Bidirectional sex-change behavior and physiological aspects in the Gorgeous goby Lythrypnus pulchellus (Gobiidae).

The Gorgeous goby Lythrypnus pulchellus shows extreme sexual plasticity with the bidirectional sex-change ability socially controlled in adults. Therefore, this study describes how the hierarchical status affects hormone synthesis through newborn hormone waste products in water and tests the influence of body size and social dominance establishment in sex reversal duration and direction. The associated changes in behavior and hormone levels are described under laboratory conditions in male-male and female-female pairs of similar and different body sizes, recording the changes until spawning. The status establishment occurred in a relatively shorter time period in male and female pairs of different sizes (1-3 days) compared to those of similar size (3-5 days), but the earlier one did not significantly affect the overall time of sex change (verified by pair spawning). The changes in gonads, hormones, and papilla occurred in sex-changer individuals, but the first one was observed in behavior. Courtship started at 3-5 days in male pairs and from 2 h to 1 day in female pairs of both groups of different and similar sizes. Hormones did not gradually move in the new sexual phenotype direction during the sex-change time course. Nonetheless, estradiol regulated sex change and 11-ketotestosterone enabled bidirectional sex change and was modulated by agonistic interactions. Cortisol is associated with status and gonadal sex change. In general, similar mechanisms underlie sex change in both directions with a temporal change sequence in phases. These results shed new light on sex-change mechanisms. Further studies should be performed to determine whether these localized changes exist in the steroid hormone synthesis along the brain-pituitary gonad axis during social and bidirectional sex changes in L. pulchellus.

Thyroid axis participates in high-temperature-induced male sex reversal through its activation by the stress response.

Environmental changes alter the sex fate in about 15% of vertebrate orders, mainly in ectotherms such as fish and reptiles. However, the effects of temperature changes on the endocrine and molecular processes controlling gonadal sex determination are not fully understood. Here, we provide evidence that thyroid hormones (THs) act as co-players in heat-induced masculinization through interactions with the stress axis to promote testicular development. We first demonstrated that the thyroid axis (through thyroid-related genes and T3 levels) is highly active in males during the gonadal development in medaka (Oryzias latipes). Similarly, T3 treatments promoted female-to-male sex reversal in XX embryos. Subsequently, embryonic exposure to temperature-induced stress up-regulated the genes related to the thyroid and stress axes with a final increase in T3 levels. In this context, we show that blocking the stress axis response by the loss of function of the corticotropin-releasing hormone receptors suppresses thyroid-stimulating hormone expression, therefore, heat-induced activation of the thyroid axis. Thus, our data showed that early activation of the stress axis and, in consequence, the TH axis, too, leaves us with that both being important endocrine players in inducing female-to-male reversal, which can help predict possible upcoming physiological impacts of global warming on fish populations.

Effect of dosage of orally administered 17α-methyltestosterone on sex reversion of the yellowtail tetra Astyanax lacustris (Lütken, 1875).

The females of yellowtail tetra (Astyanax lacustris), known as the freshwater sardine, are approximately 1.33 times larger than males, and thus, all-female monosex culture would increase production and reduce size variability. The present work aimed to identify the optimal dose of 17α-methyltestosterone (MT) to be used in the masculinization of A. lacustris for indirect sex reversal. Three different concentrations of MT (20, 40, and 60 mg/kg of feed in the diet) were fed to the fry for 30 days. Thirty adult individuals from each treatment, including the control (0 mg MT/kg), were evaluated for gonadal development, morphological and histological sexual identification, zootechnical performance, and the possible genotoxic effect caused by prolonged exposure to MT. MT significantly (P<0.01) affected the differentiation of the gonads, with the presence of possible inhibitory effects in all treatments. Intersex individuals were present in the 20 and 60 mg MT/kg treatments. All treatments were able to masculinize A. lacustris and the treatment with the lowest hormone concentration produced the highest percentage of males 76.7%, while the control had 46.7% males. The presence of erythrocyte nuclear alterations indicated a possible cytotoxic effect of MT in treatments 40 and 60 mg MT/kg, however, the use of the hormone did not affect the growth and the survival of the individuals. Thus, the use of MT is a viable option for obtaining neomales as a first step into the production of all-female progenies.

