Reference transcriptome assembly of a protogynous sex change fish, harlequin sandsmelt (Parapercis pulchella)

The harlequin sandsmelt (Parapercis pulchella) is a female-to-male sex change fish in which functional females possess ovotestes that consist of both ovarian and testicular tissues. These features indicate that this species could be an excellent model for studying the flexibility of sex differentiation in vertebrates. However, genetic resources in this species have so far been limited. Therefore, in this study, the reference transcriptome of this fish was constructed through RNA-sequencing, de novo transcriptome assembly, superTranscripts construction, and functional annotations. To obtain as many genes as possible, RNA was extracted from various tissues (brains, gills, hearts, livers, guts, and gonads) and various sexual stages (females, individuals during sex change, and males) and then subjected to sequencing and downstream analyses. As a result, 91,884 representative transcripts with 32,627 protein-coding sequences were generated. 72.2% of protein-coding sequences (23,566 sequences) were functionally annotated. Also, our analysis shows that the superTranscripts method effectively removes redundant sequences from raw-assembled data compared with other strategies. The resultant dataset is a valuable resource for future molecular developmental studies on sex change in P. pulchella.

Ovotesticular disorder of sex development in a 46 XY adolescent: a rare case report with review of the literature

INTRODUCTION

Ovotestis is a rare cause of sexual ambiguity characterized by the presence in a patient of both testicular and ovarian tissue, leading to the development of both male and female structures. We report a case of ovotestis diagnosed in an adolescent, with a review of the literature.

CASE REPORT

A 15-year-old patient presented with a right scrotal swelling associated with gynecomastia. Histology showed a juxtaposition of ovarian stroma with ovarian follicle and seminiferous tubules. Karyotype revealed a male subject (XY). We have therefore retained the diagnosis of ovotesticular disorders of sex development.

CONCLUSION

Ovotestis is a rare finding, heterogeneous in its genetic etiology and clinical presentation. While many patients are diagnosed during infancy or childhood, we presented a case diagnosed in a 15-year-old adolescent.

A model to study human ovotesticular syndrome

Ovotesticular syndrome is a rare disorder of sex development characterized by the presence of testicular and ovarian tissue. The histologic characteristics of human testicular tissue are well defined by the presence of seminiferous cords or tubules containing TSPY-positive germ cells and Sox9-positive Sertoli cells surrounded by interstitial tissue containing cytochrome P450-positive Leydig cells and smooth muscle α-actin-positive peritubular myoid cells. The histological characteristics of the ovary can be defined by germ cell nests and the development of follicles. In contrast to the testis, the ovary has a paucity of defined specific protein markers, with the granulosa cell marker FOXL2 being the most widely used. In practice, defining the ovarian component of the ovotestis can be quite difficult. We developed a model of human ovotesticular syndrome by combining fetal human testis and ovary in a xenograft model. Ovotesticular xenografts were grown under the renal capsules of gonadectomized athymic nude mice for 6-32 weeks along with age matched control grafts of fetal testis and ovary. Forty ovotesticular xenografts and their controls were analyzed by histology, immunohistochemistry, and fluorescent in situ hybridization to determine the protein expression and karyotype of the cells within the grafts. The ovotesticular xenografts exhibited recognizable testicular and ovarian tissue based on testis-specific and ovary-specific markers defined above. The xenografts simulated a bipolar ovotestis in which the testicular and ovarian elements retain their separate histological characteristics and are separated by a well-defined border. This contrasts with the compartmentalized ovotestis previously described in the literature where the testicular tissue is surrounded by ovarian tissue or a mixed histology where testicular and ovarian tissues are interspersed throughout the gonad. In conclusion, we have characterized a human model of ovotestis which will allow a deeper understanding of ovotestis development in humans and facilitate a more accurate diagnosis of the ovotesticular syndrome.

