Anatomy of marsupials

Barbour, R. A.

doi:10.1007/978-1-349-02721-7_15

Cited by 17 publications

(13 citation statements)

References 216 publications

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“…Esse fenômeno provavelmente ocorre em todos marsupiais americanos (Biggers & Creed 1962, Biggers et al 1964, Biggers 1966, exceto no Dromiciops australis (Temple-Smith 1987), mas não é observado em espécies australianas (Biggers et al 1964, Harding et al 1979, Barbour 1977, Temple-Smith 1984, Taggart et al 1993.O processo de maturação espermática nos marsupiais é mais evidente e complexo que nos outros grupos de mamíferos. Durante a passagem dos espermatozóides pelo epidídimo, eles apresentam modificações estruturais da maturação espermática (Temple-Smith & Bedfort 1976, Cummins et al 1986, Temple-Smith1984, Lin & Rodger 1999.…”

Section: Discussionunclassified

“…De acordo com alguns autores, essa é uma característica peculiar de marsupiais (Harrison 1949, Barnett & Brazenor 1958, Setchell 1977, Ribeiro 1981, Temple-Smith 1984a, Martinelli 1990, Nogueira et al 2004, porém ausente em pequenas espé-cies, incluindo Notoryctes, pequeno marsupial com testí-culos abdominais. Alguns autores discutem a presença de vasos linfáticos na rede admirável (Heddle & Guiller 1970, Barbour 1977, Setchell 1977, Ribeiro 1981, Tyndale-Biscoe & Renfree 1987, Martinelli 1990). Embora se tenham observado vasos linfáticos ao longo do funículo espermático de M. nudicaudatus, bem como em P. opossum (Ribeiro 1981), parece que esses vasos não fazem parte dessa rede.…”

Section: Discussionunclassified

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Morfologia do escroto, do testículo e das vias espermáticas de Metachirus nudicaudatus (Geoffroy, 1803), Didelphidae-Marsupialia

et al. 2015

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ABSTRACT.-Costa S.F., Nogueira J.C., Soares B.A., Ambrósio N.A., Chaves A.S., Melo L. Gonads and sperm pathways of five adult male Metachirus nudicaudatus in the reproductive phase were used to describe the morphology of scrotum, testicle, and spermatic tract. M. nudicaudatus has a scrotum pre-penis which contains the testicles permanently. The scrotal skin is not pigmented and has few hairs and glands. The parietal vaginal tunic is slightly pigmented. The testicles are oval and connected to the epididymis by testicular-epididymal pedicle; they are surrounded externally by the testicular capsule and supported by a stroma of connective nature. Interstitial cells are the predominant elements in abundant intertubular tissue. The seminiferous tubules are wide, meandering and surrounded by a fibro-elastic coat, containing myoid cells. The seminiferous epithelium is composed of spermatogenic cells and Sertoli cells interspersed. The seminiferous tubules converge toward the end of the testis capitata, getting coated only support cells, featuring a transition region between the seminiferous tubules and straight tubules, occupied by a type "valve" structure that partially blocks the tubular lumen. Straight tubules together to form a single efferent ductule, which runs a small intra-testicular extent, penetrates through the tunica and the pedicle testis--epididymis. The flexuosa part of the efferent ductule forms a separate lobe in the medial part of the body of the epididymis. The epididymis is enveloped by a capsule and epididymal comprising the epididymal duct, which is quite entangled. The epididymal duct is lined by pseudostratified columnar epithelium with simple principal, basal, apical and "clear halo" cells. The main cells are prevalent and have morphological and histochemical differing characteristics along the duct, enabling to characterize nine different epididymal areas. In the lumen of the seventh area (top of tail) that starts the pairing of sperm. This phenomenon coincides well with morphological change and a larger amount of neutral muco-substances is secreted in that area. Vas deferens has three parts: fair-epididymal, abdominal and funicular part, based on histological and histochemical changes of the epithelium and surrounding components. The vas deferens has no bulb and even crosses the ureter before flowing into the urethra. The spermatic cord contains the vas deferens, testicular artery and veins, lymphatic vessels, nerves and developed cremaster muscle. Its components have structural changes in the proximal, middle and distal region, with a peculiar admirable network.

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Section: Discussionunclassified

Morfologia do escroto, do testículo e das vias espermáticas de Metachirus nudicaudatus (Geoffroy, 1803), Didelphidae-Marsupialia

et al. 2015

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“…Histological studies have shown that marsupial epidermis generally resembles that of eutherians (Gibbs, 1938;Lyne et al, 1970;Sokolov, 1982), but few ultrastructural data are available (Matoltsy, 1966;Barbour, 1977). The epidermis of monotremes, the most ancient of living mammals (Musser, 1999), has been neglected beyond histological studies of hairs and spines, which, seemingly similar to those of other mammals, have certain peculiarities (Poulton, 1894;Spencer and Sweet, 1899;Wildman and Manby, 1938;Griffith, 1978;Sokolov, 1982).…”

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Distribution of keratin and associated proteins in the epidermis of monotreme, marsupial, and placental mammals

