scholarly journals Gonad Grafts in Embryonic Chicks and Their Relation to Sexual Differentiation

1925 ◽  
Vol 2 (2) ◽  
pp. 165-188
Author(s):  
A. W. GREENWOOD
Keyword(s):  
Sexual Differentiation ◽  
Physiological Activity ◽  
Histological Structure ◽  
Urogenital System ◽  
Microscopical Examination ◽  
Plumage Colour ◽  
Typical Structure ◽  
Opposite Sex ◽  
Wolffian Body ◽  
Embryo Chick

1. An experimental study on the effects of gonad grafts in the embryo chick was undertaken in an attempt to reproduce the results obtained by Minoura and to define the bearing of this experiment on Lillie's theory of the free-martin in cattle. 2. Eggs from a sex-linked cross were used so as to be able to identify the original sex of the embryos. 3. In the majority of cases the egg received the graft at the seventh day of incubation and was examined at the seventeenth day, at which stage the progress of sexual differentiation is almost as complete as at the time of hatching. 4. In all 540 embryos were operated on. Of this number 233 received testis grafts and 168 ovary grafts. Other tissues grafted were thyroid, adrenal, pancreas, spleen, gall-bladder, liver, Wolffian body, kidney, lung, lens, and heart. 5. The age of the grafted tissue varied from the fourteenth day of incubation up to ten weeks old. 6. Of the gonad grafts, 150 survived the operation, 71 ♂ and 79 ♀. 47 ♀ chicks were obtained after testis grafts, and 27 ♂ chicks were obtained after ovary grafts. Healthy active testis grafts were found in 20 ♀ and 5 ovary grafts in ♂. 7. The sex ratio in the surviving chicks showed no deviation from the normal. 8. Macroscopical examination of the urogenital system showed no deviation from the typical structure consonant with the sex of the chick as determined by its plumage colour. 9. Microscopical examination of the gonads revealed no abnormalities in histological structure. 10. These results lend no confirmation to the view that the process of sexual differentiation in the chick can be profoundly modified by the specific physiological activity of a gonad graft of the opposite sex. 11. Minoura's interpretation of his results are criticised. 12. The grafting of gonad tissue in the embryo chick does not reproduce experimentally the conditions existing in the bovine free-martin in that in the former the embryo is exposed to the specific action of the grafted gonad alone, whereas in the latter the female co-twin is exposed to the action of all the internal secretions from the male.

Transplantations de gonades indifférenciées chez l'hermaphrodite simultané Eisenia foetida (Oligochète, Lumbricidae)

Development ◽  
1973 ◽  
Vol 30 (1) ◽  
pp. 143-161
Author(s):  
Par J. C. Relexans
Keyword(s):  
Nervous System ◽  
Sexual Differentiation ◽  
The Body ◽  
Simultaneous Hermaphrodite ◽  
Eisenia Foetida ◽  
Turn On ◽  
Opposite Sex ◽  
Adjacent Wall ◽  
Physiological Gradients ◽  
Different Parts

Transplantations of undifferentiated gonads in the simultaneous hermaphrodite Eisenia foetida (Oligochaeta, Lumbricidae) leading to evidence of local factors (inductors?) of sexual differentiation The hypothesis of a ♀ sex capable of autodifferentiation and of a ♂ sex depending on an androgen hormone has been verified in several gonochoric or hermaphrodite invertebrates. In order to test the validity of this hypothesis in the hermaphrodite Eisenia foetida we have investigated the influence of the gonads' environment on their differentiation by transplanting undifferentiated gonads, dorsally and ventrally, on different parts of the body. The gonads, taken with the adjacent wall of the body from new-born worms, are grafted on worms of the same age; some grafts do, others do not, retain their nervous system. The control transplantation in which a graft of a given presumptive sex is transplanted in a region of the same sex can lead to inversions. These inversions have a rare and short-lived character in the gonads coming from presumptive testes. They are more frequent and more or less durable in the gonads coming from presumptive ovaries. These results can only be explained by the existence, within the grafts of the two presumptive sexes, of a dominant relationship between one and the other sexual potentiality which can be momentarily inverted by trophic disturbances caused by the transplantation. The heterosexual transplantations, in which a graft of a given presumptive sex is transplanted in the region of the opposite sex, show that the frequency of the inversions is doubled in relation to the frequency obtained in the control transplantations. The inversions which occur in the presumptive testes can be lasting and even permanent. These results lead to the opinion that to the effects of transplantation is added an inductive action from the host, leading to masculinity in the ♂ region and femininity in the ♀ region. The transplantations outside of the sexual ventral regions lead to inversions of which the character and frequency recall those obtained in the control transplantations. They suggest that these regions are devoid of inductive sexualizing power. The very slight variations of frequency of the inversions observed along the antero-posterior and dorso-ventral axes can be explained by the existence of physiological gradients acting on the balance of the graft's own potentialities. The removal of the nervous system in the grafts shows that this system plays a part, probably trophic, in favour of the masculine potentialities of the graft. In conclusion, our experiments lead to the rejection of the hypothesis of the ♀ sex capable of autodifferentiation in Eisenia, in order to adopt that of a sexual balance between the ♂ and ♀ potentialities determining, according to their dominant relationship, the synthesis of ♂ or ♀ ‘inductors’ respectively in the ♂ and ♀ ventral regions. These inductors act in turn on the bipotential sexual cells.