Whole genome sequencing identifies a missense polymorphism in PADI6 associated with testicular/ovotesticular XX disorder of sex development in dogs

Disorders of sex development (DSDs) are congenital malformations defined as discrepancies between sex chromosomes and phenotypical sex. Testicular or ovotesticular XX DSDs are frequently observed in female dogs, while monogenic XY DSDs are less frequent. Here, we applied whole genome sequencing (WGS) to search for causative mutations in XX DSD females in French Bulldogs (FB) and American Staffordshire Terries (AST) and in XY DSD Yorkshire Terries (YT). The WGS results were validated by Sanger sequencing and ddPCR. It was shown that a missense SNP of the PADI6 gene, is significantly associated with the XX DSD (SRY-negative) phenotype in AST (P = 0.0051) and FB (P = 0.0306). On the contrary, we did not find any associated variant with XY DSD in YTs. Our study suggests that the genetic background of the XX DSD may be more complex and breed-specific.

Ovotesticular Difference of Sex Development: Genetic Background, Histological Features, and Clinical Management

BACKGROUND

Ovotesticular disorder/difference of sex development (DSD) refers to the co-presence of testicular and ovarian tissue in one individual. Childhood management is challenging as there are many uncertainties regarding etiology, gonadal function, and gender outcome.

SUMMARY

Ovotesticular DSD should mainly be considered in 46,XX children with atypical genitalia and normal adrenal steroid profiles. Various underlying genetic mechanisms have been described. Histological assessment of ovotestes requires expert revision and has many pitfalls. Neonatal sex assignment is essential, but as gender outcome is unpredictable, this should be regarded as provisional until a stable gender identity has developed. Therefore, it is crucial not to perform any irreversible medical or surgical procedure in affected individuals until adolescents can give their full informed consent. Gonadal function mostly allows for spontaneous pubertal development; however, fertility is compromised, especially in boys. Specific long-term outcome data for ovotesticular DSD are lacking but can be extrapolated from studies in other DSD populations. Key Messages: Management of ovotesticular DSD has changed in recent years, prioritizing the child's future right for autonomy and self-determination. The benefits and pitfalls of this new approach have not been documented yet and require intensive monitoring on an international scale.

Photoperiod controls egg laying and caudodorsal cell hormone expression but not gonadal development in the pond snail Lymnaea stagnalis

Photoperiod is a reliable cue to regulate growth and reproduction for seasonal adaptation. Although photoperiodism has been well studied in Chordata and Arthropoda, less is known about Mollusca. We examined photoperiodic effects on egg laying, body size, gonad-somatic index, oocyte size and relative amounts of caudodorsal cell hormone mRNA in individual rearing conditions in the pond snail Lymnaea stagnalis. Twenty-five weeks after hatching, the percentages of egg-laying snails under a photoperiod of 12 h light and 12 h darkness (12L:12D) were significantly smaller than those under longer days. The total numbers of eggs and egg masses under 12L:12D were significantly smaller than those under longer days. Significant differences between 16L:8D and 12L:12D were not observed in the soft body and ovotestis weight, and the gonad-somatic index. Photoperiodic effects were also not observed in oocyte diameters twenty-two weeks after hatching. Twenty-seven weeks after hatching amounts of caudodorsal cell hormone mRNA were significantly lower in the cerebral ganglia with commissure under 12L:12D than 16L:8D. L. stagnalis exhibited a clear photoperiodic response in egg laying and the amount of caudodorsal cell hormone mRNA, but not in gonadal development. Under 12L:12D suppression of caudodorsal cell hormone expression might suppress egg laying.

A novel approach in the intraoperative management of ovotesticular DSD

Ovotesticular disorder of sex development (OTD) management remains challenging. In OTD, cautious gonadal evaluation and separation of ovarian and testicular components might be required to avoid virilization of a patient with female identity. Herein we report our minimal invasive approach in this very rare condition. The gonads are externalized under laparoscopic control through trocar openings. Intraoperative ovotesticular ultrasonography (US) is used for clear identification of ovarian and testicular tissue which can then be safely separated. We strongly promote the use of a minimal invasive approach in the management of these patients undergoing long term treatment and often multiple procedures.

Various Genital and Reproductive Phenotypes in 46,XX/46,XY Chimeras

Tetragametic chimeras are due to the fusion of 2 different zygotes after fertilization. When occurring between embryos of different chromosomal sex, the phenotype ranges from fertile individuals to infertile patients and even to patients with variations in sex development. Here, we report 3 new cases of XX/XY chimeras, one in a young boy carrying an abnormal gonad which turned out to be an ovary and 2 in phenotypically normal infertile men, one of whom had been diagnosed previously as a XX-SRY negative male. These cases highlight the importance of combining several cytogenetic and molecular techniques on different tissues for a proper diagnosis and an appropriate prognosis.

