The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
Andrea Bischoff - One of the best experts on this subject based on the ideXlab platform.
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A Cloacal anomaly is not a disorder of sex development
Pediatric Surgery International, 2019Co-Authors: Andrea Bischoff, Andrew Trecartin, Veronica Alaniz, Sarah Hecht, Duncan T Wilcox, Alberto PeñaAbstract:Aim of the study Misdiagnosing a Cloaca as a disorder of sex development may lead to inappropriate testing, treatment, and negative emotional consequences to families. We were impressed by the fact that a significant number of patients suffering from a Cloaca were referred to us with the diagnosis of a “disorder of sex development” previously referred as “ambiguous genitalia” or “intersex”. On re-evaluation, none of them truly had a disorder of sex differentiation. This prompted us to conduct the following retrospective review to try to find the cause of the misdiagnosis and the way to prevent it. Methods A retrospective review of our colorectal database was performed to identify the total number of patients with Cloacas and the number initially diagnosed as “ambiguous genitalia, intersex”/disorder of sex development. The external appearance of their genitalia and unnecessary testing or treatment received were recorded. Main results A total of 605 patients with Cloacas were identified. Of these, 77 (12.7%) were referred to us with the diagnosis of “ambiguous genitalia” and 13 of them (17%) went on to receive an intervention that was not indicated: karyotyping (10), steroids (3), and ovarian biopsy (1). The karyotype result in all patients was XX. The misdiagnosis was triggered by the external appearance of the perineum, simulating a case of virilization with a hypertrophic clitoris, but was simply prominent labial skin. Careful examination of the perineal structure allowed us to determine that it consisted of folded skin with no evidence of corpora. Conclusion Patients born with a Cloaca are at risk for mismanagement from being erroneously labeled as disorders of sex development. The diagnosis of a Cloacal anomaly is a clinical one. The practitioner must distinguish between phallus-like clitoral hypertrophy and a normal clitoris with prominent labial skin.
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a Cloacal anomaly is not a disorder of sex development
Pediatric Surgery International, 2019Co-Authors: Andrea Bischoff, Andrew Trecartin, Veronica Alaniz, Sarah Hecht, Duncan T Wilcox, Alberto PeñaAbstract:Misdiagnosing a Cloaca as a disorder of sex development may lead to inappropriate testing, treatment, and negative emotional consequences to families. We were impressed by the fact that a significant number of patients suffering from a Cloaca were referred to us with the diagnosis of a “disorder of sex development” previously referred as “ambiguous genitalia” or “intersex”. On re-evaluation, none of them truly had a disorder of sex differentiation. This prompted us to conduct the following retrospective review to try to find the cause of the misdiagnosis and the way to prevent it. A retrospective review of our colorectal database was performed to identify the total number of patients with Cloacas and the number initially diagnosed as “ambiguous genitalia, intersex”/disorder of sex development. The external appearance of their genitalia and unnecessary testing or treatment received were recorded. A total of 605 patients with Cloacas were identified. Of these, 77 (12.7%) were referred to us with the diagnosis of “ambiguous genitalia” and 13 of them (17%) went on to receive an intervention that was not indicated: karyotyping (10), steroids (3), and ovarian biopsy (1). The karyotype result in all patients was XX. The misdiagnosis was triggered by the external appearance of the perineum, simulating a case of virilization with a hypertrophic clitoris, but was simply prominent labial skin. Careful examination of the perineal structure allowed us to determine that it consisted of folded skin with no evidence of corpora. Patients born with a Cloaca are at risk for mismanagement from being erroneously labeled as disorders of sex development. The diagnosis of a Cloacal anomaly is a clinical one. The practitioner must distinguish between phallus-like clitoral hypertrophy and a normal clitoris with prominent labial skin.