scholarly journals X. On the existence of a rudimentary head-kidney in the embryo chick

1878 ◽  
Vol 27 (185-189) ◽  
pp. 443-446 ◽  
Keyword(s):  
Head Kidney ◽  
Wolffian Duct ◽  
Germinal Epithelium ◽  
Mullerian Duct ◽  
Short Account ◽  
Müllerian Duct ◽  
Front End ◽  
Wolffian Body ◽  
Embryo Chick ◽  
Shallow Groove

We have been for some time engaged in an investigation on the mode of growth of the developing Müllerian duct in the chick, and its possible derivation from the Wolffian duct; and, while carrying on our investigations on this point, were struck by some remarkable features of the abdominal opening of the Müllerian duct in its very early condition. We did not for some time pay much attention to these features, but finally devoted ourselves to their interpretation, and have been led to the conclusion that they form the rudiment of a head-kidney, “Vomiere” or “Kopfniere,” identical with that present in Amphibia, Marsipobranchii, and Teleostei. We purpose first to give a short account of our observations,, and then to proceed to state the grounds on which we have been led to compare the structures we have found with the head-kidney of the Ichthyopsida The first trace of the Müllerian duct we have met with is a very shallow groove in the germinal epithelium some little way behind the front end of the Wolffian body, and nearly overlying, though slightly external to, the Wolffian duct. This stage corresponds with the earliest stage described by Dr. Gasser. In the next stage, which follows very closely upon the first one, remarkable changes have taken place in the groove, which can best be explained by describing the appearance of a series of successive sections from before backwards through the groove and its continuation.

Transsexualism

2011 ◽  
pp. 1463-1468
Author(s):  
Louis J. G. Gooren
Keyword(s):  
Sexual Differentiation ◽  
External Genitalia ◽  
The Other ◽  
Stria Terminalis ◽  
Bed Nucleus ◽  
Psychological Phenomenon ◽  
Opposite Sex ◽  
Male To Female ◽  
The Brain

Transsexualism is the condition in which a person with apparently normal somatic sexual differentiation is convinced that he/she is actually a member of the opposite sex. It is associated with an irresistible urge to be hormonally and surgically adapted to that sex. Traditionally transsexualism has been conceptualized as a purely psychological phenomenon, but research on the brains of male-to-female transsexuals has found that the sexual differentiation of the brain—the bed nucleus of the stria terminalis (BSTC) and the hypothalamic uncinate nucleus—had followed a female pattern (1). This finding may lead to a concept of transsexualism as a form of intersex, where the sexual differentiation of the brain (which in mammals also undergoes sexual differentiation) is not consistent with the other variables of sex, such as chromosomal pattern, nature of the gonad and nature of internal/external genitalia. Thus it can be argued that transsexualism is a sexual differentiation disorder.