Puberty in Patients with Ovotesticular DSD: Evaluation of 20 Patients and Review of the Literature

BACKGROUND

Ovotesticular Difference of Sex Development (OT DSD) is a rare condition characterized by histologic demonstration of ovarian and testicular tissue in the same individual. Descriptions in literature usually do not include long term follow-up data.

OBJECTIVES

The aim of this study is to describe clinical, biochemical and histological findings, as well as long term outcomes (including onset and progression of puberty) in patients with OT DSD.

RESULTS

In a retrospective study of 31 patients, findings include predominantly male gender assignment at the time of referral (54.8%) and subsequent female gender of rearing (54.8%). The most frequent karyotype was 46,XX (58.1%). Ovotestis was the most frequent gonad (48.4%) Puberty could be evaluated in 20 patients, being spontaneous in 12 of them. Four patients with partial gonadectomy in infancy were able to enter female puberty spontaneously.

CONCLUSION

It was observed that patients who preserved gonadal tissues were able to enter puberty spontaneously.

Endocrine Management of Ovotesticular DSD, an Index Case and Review of the Literature

Ovotesticular Differences in Sexual Development (OT-DSD) is a rare subset of DSD with great phenotypic variability characterized by the presence of both testicular and ovarian tissue in the same individual. Here, we describe the case of 46,XX, SRY-negative baby with ambiguous genitalia and ovotestis discovered during laparoscopy. As the family decided on female gender of rearing, the testicular component of the ovotestis was removed while the ovarian component was preserved. Stemming from this case, we review the clinical presentation of OT-DSD throughout ages, the role of genetics and risk for gonadal tumors when making decisions about prophylactic gonadectomy. Finally, we summarize the most recent information of the spontaneous endocrine function, with or without conservative therapy, and fertility potential of people with OT-DSD.

Ovotesticular Disorder of Sex Development: An Unusual Presentation

Disorder of sex development is an inclusive term that refers to any problem where the genital organ is atypical in relation to chromosomes or gonads. Ovotesticular disorder of sex development, which is formerly known as "true hermaphroditism," is the most rare form among all disorders of sex development in humans. It is characterized by the simultaneous presence of both ovarian and testicular tissues in the same individual and characteristically presents with ambiguous genitalia in neonates or infants. Herein, we present an unusual case of a 19-year-old individual with phenotypically nearly normal male genitalia who presented with the complaint of bilateral breast enlargement.

Ovotesticular differences of sex development: male or female? Case series

BACKGROUND

The choice of the sex of rearing in patients with ovotesticular differences of sex development (OT-DSD) is difficult. The final decision should be given by the patient himself or herself, but families' opinion is not to neglect especially when the diagnosis is precocious and the patient can't give the consent to medical or surgical procedures. How should we behave if the parents refuse to raise a child with genital ambiguity?

CASE PRESENTATION

We describe and comment on our multidisciplinary approach in three patients with neonatal diagnosis of OT-DSD. The families expressed a strong desire for that which concerned the sex of rearing of their babies in contrast to the International trend of "wait and see". A specific counselling and a constant psychological support were given.

CONCLUSIONS

Recent trends suggest of postponing surgery to involve the patient in the decision. Child's well-being is the goal of therapy. When medical and psychological support is not able to force parents to accept a child suffering from genital ambiguity, we think that it is better to opt for reversible medical/surgical treatments rather than allowing patients to grow up within a family that does not accept them.

Ovotesticular Disorders of Sex Development: Improvement in Spermatogonia after Removal of Ovary and Müllerian Structures

BACKGROUND

Ovotesticular disorders of sex development is a condition defined as the presence of ovarian tissue containing ovarian follicles and testicular tissue containing seminiferous tubules in the same individual.

CASE

We report on a 19-year-old who is phenotypically male, with a 46,XX/46,XY mosaicism karyotype, who presented later in life with cyclical abdominal pain that resembled menstrual cramps and unilateral undescended testes.