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The surgical treatment of Cloaca
Seminars in Pediatric Surgery, 2015Co-Authors: Andrea BischoffAbstract:Similar to other anorectal malformations, Cloaca also represents a spectrum of defects that goes from "benign" Cloaca with a good functional prognosis that can be repaired with a relatively simple surgical technique, to very complex malformations with many anatomic variations that require different surgical maneuvers to be able to successfully reconstruct those patients. The group of patients born with a "benign" type of Cloaca will have bowel and urinary control, will become sexually active and may get pregnant and deliver by cesarean section. All this is possible, provided the malformation is repaired with a meticulous and delicate technique. Fortunately this represents more than 50% of all Cloacas. Our belief is that the surgical technique to repair this group of defects is reproducible and can be taught to pediatric surgical trainees. On the other hand, complex Cloaca with a common channel longer than 3 cm should be repaired by surgeons fully dedicated to repair these malformations. The experience reported in this paper is based on 570 patients with Cloaca operated by Dr. Alberto Pena and the author in the last 8 years.
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Cloaca, Posterior Cloaca and Absent Penis Spectrum
Surgical Treatment of Colorectal Problems in Children, 2015Co-Authors: Alberto Peña, Andrea BischoffAbstract:Cloaca This is one of the most extensive chapters of the book because of its relevance. Since 1982, when the first Cloaca was repaired via posterior sagittal approach, over 500 cases have been operated by the senior author, and many lessons have been learned. Based on this experience, it is that now Cloacas are described as a spectrum of defects with multiple anatomic variations. For each anatomic variation, a different surgical maneuver is indicated. This experience is presented in a systematic way, describing what is called the decision-making algorithm in the management of Cloacas, beginning with a simple type of defects with excellent functional prognosis and going into more complex defects, describing different surgical alternatives. Special emphasis is placed on the surgical treatment of Cloacas with good functional prognosis with a common channel shorter than 3 cm, describing in detail a very valuable surgical maneuver called “total urogenital mobilization.” This is illustrated with photographic intraoperative material, artwork, and special animations. Also, this type of material is presented to describe more complex maneuvers like “vaginal switch” and vaginal replacement. Space is dedicated to the neonatal management of patients with Cloacas because of its relevance for the preservation of renal function. Subsequently, the authors present a detailed description of the best way to protect the kidneys after the repair, considering the fact that most of these patients have very important urologic issues. Further discussion is focused on the obstetric and gynecologic implications of Cloacas based on the long-term follow-up of patients born with these defects.
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The great divide: septation and malformation of the Cloaca, and its implications for surgeons
Pediatric Surgery International, 2014Co-Authors: Anita Gupta, Andrea Bischoff, Alberto Peña, Laura A. Runck, Géraldine GuaschAbstract:The anorectal and urogenital systems arise from a common embryonic structure termed Cloaca. Subsequent development leads to the division/septation of the Cloaca into the urethra, urinary bladder, vagina, anal canal, and rectum. Defective Cloacal development and the resulting anorectal and urogenital malformations are some of the most severe congenital anomalies encountered in children. In the most severe form in females, the rectum, vagina, and urethra fail to develop separately and drain via a single common channel known as a Cloaca into the perineum. In this review, we summarize our current knowledge of embryonic Cloaca development and malformation, and compare them to what has already been described in the literature. We describe the use of mouse models of Cloaca malformation to understand which signaling pathways and cellular mechanisms are involved in the process of normal Cloaca development. We also discuss the embryological correlation of the epithelial and stromal histology found in step sections of the common channel in 14 human Cloaca malformations. Finally, we highlight the significance of these findings, compare them to prior studies, and discuss their implications for the pediatric surgeons. Understanding and identifying the molecular basis for Cloaca malformation could provide foundation for tissue engineering efforts that in the future would reflect better surgical reconstruction and improved quality of life for patients.
Alberto Peña - One of the best experts on this subject based on the ideXlab platform.
