Reproduction of the Spinifex Hopping Mouse (Notomys-Alexis) in the Natural-Environment

1992 ◽  
Vol 40 (1) ◽  
pp. 57 ◽  
Author(s):  
WG Breed
Keyword(s):  
Germ Cell ◽  
Cross Sections ◽  
Natural Environment ◽  
Reproductive Activity ◽  
Field Trips ◽  
Seminal Vesicles ◽  
Seminiferous Tubules ◽  
Corpora Lutea ◽  
Adult Males ◽  
Sexually Mature

Seven field trips to Curtin Springs Station, in the south of the Northern Territory (two in July and five in December-January), were carried out between July 1984 and January 1991 to investigate the reproductive activity of spinifex hopping mice in the natural environment. Gonadal activity was determined from most samples of animals collected. Pregnant animals were present on only one occasion (December 1988-January 1989), but two females collected in December 1985 had corpora lutea in their ovaries. Most adult males were, by contrast, sexually mature, as indicated by germ-cell associations in the seminiferous tubules, spermatozoa in the excurrent ducts, and secretion in the lumina of the ventral prostates and seminal vesicles. Nevertheless, the testes were invariably very small, 2-4 germ-cell associations were sometimes present in tubule cross-sections, epididymal spermatozoa were highly pleiomorphic and seminal vesicles minute. Such morphological traits are thus invariable features of the reproductive biology of males of this species.

Development in calves and heifers after hypophysial stalk transection or hypophysectomy.

1977 ◽  
Vol 232 (5) ◽  
pp. E497
Author(s):  
L L Anderson
Keyword(s):  
Epithelial Cells ◽  
Sexual Development ◽  
Follicular Development ◽  
Seminal Vesicles ◽  
Corpora Lutea ◽  
Gonadal Function ◽  
Ovarian Weight ◽  
Thyroid Glands ◽  
Estrous Behavior ◽  
Sexually Mature

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.

The annual testicular cycle in an equatorial colony of lesser rock hyrax, Heterohyrax brucei

1979 ◽  
Vol 206 (1163) ◽  
pp. 183-189 ◽  
Keyword(s):  
Annual Cycle ◽  
Leydig Cells ◽  
Seminal Vesicles ◽  
Seminiferous Tubules ◽  
Testicular Development ◽  
Adult Males ◽  
Sperm Production ◽  
Rock Hyrax ◽  
Germinal Cells ◽  
Caput Epididymidis

Adult males from a colony of lesser rock hyrax found near the equator in Kenya exhibited an annual cycle of testicular activity characterized by intense spermatogenesis and elevated androgen status from May to July. Average masses of testes and seminal vesicles taken in these months were almost fourfold greater than those from September to January. During the months of peak testicular activity average diameters of Leydig cells and seminiferous tubules were increased by approximately one half and total tubule length was doubled, compared with values for the quiescent months. Variable testicular development occurred during transitional intervals preceding and following peak testicular activity. From February to April thickening of the seminiferous epithelium and appearance of spermatozoa in the caput epididymidis signalled re-establishment of sperm production. In August shedding of germinal cells from the epithelium heralded impending failure of spermatogenesis. Evidence of an annual testicular cycle contradicted the prevalent belief that equatorial hyrax breed all year and suggested that the testicular cycle is a conservative element of hyracoid reproductive strategy.

scholarly journals The Male Reproductive Cycle of the Spotted Toad-Headed Agama,Phrynocephalus maculatus, in Iran

2015 ◽  
Vol 2015 ◽  
pp. 1-5
Author(s):  
Soheila Rahmani ◽  
Vida Hojati
Keyword(s):  
Reproductive Cycle ◽  
Arid Regions ◽  
Tunica Albuginea ◽  
Reproductive Activity ◽  
Seminal Vesicles ◽  
Adult Males ◽  
Germinal Layer ◽  
Histological Studies ◽  
The Right ◽  
Semnan Province