Sudden Infant Death Syndrome in Twins and Singletons

2007 ◽  
Vol 10 (4) ◽  
pp. 644-648 ◽  
Author(s):  
Peter O. D. Pharoah ◽  
Mary J. Platt
Keyword(s):  
Risk Factor ◽  
Sudden Infant Death Syndrome ◽  
Infant Death ◽  
Low Birthweight ◽  
Sudden Infant Death ◽  
Multiple Births ◽  
Sudden Infant ◽  
Microscopical Examination ◽  
Increased Risk ◽  
Opposite Sex

AbstractTwins compared with singletons and monozygous (MZ) compared with dizygous (DZ) twins are at increased risk of fetal and infant death, cerebral palsy and many congenital anomalies. The aim of this study is to investigate whether zygosity is a risk factor for the sudden infant death syndrome (SIDS). Birth registration data and draft infant death certificates for all multiple births in England and Wales 1993 to 2003 were provided by the Office for National Statistics. As a partial proxy for zygosity, same-sex was compared with opposite-sex twins for birthweight-specific mortality and mortality attributed to SIDS. Data on singleton infants were obtained by subtraction of multiple births from routinely published population births and infant deaths. SIDS mortality among low birthweight infants was significantly less in twins than singletons. The twin-singleton relative risk was reversed in infants of normal birthweight. Among infants of normal birthweight, neonatal SIDS was significantly more common in same- compared with opposite-sex pairs. Among infants of low birthweight, postneonatal SIDS was significantly more common in same- compared with opposite-sex pairs. The difference in birthweight distribution of same- compared with opposite-sex twins for neonatal SIDS suggests that zygosity is a risk factor for SIDS. As congenital cerebral anomalies are a feature of many monozygous twin conceptions, a detailed macro- and microscopical examination of the brain in twin SIDS may indicate an otherwise unrecognised pathology.

Behavior of Male and Female Zebra Finches Treated With an Estrogen Synthesis Inhibitor as Nestlings

Behaviour ◽  
1996 ◽  
Vol 133 (11-12) ◽  
pp. 847-862 ◽  
Author(s):  
E. Adkins-Regan ◽  
S. Yang ◽  
V. Mansukhani
Keyword(s):  
Sexual Differentiation ◽  
Testing Procedure ◽  
Daily Injection ◽  
Zebra Finches ◽  
Synthesis Inhibitor ◽  
Choice Preference ◽  
Female Partners ◽  
Estrogen Synthesis ◽  
Opposite Sex ◽  
Important Exception

In order to test hypotheses about the organizational role of early estrogen in the sexual differentiation of behavior in zebra finches (Taeniopygia guttata), newly hatched birds were given one of three treatments: (1) daily injection with an aromatase inhibitor (fadrozole hydrochloride) for the first week; (2) the same treatment for the first two weeks; (3) daily injection of the vehicle for one or two weeks. As adults, birds were implanted with testosterone propionate and underwent a three-phase testing procedure designed to measure singing, dancing, copulation, and preferences for male vs female partners. Males were completely unaffected by fadrozole hydrochloride treatment; they sang, danced, and mounted at control levels, and like control males they preferred female partners. Females were similarly unaffected, with one important exception: those treated with fadrozole hydrochloride during the first week preferred to be spend time near females instead of males in choice tests, unlike control females. These results suggest that a model of zebra finch sexual differentiation in which estrogen organizes male-typical behavior is unlikely to be correct. At the same time, they provide evidence that a key dimorphic feature of mate choice, preference for opposite-sex birds (sexual orientation), may result from organizational hormone actions during the early post-hatching period in this pair-bonding species.

scholarly journals Morphology of the genital organs of male and female giant anteaters (Myrmecophaga tridactyla)

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11945
Author(s):  
Lilja Fromme ◽  
Débora R. Yogui ◽  
Mario Henrique Alves ◽  
Arnaud L.J. Desbiez ◽  
Marion Langeheine ◽  
...  
Keyword(s):  
Sexual Differentiation ◽  
Prostate Gland ◽  
Uterine Wall ◽  
Reproductive Characteristics ◽  
Caudal Portion ◽  
Mullerian Ducts ◽  
Opposite Sex ◽  
Vaginal Canal ◽  
Glandular Structures ◽  
Well Differentiated

