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

Abstract

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.

Descriptive morphometry and stereology in accessing the testis structure and function of the marsupial Philander frenatus (Olfers, 1818) (Didelphimorphia: Didelphidae)

“…The tubular diameter for P. frenatus was similar to that described for Macrotis nudicaudatus (269.2 µm) (Costa et al, 2015). Although the tubular diameter in some marsupials species can reach values above 500 µm (Woolley, 1975), the value found for P. frenatus is within the range established by Woolley (1987) (241 to 297 µm).…”

“…The Leydigosomatic index for P. frenatus was similar to that observed in capybara H. hydrochaeris (0.04%) (Carretta-Júnior, 2012) and bat M. molossus (0.04%) (Morais et al, 2013), and higher than the values found for other rodents which presented values of 0.02% or less (Balarini, 2013;Carretta-Júnior, 2012;Cordeiro-Júnior et al, 2010;Costa et al, 2015;Lara et al, 2018;Morais et al, 2013).…”

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

“…Trata-se de um marsupial de hábitos noturnos, terrestre e com ampla distribuição na América do Sul, sendo encontrado em quase todo o Brasil, em locais de florestas densas e campos arbustivos. Estudos sobre a morfologia dos órgãos genitais de M. nudicaudatus foram realizados por Costa et al (1994Costa et al ( , 1996Costa et al ( , 2015, Costa (1995), Cruz et al (2011aCruz et al ( , 2011b. Entretanto, pouco se sabe sobre a morfologia e a natureza das secreções prostática e das glândulas bulbouretrais do Jupati.…”