Lipophilic compounds in femoral secretions of male collared lizards,Crotaphytus bicinctores (Iguania,Crotaphytidae)

In many lizards, chemical compounds from the femoral gland secretions are used in intraspecific communication, but most studies describing these chemicals are for lizard species included in the Scleroglossa clade, whereas lizards within the Iguanian clade have been much less studied, probably because these lizards were considered to rely more on visual cues. However, many iguanian lizards have abundant femoral secretions and are able of chemosensory conspecific recognition, which might be based on compounds secreted by femoral glands. By using GC–MS analyses, we found 58 lipophilic compounds in femoral gland secretions of male Great Basin collared lizard, Crotaphytus bicinctores (Iguania, Crotaphytidae). Main compounds were steroids (mainly two triunsaturated steroids and cholesterol), carboxylic acids (mainly hexadecanoic acid), waxy esters of long chain fatty acids, alcohols (mainly hexadecanol), aldehydes and other minor compounds. We compared these compounds with those found in other lizard species and discussed the potential signaling function of some compounds and how the xeric habitat of this lizard could have conditioned the composition of secretions.     

Immunohistochemical evidence: testicular and scented glandular androgen synthesis in muskrats (Ondatra zibethicus) during the breeding season

In order to elucidate the relationship between androgens and the function of the muskrat (Ondatra zibethicus) scented glands during the breeding season, we investigated immunolocalization of steroidogenic enzymes P450scc, 3βHSD and P450c17 in the muskrat testes and scented glands. Nine adult muskrats were obtained in March (n=3), May (n=3) and July (n=3) 2010. Steroidogenic enzymes were immunolocalized using polyclonal antisera raised against bovine adrenal P450scc, human placental 3βHSD and porcine testicular P450c17. Histologically, all types of spermatogenic cells including mature-phase spermatozoa in seminiferous tubules were observed in all testes. Glandular cells, interstitial cells, epithelial cells and excretory tubules were identified in scented glands during the breeding season. P450scc, 3βHSD and P450c17 were only identified in Leydig cells during the breeding season; P450scc and P450c17 were observed in glandular cells of scented glands, however, 3βHSD was not found in scented glands during the breeding season. These novel findings provide the first evidence showing that scented glands of the muskrats are capable of locally synthesizing androgens and androgens acting via an endocrine, autocrine or paracrine manner may play an important role in scented gland function during the breeding season.     

四川短尾鼩包皮腺的挥发性化学成分分析

哺乳动物的包皮腺分泌物对个体间性引诱及繁殖行为的信息交流和种群调节有着重要的作用。本研究以四川短尾鼩（Anourosorex squamipes）为研究对象对劳亚食虫目动物包皮腺挥发性化学成分和化学通讯功能进行报道。采用顶空固相微萃取—气质联用（HS-SPME-GC/MS）的方法,分析四川短尾鼩雄体包皮腺中挥发性物质的化学组成。结果表明：（1）四川短尾鼩雄体包皮腺的挥发性化学成分主要含烷烃类、醇类、酮类、醛类、醚类、酯类、酸类、芳香烃类等45种化合物;（2）成年雄性四川短尾鼩的包皮腺中挥发性成分有39种,幼年雄性含有28种,说明四川短尾鼩成年雄体的包皮腺中挥发性化学成分多于幼年雄体;（3）成年雄体的包皮腺分泌物中含有4种特有的挥发性化学成分,幼年雄体中特有成分仅为1种,表明四川短尾鼩包皮腺中的挥发性化学成分存在年龄差异;（4）四川短尾鼩包皮腺分泌物中不同化学成分相对含量不同,同种化学成分在不同个体间的相对含量存在差异。四川短尾鼩雄性包皮腺挥发性化合物种类丰富,个体、年龄差异明显。推测挥发性化合物中丁酸（Butanoicacid）、乙酸乙酯（Ethyl acetate）、苯酚（Phenol）为四川短尾鼩的信息素。本研究为进一步验证该物种的信息素成分及其传递机制提供了基础数据。     

Lipophilic compounds in femoral secretions of males and females of the El Hierro giant lizard Gallotia simonyi (Lacertidae)

Many lizards use femoral gland secretions in reliable intraspecific communication. Based on mass spectra, obtained by GC–MS, we found 57 lipophilic compounds in femoral secretions of males and females of El Hierro giant lizards, Gallotia simonyi (fam. Lacertidae). Compounds included steroids (mainly cholesterol) and fatty acids ranging between n-C₁₆ and n-C₂₂ (mainly hexadecanoic and octadecanoic acids), followed by aldehydes, alcohols, ketones, squalene and waxy esters. There were important intersexual differences in the presence, abundance and number of compounds (more numerous in males). Males had higher proportions of the most odoriferous compounds (fatty acids and aldehydes), while females had higher proportions of more stable compounds (steroids, waxy alcohols, waxy esters and terpenoids). This suggests sexual differences in function of femoral secretions. In addition, some compounds could reflect the physiological state, allowing monitoring health of lizards from secretions samples, which is especially important given the critical conservation status of this lizard.     

