共查询到20条相似文献,搜索用时 15 毫秒
1.
R K Linskens R J Odink J C van der Linden S Ekkelkamp H A Delemarre-van de Waal 《Hormone research》1992,37(6):241-244
This report discusses the clinical findings on two patients with 45,X/46,XY mosaicism, two boys presented with penile hypospadias and cryptorchidism. A dysgenetic ovary and a testis were found in one boy, and a dysgenetic ovary in the other. Both patients can be considered to be true hermaphrodites on the basis of histology and clinical and hormonal observations. 45,X/46,XY mosaics have a wide range of phenotypic appearances and their gonadal morphology can also show great differences. However, the incidence of true hermaphroditism in individuals with 45,X/46,XY mosaicism is low and the reports in the literature rare. It is likely that males with 45,X/46,XY who suffer only mild maldevelopment of the external genitalia will not be recognized. In all patients with penoscrotal hypospadias and cryptorchidism with 45,X/46,XY mosaicism, the possibility of true hermaphroditism should be considered. 相似文献
2.
The breadth of anatomical and functional diversity among amniote external genitalia has led to uncertainty about the evolutionary origins of the phallus. In several lineages, including the tuatara, Sphenodon punctatus, adults lack an intromittent phallus, raising the possibility that the amniote ancestor lacked external genitalia and reproduced using cloacal apposition. Accordingly, a phallus may have evolved multiple times in amniotes. However, similarities in development across amniote external genitalia suggest that the phallus may have a single evolutionary origin. To resolve the evolutionary history of amniote genitalia, we performed three-dimensional reconstruction of Victorian era tuatara embryos to look for embryological evidence of external genital initiation. Despite the absence of an intromittent phallus in adult tuataras, our observations show that tuatara embryos develop genital anlagen. This illustrates that there is a conserved developmental stage of external genital development among all amniotes and suggests a single evolutionary origin of amniote external genitalia. 相似文献
3.
Kamikawa-Miyado M Ogi H Ogino Y Katoh H Suzuki K Uemura M Kitoh J Oda S Yamada G 《Zoological science》2005,22(4):463-468
External genitalia are the reproductive organs necessary for efficient copulation and internal fertilization in various mammalian species. Their morphogeneses display significant morphological and developmental differences among species. The house musk shrew, Suncus murinus (hereafter described as suncus) is a species of the order Insectivora, which has been considered as primitive and one of the earliest eutheria phylogenetically. Comparative anatomical analyses of phylogenetically different mammals will contribute to the better understanding of morphological diversity of external genitalia. This study performed various anatomical and histological analyses concerning the organization of the external genitalia of male suncus. It was shown that the external genitalia of suncus possessed a muscular structure, which we proposed as musculus ischiocavernosus dorsalis of suncus. The musculus ischiocavernosus dorsalis is originated from the inner surface of the tuber ischiadicum and was allocated adjacent to the corpus cavernosum penis. In addition, a pair of alpha-smooth muscle actin positive muscles was located bilaterally to the urethra. This unique morphology of the external genitalia of suncus males may provide a unique model system to investigate genital morphogenesis. 相似文献
4.
Freemartinism in two animals from a captive herd of Rocky Mountain bighorn sheep (Ovis canadensis) at the Denver Zoological Gardens (Denver, Colorado, USA) is described. A young ewe had female external genitalia, a masculine appearance, and demonstrated male behavior as she matured. Another ewe with female external genitalia died as a yearling. Necropsy revealed a non-patent vagina and internal male genitalia. Both females were chimeric with karyotypes containing XX and XY sex chromosomes. 相似文献
5.
The appearance of the external genitalia is the major determinant of the social sex, which is announced at or shortly after birth. In the absence of normal development of the external genitalia, definitive gender assignment and its announcement have to be postponed. While over the past 20 years the pathogenesis of most disorders causing abnormal development of the genitalia have been elucidated, our knowledge regarding the impact of these defects upon the psychosexual development is rather rudimentary. This information, however, is needed not only to establish criteria for correct sex assignment but also to design relevant outcome studies. Culture is an important part of the context in which decisions are made on sex assignment of patients with abnormalities of the external genitalia. Cultural differences in dealing with intersexuality and intersex individuals not only influences the patient's own psychosexual development but also medical decisions regarding sex assignment and consecutive management. There is evidence that attitudes concerning gender and sexuality, including the acceptance of intersexuality, differ significantly between various cultures. Thus cross-cultural studies might allow a new approach in dealing with intersexed persons, their families, and their social background, a most important aspect considering the recent discussions and criticisms of patients and individuals affected with intersex disorders. 相似文献
6.
