Experimental manipulation of sexual differentiation in wallaby pouch young treated with exogenous steroids

Development ◽  
1988 ◽  
Vol 104 (4) ◽  
pp. 689-701 ◽  
Author(s):  
G. Shaw ◽  
M.B. Renfree ◽  
R.V. Short ◽  
W.S. O
Keyword(s):  
Germ Cells ◽  
Fibrous Tissue ◽  
Experimental Treatment ◽  
Experimental Manipulation ◽  
Hormonal Control ◽  
Urogenital Sinus ◽  
Seminiferous Tubules ◽  
Initial Development ◽  
Oestrogen Treatment ◽  
Mullerian Ducts

We have investigated the effects of androgen or oestrogen treatment of female or male tammar wallabies from the day of birth, when the gonads are histologically undifferentiated, to day 25 of pouch life, when the gonads and the Wolffian and Mullerian ducts have differentiated and the testes have migrated through the inguinal canal. Female tammars treated with testosterone propionate (24–50 mg kg-1 day-1) orally for 25 days had enlarged Wolffian and Mullerian ducts. Mammary and pouch development, however, was indistinguishable from that of control females. The treatment had no apparent effect on ovarian development, or on ovarian position in the abdomen. The phallus of males and females was similar in size, and neither experimental treatment had a significant effect on its size at day 25. Male tammars treated with oestradiol benzoate (1.2–2.5 mg kg-1 day-1) orally for 25 days had gross hypertrophy of the urogenital sinus. Testicular morphology was abnormal; many of the germ cells appeared necrotic, the seminiferous tubules were of reduced diameter, and there were few Leydig cells and increased amounts of fibrous tissue between the tubules. The cortex of these gonads contained some areas which had an ovarian appearance, lacking tubules and containing numerous germ cells. The Mullerian ducts of control males had regressed, but this was prevented by oestrogen treatment, suggesting an inhibition of either Mullerian Inhibiting Substance (MIS) production or its action. Normal testicular migration was inhibited in treated males; the testes remained high in the abdomen, similar in position to the ovaries of control females, whilst control males all had testes in the inguinal region. The gubernaculum and processus vaginalis of control males extended into the scrotum, but in treated males they terminated outside it. Oestrogen treatment had no effect on the size of the scrotum and did not induce mammary or pouch development. These experiments show that marsupials, like eutherians, have a dual hormonal control of Wolffian and Mullerian development. By contrast, the initial development of the mammary glands, pouch, gubernaculum and scrotum does not appear to be under hormonal control and is therefore likely to be autonomous and dependent on genotype.

scholarly journals Effects of oestrogen treatment on testicular descent, inguinal closure and prostatic development in a male marsupial, Macropus eugenii

Reproduction ◽  
2002 ◽  
pp. 73-83 ◽  
Author(s):  
D Coveney ◽  
G Shaw ◽  
MB Renfree
Keyword(s):  
Inguinal Canal ◽  
Prostate Gland ◽  
Tammar Wallaby ◽  
Hormonal Control ◽  
Testicular Descent ◽  
Oestrogen Treatment ◽  
Model Animal ◽  
Internal Genitalia ◽  
Mullerian Ducts ◽  
Testicular Migration

This study reports the effect of oestrogen treatment on the development of the genital ducts, prostate gland, testicular descent and inguinal canal closure in male tammar wallaby young treated with oestrogen over four time spans during the first 25 days of pouch life (days 0-10, 10-15, 15-25 and 0-25) and sampled at day 50. In control males, the Mullerian ducts had regressed and the Wolffian ducts had developed into the vas deferens and epididymis. The prostate gland had formed epithelial buds extending from the ventral, lateral and posterior walls of the urethra. The testes were in the neck of the scrotum and the gubernaculum and processus vaginalis were present at the base of the scrotum. In most males treated with oestradiol from day 0 to day 25, the testes had failed to descend by day 50. The gubernaculae were long and thin. The retained Mullerian ducts formed a lateral vaginal expansion like that of normal day 50 females. The Wolffian ducts of the males treated on days 0-25 were regressed, but were present in males in the other three treatment groups. The prostate glands were hyperplastic and epithelial budding was highly invasive. Some treated males from the day 10-25 and 0-25 groups had inguinal hernias. These results demonstrate that oestrogen treatment has profound effects on the development of the internal genitalia of a male marsupial, preventing inguinal closure and interfering with testicular descent. Therefore, the tammar wallaby may provide a useful experimental model animal in which to investigate the hormonal control of testicular migration and closure of the inguinal canal.