Chemistry of the oil gland secretion of Collohmannia gigantea (Acari: Oribatida)

The chemistry of the lemon-scented oil gland secretion ofCollohmannia gigantea, a middle-derivative mixonomatanoribatid mite, was investigated by gas chromatography – massspectrometry.Gas chromatographic profiles of whole body extracts of C.gigantea revealed two distinct chromatographic zones, the firstcontaining a set of six volatile compounds, comprising the lemon-scentedmonoterpene aldehydes neral and geranial, the scented monoterpene ester nerylformate, a distinctly scented aromatic aldehyde(2-hydroxy-6-methyl-benzaldehyde= 2,6-HMBD), and the two non-scented hydrocarbons, tridecane and pentadecane.All six components appeared to be present in steady relative proportions inscenting mites only, indicating their unity within the scented secretion. Incontrast, the components of the second chromatographic zone were less volatileand found in both, scenting and non-scenting mites. Chemically, they representaset of fatty acids of already known cuticular origin.The secretion bouquet ofthe first chromatographic zone was linked with oil glands by histochemicalmeans: large amounts of aldehydes were present only in oil gland reservoirs,notin any other region of the mite body. While chemical profiles of oil glandsecretions of several dozen astigmatid mites are known, only one other oribatidoil gland composition, from a desmonomatan species, has been elucidated, beingalmost the same as that of C. gigantea. Moreover, allcomponents of these two secretions are widely distributed amongst astigmatidmite species and may also be common in a restricted set of middle-derivativeoribatids. These findings are consistent with the idea of astigmatid miteoriginfrom a mixonomatan-desmonomatan group.     

Histochemical analysis of accessory genital gland secretions in female Pimpla turionellae L. (Hymenoptera: Ichneumonidae)

The secretions produced by the 3 accessory glands of the female genital tract of Pimpla turionellae were investigated histochemically. The uterus gland secretion was identified as a mixture of hyaluronic acid and lipoprotein, that of the poison gland as a neutral mucoprotein. The product of the alkaline gland (Dufour's gland) consists of lecithin and a cholesterol ester. Pimpla females, as parasites of Lepidoptera pupae, inject these secretions into the host hemocoel during oviposition, thus preventing hemocytic encapsulation of their eggs. The physiological functions of the secretions are briefly discussed.     

Mapping Relative Differences in Human Salivary Gland Secretions by Dried Saliva Spot Sampling and nanoLC–MS/MS

Dried saliva spot sampling is a minimally invasive technique for the spatial mapping of salivary protein distribution in the oral cavity. In conjunction with untargeted nano‐flow liquid chromatography tandem mass spectrometry (nanoLC–MS/MS) analysis, DSS is used to compare the proteomes secreted by unstimulated parotid and submandibular/sublingual salivary glands. Two hundred and twenty proteins show a statistically significant association with parotid gland secretion, while 30 proteins are at least tenfold more abundant in the submandibular/sublingual glands. Protein identifications and label‐free quantifications are highly reproducible across the paired glands on three consecutive days, enabling to establish the core proteome of glandular secretions categorized into eight salivary protein groups according to their biological functions. The data suggest that the relative contributions of the salivary glands fine‐tune the biological activity of human saliva via medium‐abundant proteins. A number of biomarker candidates for Sjögren's syndrome are observed among the gland‐specifically expressed proteins, which indicates that glandular origin is an important factor to consider in salivary biomarker discovery.     

Dissecting lipid metabolism in meibomian glands of humans and mice: An integrative study reveals a network of metabolic reactions not duplicated in other tissues

Lipids comprise the bulk of the meibomian gland secretion (meibum) which is produced by meibocytes. Complex arrays of lipogenic reactions in meibomian glands, which we collectively call meibogenesis, have not been explored on a molecular level yet. Our goals were to elucidate the possible biosynthetic pathways that underlie the generation of meibum, reveal similarities in, and differences between, lipid metabolism in meibomian glands and other organs and tissues, and integrate meibomian gland studies into the field of general metabolomics. Specifically, we have conducted detailed analyses of human and mouse specimens using genomic, immunohistochemical, and lipidomic approaches. Among equally highly expressed genes found in meibomian glands of both species were those related to fatty acid elongation, branching, desaturation, esterification, reduction of fatty acids to alcohols, and cholesterol biosynthesis. Importantly, corresponding lipid products were detected in meibum of both species using lipidomic approaches. For the first time, a cohesive, unifying biosynthetic scheme that connects genomic, lipidomic, and immunohistochemical observations is outlined and discussed.     

