Comparative analysis of the male reproductive accessory glands of bats Noctilio albiventris (Noctilionidae) and Rhynchonycteris naso (Emballonuridae)

Abstract

In eutherian mammals, the male reproductive accessory glands (RAGs) comprise the prostate, bulbourethral glands, ampullary glands, and the seminal vesicles. Their composition, anatomy and function vary widely between species. This study aimed to characterize histologically and compare the RAGs of bats. The RAGs of Noctilio albiventris (Noctilionidae) and Rhynchonycteris naso (Emballonuridae) were studied using anatomical and histological methods, and were reconstructed three dimensionally. The RAGs of N. albiventris and R. naso are composed of a compact glandular complex that surrounds the urethra and a pair of bulbourethral glands, which are extra-abdominally located in the inguinal region. In both species, the glandular complex is composed of two well-defined prostatic regions (ventral and dorsal). The ventral region showed an atypical epithelium (holocrine), where no obvious cellular limits were observed, and PAS-positive secretion. The dorsal region had a pseudostratified cuboidal epithelium, with basal and secretory cells, and PAS-negative secretion. Noctilio albiventris also had urethral glands (Littre glands) surrounding the urethra, however, R. naso had only muscles. Both species had bulbourethral glands, with simple columnar epithelium and PAS-positive secretion. In conclusion, the RAGs of N. albiventris and R. naso comprised a pair of bulbourethral glands and an intra-abdominal complex, composed of a prostate with two different regions (ventral and dorsal), while the ampullary glands and seminal vesicles were missing in both species. This morphology was more closely related between N. albiventris and R. naso, and to species of the family Phyllostomidae than to families Molossidae and Vespertilionidae. J. Morphol. 277:1459-1468, 2016. © 2016 Wiley Periodicals, Inc.

Morphological analysis of the male reproductive accessory glands of the bat Artibeus lituratus (Phyllostomidae: Chiroptera)

“…This variation is possibly due to its holocrine‐type of secretion, in which the entire cells are released in the lumen of the acini, together with their secretion. A similar histological pattern was observed in the ventral prostate of other bats (Beguelini et al, ; Christante et al, ; Martins et al, ; Negrin et al, ; Puga et al, ), indicating that this pattern was established early during the evolution of the prostatic complex in bats. However, studies of RAGs in other mammals did not show the presence of a holocrine gland in the complex, which shows that this pattern is possibly exclusive to bats.…”

“…This morphology seems to be the typical arrangement of the dorsal prostate in bats (Beguelini et al, ; Christante et al, ; Martins et al, ; Negrin et al, ; Puga et al, ) and is very similar to the morphology of the ventral prostate of Rodentia (Rochel et al, ). However, its PAS‐negative secretion differs from the PAS‐positive secretion observed in the dorsal region of other bat species (Beguelini et al, ; Christante et al, ; Martins et al, ; Negrin et al, ; Puga et al, ). This indicates a variation in the composition of the secretion in A. lituratus , which seems to be more protein than glycosidic.…”

“…Although the presence of seminal vesicles was proposed for species of bats from other families, such as Pteropodidae (Danmaigoro et al, ; Fard & Ghassemi, ; Krutzsch, ), Miniopteridae (Krutzsch & Crichton, ), Molossidae (Krutzsch & Crichton, ), and Vespertilionidae (Gadegone & Sapkal, ), the absence of seminal vesicles is not exclusive to A. lituratus . Its absence was also reported in other species of phyllostomid bats (Martins et al, ; Puga et al, ), as well as in bats from other families, such as Hipposideros speoris (Hipposideridae – Pal, ), Molossus molossus (Molossidae – Christante et al, ), Myotis nigricans (Vespertilionidae – Negrin et al, ), Noctilio albiventris (Noctilionidae – Beguelini et al, ), Rhinolophus capensis (Rhinolophidae – Bernard, ), and Rhynchonycteris naso (Emballonuridae – Beguelini et al, ). This demonstrates that this gland is absent in the Phyllostomidae family, as well as, possibly, in other bat families.…”

“…Compact prostatic complexes with two regions (ventral and dorsal) were also observed in the Noctilionidae (Beguelini et al, ) and Emballonuridae (Beguelini et al, ). This differs from that observed in Molossidae species (Christante et al, ), which have a semilobulated prostatic complex with two prostatic regions (a single and more prominent ventral region and a tetralobulated dorsal region); and from Vespertilionidae (Negrin et al, ), which have a multilobulated prostatic complex, consisting of two ventral, two dorsolateral, and two dorsal lobes.…”

“…Recent studies have indicated marked morphological and functional variability of these glands in bats, including the fusion of prostatic lobes in some species; a lobulated pattern, very similar to that observed in rodents, in others; and the absence of a seminal vesicle (Beguelini, Góes, Rahal, Morielle‐Versute, & Taboga, ; Beguelini et al, ; Christante et al, ; Martins et al, ; Negrin et al, ; Puga, Beguelini, Morielle‐Versute, Vilamaior, & Taboga, ; Puga et al, ). In view of the great variation observed in these glands in bats, together with the lack of a description of these glands in one of the most important and representative bat species in Brazil, this study aims to analyze and characterize the composition, anatomy, histology, histochemistry, and ultrastructure of the male RAGs in the bat, Artibeus lituratus (Phyllostomidae: Chiroptera).…”