scholarly journals Intratesticular Injection of Calcium Chloride Is a Useful Alternative for Neutering the Male Dog

2018 ◽  
Vol 6 (2) ◽  
pp. 158-163
Author(s):  
Bikash Puri ◽  
Manoj Kumar Shah ◽  
Bablu Thakur ◽  
Bharat Regmi ◽  
Ishwor Dhakal
Keyword(s):  
Calcium Chloride ◽  
Germ Cells ◽  
Fibrous Tissue ◽  
Seminiferous Tubules ◽  
Group Iii ◽  
Group I ◽  
Cell Association ◽  
Sterile Normal Saline ◽  
Life Threatening ◽  
Apparently Healthy

Nepal is a rabies endemic country where stray and community dogs are the main reservoir of this life threatening diseases. The orchidectomy is performed to control the male dog population, which is supposed to be very painful and invasive thereby not rational in context of animal welfare. Therefore present study was undertaken to study the efficacy of single intratesticular injection of calcium chloride for neutering of the male dog. Twelve apparently healthy male dogs were randomly allocated into 3 groups (n=4). Group-I received single bilateral intratesticular injection of 20% calcium chloride together with 1% lignocaine-HCl at dose determined accordingly with testicular width. Similarly, Group-II received a single bilateral intratesticular injection of sterile normal saline containing 1% lignocaine-HCl. However, the orchidectomy was performed following the standard surgical protocol in the dogs of Group-III. Histopathologically, the calcium chloride injected testicular section demonstrated dissolution of the germ cell association, atrophied seminiferous tubules and washing out of the germ cells from the tubules. In some area, there was coagulative necrosis of the seminiferous epithelium and interstitial spaces as well as degenerated and coagulated germ cells in combination with fibrous tissue. Intertubular edema, fibrosis, hemorrhage were also evident. Some necrotic cells showed desquamation or even calcification. Intertubular vessels were severely congested. There was complete loss of tubular architecture without any distinct boundary between the tubular and extra tubular compartment in some region of testis. The intratesticular injection of 20% calcium chloride did not show any apparent pain, stress, metabolic toxicity and untoward side effect. Histomorphological findings revealed the uneven distribution of damage and inconsistent affect on seminiferous tubules. Therefore, intratesticular injection of calcium chloride could be useful alternative for neutering the male dog.Int. J. Appl. Sci. Biotechnol. Vol 6(2): 158-163

The influence of estrogen on the developing male marsupial

2001 ◽  
Vol 13 (4) ◽  
pp. 231 ◽  
Author(s):  
Marilyn B. Renfree ◽  
Douglas Coveney ◽  
Geoffrey Shaw
Keyword(s):  
Germ Cells ◽  
Gonadal Hormones ◽  
Sex Reversal ◽  
Urogenital Sinus ◽  
Testicular Descent ◽  
South American ◽  
Estradiol Treatment ◽  
Internal Genitalia ◽  
Mullerian Ducts ◽  
Normal Males

The genes and hormones involved in gonadal differentiation are highly conserved between eutherians and marsupials, although the timing of the developmental events differs. In marsupials, the testis develops seminiferous cords two days after birth, and the ovaries are not distinguishable until around eight days after birth. Differentiation of the internal genitalia is controlled in marsupials, as in eutherians, by testicular testosterone and MÜllerian inhibiting substance, but differentiation of the scrotum in males and mammary primordia in females is hormone-independent. Since the young are easily accessible in the pouch, it is possible to administer gonadal hormones during the period of sexual differentiation. In both Australian and South American marsupials, estradiol treatment of neonatal males can induce male-to-female gonadal sex reversal. The testicular transformations range from partial suppression of seminiferous tubule development to the development of a morphologically normal ovary depending on the stage that treatment starts. The sex-reversed testes have a clearly defined cortex and medulla, and there are significantly fewer germ cells. The germ cells are surrounded by follicle-like cells and are in the early stages of meiosis, as is normal for XX germ cells in ovaries. In normal males, germ cells only enter meiosis at the onset of puberty. As in eutherians, estrogen treatment of neonatal male marsupials prevents regression of the MÜllerian ducts, which are hypertrophic. Neonatal estradiol exposure also causes hypertrophy of the prostate and urogenital sinus. Estradiol treatment also inhibits transabdominal testicular descent and many animals develop inguinal hernias. The ability of estradiol to cause testis-to-ovary sex reversal in marsupials provides a new way of studying the interactions between genes and hormones in testicular differentiation.

