Seasonal expression of P450c17 and 5α-reductase-2 in the scented gland of male muskrats (Ondatra zibethicus).

Cytochrome P450 17A1 (P450c17) is the key enzyme required for the production of androgenic sex steroids by converting progestogens to androgens. 5α-reductases are enzymes that convert testosterone (T) to dihydrotestosterone (DHT), which has a greater affinity for androgen receptors (AR) and stronger action than T. Our previous studies revealed that the scented glands of male muskrats expressed AR during the breeding and nonbreeding seasons. To further seek evidence of the activities of androgens in scented glands, the expression patterns of P450c17 and 5α-reductase 2 were investigated in the scented glands of male muskrats during the breeding and nonbreeding seasons. The weight and size of scented glands in the breeding season were significantly higher than those of the nonbreeding season. Immunohistochemical data showed that P450c17 and 5α-reductase 2 were presented in the glandular cells and epithelial cells of scented glands in both the seasons. The protein and mRNA expression of P450c17 and 5α-reductase 2 were significantly higher in the scented gland during the breeding season than those during the nonbreeding season. In addition, the levels of DHT and T in the scented gland were remarkably higher during the breeding season. Taken together, these results suggested that the scented glands of male muskrats were capable of locally synthesizing T and DHT, and T and DHT might play an important role in the scented glandular function via an autocrine or paracrine manner.

Seasonal Expression of Prolactin Receptor in the Scented Gland of Male Muskrat (Ondatra zibethicus).

Prolactin (PRL) has numerous actions in mammalian biological systems including mammary development and biological processes. The aim of this study was to investigate the seasonal changes of prolactin receptor (PRLR) expression in the scented gland of muskrat during the breeding and nonbreeding seasons. Histologically, glandular cells, interstitial cells and excretory tubules were identified in the scented glands in both seasons, whereas epithelial cells were sparse in the nonbreeding season. PRLR was observed in glandular cells of scented glands during the breeding and nonbreeding seasons with stronger immunostaining during the breeding season. Consistent with the immunohistochemical results, both the mean of protein and mRNA levels of PRLR were higher in the scented glands of the breeding season, and relatively lower level in the nonbreeding season. In addition, differential seasonal changes were also detected in the expression profile of microRNAs (miRNAs) in the scented gland of muskrat. Besides, plasma PRL concentration was remarkably higher in the breeding season than that in the nonbreeding season. These results suggested that muskrat scented gland was the direct target organ of PRL, and stronger expression of PRLR in scented glands during the breeding season indicated that PRL may directly regulate scented glandular function of the muskrats.

Histology of the suprapubic and anogenital cutaneous glands in male cotton top tamarins (Saguinus oedipus).

In cotton top tamarins (Saguinus oedipus), scent glands have been mostly studied in females from museum collections. This work aims to extend the investigation to male specimens, introducing a novel source of skin samples. Two adult males from zoo populations, one intact and one castrated, were immediately frozen after natural death. Skin samples were later collected at the thawing onset, soaked with cold fixative and processed for light microscopy. Sebaceous units of scent glands showed phasic secretory activity in the intact male and marked fibrosis in the castrated male. It appears, therefore, that light microscopy samples from frozen tissues provide detailed features that can disclose distinctive traits in specimens characterized by different hormonal balances.

Fine structure and chemical analysis of the metathoracic scent gland secretion in Graphosoma lineatum (Linnaeus, 1758) (Heteroptera, Pentatomidae).

Morphology and ultrastructure of metathoracic scent glands (MTGs) of Graphosoma lineatum (Heteroptera, Pentatomidae) were studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Extracts of the volatile fraction of the MTG secretion from males and females were subjected to initial analysis. One pair of the MTG is composed of a reservoir and a pair of lateral glands connected to the reservoir with a duct. MTGs are open in between the meso- and metacoxae, on evaporation areas with a mushroom-like structure. Reservoir walls embody two types of cells, type I and type II, respectively. Cells of type I have numerous organelles, while type II cells have only been found in a certain area of the reservoir wall. They have large secretory ducts lined by a cuticular intima layer. The lateral glands connected to reservoir have two further types of cells. Lateral glands are lined by type A secretory cells and secretory duct is found in their cytoplasm. Type B cells are poor in organelles and are smaller than type A cells. Coupled gas chromatography-mass spectrometry examinations revealed that both in males and females of G. lineatum MTGs 14 chemical compounds occur, among which only 10 are common. These secretions indicate information such as defensive and pheromonal activities, other functions could be attributed to the secretion of the MTG of G. lineatum by comparison with other closely related bug species. In the analyses of MTGs of females of G. lineatum, n-octadecanoic acid was observed at the most and n-undecane was determined at lowest level, while males of G. lineatum n-tridecane was determined at the highest level; and (E)-2-hexenyl acetate has been observed at the lowest.