Effect of dosage of orally administered 17α-methyltestosterone on sex reversion of the yellowtail tetra Astyanax lacustris (Lütken, 1875)

The females of yellowtail tetra (Astyanax lacustris), known as the freshwater sardine, are approximately 1.33 times larger than males, and thus, all-female monosex culture would increase production and reduce size variability. The present work aimed to identify the optimal dose of 17α-methyltestosterone (MT) to be used in the masculinization of A. lacustris for indirect sex reversal. Three different concentrations of MT (20, 40, and 60 mg/kg of feed in the diet) were fed to the fry for 30 days. Thirty adult individuals from each treatment, including the control (0 mg MT/kg), were evaluated for gonadal development, morphological and histological sexual identification, zootechnical performance, and the possible genotoxic effect caused by prolonged exposure to MT. MT significantly (P<0.01) affected the differentiation of the gonads, with the presence of possible inhibitory effects in all treatments. Intersex individuals were present in the 20 and 60 mg MT/kg treatments. All treatments were able to masculinize A. lacustris and the treatment with the lowest hormone concentration produced the highest percentage of males 76.7%, while the control had 46.7% males. The presence of erythrocyte nuclear alterations indicated a possible cytotoxic effect of MT in treatments 40 and 60 mg MT/kg, however, the use of the hormone did not affect the growth and the survival of the individuals. Thus, the use of MT is a viable option for obtaining neomales as a first step into the production of all-female progenies.(AU)

Testosterone nanoemulsion produced masculinized Nile tilapia (Oreochromis niloticus).

The objective of this work was to develop a food additive for the sex reversal of Nile tilapia (Oreochromis niloticus) based on a simple oil in water (O/W) nanoemulsion with testosterone propionate for incorporation into commercial feed. Oil screening and evaluation of the organoleptic and physicochemical characteristics were carried out to determine the best formulation. A palatability test was also performed. Sex reversal test was assayed using 5 experimental groups: negative control - macerated feed without hormone; free testosterone - macerated feed with 60 mg/kg of testosterone propionate diluted in ethanol; and macerated feed with testosterone propionate nanoemulsion at a concentration of 30, 60, and 90 mg/kg. Stable nanoemulsions (size 76-210 nm) with testosterone propionate were produced. All nanoemulsion-added feed was palatable to tilapia. We obtained sex reversal values of ≈65, 75, and 72% in the groups of 30, 60, and 90 mg/kg, respectively. We can conclude that the nanoemulsion showed promising results; it is capable of inducing sex reversal in tilapia, is suitable as a commercial product, and has the potential to promote safety for rural staff and reduce the environmental impact of hormones.

Molecular screening of XY SRY-negative sex reversal cases in horses revealed anomalies in amelogenin testing.

Male-to-female sex reversal in horses is a developmental disorder in which phenotypic females have a male genetic constitution. Male-to-female sex reversal is the second most common genetic sex abnormality, after X chromosome monosomy. All male-to-female sex reversal cases studied to date have been found to be infertile. Therefore, a screening test is particularly useful in laboratories doing DNA genotyping in horses. Our laboratory has tested > 209,000 horses for parentage using a panel of microsatellite markers and the sex marker gene amelogenin (AMEL). Suspect XY sex reversal cases are reported females with a male profile by AMEL testing. After routine genotyping, 49 cases were detected and further tested using the sex-determining region Y (SRY) gene, confirming the XY SRY-negative genotype of suspect sex reversal cases. When some inconsistencies arose in the initial result, a molecular panel of X- and Y-linked markers was analyzed for these samples. Of the 49 cases, 33 were confirmed as XY SRY-negative. The remaining 16 cases were identified as false-positives as a result of anomalies of AMEL testing in horses.

High temperature stress response is not sexually dimorphic at the whole-body level and is dependent on androgens to induce sex reversal.