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A Cloacal anomaly is not a disorder of sex development
Pediatric Surgery International, 2019Co-Authors: Andrea Bischoff, Andrew Trecartin, Veronica Alaniz, Sarah Hecht, Duncan T Wilcox, Alberto PeñaAbstract:Aim of the study Misdiagnosing a Cloaca as a disorder of sex development may lead to inappropriate testing, treatment, and negative emotional consequences to families. We were impressed by the fact that a significant number of patients suffering from a Cloaca were referred to us with the diagnosis of a “disorder of sex development” previously referred as “ambiguous genitalia” or “intersex”. On re-evaluation, none of them truly had a disorder of sex differentiation. This prompted us to conduct the following retrospective review to try to find the cause of the misdiagnosis and the way to prevent it. Methods A retrospective review of our colorectal database was performed to identify the total number of patients with Cloacas and the number initially diagnosed as “ambiguous genitalia, intersex”/disorder of sex development. The external appearance of their genitalia and unnecessary testing or treatment received were recorded. Main results A total of 605 patients with Cloacas were identified. Of these, 77 (12.7%) were referred to us with the diagnosis of “ambiguous genitalia” and 13 of them (17%) went on to receive an intervention that was not indicated: karyotyping (10), steroids (3), and ovarian biopsy (1). The karyotype result in all patients was XX. The misdiagnosis was triggered by the external appearance of the perineum, simulating a case of virilization with a hypertrophic clitoris, but was simply prominent labial skin. Careful examination of the perineal structure allowed us to determine that it consisted of folded skin with no evidence of corpora. Conclusion Patients born with a Cloaca are at risk for mismanagement from being erroneously labeled as disorders of sex development. The diagnosis of a Cloacal anomaly is a clinical one. The practitioner must distinguish between phallus-like clitoral hypertrophy and a normal clitoris with prominent labial skin.
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a Cloacal anomaly is not a disorder of sex development
Pediatric Surgery International, 2019Co-Authors: Andrea Bischoff, Andrew Trecartin, Veronica Alaniz, Sarah Hecht, Duncan T Wilcox, Alberto PeñaAbstract:Misdiagnosing a Cloaca as a disorder of sex development may lead to inappropriate testing, treatment, and negative emotional consequences to families. We were impressed by the fact that a significant number of patients suffering from a Cloaca were referred to us with the diagnosis of a “disorder of sex development” previously referred as “ambiguous genitalia” or “intersex”. On re-evaluation, none of them truly had a disorder of sex differentiation. This prompted us to conduct the following retrospective review to try to find the cause of the misdiagnosis and the way to prevent it. A retrospective review of our colorectal database was performed to identify the total number of patients with Cloacas and the number initially diagnosed as “ambiguous genitalia, intersex”/disorder of sex development. The external appearance of their genitalia and unnecessary testing or treatment received were recorded. A total of 605 patients with Cloacas were identified. Of these, 77 (12.7%) were referred to us with the diagnosis of “ambiguous genitalia” and 13 of them (17%) went on to receive an intervention that was not indicated: karyotyping (10), steroids (3), and ovarian biopsy (1). The karyotype result in all patients was XX. The misdiagnosis was triggered by the external appearance of the perineum, simulating a case of virilization with a hypertrophic clitoris, but was simply prominent labial skin. Careful examination of the perineal structure allowed us to determine that it consisted of folded skin with no evidence of corpora. Patients born with a Cloaca are at risk for mismanagement from being erroneously labeled as disorders of sex development. The diagnosis of a Cloacal anomaly is a clinical one. The practitioner must distinguish between phallus-like clitoral hypertrophy and a normal clitoris with prominent labial skin.
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Cloaca, Posterior Cloaca and Absent Penis Spectrum
Surgical Treatment of Colorectal Problems in Children, 2015Co-Authors: Alberto Peña, Andrea BischoffAbstract:Cloaca This is one of the most extensive chapters of the book because of its relevance. Since 1982, when the first Cloaca was repaired via posterior sagittal approach, over 500 cases have been operated by the senior author, and many lessons have been learned. Based on this experience, it is that now Cloacas are described as a spectrum of defects with multiple anatomic variations. For each anatomic variation, a different surgical maneuver is indicated. This experience is presented in a systematic way, describing what is called the decision-making algorithm in the management of Cloacas, beginning with a simple type of defects with excellent functional prognosis and going into more complex defects, describing different surgical alternatives. Special emphasis is placed on the surgical treatment of Cloacas with good functional prognosis with a common channel shorter than 3 cm, describing in detail a very valuable surgical maneuver called “total urogenital mobilization.” This is illustrated with photographic intraoperative material, artwork, and special animations. Also, this type of material is presented to describe more complex maneuvers like “vaginal switch” and vaginal replacement. Space is dedicated to the neonatal management of patients with Cloacas because of its relevance for the preservation of renal function. Subsequently, the authors present a detailed description of the best way to protect the kidneys after the repair, considering the fact that most of these patients have very important urologic issues. Further discussion is focused on the obstetric and gynecologic implications of Cloacas based on the long-term follow-up of patients born with these defects.
