Structure, histochemistry, ultrastructure and seasonal variations of the male prostatic complex in the black Myotis bat, Myotis nigricans (Chiroptera: Vespertilionidae)

2014 ◽  
Vol 26 (8) ◽  
pp. 1188 ◽  
Author(s):  
Ana C. Negrin ◽  
Mateus R. Beguelini ◽  
Cintia C. I. Puga ◽  
Caroline M. Christante ◽  
Larissa M. Bueno ◽  
...  

Chiroptera are one of the most diverse orders of mammals and a unique group within Mammalia that posses a wide geographic distribution and considerable variability in reproductive strategies. The aims of the present study were to characterise the male prostatic complex of the bat Myotis nigricans (Vespertilionidae) and evaluate seasonal variations in the prostatic complex of M. nigricans specifically. Twenty-three sexually mature specimens (four sample groups: winter, spring, summer and autumn) were subjected to macroscopic, microscopic, morphometric and ultrastructural analyses. The reproductive accessory glands of M. nigricans were found to be composed of a multilobed complex associated with the urethra and a pair of inguinal bulbourethral glands. The complex was composed of three bilobed prostatic regions (ventral, dorsolateral and dorsal) with no ampullary gland and seminal vesicles. This pattern of lobulation is very similar to that described for the prostate of rodents; however, it differs from that of other mammals and even other families of bats (e.g. Phyllostomidae and Molossidae). Each prostatic region in M. nigricans has unique and distinctive characteristics, which synchronise to establish the main reproductive peak of the species in summer. The data also indicated an asynchrony in the activity of primary and secondary reproductive organs in the annual reproductive cycle of M. nigricans in São Paulo State, Brazil.

2015 ◽  
Vol 27 (2) ◽  
pp. 313 ◽  
Author(s):  
Caroline M. Christante ◽  
Mateus R. Beguelini ◽  
Cintia C. I. Puga ◽  
Ana C. Negrin ◽  
Eliana Morielle-Versute ◽  
...  

Due to their wide geographical distribution, bats suffer considerable influence from abiotic factors on their reproductive strategies, detected through behavioural or functional assessment of the gonads and accessory glands. The present study aimed to characterise anatomically and morphologically the reproductive accessory glands (RAGs) of Molossus molossus (Molossidae) and evaluate their seasonal variations. The RAGs were removed, fixed, sectioned after histological processing and submitted to the following stains: haematoxylin–eosin, periodic acid­–Schiff (PAS) and Gömöri’s reticulin. Our data demonstrated that the RAGs of M. molossus are composed of a semi-lobed prostatic complex associated with the urethra and a pair of inguinal bulbourethral glands. Histology and three-dimensional reconstruction of the prostatic complex demonstrated the existence of two regions: ventral and dorsal (named according to the position around the urethra). The two regions had distinctive morphological and histological differences, with the ventral region being the most prominent and the dorsal formed by four lobes. Considering the seasonal evaluation, we can infer that the prostatic complex of M. molossus is active throughout the seasons in São Paulo State (Brazil) and, although each of the prostatic regions has inherent characteristics, they synchronise to establish the main reproductive peak in spring (early rainy season).


1990 ◽  
Vol 38 (2) ◽  
pp. 207 ◽  
Author(s):  
PA Woolley

The breeding season of S. macroura extends from June to February, and individual males (both wild- caught and laboratory-reared) are capable of breeding over extended periods during the breeding season, and for up to three seasons, in the laboratory. Gross and histological changes in the reproductive organs and endocrine changes in relation to reproductive activity have been investigated. Males do not appear to reach sexual maturity until the season following that in which they were born, although spermatorrhoea may commence in the season of birth. Testis and epididymis weight of these males, which commence spermatorrhoea late in the season, approximates that of sexually mature males early in the season but androgen levels and the weight of the accessory glands are low in all males except during the early months of the season. The age at which spermatorrhoea commences ranges from 141 to 350 days. The minimum scrota1 width at which it commences is 7.9 mm and the minimum body weight, 14.0 g. The onset of spermatorrhoea is not a function of age or season and in S. macroura should be used with caution as an indicator of impending sexual maturity. Maximum corticosteroid- binding capacity (MCBC) generally exceeded corticosteroid concentration and no androgen-related fall in MCBC was evident.


2016 ◽  
Vol 44 (8) ◽  
pp. 1105-1122 ◽  
Author(s):  
Akihisa Kangawa ◽  
Masayoshi Otake ◽  
Satoko Enya ◽  
Toshinori Yoshida ◽  
Masatoshi Shibata

Microminipigs are becoming increasingly attractive alternatives for various experimental applications, such as general toxicology studies, owing to their manageable size. However, there are limited studies on the male reproductive organs of microminipigs, particularly on the histological aspects of sexual maturity. To clarify the development of male reproductive organs, 35 male microminipigs, aged 0 to 12 months, were used in this study. Histological and histomorphological evaluation was performed based on spermatogenic development, measurement of tubular structure in testes and epididymides, and histological progress of accessory glands. In addition, spontaneous testicular changes were quantitatively assessed. Histologically, male microminipigs sexually matured around 4.5 months of age, when spermatogenesis in testes and structural development in genital organs were completed. Spontaneous testicular changes occurred in all the animals investigated. Multinucleated giant cell was most commonly observed, followed by hypospermatogenesis and tubular atrophy/hypoplasia. However, the number of affected tubules was less than 1% in testes after 4.5 months of age, suggesting that the influence of these changes on evaluation of toxicity studies may be minimal. It is preferable to use sexually mature animals in toxicology studies; therefore, the information obtained by the present study will be helpful for future toxicity evaluations in microminipigs.