The understanding of the molecular and endocrine mechanisms behind environmentally-induced sex reversal in fish is of great importance in the context of predicting the potential effects of climate change, especially increasing temperature. Here, we demonstrate the global effects of high temperature on genome-wide transcription in medaka (Oryzias latipes) during early development. Interestingly, data analysis did not show sexual dimorphic changes, demonstrating that thermal stress is not dependent on genotypic sex. Additionally, our results revealed significant changes in several pathways under high temperature, such as stress response from brain, steroid biosynthesis, epigenetic mechanisms, and thyroid hormone biosynthesis, among others. These microarray data raised the question of what the exact molecular and hormonal mechanisms of action are for female-to-male sex reversal under high temperatures in fish. Complementary gene expression analysis revealed that androgen-related genes increase in females (XX) experiencing high water temperature. To test the involvement of androgens in thermal-induced sex reversal, an androgen antagonist was used to treat XX medaka under a high-temperature setup. Data clearly demonstrated failure of female-to-male sex reversal when androgen action is inhibited, corroborating the importance of androgens in environmentally-induced sex reversal.

Activation of stress response axis as a key process in environment-induced sex plasticity in fish.

The determination of sex is an important hallmark in the life cycle of organisms, in which the fate of gonads and then the individual sex are defined. In gonochoristic teleost fish, this process is characterized by a high plasticity, considering that in spite of genotypic sex many environmental factors can cause shifts from one to another molecular pathway, resulting in organisms with mismatching genotypic and phenotypic sexes. Interestingly, in most instances, both female-to-male or male-to-female sex-reversed individuals develop functional gonads with normal gametogenesis and respective progenies with full viability. The study of these mechanisms is being spread to other non-model species or to those inhabiting more extreme environmental conditions. Although water temperature is an important mechanism involved in sex determination, there are other environmental stressors affected by the climate change which are also implicated in stress response-induced masculinization in fish. In this regard, the brain has emerged as the transducer of the environment input that can influence the gonadal fate. Furthermore, the evaluation of other environmental stressors or their synergic effect on sex determination at conditions that simulate the natural environments is growing gradually. Within such scope, the concerns related to climate change impacts rely on the fact that many of biotic and abiotic parameters reported to affect sex ratios are expected to increase concomitantly as a result of increased greenhouse gas emissions and, particularly worrying, many of them are related to male bias in the populations, such as high temperature, hypoxia, and acidity. These environmental changes can also generate epigenetic changes in sex-related genes affecting their expression, with implications on sex differentiation not only of exposed individuals but also in following generations. The co-analysis of multi-stressors with potential inter- and transgenerational effects is essential to allow researchers to perform long-term predictions on climate change impacts in wild populations and for establishing highly accurate monitoring tools and suitable mitigation strategies.

Gene dosage of DAX-1, determining in sexual differentiation: duplication of DAX-1 in two sisters with gonadal dysgenesis.

Two sisters phenotypically normal females, presenting with tumor abdominal mass with histopathological findings of teratoma and gonadoblastoma associated to 46,XY male-to-female sex reversal syndrome, secondary to a duplication in DAX-1, possibly inherited of maternal gonadal mosaicism. Copy number variation and functional effects of the duplication were done by MLPA multiplex ligation-dependent probe amplification and real time PCR. DAX-1, also known as dosage sensitive sex reversal gene (DSS), is considered the most likely candidate gene involved in XY gonadal dysgenesis when overexpressed. The excess of DAX-1 gene disturbs testicular development by down regulation of SF-1, WT1, and SOX9. This is the first report of 46,XY sex reversal in two siblings who have a maternally inherited duplication of DAX-1 associated with reduced levels of expression of downstream genes as SOX9-SF1.

The external genitalia in juvenile Caiman latirostris differ in hormone sex determinate-female from temperature sex determinate-female.