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The great divide: septation and malformation of the Cloaca, and its implications for surgeons
Pediatric Surgery International, 2014Co-Authors: Anita Gupta, Andrea Bischoff, Alberto Peña, Laura A. Runck, Géraldine GuaschAbstract:The anorectal and urogenital systems arise from a common embryonic structure termed Cloaca. Subsequent development leads to the division/septation of the Cloaca into the urethra, urinary bladder, vagina, anal canal, and rectum. Defective Cloacal development and the resulting anorectal and urogenital malformations are some of the most severe congenital anomalies encountered in children. In the most severe form in females, the rectum, vagina, and urethra fail to develop separately and drain via a single common channel known as a Cloaca into the perineum. In this review, we summarize our current knowledge of embryonic Cloaca development and malformation, and compare them to what has already been described in the literature. We describe the use of mouse models of Cloaca malformation to understand which signaling pathways and cellular mechanisms are involved in the process of normal Cloaca development. We also discuss the embryological correlation of the epithelial and stromal histology found in step sections of the common channel in 14 human Cloaca malformations. Finally, we highlight the significance of these findings, compare them to prior studies, and discuss their implications for the pediatric surgeons. Understanding and identifying the molecular basis for Cloaca malformation could provide foundation for tissue engineering efforts that in the future would reflect better surgical reconstruction and improved quality of life for patients.
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Defining the molecular pathologies in Cloaca malformation: similarities between mouse and human
Disease Models & Mechanisms, 2014Co-Authors: Laura A. Runck, Andrea Bischoff, Alberto Peña, Marc A. Levitt, Anita Gupta, Anna M. Method, Margaret H. Collins, Shiva Kumar Shanmukhappa, James M. Wells, Géraldine GuaschAbstract:Anorectal malformations are congenital anomalies that form a spectrum of disorders, from the most benign type with excellent functional prognosis, to very complex, such as Cloaca malformation in females in which the rectum, vagina and urethra fail to develop separately and instead drain via a single common channel into the perineum. The severity of this phenotype suggests that the defect occurs in the early stages of embryonic development of the organs derived from the Cloaca. Owing to the inability to directly investigate human embryonic Cloaca development, current research has relied on the use of mouse models of anorectal malformations. However, even studies of mouse embryos lack analysis of the earliest stages of Cloaca patterning and morphogenesis. Here we compared human and mouse Cloaca development and retrospectively identified that early mis-patterning of the embryonic Cloaca might underlie the most severe forms of anorectal malformation in humans. In mouse, we identified that defective sonic hedgehog (Shh) signaling results in early dorsal-ventral epithelial abnormalities prior to the reported defects in septation. This is manifested by the absence of Sox2 and aberrant expression of keratins in the embryonic Cloaca of Shh knockout mice. Shh knockout embryos additionally develop a hypervascular stroma, which is defective in BMP signaling. These epithelial and stromal defects persist later, creating an indeterminate epithelium with molecular alterations in the common channel. We then used these animals to perform a broad comparison with patients with mild-to-severe forms of anorectal malformations including Cloaca malformation. We found striking parallels with the Shh mouse model, including nearly identical defective molecular identity of the epithelium and surrounding stroma. Our work strongly suggests that early embryonic Cloacal epithelial differentiation defects might be the underlying cause of severe forms of anorectal malformations in humans. Moreover, deranged Shh and BMP signaling is correlated with severe anorectal malformations in both mouse and humans.
Prem Puri - One of the best experts on this subject based on the ideXlab platform.
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Vagal neural crest contribution to the chick embryo Cloaca.
