Cycle of the seminiferous epithelium in a marsupial species, the brushtail possum (Trichosurus vulpecula), and estimation of its duration

2004 ◽  
Vol 16 (3) ◽  
pp. 307 ◽  
Author(s):  
Minjie Lin ◽  
Amanda Harman ◽  
Terry P. Fletcher

We investigated the cycle of the seminiferous epithelium in a marsupial, namely the brushtail possum (Trichosurus vulpecula), using semithin sections of seminiferous tubules embedded in Spurr’s resin. Using 14 steps of spermatid development as markers, we were able to class tubular cross-sections into 10 well-defined stages of the seminiferous epithelial cycle. The duration of one cycle was 13.5 days, as determined by injections of [3H]-thymidine and autoradiographic examination of the most advanced sperm cells at 2 h and 17 days after injection. The durations of stages I–X were 21.4, 66.4, 54.1, 47.0, 29.8, 28.5, 25.3, 25.0, 12.0 and 15.9 h, respectively, estimated by the relative percentage of occurrence of each stage. It was estimated that the life spans of the main germ cells were as follows: type B spermatogonia, 5.4 days; primary spermatocytes, 16.7 days; secondary spermatocytes, 0.7 days; and spermatids, 21.4 days. The results suggest that the kinetics of spermatogenesis in marsupials show a similar pattern to that in eutherians.

2021 ◽  
Vol 37 ◽  
pp. e37035
Author(s):  
Fernanda Carolina Ribeiro Dias ◽  
Jullyana Costa Machado ◽  
Sérgio Luis Pinto da Matta ◽  
Angelica de Oliveira Gomes ◽  
Marcos de Lucca Moreira Gomes

Many studies have been trying to establish standard protocols for animal experimentation, especially for animal species or strains, to master research variables with high precision. The main mouse strains used in the field of the biology of reproduction are Swiss, Balb/c, and C57BL/6. Since some of the strains show reproduction limitations, such as the size of the litter, the present study aimed to compare their spermatogenic processes to verify differences regarding the testicular parenchyma and germ cell populations, which could explain low offspring production. In addition, the present study provides additional information concerning the testicular parenchyma of such strains, which consequently would help researchers to choose the most suitable strain for reproductive studies. Six adult male mice were used for each of the strains. After euthanasia, the testes were weighed, fixated with Karnovsky fixative, embedded in methacrylate, sectioned, and stained with toluidine blue/sodium borate 1%. Morphometrical analyses from the testicular parenchyma (seminiferous tubules and interstitium) were made using the software ImageJ. Germ and Sertoli cells populations were counted in seminiferous tubules cross-sections at stage I of the seminiferous epithelium cycle. The lowest body and testicular weights were observed in C57BL/6 animals, followed by Balb/c and Swiss, however, the relative testes, parenchyma, and albuginea weights were significantly lower only in C57BL/6. Despite the seminiferous tubules and seminiferous epithelium proportions were lower in Swiss animals, their relative amount related to the body weight was the same among strains. The total number of germ cells was higher in Swiss animals, reflecting higher spermatogenic yield and daily sperm production. Due to the lower relative number of Sertoli cells, the Swiss animals showed the highest Sertoli cell index and support capacity. On the other hand, the lowest pathological indexes regarding the germ cells were observed in Balb/c animals, followed by Swiss and C57BL/6. In the interstitium, the proportion of blood vessels was lower in Swiss mice, while the lymphatic cell proportion was lower in C57BL/6 animals. Moreover, the highest proportions of Leydig cells and macrophages were noticed in Swiss mice, which may indicate increased testosterone levels. Altogether, such observations must be taken into account when choosing any of the studied strains for reproduction studies.


1989 ◽  
Vol 37 (11) ◽  
pp. 1667-1673 ◽  
Author(s):  
R Schulz ◽  
F Paris ◽  
P Lembke ◽  
V Blüm

Androgens drive spermatogenesis by processes that are largely unknown. Direct effects on germ cells and indirect effects mediated via testicular somatic elements are currently under consideration, and specific localization of androgens in seminiferous tubules may provide information as regards this. Adult male rats were injected with ethane dimethanesulfonate (EDS; 75 mg/kg body weight) or vehicle. Testes were fixed and paraffin-embedded for localization of testosterone immunoreactivity 1 and 2 weeks after treatment, using the unlabeled antibody (PAP) technique. Plasma testosterone dropped from a pre-treatment level of 2.3 ng/ml to below 0.2 ng/ml 3 days after EDS injection and remained at low levels until the end of observation, accompanied by a progressive decrease in testicular weight. In the seminiferous tubules of vehicle-injected males, testosterone immunoreactivity was found in nuclei of spermatocytes and spermatids and in nuclei and the cytoplasm of Sertoli cells, and showed typical variations according to the stage of spermatogenesis. One week after EDS treatment, immunoreactivity had disappeared from the seminiferous epithelium. Two weeks after treatment, staining of germ cells was detected in two out of four males. The disappearance and reappearance of immunoreactivity coincided with the time course of EDS effects on rat Leydig cells, and we conclude that it corresponds to androgen specifically localized in fixed, paraffin-embedded tissue. Because staining of germ cell nuclei varied with the stage of spermatogenesis, the technique may detect a physiologically relevant androgen fraction; its location suggests that androgens may also directly affect certain germ cell stages.