The spotted toad-headed agama,Phrynocephalus maculatus, distributed in the central and southeastern arid regions of Iran, belongs to the Agamidae family. In this research, the male reproductive cycle of this species was studied from 5 April to 5 August, 2013. Totally, 40 adult males were collected at midday from southern deserts of Damghan County, located in Semnan Province of Iran. Testes were removed and processed for morphometric and histological studies. The spermatogenic cycle begins from early April, mating occurs in mid-May, and it ends in August. Maximum reproductive activity occurs in early June and reduces from early July and ends in August. The numbers of seminal vesicles were 33–127 and their diameter varied between 69.0 and 258.3 microns. The diameter of tunica albuginea varied between 3.0 and 8.1 microns. The diameter of germinal layer varied between 10.0 and 110.0 microns. There were significant differences in macroscopic and microscopic testicular characters between months. Also, there were no significant differences in the testicular and hemipenal characters between the left side and the right side of body. Since spermatogenesis occurs from April through August,P. maculatusfollows an associated reproductive cycle typical for temperate species.

1 XENOGRAFTING OF ADULT MAMMALIAN TESTIS TISSUE

2007 ◽  
Vol 19 (1) ◽  
pp. 119
Author(s):  
L. Arregui ◽  
R. Rathi ◽  
W. Zeng ◽  
A. Honaramooz ◽  
M. Gomendio ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
Germ Cell ◽  
Germ Cells ◽  
Sertoli Cells ◽  
Human Testis ◽  
Seminiferous Tubules ◽  
Donor Tissue ◽  
Germ Cell Differentiation ◽  
Sexually Mature ◽  
Testis Tissue

Testis tissue grafting presents an option for preservation of genetic material when sperm recovery is not possible. Grafting of testis tissue from sexually immature males to immunodeficient mice results in germ cell differentiation and production of fertilization-competent sperm from different mammalian species (Honaramooz et al. 2002 Nature 418, 778–781). However, the efficiency of testis tissue xenografting from adult donors has not been critically evaluated. Spermatogenesis was arrested at meiosis in grafts from mature horses (Rathi et al. 2006 Reproduction 131, 1091–1098) and hamsters (Schlatt et al. 2002 Reproduction 124, 339–346), and no germ cell differentiation occurred in xenografts of adult human testis tissue (Schlatt et al. 2006 Hum. Reprod. 21, 384–389). The objective of this study was to investigate survival and germ cell differentiation of testis xenografts from sexually mature donors of different species. Small fragments of testis tissue from 10 donor animals of 5 species were grafted under the back skin of immunodeficient, castrated male mice (n = 37, 2–6/donor). Donors were pig (8 months old), goat (18 months old and 4 years old) (n = 2), bull (3 years old), donkey (13 months old), and rhesus monkey (3, 6, 11, and 12 years old). At the time of grafting, donor tissue contained elongated spermatids, albeit to different degrees (>75% of seminiferous tubules in testis tissue from pig, goat, bull, and 6–12-year-old monkeys, and 33 or 66% of tubules in tissue from donkey or 3-year-old monkey, respectively). Grafts were recovered <12 weeks (n = 14 mice), 12–24 weeks (n = 16 mice), and >24 weeks (n = 7 mice) after grafting and classified histologically as completely degenerated (no tubules found), degenerated tubules (only hyalinized seminiferous tubules observed), or according to the most advanced type of germ cell present. Grafts from pig, goat, bull, and 6–12-year-old monkeys contained >60% degenerated tubules or were completely degenerated at all time points analyzed. In contrast, in grafts from the 3-year-old monkey, only 18% of tubules were degenerated, 14% contained Sertoli cells only, 64% contained meiotic, and 4% haploid germ cells at 24 weeks after grafting. Similarly, donkey testis grafts recovered 12–24 weeks after grafting contained <2% degenerated tubules, 46% of tubules had Sertoli cells only, 45% contained meiotic, and 7% haploid germ cells. These results show that survival and differentiation of germ cells in testis grafts from sexually mature mammalian donors is poor. However, better graft survival and maintenance of spermatogenesis occurred in donor tissue from donkey and 3-year-old monkey that were less mature at the time of grafting. Therefore, species and age-related differences appear to exist with regard to germ cell survival and differentiation in xenografts from adult donors. This work was supported by USDA/CSREES 03-35203-13486, NIH/NCRR 5-R01-RR17359-05, the Spanish Ministry of Education, and Science (BES-2004-4112).

scholarly journals Histology and structure of the testicles in three species of Atelopus frogs (Anura: Bufonidae) endemic to the Sierra Nevada de Santa Marta, Colombia