SUMMARY AND CONCLUSION

He underwent laparoscopic hysterectomy and right salpingo-oophorectomy, resulting in cessation of his symptoms and improved sperm count.

46,XY ovotesticular disorders of sex development: A therapeutic challenge

46,XY ovotesticular disorder of sex development is extremely rare and indicates the presence of both testis and ovary in the same patient. Gender assignment in newborns represents a therapeutic challenge. We describe and comment on our multidisciplinary approach, ten years after the Chicago consensus meeting on disorder of sex development.

Multiparameter Investigation of a 46,XX/46,XY Tetragametic Chimeric Phenotypical Male Patient with Bilateral Scrotal Ovotestes and Ovulatory Activity

We report on an adult male initially presenting with gynecomastia and a painless scrotal mass without additional genital anomalies. Hyperpigmentation of the skin following the Blaschko's lines was identified. He underwent gonadectomy because of suspected cancer. Histological analyses revealed an ovotestis with ovulatory activity confirmed by immunohistochemistry with multiple markers. Karyotyping of cultured peripheral blood lymphocytes and a buccal smear revealed a 46,XX/46,XY chimeric constitution with different percentages. Multiple molecular analyses as well as blood typing implied a tetragametic origin. After the unilateral gonadectomy, the patient developed recurrent painful cystic swellings of the remaining gonad. Because of the wish to preserve hormonal activity as well as future fertility, the patient underwent surgical resection of a cystic gonadal area. The removed tissue showed ovulation-related features in addition to both testicular and ovarian tissue, diagnosed as an ovotestis. Testosterone therapy was initiated to suppress the persistently elevated gonadotropins and thereby suppress ovarian activity. During treatment, the recurrent pain complaints and cystic swellings ceased, although gonadotropin levels were not fully suppressed. Based on these observations, the importance of a detailed genetic and pathological diagnosis and the clinical dilemmas including the pros and cons of personalized treatment with gonadal preservative surgery are discussed.

Evaluation and treatment for ovotesticular disorder of sex development (OT-DSD) - experience based on a Chinese series

Background

The aim of this study is to review and present the clinical features and process of evaluation and treatment for OT-DSD in a single center in recent years in China.

Methods

Sixteen patients with OT-DSD during the past 4 years underwent the evaluation and treatment in a single center. The clinical characteristics and outcomes of surgery were analyzed.

Results

The surgical age ranged from 17 months to 66 months with a mean age of 20 months, and the mean follow-up was 30 months (4 months to 56 months). The presentation in 11 patients was ambiguous genitalia, and the rest 5 patients were suspected to have DSD in preoperative examination before hypospadias repair. The karyotypes were 46, XX in 11 patients, 46, XX/46, XY in 3, 46, XX/47, XXY in 1, and 46, XY in 1. Initial reared sex was male in 14 patients, female in 1, and undetermined in 1. After surgery, genders were reassigned in 3 patients, while 15 patients were raised as male with testicular tissue left. Only 1 patient with ovarian tissue left was raised as female. Repair was completed in 11 males and 1 female, and stage I urethroplasty was done in 4 males. No further surgery to remove the gonads was needed for inconsonance of gender assignment. No gonadal tumors were detected.

Conclusions

OT-DSD is a rare and complex deformity with few systematic reports in China. It’s important to establish a regular algorithm for evaluation and treatment of OT-DSD.

Cloning and transcriptional expression of a novel gene during sex inversion of the rice field eel (Monopterus albus)

We performed annealing control primer (ACP)-based differential-display reverse transcription-polymerase chain reaction (DDRT-PCR) to isolate differentially expressed genes (DEGs) from the stage IV ovary and ovotestis of the rice field eel, Monopterus albus. Using 20 arbitrary ACP primers, 14 DEG expressed-sequence tags were identified and sequenced. The transcriptional expression of one DEG, G2, was significantly greater in the ovotestis than the stage IV ovary. To understand the role of G2 in sex inversion, G2 cDNA was cloned and semi-RT-PCR, real time PCR were performed during gonad development. The full-length G2 cDNA was 650 base pairs (bp) and it comprised a 5′-untranslated region (UTR) of 82 bp, a 3′-UTR of 121 bp and an open reading frame of 444 bp that encoded a 148-amino acid protein. The expression of G2 was weak during early ovarian development until the stage IV ovary, but expression increased significantly with gonad development. We speculate that G2 may play an important function during sex inversion and testis development in the rice field eel, but the full details of the function of this gene requires further research.

