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 Effect of an anti-androgen on testicular descent and inguinal closure in a marsupial, the tammar wallaby (Macropus eugenii)

Reproduction ◽  
2002 ◽  
pp. 865-874 ◽  
Author(s):  
D Coveney ◽  
G Shaw ◽  
JM Hutson ◽  
MB Renfree
Keyword(s):  
Dorsal Root ◽  
Inguinal Canal ◽  
Prostate Gland ◽  
Tammar Wallaby ◽  
Calcitonin Gene Related Peptide ◽  
Hormonal Control ◽  
Testicular Descent ◽  
Genitofemoral Nerve ◽  
Related Peptide ◽  
Calcitonin Gene

Androgens are essential for testicular descent in eutherian mammals, but little is known about its hormonal control in marsupials. This study reports the effects of daily treatment with the anti-androgen flutamide (10 mg kg(-1)) from day 9 to day 75 after birth on the descent of the testis and inguinal closure in tammar wallabies. By day 75 after birth, the testes of control males had descended and the prostate gland was well developed. The testes of all flutamide-treated males had passed through the inguinal canal and were situated in the base of the scrotum. Three of the nine flutamide-treated males had unilateral inguinal hernias. The size of the inguinal canal, regardless of whether a hernia was present, was significantly wider than that of control males. Development of the prostate gland was significantly inhibited. By day 75 after birth, the phallus was significantly longer in control males than in females, whereas the phallus of flutamide-treated males was similar to that of control females. In flutamide-treated males, the lumbar 1 dorsal root ganglia was feminized and significantly fewer cell bodies expressed calcitonin gene- related peptide. As the anti-androgen treatment resulted in a reduction in the number of calcitonin gene-related peptide-positive cell bodies in the dorsal root ganglion supplying the genitofemoral nerve, the process of inguinal closure in tammar wallabies may be mediated by calcitonin gene-related peptide via the genitofemoral nerve, as indicated in humans. Flutamide treatment inhibited development of the prostate gland and phallus, which are both androgen-dependent structures, but it did not affect the normal descent of the testis, indicating that testicular descent can proceed when the action of androgens is blocked.

Mullerian inhibiting substance production and testicular migration and descent in the pouch young of a marsupial

Development ◽  
1988 ◽  
Vol 104 (4) ◽  
pp. 549-556 ◽  
Author(s):  
J.M. Hutson ◽  
G. Shaw ◽  
W.S. O ◽  
R.V. Short ◽  
M.B. Renfree
Keyword(s):  
Tammar Wallaby ◽  
Testicular Descent ◽  
Future Studies ◽  
Macropus Eugenii ◽  
Müllerian Inhibiting Substance ◽  
Sequence Of Events ◽  
Testicular Differentiation ◽  
Testicular Migration ◽  
Australian Marsupial ◽  
Mullerian Inhibiting Substance

The ontogeny of Mullerian inhibiting substance (MIS) production by the developing testis of an Australian marsupial, the tammar wallaby (Macropus eugenii), was determined during pouch life using an organ-culture bioassay of mouse fetal urogenital ridge. This information was related to the morphological events during testicular migration and descent. MIS biological activity was found in testes (but not ovaries or liver) of pouch young from 2 to 85 days of age. MIS production had commenced by day 2, which is within a day of the first gross morphological signs of testicular differentiation. Mullerian duct regression occurred between 10 and 30 days, which partly coincided with testicular migration to the inguinal region and enlargement of the gubernacular bulb (15 to 30 days). These observations are consistent with the hypothesis that MIS may be involved in testicular transabdominal migration. The epididymis commenced development and growth only after the testis had descended through the inguinal ring. This provides no support for the suggestion that the epididymis is involved in testicular descent into the scrotum. The basic sequence of events in post-testicular sexual differentiation in the wallaby is sufficiently similar to that seen in eutherian mammals to make it an excellent experimental model for future studies of testicular differentiation, migration and descent.

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.

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.