Pediatric Surgery International, 2006Co-Authors: Anne-marie O’ Donnell, John Bannigan, Prem PuriAbstract:Intrinsic innervation of the developing chick Cloaca is provided by the enteric nervous system, a network of neurons and glia that lies within its walls. The enteric nervous system originates from neural crest cells that migrate from the vagal and sacral regions of the neural tube during the early stages of development. Abnormal Cloacal development can cause a number of anorectal anomalies including persistent Cloaca. Our study aimed to investigate the contribution of vagal neural crest cells to the total population of enteric neurons and glia within the chick embryo Cloaca, using quail-chick chimeras. Chicken embryos were incubated until the 10–12 somite stage (ss). The vagal neural tube, corresponding to somites 1–7, was then microsurgically ablated in ovo and isochronic and isotopic quail grafts were performed. The eggs were then reincubated until embryos were harvested at E12. Whole embryos were fixed in Bouin’s fluid, embedded in paraffin wax and sectioned. Immunohistochemistry was carried out using the HNK-1 antibody to label all neural crest cells, and the quail-specific antibody, QCPN, to label quail cells. QCPN-immunoreactive cells were seen to make up a large proportion of enteric neurons and glia within the walls of the embryonic Cloaca. HNK-1 labelled all neural crest cells in the myenteric and submucosal plexuses as well as the sacral crest-derived nerve of Remak, while QCPN-positive cells were evident in both plexuses but mostly in the submucosal plexus, where they appeared to make up the majority of neurons. Results show that the chick embryo Cloaca is primarily innervated by vagal neural crest cells. Further studies to investigate the contribution of sacral neural crest cells to the same region will give further insight into the development of the enteric nervous system within the embryonic Cloaca.
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differences in nitrergic innervation of the developing chick Cloaca and colorectum
Pediatric Surgery International, 2006Co-Authors: John Bannigan, A M O Donnell, Prem PuriAbstract:The intrinsic innervation of the developing gut has long been a subject of investigation, but little is known regarding that of the embryonic Cloaca. The Cloaca, like the rest of the gastrointestinal tract, is intrinsically innervated by the enteric nervous system. Nitrergic neurons and fibres make up a large part of this system, thus, their distribution provides us with a useful insight into its development. Cloacal and colorectal tissue specimens were removed from chick embryos at embryonic days 11 (E11), E15 and E19. NADPH-diaphorase (NADPH-d) histochemistry was carried out using whole mount tissue preparations. Ganglia density, the number of NADPH-d-positive cells per ganglia in the myenteric plexus and cell size were calculated and statistical analysis was performed to compare both regions of the gut (P<0.001). There were significant differences in the ganglia density in the Cloaca compared to the colorectum at E11 (P<0.05) and E15 (P<0.01), with the colorectum having a much denser network. In both the Cloaca and the colorectum, ganglia density significantly decreased with age (P<0.001), while significant differences were observed in the number of NADPH-d-positive cells per ganglia in both regions through development. Total cell size was similar in both the Cloaca and colorectum at each stage and increased in both regions through development, predominantly due to an increase in the cytoplasm. Results reveal striking differences in innervation between the chick embryo Cloaca and colorectum. The sparse network of innervation evident within the Cloaca in contrast to the dense network within the colorectum emphasizes the individuality of both regions. These results highlight the need for a further in-depth analysis of the enteric nervous system’s development within the embryonic Cloaca.
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Differences in nitrergic innervation of the developing chick Cloaca and colorectum.