scholarly journals Deficient pregnenolone synthesis associated with congenital adrenal hyperplasia and organelle dysfunction

2019 ◽  
Vol 2019 ◽  
Author(s):  
Himangshu S Bose ◽  
Alan M Rice ◽  
Brendan Marshall ◽  
Fadi Gebrail ◽  
David Kupshik ◽  
...  
Keyword(s):  
Germ Cells ◽  
Adrenal Glands ◽  
Interstitial Fibrosis ◽  
Ambiguous Genitalia ◽  
Rete Testis ◽  
Seminiferous Tubules ◽  
List Type ◽  
Chain Cleavage ◽  
Cleavage Enzyme ◽  
Mullerian Ducts

Summary Steroid hormones are essential for the survival of all mammals. In adrenal glands and gonads, cytochrome P450 side chain cleavage enzyme (SCC or CYP11A1), catalyzes conversion of cholesterol to pregnenolone. We studied a patient with ambiguous genitalia by the absence of Müllerian ducts and the presence of an incompletely formed vagina, who had extremely high adrenocorticotropic hormone (ACTH) and reduced pregnenolone levels with enlarged adrenal glands. The testes revealed seminiferous tubules, stroma, rete testis with interstitial fibrosis and reduced number of germ cells. Electron microscopy showed that the patient’s testicular mitochondrial size was small with little SCC expression within the mitochondria. The mitochondria were not close to the mitochondria-associated ER membrane (MAM), and cells were filled with the microfilaments. Our result revealed that absence of pregnenolone is associated with organelle stress, leading to altered protein organization that likely created steric hindrance in testicular cells. Learning points: Testes revealed seminiferous tubules, stroma, rete testis with interstitial fibrosis and reduced number of germ cells; Testicular mitochondrial size was small with little SCC expression within the mitochondria; Absence of pregnenolone is associated with organelle stress.

scholarly journals Germ cell-induced immune suppression in mice. Effect of inoculation of syngeneic spermatozoa on cell-mediated immune responses.

1982 ◽  
Vol 155 (6) ◽  
pp. 1719-1729 ◽  
Author(s):  
U Hurtenbach ◽  
G M Shearer
Keyword(s):  
Germ Cells ◽  
Immune Suppression ◽  
Natural Killer Cell Activity ◽  
Killer Cell ◽  
Cell Activity ◽  
Seminiferous Tubules ◽  
Immune Functions ◽  
Cytotoxic Lymphocyte ◽  
Testicular Cells ◽  
Killer Cell Activity

Spleen cells from mice injected intravenously with syngeneic male germ cells exhibited reduced immune functions as determined by natural killer cell activity, mixed lymphocyte reactivity and cytotoxic lymphocyte (CTL) function. The decrease in CTL responses to trinitrophenyl-modified self (TNP-self) was detected as early as 4 d after sperm injection and was observed to H-2 alloantigens 3 wk after injection. Radiosensitive suppressor T cells were found to suppress the CTL response to TNP-self. Suppression lasted for a period of at least 7 wk after a single inoculation of the germ cells. Some variability in immune suppression capability was observed using different preparations of germ cells which are not yet completely understood. Sperm were more effective in inducing suppression than testicular cells derived from the seminiferous tubules. Furthermore, sperm from older animals were more effective than those from younger mice. These findings are discussed with respect to possible regulatory influences of germ cells on the immune system when the blood-testes barrier is broken.

scholarly journals Minireview: Transcriptional Regulation of Gonadal Development and Differentiation

Endocrinology ◽  
2005 ◽  
Vol 146 (3) ◽  
pp. 1035-1042 ◽  
Author(s):  
Susan Y. Park ◽  
J. Larry Jameson
Keyword(s):  
Germ Cells ◽  
Sertoli Cells ◽  
Leydig Cells ◽  
Cell Types ◽  
Gonadal Development ◽  
Targeted Mutagenesis ◽  
Seminiferous Tubules ◽  
Molecular Pathways ◽  
Theca Cells ◽  
Main Cell