Fertility Issues in Disorders of Sex Development

Fertility potential should be considered by the multidisciplinary team when addressing gender assignment, surgical management, and patient and family counselling of individuals with disorders of sex development. In 46,XY individuals, defects of gonadal differentiation or androgen or anti-Müllerian hormone synthesis or action result in incomplete or absent masculinization. In severe forms, raised as females, motherhood is possible with oocyte donation if Müllerian ducts have developed. In milder forms, raised as males, azoospermia or oligospermia are frequently found, however paternity has been reported. Most 46,XX patients with normal ovarian organogenesis are raised as females, and fertility might be possible after treatment.

Histopathological assessment of liver and gonad pathology in continental slope fish from the northeast Atlantic Ocean

The deep-sea environment is a sink for a wide variety of contaminants including heavy metals and organic compounds of anthropogenic origin. Life history traits of many deep-water fish species including longevity and high trophic position may predispose them to contaminant exposure and subsequent induction of pathological changes, including tumour formation. The lack of evidence for this hypothesis prompted this investigation in order to provide data on the presence of pathological changes in the liver and gonads of several deep-water fish species. Fish were obtained from the north east region of the Bay of Biscay (north east Atlantic Ocean) by trawling at depths between 700 and 1400 m. Liver and gonad samples were collected on board ship and fixed for histological processing and subsequent examination by light microscopy. Hepatocellular and nuclear pleomorphism and individual cases of ovotestis and foci of cellular alteration (FCA) were detected in black scabbardfish (Aphanopus carbo). Six cases of FCA were observed in orange roughy (Hoplostethus atlanticus) (n = 50) together with a single case of hepatocellular adenoma. A wide variety of inflammatory and degenerative lesions were found in all species examined. Deep-water fish display a range of pathologies similar to those seen in shelf-sea species used for international monitoring programmes including biological effects of contaminants. This study has confirmed the utility of health screening in deep-water fish for detecting evidence of prior exposure to contaminants and has also gained evidence of pathology potentially associated with exposure to algal toxins.

Construction and analysis of gonad suppression subtractive hybridization libraries for the rice field eel, Monopterus albus

The objective of this study was to investigate gene transcription profiles of the stage IV ovary and the ovotestis of the rice field eel (Monopterus albus) in an attempt to uncover genes involved in sex reversal and gonad development. Suppression subtractive hybridization (SSH) libraries were constructed using mRNA from the stage IV ovary and the ovotestis. In total 100 positive clones from the libraries were selected at random and sequenced, and then expressed sequence tags (ESTs) were used to search against sequences in the GenBank database using the BLASTn and BLASTx search algorithms. High quality SSH cDNA libraries and 90 ESTs were obtained. Of these ESTs, 43 showed high homology with genes of known function and these are associated with energy metabolism, signal transduction, transcription regulation and so on. The remaining 47 ESTs shared no homology with any genes in GenBank and are thus considered to be hypothetical genes. Furthermore, the four genes F11, F63, R11, and R47 from the forward and reverse libraries were analyzed in gonad, brain, heart, spleen, liver, kidney and muscle tissues. The results showed that the transcription of the F11 and F63 genes was significantly increased while the expression of the R11 and R47 genes was significantly decreased from IV or V ovary. In addition, the results also indicated that the four genes' expression was not gonad-tissue specific. This results strongly suggested that they may be involved in the rice field eel gonad development and/or sex reversal.

Two cases of late-diagnosed ovotesticular disorder of sex development

Ovotesticular disorder of sex development (ovotesticular DSD) is defined as the presence of testicular and ovarian tissue in the same individual. Both external and internal genitalia of patients with ovotesticular DSD display a spectrum of phenotypes. Most children present with ambiguous genitalia in combination with unilateral or bilateral undescended gonads. We experienced two late-diagnosed children who presented with proximal hypospadias and bilateral scrotal gonads. One should consider the possibility of ovotesticular DSD when managing patients with proximal hypospadias even if both gonads are palpable in the scrotum.