Pediatric Surgery International, 2005Co-Authors: A M O Donnell, John Bannigan, Prem PuriAbstract:The intrinsic innervation of the developing gut has long been a subject of investigation, but little is known regarding that of the embryonic Cloaca. The Cloaca, like the rest of the gastrointestinal tract, is intrinsically innervated by the enteric nervous system. Nitrergic neurons and fibres make up a large part of this system, thus, their distribution provides us with a useful insight into its development. Cloacal and colorectal tissue specimens were removed from chick embryos at embryonic days 11 (E11), E15 and E19. NADPH-diaphorase (NADPH-d) histochemistry was carried out using whole mount tissue preparations. Ganglia density, the number of NADPH-d-positive cells per ganglia in the myenteric plexus and cell size were calculated and statistical analysis was performed to compare both regions of the gut (P
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The effect of vagal neural crest ablation on the chick embryo Cloaca
Pediatric Surgery International, 2004Co-Authors: A M O Donnell, John Bannigan, Prem PuriAbstract:The Cloaca, the caudal limit of the avian gastrointestinal tract, acts as a collecting chamber into which the gastrointestinal, urinary, and genital tracts discharge. It is intrinsically innervated by the enteric nervous system, which is derived from neural crest emigres that migrate from the vagal and sacral regions of the neural tube. Abnormal Cloacal development can cause a number of anorectal anomalies, including persistent Cloaca. Ablation of the vagal neural crest has previously been shown to result in an aganglionic hindgut to the extent of the colorectum. The aim of our study was to investigate the effect of vagal neural crest ablation on the Cloaca, the limit of the hindgut in the developing chick embryo. Chick embryos were incubated until the 10–12 somite stage. The vagal neural tube corresponding to the level of somites 3–6 was then ablated, and eggs were incubated until harvested on embryonic day 11 (E11). Whole chick embryos were fixed, embedded in paraffin, and sectioned. Immunohistochemistry was then carried out using the HNK-1 monoclonal antibody to label neural crest cells, and results were assessed by light microscopy. Vagal neural crest ablation resulted in a dramatic decrease in the number of neural crest cells colonizing the chick embryo Cloaca compared with control embryos. Ablated embryos contained only a small number of HNK-1-positive neural crest cells, which were scattered within the myenteric plexus in a disorganised pattern. Hypoganglionosis was also evident in other regions of the hindgut in ablated embryos. Ablation of the vagal neural crest results in a hypoganglionic Cloaca in addition to hypoganglionosis of the hindgut. These results suggest that the Cloaca is largely innervated by vagal neural crest emigres. Further studies involving quail-chick chimeras to investigate the exact contribution provided by both vagal and sacral neural crest cells to the Cloaca should increase our understanding of the pathophysiology of conditions like persistent Cloaca.
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The timing of enteric neural crest cell colonisation of the chick embryo Cloaca.
Pediatric Surgery International, 2004Co-Authors: A.m. O’donnell, A. Mortell, J. Giles, John Bannigan, Prem PuriAbstract:Neural crest cell (NCC) migration and formation of the enteric nervous system (ENS) is an essential process in the development of the normal human gut. Abnormalities of the ENS lead to a number of neurochristopathies. In avian embryos, the Cloaca acts as a common chamber into which gastrointestinal, urinary and genital tracts emerge. Previous studies have elucidated the specific timeframes at which NCCs reach the various regions of the developing chick gut but, to date, none have looked at NCC colonisation of the Cloaca. The aim of our study was to investigate the exact timing of the appearance of NCCs in the Cloaca of chick embryos. Chicken embryos were harvested on embryonic days (E) 8–12. Whole embryos were fixed, embedded in paraffin and sectioned. Fluorescent immunohistochemistry, using an anti-HNK-1/N-CAM monoclonal antibody, was performed and images were obtained by confocal microscopy. There was no evidence of NCCs in the Cloaca of embryos from E8 to E11. Intense immunoreactivity to HNK-1 first appeared in the Cloaca of E12 embryos, demonstrating a profuse circumferential colonisation by NCCs at this time. Our study is the first to show the exact timing of enteric NCC colonisation of the chick embryo Cloaca. Further studies, involving quail-chick chimeras, are required to establish the true origin of Cloacal NCCs and to establish the relationship between NCCs and persistent Cloaca.
Edwin A Smith - One of the best experts on this subject based on the ideXlab platform.
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disorders of the bladder and Cloacal anomaly
Clinics in Perinatology, 2014Co-Authors: Angela M Arlen, Edwin A SmithAbstract:The incidence of congenital urachal, bladder, and Cloacal anomalies is low. Urachal remnants are the result of failure or delay in obliteration of the allantois. Exstrophy of the bladder or Cloaca can be diagnosed on prenatal ultrasonography and represent a deviation from the normal embryologic sequence. Persistent Cloaca is an anomaly occurring in girls, in which a common cavity exists into which the intestinal, urinary, and reproductive tracts all open. It is also often diagnosed on prenatal imaging.