The embryonic gonad is undifferentiated in males and females until a critical stage when the sex chromosomes dictate its development as a testis or ovary. This binary developmental process provides a unique opportunity to delineate the molecular pathways that lead to distinctly different tissues. The testis comprises three main cell types: Sertoli cells, Leydig cells, and germ cells. The Sertoli cells and germ cells reside in seminiferous tubules where spermatogenesis occurs. The Leydig cells populate the interstitial compartment and produce testosterone. The ovary also comprises three main cell types: granulosa cells, theca cells, and oocytes. The oocytes are surrounded by granulosa and theca cells in follicles that grow and differentiate during characteristic reproductive cycles. In this review, we summarize the molecular pathways that regulate the distinct differentiation of these cell types in the developing testis and ovary. In particular, we focus on the transcription factors that initiate these cascades. Although most of the early insights into the sex determination pathway were based on human mutations, targeted mutagenesis in mouse models has revealed key roles for genes not anticipated to regulate gonadal development. Defining these molecular pathways provides the foundation for understanding this critical developmental event and provides new insight into the causes of gonadal dysgenesis.

Developmental stage- and spermatogenic cycle-specific expression of transcription factor GATA-1 in mouse Sertoli cells

Development ◽  
1994 ◽  
Vol 120 (7) ◽  
pp. 1759-1766 ◽  
Author(s):  
K. Yomogida ◽  
H. Ohtani ◽  
H. Harigae ◽  
E. Ito ◽  
Y. Nishimune ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Developmental Stage ◽  
Sertoli Cell ◽  
Germ Cells ◽  
Sertoli Cells ◽  
Transcriptional Activation ◽  
Germ Line ◽  
Mouse Testis ◽  
Seminiferous Tubules ◽  
Specific Expression

GATA-1 is an essential factor for the transcriptional activation of erythroid-specific genes, and is also abundantly expressed in a discrete subset of cells bordering the seminiferous epithelium in tubules of the murine testis. In examining normal and germ-line defective mutant mice, we show here that GATA-1 is expressed only in the Sertoli cell lineage in mouse testis. GATA-1 expression in Sertoli cells is induced concomitantly with the first wave of spermatogenesis, and GATA-1-positive cells are uniformly distributed among all tubules during prepubertal testis development. However, the number of GATA-1-positive cells declines thereafter and were found only in the peripheral zone of seminiferous tubules in stages VII, VIII and IX of spermatogenesis in the adult mouse testis. In contrast, virtually every Sertoli cell in mutant W/Wv, jsd/jsd or cryptorchid mice (all of which lack significant numbers of germ cells) expresses GATA-1, thus showing that the expression of this transcription factor is negatively controlled by the maturing germ cells. These observations suggest that transcription factor GATA-1 is a developmental stage- and spermatogenic cycle-specific regulator of gene expression in Sertoli cells.

Stem cell factor protects germ cells from apoptosis in vitro

2000 ◽  
Vol 113 (1) ◽  
pp. 161-168 ◽  
Author(s):  
W. Yan ◽  
J. Suominen ◽  
J. Toppari
Keyword(s):  
Stem Cell ◽  
Germ Cells ◽  
Stem Cell Factor ◽  
Primordial Germ Cells ◽  
Survival Function ◽  
Seminiferous Tubules ◽  
Testicular Development ◽  
Dna Laddering ◽  
Survival Effect

Stem cell factor (SCF) plays an important role in migration, adhesion, proliferation, and survival of primordial germ cells and spermatogonia during testicular development. However, the function of SCF in the adult testis is poorly described. We have previously shown that, in the presence of SCF, there were more type A spermatogonia incorporating thymidine at stage XII of rat seminiferous tubules cultured in vitro than in the absence of SCF, implying that the increased DNA synthesis might result from enhanced survival of spermatogonia. To explore the potential pro-survival function of SCF during spermatogenesis, the seminiferous tubules from stage XII were cultured in the presence or absence of SCF (100 ng/ml) for 8, 24, 48, and 72 hours, respectively, and apoptosis was analyzed by DNA laddering and in situ 3′-end labeling (ISEL) staining. Surprisingly, not only spermatogonia, but also spermatocytes and spermatids, were protected from apoptosis in the presence of SCF. Apoptosis took place much later and was less severe in the SCF-treated tubules than in the controls. Based on previous studies showing that FSH prevents germ cells from undergoing apoptosis in vitro, and that SCF level is increased dramatically in response to FSH stimulation, we also tested if the pro-survival effect of FSH is mediated through SCF by using a function-blocking monoclonal antibody, ACK-2, to block SCF/c-kit interaction. After 24 hours of blockade, the protective effect of FSH was partially abolished, as manifested by DNA laddering and ISEL analyses. The present study demonstrates that SCF acts as an important survival factor for germ cells in the adult rat testis and FSH pro-survival effect on germ cells is mediated partially through the SCF/c-kit pathway.