Testicular feminization is a classic form of complete male pseudohermaphroditism. The individuals have a normal XY karyotype but unambiguously female external genitalia. They have congenital complete insensitivity to androgen due to an X-linked mutation. In four patients (from tow families with several affected members) with the typical phenotype of testicular feminization, a severe deficit of specific androgen-binding activity was detected in cultured fibroblasts from labium majus skin. Measurement of this activity in genital skin fibroblasts improves the differential diagnosis in patients with complete or imcomplete male pseudohermaphroditism before puberty. 相似文献
7.
Iram Shabir Madan L. Khurana Eunice Marumudi Rajesh Khadgawat Ariachery C. Ammini 《Steroids》2013,78(12-13):1159-1163
T is converted to a more potent androgen, DHT by the action of microsomal membrane enzyme 5α reductase 2. Defects in 5α reductase 2 isozyme results in incomplete virilisation of external male genitalia. Mutations in SRD5A2 gene leads to diminished enzyme activity, thus hampering DHT synthesis from T. We describe two unrelated patients from India with 5αRD2 due to novel insertion of nucleotides in the exon 1 of SRD5A2 gene that lead to premature termination of protein. Master S (case 1; III.8) was 3 years old at initial evaluation, had perineoscrotal hypospadias, microphallus and both testes were palpable in the inguinal region. Master P (case 2; III.9) was born as normal full term baby. He had primary complaint of microphallus, penoscrotal hypospadias and gonads in the inguinal region. Diagnosis of 5αRD2 was made, as T/DHT ratio in the two cases was 41 and 131.2 respectively. Sequence analysis of SRD5A2 gene showed an insertion of nucleotides TA in exon 1 (c.188_189). This resulted in premature termination of the protein due to stop codon at amino acid position 7. The protein formed is drastically truncated and inadequate protein synthesized explains the phenotypic characteristics of our patients. 相似文献
8.
Human bites of male external genitalia are rare. We report a case of scrotal wound caused by human bite during a sexual dispute. Lesion was recent wound caused by tearing off the summit of scrotal skin without any testicular injury. The wound was successfully treated by antibiotics, surgical debridement and suture. The patient was immunized against tetanus. 相似文献
9.
MARKO MUTANEN ARJA KAITALA 《Biological journal of the Linnean Society. Linnean Society of London》2006,87(2):297-307
Insect genitals vary greatly among species and provide a key tool for species-level taxonomy. Insects differing in the genitalia are often treated as discrete, reproductively isolated species. This principle dates back to the lock-and-key hypothesis, which states that genitalia vary between species in order to provide a mechanical reproductive isolation system. Thus, the hypothesis assumes low within-species variability in genital traits. However, recent studies suggest that sexual selection may be responsible for the evolution of insect genitalia. We studied allometry and genital size and shape variation in a dimorphic moth Selenia tetralunaria . We found that the genitalia showed negative allometry in relation to body size as reported in many insect and spider species. This allometry was stronger in internal genital structures than it was in external genitalia. We also found that there was more variation in internal compared with external genitalia. Finally, we found that the shape of genital structures differed between morphs in all three examined areas. S. tetralunaria is among the first reported cases of genitally dimorphic insect species. Considerable variation in internal genitalia and especially the presence of genital shape differences between morphs were not consistent with the predictions of the lock-and-key hypothesis. © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 87 , 297–307. 相似文献
10.
Murine reproductive tissues of the external genitalia and perineum develop with remarkably distinctive characteristics in males and females. Although many researches on such mouse organ development have been reported, there are still limited parameters that evaluate the developmental sexual differences of external genitalia and perineum. Furthermore, elucidation of the recent developmental signals for the external genitalia and perineum requires up‐to‐date knowledge of gene functions in reproductive science. To promote researches on reproductive organ formation, establishment of parameters for the androgen‐mediated formation of external genitalia and perineum is essential. In this study, we propose genital sex differentiation parameters (GSDP), a set of developmental parameters based on systematic three‐dimensional tissue reconstruction and cumulative histological analyses. We define the sexual differences of external genitalia and perineum by GSDP through analyzing mouse models, androgen inhibitor‐induced feminization experiments and Mafb mutant mouse with defective urethral differentiation. The urethral parameters displayed prominent reduction by the androgen inhibitor (finasteride) treatment. However, genital tubercle (GT) size parameters were not affected by such treatment. These results indicated that sensitivity to dihydrotestosterone was different between embryonic GT size and urethral formation. Furthermore, we evaluated the extent of urethral defects of Mafb mutant mice by GSDP. Thus, GSDP is a set of useful parameters to define the sexual differences during external genitalia and perineum development. 相似文献
11.