Inter-island variation in femoral secretions of the Balearic lizard,Podarcis lilfordi (Lacertidae)

Many lizards use femoral gland secretions in intraspecific communication. Although there is a consistent interspecific variation in chemical composition of secretions, considerable variation is also often found between populations, which may affect conspecifc recognition and lead to speciation processes. Balearic lizards (Podarcis lilfordi) are currently distributed only in several isolated islets offshore of the main islands with different environmental conditions (vegetation, diet, density of population, etc). Also, there is a high genetic variability between populations. We examined whether there was a similar variation in the composition of the femoral secretions of male lizards, and which could be the causes of such variation. By using GC–MS analyses, we found 75 lipophilic compounds in femoral gland secretions of male P. lilfordi from three representative island populations. Main compounds were steroids (94.4%), mainly cholesterol, but we also found alkanes, ketones, waxy esters, squalene, carboxylic acids and their ethyl esters, alcohols and other minor compounds. However, there were clear differences between populations with respect to the number and relative proportions of compounds. Using the patterns of presence and abundance of compounds in secretions it is possible to predict the population of origin of a lizard. We discuss how these differences could be explained considering genetic and environmental differences between populations.     

Ultrastructure of multicellular foregut glands in selected Solenogastres (Mollusca)

Foregut glands in Solenogastres are not only of importance in biological processes like feeding and digestion, but multicellular foregut glands also provide valuable characters for taxonomy and systematics. Here, the fine structure of four different types of foregut glands is investigated: the Meioherpia-type ventrolateral foregut gland of Meioherpia atlantica, the Simrothiella-type ventrolateral foregut gland of Simrothiella cf. margaritacea, and the Pararrhopalia-type ventrolateral foregut gland as well as the dorsal gland of Pararrhopalia pruvoti. Thereby, special focus is set on the arrangement of glandular and supporting cells within the glands, and on the characterization of glandular cells according to the size, shape and electron-density of their secretional vesicles. It is shown that the investigated glands are complex organs composed of non-glandular supporting cells and two to five glandular cell types producing discrete secretions.     

Regulation of acyl coenzyme A reductase by a heat-stable cytosolic protein during preputial gland development

A low-molecular-weight protein located in the cytosol of mouse preputial glands has been shown to stimulate the activity of a microsomal acyl coenzyme A (CoA) reductase in the gland. This cytoplasmic protein was stable to heating and lyophilization, but was destroyed by trypsin digestion. It was able to bind palmitoyl-CoA and gel elution behavior indicated it had a molecular weight of 10,000–12,000. The level of this stimulatory cytosolic protein and the activity of acyl-CoA reductase were shown to correlate with differentiation of the preputial gland during development of puberty in male mice; the acyl-CoA reductase activity first appeared at 4 weeks of age and increased dramatically up to 6 weeks of age. By 8 weeks, when sexual maturity was attained, the reductase activity decreased to that level found in mature male mice. The cytosol from the preputial glands of the youngest mice (3 weeks) contained sufficient heat-stable acyl-CoA binding protein to stimulate acyl-CoA reduction; however, the 3-week-old preputial gland microsomes had little or no acyl-CoA reductase activity. As the animal matured, the stimulatory capacity in the heat-treated cytosol increased, reaching a maximum at 6 weeks; by 8 weeks, the stimulatory capacity of the soluble fraction had decreased to that found in mature male mouse. Results of this study suggest that the concentration of acyl-CoA, cytoplasmic acyl-CoA binding protein, and acyl-CoA reductase activity regulate the level of fatty alcohols in vivo and that the reductase activity and binding protein have similar patterns of development during puberty.     

Characteristics of microbial association in secretions of various mammalian sebaceous glands

The following secretions of mammalian skin glands were subjected to a microbiological survey: the middle-abdominal glands of great and Mongolian gerbils, the preputial gland of musk deer, the perineal organ of African civet cat, the interdigital skin regions and interdigital glands of bison, European bison, European roe deer, and musk deer. All the secretions were found to contain microbial associations. The composition of bacterial species in the secretions and the quantity of microorganisms varied among different animal species, during the ontogenesis of an animal, and depended on the topography of a gland on an animal body as well as on its functional state in different seasons or upon hormonal changes. The secretions of certain glands contain factors which determine the composition of microbial species in a particular ecological niche and the stability of such a cenosis.     