Osmetrichia in the grey brocket deer (Mazama gouazoubira)

Osmetrichia have been defined as hairs specialized in the storage of secretions used in olfactory communication between conspecifics (M³ller-Schwarze, et al. 1977). These authors found highly specialized osmetrichia in the tarsal gland tufts of black-tailed but not white-tailed deer. Chemical communication appears to be well developed in grey brocket deer: the bucks scent mark by rubbing their foreheads on bushes, and all deer urinate and defecate almost exclusively on dung heaps. Brocket deer also possess tarsal tufts. The purpose of this study was to examine hairs from several glandular areas in this species. Osmetrichia, similar to those found in black tailed deer, were found in tarsal tufts and in interdigital gland hairs; these hairs possessed open scales with deep pockets suitable for holding secretions, in comparison to the flat scales seen on control hairs. Hairs with different morphological characteristics (slightly open scales) were found over the frontal gland. Specialized hairs were not found in the tarsal tufts of one specimen of a related species, the red brocket deer (Mazama americana). The similarities in the hairs of grey brocket and black-tailed deer are remarkable in light of the ecological and behavioral differences between these two species

Osmetrichia in the grey brocket deer (Mazama gouazoubira)

Osmetrichia have been defined as hairs specialized in the storage of secretions used in olfactory communication between conspecifics (Müller-Schwarze, et al. 1977). These authors found highly specialized osmetrichia in the tarsal gland tufts of black-tailed but not white-tailed deer. Chemical communication appears to be well developed in grey brocket deer: the bucks scent mark by rubbing their foreheads on bushes, and all deer urinate and defecate almost exclusively on dung heaps. Brocket deer also possess tarsal tufts. The purpose of this study was to examine hairs from several glandular areas in this species. Osmetrichia, similar to those found in black tailed deer, were found in tarsal tufts and in interdigital gland hairs; these hairs possessed open scales with deep pockets suitable for holding secretions, in comparison to the flat scales seen on control hairs. Hairs with different morphological characteristics (slightly open scales) were found over the frontal gland. Specialized hairs were not found in the tarsal tufts of one specimen of a related species, the red brocket deer (Mazama americana). The similarities in the hairs of grey brocket and black-tailed deer are remarkable in light of the ecological and behavioral differences between these two species

Detection of glycosidic residues in carpal glands of wild and domestic pig revealed by basic and lectin histochemistry.

Carpal glands are compound tubuloalveolar glands, located on the medial surface of the carpus. This study was carried out on samples from carpal glands of adult wild and domestic pigs of both sexes. We elucidated the glycosidic composition of carpal gland secretion in situ using traditional histochemical methods and lectin histochemistry. Some secretory cells exhibited an intense reaction with PAS in both wild and domestic pigs. Lectin histochemistry showed differences in the localization and composition of glycoconjugates secreted by carpal glands. A cytoplasmic positivity was revealed in the wild pig by the sequence sialidase-PNA and WGA, whereas in the domestic pig the reactivity was localized at the apical surface of some cells. LTA positive cells were found only in the carpal glands of the domestic pig.

"Osmetrichia" in the grey brocket deer (Mazama gouazoubira).