SD Blaschko GR Cunha LS Baskin 《Differentiation; research in biological diversity》2012,84(3):261-268
External genitalia development occurs through a combination of hormone independent, hormone dependent, and endocrine pathways. Perturbation of these pathways can lead to abnormal external genitalia development. We review human and animal mechanisms of normal and abnormal external genitalia development, and we evaluate abnormal mechanisms that lead to hypospadias. We also discuss recent laboratory findings that further our understanding of animal models of hypospadias. 相似文献
12.
13.
作者对墨蚜蝇族中3属8种昆虫:东方墨蚜蝇Melanostoma orientale,方斑墨蚜蝇M.mellinum,梯斑墨蚜蝇M.scalare,天台墨蚜蝇M.tiantaiensis,黑腹宽跗蚜蝇Platycheirus albimanus,叉尾宽跗蚜蝇P.bidentatus,斜斑宽跗蚜蝇P.scutatus,圆斑宽扁蚜蝇Xanthandrus comtus进行了雄性外生殖器的比较研究,并分别予以绘图和描述。结果表明,雄性外生殖器在属内种间形态结构很相似,仅在尾器颜色、阳茎基部形状等方面有微小的区别;而在属间主要是背针突和上叶的形态和结构存在较大的不同。 相似文献
14.
Payan-Carreira R Pires MA Quaresma M Chaves R Adega F Guedes Pinto H Colaço B Villar V 《Animal reproduction science》2008,103(1-2):154-163
A case of disrupted embryonic development of the genital tract in a newborn Holstein calf is described. The physical examination of the calf evidenced several abnormalities, like atresia ani, rudimentary external genitalia and caudal vertebral agenesis. On necropsy, the excised genitalia consisted of bilateral streak gonads, apparently normal uterine tubes, a fluid-filled uterus, a long vagina and a very narrow clitoris-like structure covered with a discrete skin-fold. The urinary tract seemed normal and the urethra's opening was at the vestibule-vaginal junction. A cytogenetic analysis was requested. Karyotype revealed the existence of Y chromosome material in the two X chromosomes. However, the search for the sex-determining region Y (SRY) showed that this was an apparently absent gene. The histological examination of the gonads revealed the existence of ovarian dysplasia. Uterine sections evidenced the absence of the uterine epithelium, with only sporadic caruncles. Under microscopic examination, the uterine tubes and vagina structure was normal. The external genitalia sections revealed the existence of a skin-fold covering an erectile structure surrounding the urethra, a structure more similar to a penis than to a clitoris. This is an unusual situation of gonadal dysplasia combined with genital tract anomalies in cattle, probably associated to a genetic defect. 相似文献
15.
The process of sexual differentiation leaves genetically female individuals at risk of being masculinized by exogenous androgens. Previous research with sheep indicates that exposure to excess testosterone from Gestational Day (GD) 30 to GD 90 of the 147-day gestation masculinizes and defeminizes behavior as well as genitalia. Lower doses and shorter durations produce animals with varying degrees of genital virilization and alterations of the hypothalamic-pituitary-gonadal axis, but to our knowledge, the effects on complex behavior and its prediction by the amount of external virilization have not been explored. Previous research in rodents has suggested that sexual differentiation of the central nervous system and the external genitalia can be dissociated. Therefore, we hypothesized that the extent of virilization of external genitalia would not be predictive of the lack of female-typical, or the presence of male-typical, mating behavior. To test this hypothesis, we compared control females, females exposed to exogenous testosterone from GD 30 to GD 90 (T60 females) that have virilized genitalia, and females exposed to testosterone from GD 60 to GD 90 (T30 females) that have female-typical genitalia. Both natural behavioral estrus in the flock and hormonally controlled behavioral tests were used to explore reproductive behavior. The T60 and T30 females exhibited more masculinized reproductive behavior than the controls; however, the T30 females also exhibited feminine behavior. Neither testosterone-treated group was receptive or was mounted at rates comparable to those of controls. These data illustrate that variation in the timing or duration of exposure to prenatal testosterone during a critical period for masculinization can have variable effects on defeminization and that the effects of testosterone on genitalia are not entirely predictive of behavior. 相似文献
16.
