingdom for transferring information on e.g. 18 species, sex, group membership or reproductive parameters. Its relevance has been 19 established in primates including humans, yet research on great apes still is 20 fragmentary. Observational evidence indicates that great apes use their sense of smell in 21 various contexts, but the information content of their body odor has not been analyzed. 22 Our aim was therefore to compare the chemical composition of body odor in great ape 23 species, namely Sumatran orangutans (Pongo abelii (Lesson, 1827), 1 adult male, 5 24 adult females, 4 non-adults), Western lowland gorillas (Gorilla gorilla gorilla (Savage, 25 1847), 1 adult male, 2 adult females, 1 non-adult), Common chimpanzees (Pan 26 troglodytes (Blumenbach, 1775), 4 adult males, 9 adult females, 4 non-adults) and 27 bonobos (Pan paniscus (Schwartz, 1929), 2 adult males, 4 adult females, 2 non-adults). 28 We collected 195 samples (five per individual) of 39 captive individuals using cotton 29 swabs and analyzed them using gas chromatography – mass spectrometry. We 30 compared the sample richness and intensity, similarity of chemical composition and 31 relative abundance of compounds. Results show that species, age and potentially sex 32 have an impact on the variance between odor profiles. Richness and intensity varied 33 significantly between species (gorillas having the highest, bonobos the lowest richness 34 and intensity), and with age (both increasing with age). Richness and intensity did not 35 vary between sexes. Odor samples of the same species were more similar to each other 36 than samples of different species. Among all compounds identified some were 37 associated with age- (N = 7), sex- (N = 6), and species-related (N = 37) variance. Our 38 study contributes to the basic understanding of olfactory communication in hominids by showing that the chemical composition of body odor varies across species and 40 individuals, containing potentially important information for social communication

Metabolome analysis: the potential of in vivo labeling with stable isotopes for metabolite profiling

Metabolome analysis technologies are still in early development because, unlike genome, transcriptome and proteome analyses, metabolome analysis has to deal with a highly diverse range of biomolecules. Combinations of different analytical platforms are therefore required for comprehensive metabolomic studies. Each of these platforms covers only part of the metabolome. To establish multiparallel technologies, thorough standardization of each measured metabolite is required. Standardization is best achieved by addition of a specific stable isotope-labeled compound, a mass isotopomer, for each metabolite. This suggestion, at first glance, seems unrealistic because of cost and time constraints. A possible solution to this problem is discussed in this article. Saturation in vivo labeling with stable isotopes enables the biosynthesis of differentially mass-labeled metabolite mixtures, which can be exploited for highly standardized metabolite profiling by mass isotopomer ratios