2021 ◽  
Vol 69 (3) ◽  
Author(s):  
Arantxa Sánchez-Ferreira ◽  
Edgar J. Rincón-Barón ◽  
Luis A. Rueda-Solano
Keyword(s):  
Connective Tissue ◽  
Sierra Nevada ◽  
Population Decline ◽  
Reproductive Activity ◽  
Seminiferous Tubules ◽  
Interstitial Tissue ◽  
Adult Males ◽  
Blood Capillaries ◽  
Population Decrease ◽  
Microscopy Technique

Introduction: Testicular histology constitutes one of the least explored aspects in frogs of the genus Atelopus. This taxonomic group shows an alarming population decline; therefore, its reproductive biology is one of the greatest topics of interest for its conservation. Objective: To describe the testicular morphology and the spermatogenetic lineage cells in adult males of Atelopus laetissimus, Atelopus nahumae, and Atelopus carrikeri in the Sierra Nevada de Santa Marta, Colombia. Methods: During June – July 2017 and 2018, sampling was conducted in the localities of San Lorenzo and Páramo Cebolletas, Sierra Nevada de Santa Marta (SNSM), to collect 15 adult males, 5 per species. Testes samples were fixed in Bouin to be processed by the standard paraffin-embedding technique. Histological sections (3 mμ) were stained with Hematoxylin-eosin and Mallory-Heidenhain-Azan-Gomori's. For the description and photographic register of the germ cells, the photonic microscopy technique was used with the differential interference contrast system. Results: The testes are oval organs, compact, light yellow color, and with little vascularization. Externally, they are surrounded by a thin albuginea tunic constituted by regular dense connective tissue. Inside this layer, they are composed of numerous seminiferous tubules of hexagonal contour, in which germ cell cysts are distinguished at different stages of spermatogenesis (spermatogonia I and II, spermatocyte I and II, and early and late spermatids) and spermiogenesis (spermatozoa in fascicles and free spermatozoa). Separating the seminiferous structures is the interstitial tissue in which Leydig cells and blood vessels stand out. Additionally, in the cranial part of the testis, the Bidder's organ was found, formed by two distinguishable regions, the cortex and the medulla. In the cortex, there are previtellogénic oocytes of different sizes surrounded by a monolayer of flat follicular cells. For its part, the medullary region is the connective tissue that nourishes the oocytes and is constituted by blood capillaries. Conclusions: The gonads of the three species analyzed present a cystic cellular organization similar to other anurans, where all stages of spermatogenesis and spermiogenesis were identified, possibly indicating a continuous reproductive activity. Likewise, the Bidder’s organ is reported for the first time in the three Atelopus species, which allows suggesting a possible sexual reversion in case of a population decrease of females as a reproductive strategy.

Seasonal variation in the reproductive activity of the wild rabbit (Oryctolagus cuniculus algirus) in a Mediterranean ecosystem

2002 ◽  
Vol 29 (2) ◽  
pp. 165 ◽  
Author(s):  
H. Gonçalves ◽  
P. C. Alves ◽  
A. Rocha
Keyword(s):  
Oryctolagus Cuniculus ◽  
Seasonal Pattern ◽  
Reproductive Activity ◽  
Mediterranean Ecosystem ◽  
Seminiferous Tubules ◽  
Corpora Lutea ◽  
Clear Understanding ◽  
Wild Rabbit ◽  
Sperm Production ◽  
Daily Sperm Production

To establish a successful strategy for managing wild rabbit (Oryctolagus cuniculus algirus) populations it is essential to have a clear understanding of reproductive biology. In Portugal, previous work suggested a seasonal pattern of reproductive activity for this species. In this study we present additional information on the seasonal reproductive activity of the wild rabbit as well as data on the influence that environmental factors have on the onset and length of the breeding season. The study was carried out in Pancas, southern Portugal, from October 1997 to September 1998. Rabbits were collected every two months and post mortem analyses were performed. In the males, circulating concentration of testosterone, gonadal weight, daily sperm production, diameter of the seminiferous tubules and the thickness of epithelial cells were measured. The numbers of corpora lutea, embryos and placental scars were recorded in the females. To assess abundance and quality of food, samples of herbaceous vegetation were collected and analysed for water, fibre and crude protein content. The reproductive season extended from November to June with a peak in March/April, with both sexes showing an annual cycle of gonadal development and subsequent regression. All analysed females were pregnant and/or lactating between March and June. The mean litter size estimated by counting the embryos in the uteri was 3.90 ± 0.50. Daily sperm production was highest between November and April. Testicular function was strongly correlated with environmental temperature and the water content of the vegetation, and both testicular and ovarian development were correlated with vegetation biomass.