Stimulation of growth by testosterone via the mesenchyme

Summary To establish testosterone-dependent growth in organ-culture, anlagen of preputial glands from normal wild-type and from androgeninsensitive mouse embryos carrying the testicular feminization mutation (Tfm) were explanted and cultured in the presence of testosterone. Within six days a size difference developed between Tfm and wild-type explants involving length of hair follicle, amount of preputial gland tissue, and overall size.Anlagen from Tfm and wild-type preputial glands were then separated into epithelial bud and mesenchyme. Reciprocal recombinants were prepared and cultured with testosterone. In the recombinants development of hair follicles and gland tissue was inconsistent. Nevertheless, the effect of testosterone was expressed in the overall size of the explants. The size correlated with the type of mesenchyme used, but not with the type of epithelium: Androgen-insensitive Tfm epithelium combined with wild-type mesenchyme reached the same size as whole wild-type glands and wild-type/wild-type recombinants. Wild-type epithelium with Tfm mesenchyme resulted in small explants, which were in the range of the whole androgen-insensitive Tfm glands. Tfm/Tfm recombinants showed very poor growth, probably related to the fact that in this group no hair or gland structures developed.     

Seasonal, sexual and developmental differences in hoopoe Upupa epops preen gland morphology and secretions: evidence for a role of bacteria

The uropygial glands of birds serve multiple functions, and there is great interspecific variability in the composition and properties of their secretions. A special case is the secretion in the hoopoes Upupa epops, and green woodhoopoes Phoeniculus purpureus, which, contrary to the commonly white and odourless secretions, are dark with pungent odour. Recently, bacteria have been isolated from glands of both woodhoopoes and hoopoes and here we test the hypothesis that bacteria are responsible of some of the special properties of glands and secretions of this group of birds. We explore natural seasonal changes and intersexual differences in the properties of hoopoe glands and secretions, check the natural occurrence of bacteria within secretions, and analyse the effect of experimental injection of antibiotics on uropygial gland properties. Male glands underwent no seasonal changes, and their secretions were invariably white and odourless, very similar to female glands outside the breeding season. However, in comparison to the uropygial gland of non‐breeding females, those of incubating females showed a marked increase in size and volume of secretion produced, which became dark and pungent. All these parameters increased until the hatching date and returned to values similar to those in the prelaying phase towards the end of the nestling period. Nestling glands produced secretions similar to those of females in colour and odour. Gland size of both females and nestlings predicted the amount of secretion produced. Microscopic techniques confirmed the presence of bacteria at high density and in active division in all dark secretions examined. The antibiotic treatment significantly reduced the load of enterococci in nestling glands, did not affect size of glands, but diminished the volume of secretion, which was lighter in colour than that of control nestlings. In nesting females, the experimental injection of antibiotic affected some measurements of gland size and secretion colour. Because the experiment did not affect general health estimates (immunocompetence, body condition or growing) of nestlings, our results suggest that some of the special properties of hoopoe glands are mediated by the presence of symbiotic bacteria.     

Fine structure and function of the prosomal glands of the two-spotted spider mite,Tetranychus urticae (Acari,Tetranychidae)

Summary The prosomal glands of Tetranychus urticae (Acari, Tetranychidae) were examined light and electron microscopically. Five paired and one unpaired gland are found both in females and males. The silk spinning apparatus consists of paired silk glands which extend laterally on both sides of the esophagus into the pedipalps. There, they enter the terminal silk gland bag which opens into a silk bristle at the apex of the pedipalps. The salivary secretions are formed in three paired glands which have an interconnecting duct, the podocephalic canal. The dorsal podocephalic glands may produce a serous secretion, the anterior podocephalic glands a mucous secretion, and the coxal organ may add a liquid, ion-rich secretion. These secretions pass the podocephalic canal and reach the mouth at the apex of the gnathosome. The function of the paired tracheal organs and the unpaired tracheal gland is still unclear. The tracheal gland may produce a secretion which facilitates the movement of the fused chelicerae and the stylets.This study was financed by a grant from the Deutsche Forschungsgemeinschaft (DFG Se 162/12)     

Male labial gland secretions and mitochondrial DNA markers support species status of Bombus cryptarum and B. magnus (Hymenoptera, Apidae)