David M. Sever - One of the best experts on this subject based on the ideXlab platform.
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A Description of the Skin Glands and Cloacal Morphology of the Plethodontid Salamander Karsenia koreana
Copeia, 2016Co-Authors: David M. Sever, Adrienne D. Pinsoneault, Brett Wagner Mackenzie, Dustin S. Siegel, Nancy L. StaubAbstract:The skin glands and Cloacal morphology of the Korean crevice salamander, Karsenia koreana, were similar to those of other plethodontids. The skin contained mucous, granular, and modified granular glands in varying frequencies and sizes. Males had sexually dimorphic glands in the skin of the chin (mental glands) and the dorsal tail base (caudal courtship glands). On the ventral surface of the tail base, modified granular glands were sexually dimorphic in size, with male glands larger than those in females. The Cloacal glands in males, as in other plethodontids, consisted of four eosinophilic gland clusters (dorsal pelvic glands, lateral pelvic glands, caudal pelvic glands, and vent glands) and three basophilic glands (anterior ventral glands, posterior ventral glands, and Kingsbury's glands). In females, the only Cloacal gland was the spermatheca, which, as in other plethodontids, was a compound tubulo-alveolar gland in the roof of the Cloaca.
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Cloacae Cloacal glands and female sperm storage in giant salamanders
2013Co-Authors: David M. SeverAbstract:Most of the 620+ species of salamanders are relatively small animals, rarely exceeding 200 mm total length, but members of the families Cryptobranchidae (1800 mm), Sirenidae (978 mm), Amphiumidae (1162 mm), Proteidae (486 mm) and Dicamptodontidae (351 mm) can truly be considered "giant salamanders." These families have few species (Proteidae with six species is the most speciose) and are aquatic paedomorphs except for Dicamptodontidae, in which the four species can metamorphose. All families except Cryptobranchidae, which has single species in China and Japan, are limited in distribution to North America. Cryptobranchidae and Sirenidae reproduce with external fertilization, whereas species in the other families have internal fertilization and females store sperm in Cloacal spermathecae. Males of the internal fertilizers possess Cloacal glands that make spermatophores. The only sister group relationship that has been proposed is between Sirenidae and Proteidae. This paper brings together and summarizes information from a number of separate studies on histology of the Cloaca and Cloacal glands and ultrastructure of sperm storage, when it occurs, in the giant salamanders. Proteids have Cloacae similar to those of other internal fertilizing salamanders, and if the sister group relationship with sirenids is valid, this means that internal fertilization and associated Cloacal structures were lost in sirenids or they evolved independently in proteids. The Cloacal evidence, however, supports the proposal in one recent paper to return the Dicamptodon, the only extant genus in the Dicamptodontidae, to its traditional position in the Ambystomatidae.
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sperm storage in female plethodontids with especial reference to the desmognathinae
2000Co-Authors: David M. SeverAbstract:Three families of salamanders (Sirenidae, Cryptobranchidae, and Hynobiidae) reproduce by external fertilization (Sever, 1991a; Sever et al., 1996). The remaining seven families, composing the suborder Salamandroidea, undergo internal fertilization (Duellman and Trueb, 1986). Internal fertilization occurs after a sperm-bearing spermatophore produced by the male is introduced directly or indirectly into the Cloacal orifice of the female after ritualized courtship (Sever and Houck, 1985). Sperm from the cap migrate into sperm storage tubules in the walls of the female Cloaca (Sever and Brizzi, 1998). In the Plethodontidae, these tubules are organized into a single compound tubuloalveolar gland, a complex spermatheca (Fig. 1). Multiple simple tubular glands, simple spermathecae, are found in other families in the Salamandroidea. Sperm are stored in these female Cloacal glands in oviparous species until oviposition, when sperm are released onto eggs as they pass through the Cloaca, providing the means for internal fertilization (Jordan, 1893). In the few species in the Salamandridae that are ovoviviparous or viviparous, fertilization occurs in the oviduct (Boisseau and Joly, 1975).