Osmetrichia have been defined as hairs specialized in the storage of secretions used in olfactory communication between conspecifics (Müller-Schwarze, et al. 1977). These authors found highly specialized osmetrichia in the tarsal gland tufts of black-tailed but not white-tailed deer. Chemical communication appears to be well developed in grey brocket deer: the bucks scent mark by rubbing their foreheads on bushes, and all deer urinate and defecate almost exclusively on dung heaps. Brocket deer also possess tarsal tufts. The purpose of this study was to examine hairs from several glandular areas in this species. Osmetrichia, similar to those found in black tailed deer, were found in tarsal tufts and in interdigital gland hairs; these hairs possessed open scales with deep pockets suitable for holding secretions, in comparison to the flat scales seen on control hairs. Hairs with different morphological characteristics (slightly open scales) were found over the frontal gland. Specialized hairs were not found in the tarsal tufts of one specimen of a related species, the red brocket deer (Mazama americana). The similarities in the hairs of grey brocket and black-tailed deer are remarkable in light of the ecological and behavioral differences between these two species.

[Histological studies on postnatal development of the musk gland in house musk shrews (Suncus murinus)].

The development of the musk gland in house musk shrews aged 0 to 21 days was studied lectin histochemically. On about 3 days of age, the musk gland could be discriminated from surrounding skin. This organ developed markedly on days 3 to 7, and its development continued to 21 days of age. Histologically, on day 1, the bulges that should develop into musk glands were identified in the vicinity of hair germs. On days 3 to 7, these bulges developed markedly, and on day 21 their structure revealed almost the same morphology with that in mature musk glands. We used 7 lectins; ConA, RCA I, PNA, SBA, UEA-I, DBA, and WGA. On day 1, 6 lectins except for WGA labelled the cell of the musk gland. WGA began to label it on day 3. Until 7 days of age, lectins bound to only the cytoplasm of the cell of musk glands. On days 12, however, PNA and UEA-1 labelled the cell membrane equally, and RCA I labeled it on day 21.

[Lectin histochemical studies on the musk gland in the house musk shrew (Suncus murinus)].

The musk gland of the adult house musk shrews (Suncus murinus) of both sexes was studied lectin histochemically. The musk gland was a kind of scent gland, consisted of congregation of branched or unbranched simple tubuloalveolar gland holocrine in nature and was attached by an apocrine gland-like structure (sweat gland) in the deeper layer of its periphery. Acinar cells of the musk gland were distinguishable into three type from basal to luminal parts of the acinus; immature cells, mature cells and degenerating cells. There was no histological difference between both sexes. Lectin-binding pattern of the musk gland was examined in comparison with that of the sweat gland and ordinary sebaceous gland by histochemical staining techniques using seven lectins: ConA, RCA I, PNA, SBA, UEA-I, DBA, WGA, WGA and PNA labelled the duct of the musk gland more intense than the acinus. Several lectins showed a tendency to label the cells situated near the luminal surface more intense than those near the basement membrane in both the acinus and duct of the musk gland. In the sweat gland and ordinary sebaceous gland, the lectin-binding pattern was different with each other and from that in the musk gland. These findings suggest that the musk gland, sweat gland, and ordinary sebaceous gland are different to each other in nature of cells and the secretion.

Lectin histochemical study on the infraorbital gland of the Japanese serow (Capricornis crispus).

Histology and lectin histochemistry were performed in the infraorbital gland of the Japanese serow. The gland is composed of glandular tissues and a pouch filled with the secretion. The tissues consist of an inner layer of sebaceous glands and an outer layer of apocrine glands. The male sebaceous layer is made up of the ordinary type, whereas the female's layer consists of the ordinary and modified types. In the apocrine gland stained with Arachis hypogaea (PNA), nine different patterns of glandular tubules were distinguished on the basis of staining of the cytoplasm, the Golgi area of secretory cells and secretion. Secretory modes of apocrine secretion and exocytosis were included in these stainings. Myoepithelial cells stained constantly with Glycine max (SBA) except when only the Golgi area of secretory cells was positive. The modified sebaceous gland was stained with PNA, SBA, Ricinus communis I (RCA), Triticum vulgaris (WGA), Canavalia ensiformis (Con A) and Ulex europaeus I (UEA), while the ordinary type was positive in PNA, RCA, SBA, WGA and Con A. The secretion in the pouch was stained with PNA, RCA, SBA, Dolichos biflorus (DBA), WGA and Con A. These findings suggest that the modified sebaceous gland contains large amounts of glycoconjugates and the apocrine gland shows a cyclic secretory process of apocrine secretion and exocytosis.