Changes in the Male Reproductive Organs of the Dugong, Dugong dugon (Sirenia: Dugondidae) with Age and Reproductive Activity

1984 ◽  
Vol 32 (6) ◽  
pp. 721 ◽  
Author(s):  
H Marsh ◽  
GE Heinsohn ◽  
TD Glover
Keyword(s):  
Reproductive Tract ◽  
Prostate Gland ◽  
Reproductive Activity ◽  
Reproductive Organs ◽  
Seminal Vesicles ◽  
Growth Layer ◽  
Male Reproductive Tract ◽  
Qualitative And Quantitative ◽  
Quantitative Examination ◽  
Testicular Histology

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.

Population parameters of ringed seals (Phoca hispida Schreber, 1775) in the Svalbard area

1987 ◽  
Vol 65 (4) ◽  
pp. 1021-1027 ◽  
Author(s):  
Christian Lydersen ◽  
Ian Gjertz
Keyword(s):  
Sex Ratio ◽  
Ringed Seal ◽  
Adult Males ◽  
Population Parameters ◽  
Phoca Hispida ◽  
Age Class ◽  
Ringed Seals ◽  
Males And Females ◽  
The Mean ◽  
Sexually Mature

Samples were taken from 284 ringed seals (Phoca hispida) in the Svalbard area during April–July 1981 and March–April 1982. The age of 283 seals was determined by reading annuli in the cementum of the canine teeth. The mean age of the males was 11.3 years, and of the females, 14.9 years. Females were found to be significantly older than males. The mean length of sexually mature ringed seals was 128.9 cm for both sexes. The mean weight of adult males and females was 53.5 and 61.4 kg, respectively. Females were found to be significantly heavier than males. The sex ratio was 47.8% males and 52.2% females. Studies of microscopic sections of testis and epididymis from ringed seal males showed that 63, 75, and 80% of 5-, 6-, and 7-year-old animals, respectively, were sexually mature. The weights of testis and epididymis, diameters of tubuli, and the size of testis all showed a marked increase in the 5-year age-class. Macroscopic sections of ovaries from ringed seal females showed that 20, 60, and 80% of 3-, 4-, and 5-year-old animals, respectively, were sexually mature. The size of the ovaries showed a marked increase in the 5-year age-class. The ovulation rate of ringed seals from Svalbard was calculated to be 0.91.

scholarly journals Male germ cell transplantation in livestock

2006 ◽  
Vol 18 (2) ◽  
pp. 13 ◽  
Author(s):  
J. R. Hill ◽  
I. Dobrinski
Keyword(s):  
Stem Cells ◽  
Germ Cell ◽  
Cell Transplantation ◽  
Large Scale ◽  
Developmental State ◽  
Male Germ Cell ◽  
Seminiferous Tubules ◽  
Cell Transfer ◽  
Donor Sperm ◽  
Germ Cell Transplantation

Male germ cell transplantation is a powerful approach to study the control of spermatogenesis with the ultimate goal to enhance or suppress male fertility. In livestock animals, applications can be expanded to provide an alternative method of transgenesis and an alternative means of artificial insemination (AI). The transplantation technique uses testis stem cells, harvested from the donor animal. These donor stem cells are injected into seminiferous tubules, migrate from the lumen to relocate to the basement membrane and, amazingly, they can retain the capability to produce donor sperm in their new host. Adaptation of the mouse technique for livestock is progressing, with gradual gains in efficiency. Germ cell transfer in goats has produced offspring, but not yet in cattle and pigs. In goats and pigs, the applications of germ cell transplantation are mainly in facilitating transgenic animal production. In cattle, successful male germ cell transfer could create an alternative to AI in areas where it is impractical. Large-scale culture of testis stem cells would enhance the use of elite bulls by providing a renewable source of stem cells for transfer. Although still in a developmental state, germ cell transplantation is an emerging technology with the potential to create new opportunities in livestock production.

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