Arhopalus ferus (Coleoptera: Cerambycidae): structure and function of the female reproductive system
J.A. Hutcheson 《New Zealand journal of zoology.》2013,40(3):417-424
Abstract Arhopalus ferus (Mulsant) female pupae and adults were dissected, and both internal and external genitalia are described. The external genitalia involve segments 8 and 9. Segment 9 and its appendages are modified into a long ovipositor which telescopes with segment 8 into segment 7 when retracted. The internal genitalia include ovaries, bursa copulatrix, spermatheca, spermathecal gland, vagina, and accessory glands. The terminology applied to coleopteran genital anatomy is critically discussed. 相似文献
17.
Molecular and genetic regulation of testis descent and external genitalia development 总被引:10,自引:0,他引:10
Testicular descent as a prerequisite for the production of mature spermatozoa and normal external genitalia morphogenesis, and therefore facilitating copulation and internal fertilization, are essential developmental steps in reproduction of vertebrate species. Cryptorchidism, the failure of testis descent, and feminization of external genitalia in the male, usually in the form of hypospadias, in which the opening of the urethra occurs along the ventral aspect of the penis, are the most frequent pediatric complications. Thus, elucidating the molecular mechanisms involved in the regulation of testis descent and the formation of external genitalia merits a special focus. Natural and transgenic rodent models have demonstrated both morphogenic processes to be under the control of a plethora of genetic factors with complex time-, space-, and dose-restricted expression pattern. The review elucidates the molecular mechanisms involved in the regulation of testis descent and the formation of external genitalia and, wherever possible, assesses the differences between these rodent animal models and other mammalian species, including human. 相似文献
18.
HOJUN SONG JOHN W. WENZEL 《Biological journal of the Linnean Society. Linnean Society of London》2008,94(2):289-301
Sexual selection theory predicts that genital structures in isolated populations are likely to diverge, but male genitalia are often species-specific, which led to the idea that male genitalia are relatively invariable within species. Previous allometric studies collectively suggested that male genitalia are intraspecifically invariable in size compared with external body parts. We investigated whether male genitalia are invariable in shape in three populations of a grasshopper Schistocerca lineata Scudder, 1899, using two independent methods of geometric morphometric analyses. Specifically, we focused on the idea that male genitalia are complex structures consisting of many functionally different components, and studied how these individual parts diverge among three populations. Individual components of male genitalia show different population-level divergence, resulting in the mosaic pattern of genital divergence. Individual components diverge independently from each other. Body size is positively correlated with genitalia size, but is significantly correlated with the shape of only one of the three genital structures we measured. Thus, different components of male genitalia may be influenced by different evolutionary processes. This study is the first to show that components of complex genitalia evolve separately within a species. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society , 2008, 94 , 289–301. 相似文献
19.
E V Shvetsov 《Arkhiv anatomii, gistologii i émbriologii》1976,70(1):73-77
Lymphatic nodes on the anterior surface of the femur, in the region of the femoral triangle were studied in 56 corpses of humans of either sex from 31 to 82 years of age, dead of accidental causes or of diseases not related to lymphatic nodes. The investigation was carried on by the method of interstitial and direct injection of the Gerota's mass to some regions of foot skin, external genitalia and the skin of the anterior wall of the abdomen. It has been established that the size of inguinal lymphatic nodes (both superficial and profound) in humans of either sex, are in direct dependence on the age of the person. The amount of inguinal lymphatic nodes in young people prevails over that in old people. The external diameter of the afferent and efferent vessels in elderly humans is greater than in young ones. The amount of afferent lymphatic vessels to inguinal lymphatic nodes in most cases prevails over the amount of efferent ones, independent of age and sex. The external diameter of the former is greater than that of the latter. 相似文献
20.
U T Hinderer 《Plastic and reconstructive surgery》1989,84(2):325-337
The techniques for correction of the external genitalia in the adrenogenital syndrome, as far as known by the author, are reviewed. The goals of repair and timing of surgery are discussed. The author's one-stage technique, first published in 1974, is described with intraoperative illustrations, and the results obtained in nine patients are discussed. The advantages of the technique are preservation of a clitoral glans with erogenous sensation based exclusively on the deep dorsal neurovascular bundle. The glans of the megaloclitoris is obliquely reduced in size at its base toward the ventral surface and by resection of up to two-thirds of the ventral segment. It is relocated at its anatomic female position. The labia minora and the introitus vaginae are reconstructed at the same stage with the skin of the megaloclitoris displaced in posterior direction after a cutback incision. Dispareunia is prevented by total excision of the corpora cavernosa, including the crura. 相似文献