The influence of estrogen on the developing male marsupial

2001 ◽  
Vol 13 (4) ◽  
pp. 231 ◽  
Author(s):  
Marilyn B. Renfree ◽  
Douglas Coveney ◽  
Geoffrey Shaw

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.

Reproduction ◽  
2002 ◽  
pp. 73-83 ◽  
Author(s):  
D Coveney ◽  
G Shaw ◽  
MB Renfree

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.


Development ◽  
1988 ◽  
Vol 104 (4) ◽  
pp. 689-701 ◽  
Author(s):  
G. Shaw ◽  
M.B. Renfree ◽  
R.V. Short ◽  
W.S. O

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.


2007 ◽  
Vol 16 (23) ◽  
pp. 2795-2804 ◽  
Author(s):  
Chris Ottolenghi ◽  
Emanuele Pelosi ◽  
Joseph Tran ◽  
Maria Colombino ◽  
Eric Douglass ◽  
...  
Keyword(s):  

Author(s):  
Xenophon Sinopidis ◽  
Eirini Kostopoulou ◽  
Andrea Paola Rojas-Gil ◽  
Antonios Panagidis ◽  
Eleni Kourea ◽  
...  

Abstract Objectives Antimullerian hormone (AMH) causes regression of the mullerian ducts in the male fetus. The appendix testis (AT) is a vestigial remnant of mullerian duct origin, containing both androgen (AR) and estrogen (ER) receptors. The role of both AMH and AT in testicular descent is yet to be studied. We investigated the possible association of AMH with AT size, the AR and ER, and their expression in the AT, in congenital cryptorchidism. Methods A total of 26 patients with congenital unilateral cryptorchidism and 26 controls with orthotopic testes were investigated, and 21 ATs were identified in each group. AMH and insulin-like three hormone (INSL3) concentrations were measured with spectrophotometry. AR and ER receptor expression was assessed with immunohistochemistry using monoclonal antibodies R441 for AR and MAB463 for ER. For the estimation of receptor expression, the Allred Score method was used. Results AMH concentrations did not present significant differences between patients with congenital cryptorchidism and the controls. Also, no correlation was found between AMH, INSL3, and AT length. Allred scores did not present significant differences. However, expression percentiles and intensity for both receptors presented significant differences. Three children with cryptorchidism and the highest AMH levels also had the highest estrogen receptor scores in the AT. Conclusions No association was found between AMH and the studied major parameters. However, higher AMH concentrations, in combination with higher estrogen receptor scores in the AT, may play a role in cryptorchidism in some children. Larger population samples are needed to verify this observation.


Reproduction ◽  
2011 ◽  
Vol 141 (5) ◽  
pp. 633-641 ◽  
Author(s):  
N P Leopardo ◽  
F Jensen ◽  
M A Willis ◽  
M B Espinosa ◽  
A D Vitullo

Apoptosis-dependent massive germ cell death is considered a constitutive trait of the developing mammalian ovary that eliminates 65–85% of the germinal tissue depending on the species. After birth and during adult lifetime, apoptotic activity moves from the germ cell proper to the somatic compartment, decimating germ cells through follicular atresia until the oocyte reserve is exhausted. In contrast, the South American rodent Lagostomus maximus shows suppressed apoptosis-dependent follicular atresia in the adult ovary, with continuous folliculogenesis and massive polyovulation, which finally exhausts the oocyte pool. The absence of follicular atresia in adult L. maximus might arise from a failure to move apoptosis from the germinal stratum to the somatic compartment after birth or being a constitutive trait of the ovarian tissue with no massive germ cell degeneration in the developing ovary. We tested these possibilities by analysing oogenesis, expression of germ cell-specific VASA protein, apoptotic proteins BCL2 and BAX, and DNA fragmentation by TUNEL assay in the developing ovary of L. maximus. Immunolabelling for VASA revealed a massive and widespread colonisation of the ovary and proliferation of germ cells organised in nests that disappeared at late development when folliculogenesis began. No sign of germ cell attrition was found at any time point. BCL2 remained positive throughout oogenesis, whereas BAX was slightly detected in early development. TUNEL assay was conspicuously negative throughout the development. These results advocate for an unrestricted proliferation of germ cells, without apoptosis-driven elimination, as a constitutive trait of L. maximus ovary as opposed to what is normally found in the developing mammalian ovary.


Development ◽  
1974 ◽  
Vol 31 (3) ◽  
pp. 611-620
Author(s):  
Gregory F. Erickson

The left embryonic testis of the bird (4–8 days of incubation) was organ cultured in medium that contained 10% foetal calf serum. Under these conditions, the germinal epithelium (GE) of the 4-day gonad differentiates into an ovarian cortex and the male primordial germ cells (PGCs) complete a developmental sequence similar to normal oocytes, i.e. they divide mitotically, develop a Balbiani body, divide synchronously in groups of two, four, and eight germ cells, and some enter pre-leptotene. No medullary tissue develops in the 4-day explants. The pieces of 6- and 8-day gonad differentiate into true ovotestes in which the GE develops into a cortex and the medulla develops into seminiferous cords. The PGCs in the cortex differentiate as oocytes and those in the seminiferous cords differentiate as spermatogonia. The possibility that biologically active oestrogens are present in the growth medium is discussed.