Background The giant anteater belongs to the supraorder Xenarthra which occupies a systematically isolated position among placental mammals. The species is categorized as Vulnerable by the International Union for Conservation of Nature, and understanding its reproductive characteristics is critical for future conservation efforts. Methods Gross and microscopic anatomy of the genital organs of 23 male and 21 female adult and young roadkill giant anteaters in Brazil were studied. Results Male giant anteaters presented a short conical penis, intraabdominal testes, and prostate, vesicular and bulbourethral glands. A tubular remnant of the partially fused Müllerian ducts extended from the seminal colliculus through the prostate gland, continued cranially in the genital fold, bifurcated, and attached with one elongation each to the left and right epididymal corpus. The structure presented a total length of up to 10 cm and contained a yellowish liquid in its lumen. Histologically, the caudal section of this structure resembled the female vagina, the middle portion corresponded to the uterus, and the extensions showed characteristics of uterine tubes. In adult female giant anteaters, ovoid ovaries with occasional seminiferous cord-like structures were observed. The animals possessed a simple uterus, which was directly continuous with the vaginal canal. The caudal portion of the vagina had two lumina, separated by a longitudinal septum and opening into two apertures into the vaginal vestibule, cranial to the urethral opening. In the urethral and the lateral vestibular wall, glandular structures with characteristics of male prostate and bulbourethral glands, respectively, were found. The vestibule opened through a vertical vulvar cleft to the exterior. A pair of well-differentiated Wolffian ducts with a central lumen originated ventrally at the vaginal opening into the vestibule and passed in a cranial direction through the ventral vaginal and uterine wall. Each duct extended highly coiled along the ipsilateral uterine tube until the lateral pole of the ovaries where it merged with the rete ovarii. Discussion The reproductive morphology of giant anteaters reveals characteristics shared with other Xenarthrans: intraabdominal testes, a simple uterus, and a double caudal vagina. The persistence of well-differentiated genital ducts of the opposite sex in both males and females, however, singles them out among other species. These structures are the results of an aberration during fetal sexual differentiation and possess secretory functions. The possibility of a pathological degeneration of these organs should be considered in reproductive medicine of the species. Conclusion Knowledge of the unique reproductive characteristics of the giant anteater is essential for future reproductive management of the species. Additionally, further research on the peculiarities of the persisting genital duct structures might help to understand sexual differentiation in placental mammals in general.

Development of urogenital system in the Spix cavy: A model for studies on sexual differentiation

2018 ◽  
Vol 101 ◽  
pp. 25-38 ◽  
Author(s):  
Amilton Cesar dos Santos ◽  
Alan James Conley ◽  
Moacir Franco de Oliveira ◽  
Antônio Chaves de Assis Neto
Keyword(s):  
Sexual Differentiation ◽  
Urogenital System

scholarly journals Effect of Cadmium Chloride on the Histological Structure of Lung in Adult Male Mice with and without Parsley Oil

2021 ◽  
Vol 9 (A) ◽  
pp. 676-679
Author(s):  
Maha Alsammak
Keyword(s):  
Body Weight ◽  
Adult Male ◽  
Cadmium Chloride ◽  
Single Daily Dose ◽  
Control Group ◽  
Histological Structure ◽  
Microscopical Examination ◽  
Male Mice ◽  
Daily Dose ◽  
Intragastric Tube

This study is to detect the toxic effect of cadmium chloride on the histological structure of the lung and the effect of parsley oil to amilorate these changes  In this experiement 40 adult male mice were divided into four groups. Goup A (control group) in this group animals were injected with the normal saline intraperitoneally single daily dose for 30 days. Group B injected intrapertioneally with cadmium chloride single daily dose 3.5 mg/kg body weight for 30 days. Group C injected intraperetonially with cadmium chloride in a dose of 3.5 mg/kg body weight. Intragastric tube was put to recieve parsley oil in a dose of 0.5 ml/kg body weight prior to cadmium injection. The two drugs were given for 30 days. Group D recieved 0.5 ml/kg body weight by intragastric tube of parsley oil for 30 days. At the end of this experiement, the animals were sacrified the lungs were collected from all groups and prepared for light microscopical examination. Histological changes were detected in cadmium chloride treated group in comparison with the control group including congestion, inflammatory cell infiltration, interstial pneumonia (decreased alveolar space), thickening of interalveolar septum and damge to the alveolar cells. All these changes were eliminated by giving parsley oil.

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