Summary. Spring queens of Bombus cryptarum and B. magnus from 2 localities in Brandenburg/Germany and Scotland/United Kingdom respectively were determined by morphological characteristics. The lateral border of the collare at the border of the pronotallobus or at the episternum proved to be an especially useful character. Artificial colonies were reared from safely determined spring queens and the cephalic part of the labial glands of males from these colonies were investigated by GC/MS. The investigation identified approximately 50 compounds, as a mixture of straight chain fatty acid derivatives (alcohols, esters and hydrocarbons). The labial secretions of B. cryptarum and B. magnus are significantly different. Mitochondrial cytochrome oxidase 1 (CO1) of two queens from each locality and species were sequenced. Each species from the different localities formed a cluster. Sequence divergence between B. cryptarum and B. magnus was about 30 base substitutions and approximately 0.04 in Tamura-Nei genetic distance. Bombus cryptarum and B. magnus were closer to each other than to B. lucorum and made the sister group in the topology of the tree. Both the CO1 sequences and the labial gland secretions of males of B. cryptarum from Brandenburg and of males from artificial colonies reared from safely determined spring queens from Scotland are identical. B. cryptarum has thus, for the first time, been identified as part of the British bumble bee fauna. The differences of both the labial gland secretions, used as species recognition signals, and the genetic differences established by sequencing CO1 confirm the morphological findings that B. cryptarum and B. magnus are distinct taxa which should be treated as distinct species.Received 25 March 2004; revised 13 June 2004; accepted 15 June 2004.     

Liquid chromatography high‐resolution mass spectrometry for fatty acid profiling

Quantification of fatty acids has been crucial to elucidate lipid biosynthesis pathways in plants. To date, fatty acid identification and quantification has relied mainly on gas chromatography (GC) coupled to flame ionization detection (FID) or mass spectrometry (MS), which requires the derivatization of samples and the use of chemical standards for annotation. Here we present an alternative method based on a simple procedure for the hydrolysis of lipids, so that fatty acids can be quantified by liquid chromatography mass spectrometry (LC‐MS) analysis. Proper peak annotation of the fatty acids in the LC‐MS‐based methods has been achieved by LC‐MS measurements of authentic standard compounds and elemental formula annotation supported by ¹³C isotope‐labeled Arabidopsis. As a proof of concept, we have compared the analysis by LC‐MS and GC‐FID of two previously characterized Arabidopsis thaliana knock‐out mutants for FAD6 and FAD7 desaturase genes. These results are discussed in light of lipidomic profiles obtained from the same samples. In addition, we performed untargeted LC‐MS analysis to determine the fatty acid content of two diatom species. Our results indicate that both LC‐MS and GC‐FID analyses are comparable, but that because of higher sensitivity and selectivity the LC‐MS‐based method allows for a broader coverage and determination of novel fatty acids.     

A comparison between the dermal glands in two insects Rhodnius prolixus (Hemiptera) and Calpodes ethlius (Lepidoptera)

The results of histochemical tests performed on the type “B” dermal gland in Rhodnius and the Verson's gland in Calpodes at different stages in their secretory cycle are presented. The secretions of both glands are slightly acidic sulphated mucosubstances. They differ in their main carbohydrate component which in Rhodnius is hyaluronic acid and in Calpodes is sialic acid. The glands, though structurally similar, differ in size, number, and development.     

Detection of a New Piperideine Alkaloid in the Pygidial Glands of Some Stenus Beetles

Rove beetles of the genus Stenus produce and store bioactive alkaloids like stenusine ( 3 ), 3‐(2‐methylbut‐1‐enyl)pyridine ( 4 ), and cicindeloine ( 5 ) in their pygidial glands to protect themselves from predation and microorganismic infestation. The biosynthesis of stenusine ( 3 ), 3‐(2‐methylbut‐1‐enyl)pyridine ( 4 ), and cicindeloine ( 5 ) was previously investigated in Stenus bimaculatus, Stenus similis, and Stenus solutus, respectively. The piperideine alkaloid cicindeloine ( 5 ) occurs also as a major compound in the pygidial gland secretion of Stenus cicindeloides. The three metabolites follow the same biosynthetic pathway, where the N‐heterocyclic ring is derived from L ‐lysine and the side chain from L ‐isoleucine. The different alkaloids are finally obtained by few modifications of shared precursor molecules, such as 2,3,4,5‐tetrahydro‐5‐(2‐methylbutylidene)pyridine ( 1 ). This piperideine alkaloid was synthesized and detected by GC/MS and GC at a chiral phase in the pygidial glands of Stenus similis, Stenus tarsalis, and Stenus cicindeloides.