Reproduction ◽  
2001 ◽  
pp. 373-388 ◽  
Author(s):  
M Ricci ◽  
WG Breed

The flagellum of a mammalian spermatozoon consists of a central axoneme surrounded by two cytoskeletal structures, the outer dense fibres and the fibrous sheath, which may aid in sperm motility or stability. In this study the outer dense fibres and fibrous sheath were isolated and partially characterized in a marsupial species, the brushtail possum (Trichosurus vulpecula). Spermatozoa from the cauda epididymidis were decapitated by sonication, and the head and tail fractions were separated by centrifugation over a 20, 40 and 60% (w/v) sucrose density gradient. After confirming sperm tail purity by Nomarski microscopy, the tails were incubated in either SDS-dithiothreitol to isolate the outer dense fibres or urea-dithiothreitol to isolate the fibrous sheaths. Purified outer dense fibres and fibrous sheaths were solubilized in SDS and beta-mercaptoethanol and proteins were separated by one-dimensional PAGE. Coomassie blue staining showed that the outer dense fibres were composed of seven major proteins (molecular masses: 73, 58, 55, 54, 52, 41 and 16 kDa), and the fibrous sheath was composed of 12 major proteins (molecular masses: 106, 76, 66, 62, 55, 53, 52, 46, 40, 30, 28 and 16 kDa). A polyclonal antibody to the fibrous sheath proteins showed strong crossreactivity with those of fibrous sheath from spermatozoa of several other marsupial species, as well as those from laboratory rats. Subsequent western blotting identified the immunoreactive 76 and 62 kDa proteins from all species, thus indicating their high conservation between species. No crossreactivity of the fibrous sheath antibody to any other cytoskeletal structures, including the outer dense fibres, mid-piece fibre network or connecting laminae, or to the acrosome or underlying subacrosomal material, was evident, indicating that the fibrous sheath proteins are localized to this structure alone. Further work is in progress to determine the extent of homology of these proteins to those in eutherian mammals.


Animals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2801
Author(s):  
Muhammad Faheem Akhtar ◽  
Ejaz Ahmad ◽  
Ilyas Ali ◽  
Muhammad Shafiq ◽  
Zhe Chen

The current study investigated the effect of inhibin immunization on germ cell numbers (spermatogonia, spermatocytes, round, and elongated spermatids), seminiferous tubules (ST) diameter, Johnsen’s score, epithelial height (μm), luminal tubular diameter (μm), and number of ST per field (ST/field) of Yangzhou goose ganders. Histological evaluation showed apoptosis and regression of testes after inhibin (INH) immunization, with a concomitantly marked reduction in the round and elongated spermatids in the experiment (INH) group compared to the control group. The diameter of seminiferous tubules (ST) and epithelial height (EH) were positively correlated at 181, 200, and 227 days of age. In comparison, luminal tubular diameter (LD) was negatively correlated on day 227 to ST diameter and epithelial height. On day 227, many seminiferous tubules per field (ST/field) were negatively correlated to ST diameter, EH, and LD. INH immunization elevated ST diameter, EH, and LD, while Johnsen’s score and number of ST/field had reciprocal expression. In conclusion, the concomitant effect of INH immunization and seasonality in breeding regressed germ cells and damaged spermatogenesis in seminiferous epithelium Yangzhou ganders.


Author(s):  
Hoda H. Anan ◽  
Nashwa S. Wahba ◽  
Maha A. Abdallah ◽  
Dalia A. Mohamed

<p class="abstract"><strong>Background:</strong> Nowadays, cyclophosphamide is widely used as anticancer and immunosuppressive agent in various drug regimens in many diseases and in young and old age. The aim of this research is to study the possible histological changes that may occur in the testes of adult male albino rats as a result of chronic exposure to cyclophosphamide and the prognosis of this effect.</p><p class="abstract"><strong>Methods:</strong> Thirty healthy adult male albino rats were used in this study.  They were equally divided into three groups; a control, an experimental and a withdrawal groups. The Animals of the experimental group were treated with daily dose of 5 mg/ kg cyclophosphamide orally for successive 28 days. Animals of the withdrawal group were left without treatment and sacrificed after 28 days from the last dose of cyclophosphamide.  At the time of sacrifice, all animals were anesthetized by ether inhalation and their testes were dissected out carefully and processed for light and electron microscope examinations<span lang="EN-IN">. </span><span lang="EN-IN"> </span></p><p class="abstract"><strong>Results:</strong> Testes of the cyclophosphamide treated group revealed presence of many distorted shrunken seminiferous tubules which appeared with marked reduction in the thickness of the epithelium and wide lumina. Many germ cells with deeply stained nuclei, giant cells in mitosis and intracellular vacuoles were observed. Cross sections in mid pieces of sperms showed marked affection of axoneme, fibrous sheath and mitochondrial sheath. The cytoplasm of the Leydig cells contained mitochondria, dilated SER, Golgi cisternae and RER. Testes of the withdrawal group showed that the seminiferous tubules still had reduced height of their epithelium with wide intercellular spaces. Abnormal stratification and destructed germinal epithelium were evident with desquamated germ cells. Cross sections of mid pieces of the sperms showed distorted axoneme and swollen mitochondrial sheath. The cytoplasm of leydig cells contained many electron dense granules, RER, many dilated SER and mitochondria.</p><p class="abstract"><strong>Conclusions:</strong> Chronic cyclophosphamide treatment not only produced serious histological changes of the testis but also in its serological parameter. These changes persisted after cessation of cyclophosphamide administration which indicates the cumulative irreversible toxic effect of cyclophosphamide. So, it is advisable to avoid the usage of cyclophosphamide as possible especially in young patients<span lang="EN-IN">. </span></p><p class="abstract"> </p>