Alibardi

Maderson

2003

Journal of Morphology

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The expression of acidic and basic keratins, and of some keratinization marker proteins such as filaggrin, loricrin, involucrin, and trichohyalin, is known for the epidermis of only a few eutherian species. Using light and high-resolution immunocytochemistry, the presence of these proteins has been studied in two monotreme and five marsupial species and compared to that in eutherians. In both monotreme and marsupial epidermis lamellar bodies occur in the upper spinosus and granular layers. Development of the granular layer varies between species and regionally within species. There is great interspecific variation in the size (0.1-3.0 microm) of keratohyalin granules (KHGs) associated with production of orthokeratotic corneous tissues. Those skin regions lacking hairs (platypus web), or showing reduced pelage density (wombat) have, respectively, minute or indiscernible KHGs, associated with patchy, or total, parakeratosis. Ultrastructural analysis shows that monotreme and marsupial KHGs comprise irregular coarse filaments of 25-40 nm that contact keratin filaments. Except for parakeratotic tissues of platypus web, distribution of acidic and basic proteins in monotreme and marsupial epidermis as revealed by anti-keratin antibodies AE1, AE2, and AE3 resembles that of eutherian epidermis. Antibodies against human or rat filaggrins have little or no cross-reactivity with epidermal proteins of other mammals: only sparse areas of wombat and rabbit epidermis show a weak immunofluorescence in transitional cells and in the deepest corneous tissues. Of the available, eutherian-derived antibodies, that against involucrin shows no cross-reactivity with any monotreme and marsupial epidermal tissues and that against trichohyalin cross-reacts only with cells in the inner root sheath and medulla of hairs. These results suggest that if involucrin and trichohyalin are present throughout noneutherian epidermis, they may have species-specific molecular structures. By contrast, eutherian-derived anti-loricrin antibodies show a weak to intense cross-reactivity to KHGs and corneous tissues of both orthokeratotic and parakeratotic epidermis in monotremes and marsupials. High-resolution immunogold analysis of loricrin distribution in immature keratinocytes of platypus parakeratotic web epidermis identifies labeled areas of round or irregular, electron-pale granules within the denser keratohyalin component and keratin network. In the deepest mature tissues, loricrin-like labeling is diffuse throughout the cytoplasm, so that cells lack the preferential distribution of loricrin along the corneous envelope that characterizes mature eutherian keratinocytes. Thus, the irregular distribution of loricrin in platypus parakeratotic tissues more resembles that which has been described for reptilian and avian keratinocytes. These observations on the noneutherian epidermis show that a stratum granulosum is present to different degrees, even discontinuous within one tissue, so that parakeratotic and orthokeratotic areas may alternate: this might imply...

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“…Em marsupiais australianos as secreções das glândulas bulbouretrais podem ser constituídas por mucossubstân-cias neutras e ácidas, proteínas e lipídios (Rodger & Hughes 1973, Barbour 1977, Temple-Smith 1984.…”

Section: Microtarsus)unclassified

Morfologia e histoquímica das glândulas sexuais acessórias de Metachirus nudicaudatus, Didelphidae-Marsupialia

et al. 2016

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ABSTRACT.-Costa S.F., Nogueira J.C., Zangeronimo M. This paper describes the morphology and distribution of glycogen and mucous substances in the prostate and the bulbourethral glands of Metachirus nudicaudatus (Geoffroy, 1803), the only species of the genus. The prostate is surrounded by the tunica adventitia, and muscle and stroma is formed by connective urethral mucosa. The glandular parenchyma consists of secretory tubules, scattered throughout the connective tissue of the urethral mucosa which differs histologically and histochemically in cranial, middle, and caudal segments of the prostate. These morpho-histochemical differences are also observed in the outer, middle and inner parts of the tubular epithelium of each prostatic segment. In general, prostatic segments secrete neutral mucous substances, and the caudal segment also produces glycogen. The three pairs of bulbourethral glands (lateral, intermediate and medial) are surrounded by a capsule of dense connective tissue and skeletal striated muscle. The glandular parenchyma is formed by tubules or branched tubuloacinar, covered by simple epithelium which is characteristic for each pair of glands. The lateral bulbourethral glands and the medial bulbourethral glands produce neutral mucous substances and the secretion of the intermediate bulbourethral glands consists of neutral mucous substances, carboxylated acids, and sulfated acids. The M. nudicaudatus does not have ampullary glands, seminal vesicles or coagulating glands.

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Anatomy of marsupials

Cited by 17 publications

References 216 publications

Morfologia do escroto, do testículo e das vias espermáticas de Metachirus nudicaudatus (Geoffroy, 1803), Didelphidae-Marsupialia

Morfologia do escroto, do testículo e das vias espermáticas de Metachirus nudicaudatus (Geoffroy, 1803), Didelphidae-Marsupialia

Distribution of keratin and associated proteins in the epidermis of monotreme, marsupial, and placental mammals

Morfologia e histoquímica das glândulas sexuais acessórias de Metachirus nudicaudatus, Didelphidae-Marsupialia

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