Author(s):  
Kosaraju Reddiah

The results of a comparative study of the breeding biology of the Manx pectinids with special reference to Chlamys varia, C. distorta, C. tigerina, C. striata and C. furtiva are presented.It is shown that C. varia and C. distorta are protandric hermaphrodites with separate sexual phases similar to those of oysters, and evidence is presented on the possibility of sex reversal. The other species, C. tigerina, C. striata and C. furtiva, are truly dioecious, possessing at no stage germ cells of both sexes in the same gonad and as most individuals produce only one brood, the possibility of sex reversal is excluded.C. distorta has two large-scale or peak spawning periods, once in summer and for the second time in autumn, although some spawning occurs as a rule in most months of the year. The breeding behaviour of this species is intermittent and therefore the breeding period is prolonged.C. varia has two mass spawnings in a year, once in June and for the second time during September and October and the breeding period is not markedly different from that observed in French waters. Spawning is usually completed within a short period. C. tigerina and C. striata spawn only once annually in June and August respectively and most individuals have only one breeding cycle during their life time. C. furtiva however, may have two spawnings in a year, but the material available was inadequate to confirm this.


2019 ◽  
Author(s):  
Lars Benner ◽  
Katherine Prothro ◽  
Katherine McJunkin

AbstractThe germline sex determination pathway in C. elegans determines whether germ cells develop as oocytes or sperm, with no previously known effect on viability. The mir-35 family of microRNAs are expressed in the C. elegans germline and embryo and are essential for both viability and normal hermaphroditic sex determination, preventing aberrant male gene expression in XX hermaphrodite embryos. Here we show that combining feminizing mutations with partial loss of function of the mir-35 family results in enhanced penetrance embryonic lethality that preferentially kills XO animals. This lethal phenotype is due to altered signaling through the germline sex determination pathway, and maternal germline feminization is sufficient to induce enhanced lethality. These findings reveal a surprising pleiotropy of sperm-fate promoting pathways on organismal viability. Overall, our results demonstrate an unexpectedly strong link between sex determination and embryonic viability, and suggest that in wild type animals, mir-35 family members buffer against misregulation of pathways outside the sex determination program, allowing for clean sex reversal rather than deleterious effects of perturbing sex determination genes.


2019 ◽  
Author(s):  
Xiaochun Liu ◽  
Xi Wu ◽  
Yang Yang ◽  
Chaoyue Zhong ◽  
Yin Guo ◽  
...  

Abstract Background: Spermatogenesis is an intricate process regulated by a finely organized network. The orange-spotted grouper (Epinephelus coioides) is a protogynous hermaphroditic fish, but the process of its spermatogenesis is not well-understood. In the present study, transcriptome sequencing of the male germ cells from orange-spotted grouper was performed to explore the molecular mechanisms underlying spermatogenesis. Results: In this study, the orange-spotted grouper was induced to change sex from female to male by 17alpha-methyltestosterone implantation. During the artificial spermatogenesis, different cell types from cysts containing spermatogonia, spermatocytes, spermatids, and spermatozoa were isolated by laser capture microdissection. Subsequently, transcriptomic analysis for the isolated cells were performed. A series of genes was used to verify and investigate the expression patterns in spermatogenesis. Furthermore, we also analyzed the expression of the same set of genes involved with steroid metabolism and sex throughout spermatogenesis (early-mid, late, and maturing stages) in the orange-spotted grouper. Several generally female-related genes took significantly changes in sex reversal hinted that the female-related genes in previously recognized may also play vital roles in spermatogenesis and sex reversal. In the transcriptomic data, we focused on zbtb family genes, which may be related to the process of spermatogenesis. Their expression patterns and cellular localization were examined, and the location of Eczbtb40 in different gonadal stages was investigated. We found that Eczbtb40 was expressed throughout spermatogenesis. These preliminary findings suggest that Eczbtb40 is highly conserved during vertebrate evolution and plays roles in spermatogenesis. Besides, the expression of Eczbtb40 and Eccyp17a1a overlapped in male germ cells, especially spermatogonium and spermatocyte, which suggested that Eczbtb40 might interact with Eccyp17a1a participant in spermatogenesis and sex reversal. Conclusions: The present study first depicted RNA sequencing of the male germ cells from orange-spotted grouper, and identified many important functional genes and pathways involved in spermatogenesis. The Eczbtb40 gene was subjected to molecular characterization and expression pattern analysis. These results will contribute to future studies of the molecular mechanism of spermatogenesis and sex reversal.


Author(s):  
Mukta Agarwal ◽  
Bhawana Tiwary ◽  
Prajnanika Gurung

Genital outflow tract obstruction is a rare cause of primary amenorrhoea. Cervical agenesis is a very rare condition often associated with atresia of vagina. Clinical diagnosis is usually difficult before surgery. Transverse vaginal septum or vaginal agenesis is also a rare condition that results from incomplete fusion between vaginal components of the mullerian ducts and urogenital sinus. If the septum is complete, the menstrual flow will be obstructed causing primary amenorrhoea. The septum is basically a membrane of fibrous connective tissue with both muscular and vascular components formed anywhere along the vagina during embryological development. Here we present a case of 18 year old female who presented with primary amenorrhea, cyclical lower abdominal pain and menouria since 5 years. There was no history of attainment of menarche. The clinical examination revealed a small, blind ending lower vagina with a tough transverse membrane separating the lower portion from the upper genital tract. The ultrasound examination revealed a normal size uterus with hematometra. The magnetic resonance imaging of pelvis confirmed the presence of hematometra and transverse vaginal septum. Transverse vaginal septum resection followed by abdomino-perineal cervicoplasty was done in this patient.


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