Association of antimullerian hormone with the size of the appendix testis, the androgen and estrogen receptors and their expression in the appendix testis, in congenital cryptorchidism

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Xenophon Sinopidis ◽  
Eirini Kostopoulou ◽  
Andrea Paola Rojas-Gil ◽  
Antonios Panagidis ◽  
Eleni Kourea ◽  
...  
Keyword(s):  
Estrogen Receptor ◽  
Receptor Expression ◽  
Testicular Descent ◽  
Antimullerian Hormone ◽  
Mullerian Ducts ◽  
Score Method ◽  
Antimüllerian Hormone ◽  
Unilateral Cryptorchidism ◽  
Appendix Testis

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.

scholarly journals An observational study of the microbiome of the maternal pouch and saliva of the tammar wallaby, Macropus eugenii, and of the gastrointestinal tract of the pouch young

Microbiology ◽  
2010 ◽  
Vol 156 (3) ◽  
pp. 798-808 ◽  
Author(s):  
Kim-Ly Chhour ◽  
Lyn A. Hinds ◽  
Nicholas A. Jacques ◽  
Elizabeth M. Deane
Keyword(s):  
Immune System ◽  
Gastrointestinal Tract ◽  
16S Rdna ◽  
Young Animal ◽  
Tammar Wallaby ◽  
Birth Canal ◽  
Macropus Eugenii ◽  
Rdna Sequences ◽  
Model Animal ◽  
Study Sites

Marsupial mammals, born in an extremely atricial state with no functional immune system, offer a unique opportunity to investigate both the developing microbiome and its relationship to that of the mother and the potential influence of this microbiome upon the development of the immune system. In this study we used a well-established marsupial model animal, Macropus eugenii, the tammar wallaby, to document the microbiome of three related sites: the maternal pouch and saliva, and the gastrointestinal tract (GIT) of the young animal. We used molecular-based methods, targeting the 16S rDNA gene to determine the bacterial diversity at these study sites. In the maternal pouch, 41 unique phylotypes, predominantly belonging to the phylum Actinobacteria, were detected, while in the saliva, 48 unique phylotypes were found that predominantly belonged to the phylum Proteobacteria. The GIT of the pouch young had a complex microbiome of 53 unique phylotypes, even though the pouch young were still permanently attached to the teat and had only been exposed to the external environment for a few minutes immediately after birth while making their way from the birth canal to the maternal pouch. Of these 53 phylotypes, only nine were detected at maternal sites. Overall, the majority of bacteria isolated were novel species (<97 % identity to known 16S rDNA sequences), and each study site (i.e. maternal pouch and saliva, and the GIT of the pouch young) possessed its own unique microbiome.

Hormonal control of concentrations of endometrial oxytocin receptors in the ewe

1992 ◽  
Vol 4 (3) ◽  
pp. 313 ◽  
Author(s):  
RJ Fairclough ◽  
TM Lau
Keyword(s):  
Early Pregnancy ◽  
Hormonal Control ◽  
Oestrous Cycle ◽  
Prolonged Treatment ◽  
Inhibitory Influence ◽  
Oestrogen Treatment ◽  
Prostaglandin F2 Alpha ◽  
Oxytocin Receptors ◽  
Long Term Treatment ◽  
Alpha Response

Uterine oxytocin receptors have been shown to play a major role in the regulation of uterine prostaglandin F2 alpha release during the oestrous cycle and early pregnancy in sheep. The concentration of endometrial oxytocin receptors increases sharply from around Day 13 of the oestrous cycle to reach a maximum between Days 15 and 16. The high concentration of endometrial oxytocin receptors at this time coincides with the release of endogenous uterine prostaglandin F2 alpha during luteal regression and the maximum uterine prostaglandin F2 alpha response to an oxytocin stimulus. The concentration of uterine oxytocin receptors appears to be regulated by both progesterone and oestradiol. Studies in ovariectomized ewes have shown that initially progesterone lowers the concentration of endometrial oxytocin receptors, but after prolonged treatment with progesterone the concentration of oxytocin receptors increases; this suggests that the uterine-PGF2 alpha response to oxytocin has become refractory to the inhibitory effects of progesterone. The concentration of endometrial oxytocin receptors is also lowered by short-term oestradiol treatment. However, oestrogen treatment of ewes after long-term treatment with progesterone does not result in an increase in the concentration of oxytocin receptors following the cessation of progesterone treatment. On the basis of these and other data it is proposed that in the normal oestrous cycle the concentration of endometrial oxytocin receptors is initially depressed by both oestradiol and progesterone but that the marked increase in the concentration of oxytocin receptors over Days 13-16 of the cycle is due primarily to the withdrawal of the inhibitory influence of progesterone alone. During early pregnancy the release of uterine prostaglandin F is suppressed.(ABSTRACT TRUNCATED AT 250 WORDS)

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