Inhibition of testicular germ cell apoptosis and differentiation in mice misexpressing Bcl-2 in spermatogonia

Development ◽  
1996 ◽  
Vol 122 (6) ◽  
pp. 1703-1709 ◽  
Author(s):  
T. Furuchi ◽  
K. Masuko ◽  
Y. Nishimune ◽  
M. Obinata ◽  
Y. Matsui
Keyword(s):  
Transgenic Mice ◽  
Germ Cells ◽  
Molecular Mechanisms ◽  
Elongation Factor ◽  
Chain Elongation ◽  
Seminiferous Tubules ◽  
Testicular Germ Cell ◽  
Abnormal Accumulation ◽  
Normal Spermatogenesis ◽  
Massive Accumulation

During normal spermatogenesis, more than half of the germ cells undergo apoptosis, but the physiological significance and molecular mechanisms of this programmed cell death are largely unknown. Because Bcl-2 functions as a death repressor, we have investigated the effect of misexpressing Bcl-2 in spermatogonia in transgenic mice using the human bcl-2 cDNA under the control of the human polypeptide chain elongation factor 1alpha (EF-1alpha) promoter. In the 2-week-old transgenic testes, exogenous Bcl-2 was expressed in spermatogonia and massive accumulation of spermatogonia was observed in seminiferous tubules by 4 weeks. At this time, only a few spermatocytes were apparent, and the accumulated cells degenerated, leading to vacuolization in some seminiferous tubules by 7 weeks. In older transgenic mice, abnormal accumulation of spermatogonia and degeneration of these germ cells was still observed, but some seminiferous tubules in which the level of Bcl-2 expression was reduced recovered normal spermatogenesis. These observations indicate that spermatogonial apoptosis is part of the normal program of mammalian spermatogenesis and is regulated by a pathway affected by Bcl-2.

scholarly journals Effects of microgravity or simulated launch on testicular function in rats

1992 ◽  
Vol 73 (2) ◽  
pp. S174-S185 ◽  
Author(s):  
R. P. Amann ◽  
D. R. Deaver ◽  
B. R. Zirkin ◽  
G. S. Grills ◽  
W. J. Sapp ◽  
...  
Keyword(s):  
Germ Cells ◽  
Quantitative Methods ◽  
Smooth Endoplasmic Reticulum ◽  
Testicular Tissue ◽  
Seminiferous Tubules ◽  
Specific Gene ◽  
Fixed Tissue ◽  
Treatment Groups ◽  
Essentially Normal ◽  
Peripheral Blood Plasma

Testes from flight rats on COSMOS 2044 and simulated-launch, vivarium, or caudal-elevation control rats (5/group) were analyzed by subjective and quantitative methods. On the basis of observations of fixed tissue, it was evident that some rats had testicular abnormalities unassociated with treatment and probably existing when they were assigned randomly to the four treatment groups. Considering rats without preexisting abnormalities, diameter of seminiferous tubules and numbers of germ cells per tubule cross section were lower (P less than 0.05) in flight than in simulated-launch or vivarium rats. However, ratios of germ cells to each other or to Sertoli cells and number of homogenization-resistant spermatids did not differ from values for simulated-launch or vivarium controls. Expression of testis-specific gene products was not greatly altered by flight. Furthermore, there was no evidence for production of stress-inducible transcripts of the hsp70 or hsp90 genes. Concentration of receptors for rat luteinizing hormone in testicular tissue and surface density of smooth endoplasmic reticulum in Leydig cells were similar in flight and simulated-launch rats. However, concentrations of testosterone in testicular tissue or peripheral blood plasma were reduced (P less than 0.05) in flight rats to less than 20% of values for simulated-launch or vivarium controls. Thus spermatogenesis was essentially normal in flight rats, but production of testosterone was severely depressed. Exposure to microgravity for greater than 2 wk might result in additional changes. Sequelae of reduced androgen production associated with microgravity on turnover of muscle and bone should be considered.

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