1984 ◽  
Vol 32 (6) ◽  
pp. 721 ◽  
Author(s):  
H Marsh ◽  
GE Heinsohn ◽  
TD Glover

The anatomy and histology of the male reproductive tract of the dugong (Dugong dugon) is described. Each testis and its adjacent epididymis lie immediately caudal to the corresponding kidney. The seminal vesicles are large but there is no discrete prostate gland and the bulbo-urethral glands are also diffuse. Both qualitative and quantitative examination of the testes and epididymides of 59 males whose ages have been estimated from tusk dentinal growth layer counts indicate that the male dugong does not produce spermatozoa continuously, despite the absence of a distinct breeding season. Individual dugongs were observed with testes at all stages between complete quiescence and full spermatogenesis, and only 10 of the 40 mature males had fully spermatogenic testes and epididymides packed with spermatozoa. Androgenic and spermatogenic activity of the testes appeared to be in phase, but the testicular histology of some old males suggested that they may have been sterile for long periods.


1933 ◽  
Vol s2-76 (301) ◽  
pp. 35-61
Author(s):  
DEV RAJ MEHTA

A general account of the internal reproductive organs and the external genitalia and their development is given. The ‘penis lobes’ develop earlier than the ‘valvae lobes’, and independently of them. The tegumen is the modified ninth tergite. The tenth segment is visibly distinguished into a tergal and sternal part in the pupal stages, and the anal tube passes between the two sclerites. The uncus and the gnathos are dorsal and ventral processes respectively of the tenth segment. The anellus lobes develop as lateral processes of the ninth sternite on either side of the penis. The vasa deferentia during larval life do not extend beyond the eighth abdominal segment and lie in a latero-ventral position. They meet the extensions from the ectodermal ‘ductus ejaculatorius duplex’ during the last larval stadium. From the earliest caterpillar stage there exists a pair of ectodermal ducts formed by the differentiation of the epidermis on the ninth sternite. Towards the end of larval life they divide by constriction to form the accessory glands and the ‘ductus ejaculatory duplex’. At this stage they extend on either side to meet the vasa deferentia. The vesiculae seminales develop by distension from the region of junction between the vasa deferentia and the proximal portion of the ejaculatory duct. The ‘ductus ejaculatorius simplex’ arises as an ectodermal invagination between the pair of ‘penis lobes’ during the final larval instar. It is established that, with the exception of the vasa deferentia, all the remaining elements in the efferent genital system are derived from the ectoderm.


2015 ◽  
Vol 59 (2) ◽  
pp. 127-133 ◽  
Author(s):  
Krystyna Czekońska ◽  
Bożena Chuda-Mickiewicz

Abstract The effectiveness of two methods of collecting semen from honeybee Apis mellifera drones was compared, and the reasons for problems with ejaculating semen were analysed. Among 275 drones, 100 were stimulated to release semen using a manual method, 100 with the use of chloroform, and from 75 drones the reproductive organs were dissected for analysis and evaluation. It was found that the principal causes of problems that drones had with ejaculating their semen were anatomical changes or a delay in the development of the mucus glands. It was also found that the method employing chloroform was less efficient in the first phase of eversion of the endophallus, compared with the manual method. The method with the use of chloroform allows the determination of the proportion of drones, which do not evert the endophallus because of poor or delayed development of mucus glands, as well as the proportion of drones which evert the organ, but do not ejaculate semen because of the absence of semen in the seminal vesicles.


PLoS ONE ◽  
2014 ◽  
Vol 9 (3) ◽  
pp. e93383 ◽  
Author(s):  
William E. Burnett ◽  
Jürgen Heinze

1965 ◽  
Vol 42 (3) ◽  
pp. 373-378
Author(s):  
K. G. DAVEY

1. Mated females of Rhodnius prolixus lay eggs at approximately twice the rate of unmated females. 2. Males which have had their seminal vesicles or opaque accessory glands removed produce spermatophores at mating, but no spermatozoa appear in the spermathecae of the females. The females involved in such matings do not exhibit an increase in egg-production. 3. When females lacking their spermathecae are mated to normal males, the increase in egg production which follows normal matings does not materialize. 4. Implanting spermathecae from mated females into virgin females increases the egg-production of the host. Implanting spermathecae from virgin females or seminal vesicles or transparent accessory glands from males has no effect on the egg-production of the donor. 5. It is tentatively concluded that a blood-borne factor from the spermathecae containing spermatozoa is the primary stimulus to increased egg production in a mated female.


1977 ◽  
Vol 232 (5) ◽  
pp. E497
Author(s):  
L L Anderson

Growth was inhibited markedly in prepuberal bull and heifer calves after either hypophysial stalk transection or hypophysectomy as compared with that found in sham-operated calves or in unoperated calves. Male mounting behavior and evidence of puberal estrous behavior were lost or undetected after hypophysial stalk transection or hypophysectomy. Testes regressed, contained few spermatogonia and interstitial cells, and lacked spermatogenesis. Epithelial cells of seminal vesicles, bulbourethral glands, and prostate were cuboidal, indicating inadequate testicular androgen. Atresia of numerous ovarian follicles and reduced ovarian weight occurred in hypophysectomized heifer calves. Graafian follicles regressed after hypophysial stalk transection of sexually mature heifers, but ovaries responded to pregnant mare serum and human chorionic gonadotropin by follicular development, ovulation, and formation of multiple corpora lutea. Thyroid and adrenal gland weights decreased and adrenal cortices atrophied after hypophysectomy, but not after stalk transection. Thyroid glands contained colloid-filled follicles with flattened epithelial cells; atrophy was more extensive after hypophysectomy. Hypophysial stalk transection or hypophysectomy severely depresses growth and arrests sexual development in young calves, but in mature animals exongenous gonadotropins can sustain gonadal function.


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