2005 ◽  
Vol 17 (6) ◽  
pp. 603 ◽  
Author(s):  
Jean D. Wilson ◽  
Geoffrey Shaw ◽  
Marilyn B. Renfree ◽  
Richard J. Auchus ◽  
Michael W. Leihy ◽  
...  

The testicular androgen 5α-androstane-3α,17β-diol (androstanediol) mediates virilisation in pouch young of a marsupial, the tammar wallaby, and is the principal androgen formed in immature rodent testes. To chart the pattern of androstanediol formation in another marsupial species, the testes or fragments of testes from brushtail possums (Trichosurus vulpecula) that spanned the age range from early pouch young to mature adults were incubated with 3H-progesterone and the products were identified by high-performance liquid chromatography. The only 19-carbon steroids identified in pouch young and adult testes were the Δ4-3-keto-steroids testosterone and androstenedione. However, androstanediol and another 5α-reduced androgen (androsterone) were synthesised by testes from Day 87–200 males and these appeared to be formed from the 5α-reduction and 3-keto reduction of testosterone and androstenedione. In the prostate and glans penis of the immature male, 3H-androstanediol was converted to dihydrotestosterone. We conclude that the timing of androstanediol formation in the possum testis resembles the process in rodents rather than in the tammar wallaby and that any androstanediol in the circulation probably acts in target tissues via conversion to dihydrotestosterone.


Reproduction ◽  
2000 ◽  
pp. 1-14 ◽  
Author(s):  
M Lin ◽  
X Zhang ◽  
R Murdoch ◽  
RJ Aitken

A medium modified from eutherian systems was used to culture epididymal epithelial cells of the brushtail possum (Trichosurus vulpecula) for more than 2 months. Epididymal tubule fragments from the caput, corpus and cauda epididymides were used to generate cell monolayers. All three epididymal cell culture systems supported maturational changes in marsupial spermatozoa and enabled immature possum spermatozoa to differentiate from a T-shape to a streamlined shape, accompanied by the development of progressive motility after co-culture with 7-day-old cultured epididymal cell monolayers. This epididymal cell and sperm co-culture system for marsupial species may facilitate the identification of specific epithelial factors that affect sperm maturation, particularly in a species in which morphological maturation is readily visible.


2020 ◽  
Vol 57 (3) ◽  
pp. 418-426
Author(s):  
Naoyuki Fuke ◽  
Go Kitahara ◽  
Soma Ito ◽  
Nguyen Van Diep ◽  
Angeline Ping Ping Teh ◽  
...  

This is a histopathologic and endocrinologic study of 6 calves diagnosed with cryptorchidism. Cases 1–3 were diagnosed as resembling testicular regression syndrome. In cases 1 and 2, the extracted tissue was a small, firm, gray-white mass, and there was lack of obvious testicular tissue in case 3. Histopathologically, the excised tissue in cases 1–3 was a fibrotic testicular remnant with inflammation, mineralization, hemosiderin-laden macrophages or lipofuscin-laden macrophages, and lack of germ cells and interstitial endocrine cells. These findings were compared with cases 4–6, which were diagnosed as testicular hypoplasia due to cryptorchidism. These cases had small but otherwise grossly unremarkable intra-abdominal testicular tissue and histologically had a few germ cells and sustentacular cells with arrested spermatogenesis and an increase in interstitial endocrine cells. Cases 1–3 had more severe degenerative changes compared with cases 4–6. In case 2, the average diameter of the seminiferous tubules was much smaller than in cases 4–6, and there were few tubule cross sections. Anti-Müllerian hormone (214 pg/ml) was detected in the plasma of case 2. Based on the macroscopic and histopathologic findings as well as endocrinologic profiles, the testicular degeneration in cases 1–3 was considered similar to that of testicular regression syndrome. In this condition, it is thought that a normally developing intra-abdominal testis undergoes degeneration due to heat or a vascular disorder such as torsion.


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