The broad-snouted caiman (Caiman latirostris) is a crocodilian species that inhabits South American wetlands. As in all other crocodilians, the egg incubation temperature during a critical thermo-sensitive window (TSW) determines the sex of the hatchlings, a phenomenon known as temperature-dependent sex determination (TSD). In C. latirostris, we have shown that administration of 17-ß-estradiol (E2) during the TSW overrides the effect of the male-producing temperature, producing phenotypic females (E2SD-females). Moreover, the administration of E2 during TSW has been proposed as an alternative way to improve the recovery of endangered reptile species, by skewing the population sex ratio to one that favors females. However, the ovaries of E2SD-female caimans differ from those of TSD-females. In crocodilians, the external genitalia (i.e. clitero-penis structure or phallus) are sexually dimorphic and hormone-sensitive. Despite some morphological descriptions aimed to facilitate sexing, we found no available data on the C. latirostris phallus histoarchitecture or hormone dependence. Thus, the aims of this study were: (1) to establish the temporal growth pattern of the phallus in male and female caimans; (2) to evaluate histo-morphological features and the expression of estrogen receptor alpha (ERα) and androgen receptor (AR) in the phallus of male and female pre-pubertal juvenile caimans; and (3) to determine whether the phallus of TSD-females differs from the phallus of E2SD-females. Our results demonstrated sexually dimorphic differences in the size and growth dynamics of the caiman external genitalia, similarities in the shape and spatial distribution of general histo-morphological compartments, and sexually dimorphic differences in innervation, smooth muscle fiber distribution, collagen organization, and ERα and AR expressions. The external genitalia of E2SD-females differed from that of TSD-females in many histological features and in the expression of ERα and AR, resembling patterns described in males. Our results alert on the effects of estrogen agonist exposure during TSW and suggest that caution must be taken regarding the use of E2SD as a procedure for wildlife population management.

Masculinization of South American catfish (Rhamdia quelen) through dietary administration of 17α-methyltestosterone / Masculinización del pez Liso (Rhamdia quelen) mediante suministro dietario de 17α-metiltestosterona / Masculinização do Jundiá (Rhamdia quelen) através da administração dietética de 17α-metiltestosterona

Abstract Background: Production of monosex cultures of females is desirable in commercial aquaculture of certain species due to their higher growth rate. Ideally, females should be free of exogenous hormones. The initial step to produce hormone-free all-female offspring is masculinization of normal females to create sex reversed animals, called neomales, which are then be bred with normal females obtaining all-female offspring. Objective: To masculinize Rhamdia quelen fry by adding 17α-methyltestosterone (MT) hormone to the feed. Methods: Larvae of R. quelen were fed diets supplemented with 60, 80, or 100 mg MT/kg feed for 21 days. A control group was fed the same diet free of MT. At 150 days post-hatching, 30 fish of each treatment group were euthanized to evaluate gonadal changes using histological techniques. Results: MT significantly affected the differentiation of female gonads in the 60 and 80 mg MT/kg feed groups. Sex reversal was observed in all MT treatment groups, with 50, 40, and 20% neomales produced with 60, 80, and 100 mg MT/kg feed, respectively. Intersex gonads were observed only in the masculinization treatment groups. Inhibitory effects on gonadal development of females and males were observed at the highest MT doses. Conclusion: Dietary administration of MT effectively masculinizes R. quelen fry; however, the lowest dose of 60 mg/kg feed is recommended, since higher doses have inhibitory effects on gonadal development in both sexes.

Resumen Antecedentes: Debido a su mayor tasa de crecimiento, la producción de peces femeninos monosexo es deseable en acuicultura comercial de determinadas especies. Idealmente, las hembras deben estar libres de hormonas exógenas. El paso inicial para generar descendencia femenina libre de hormonas es la masculinización de hembras genéticas para producir animales sexualmente revertidos, llamados neomachos, los cuales se aparean luego con hembras genéticas para producir descendencia femenina. Objetivo: Masculinizar larvas de Rhamdia quelen con 17α-metiltestosterona (MT) incorporada en el alimento. Métodos: Larvas de R. quelen fueron alimentadas con dietas suplementadas con 60, 80 y 100 mg de MT/kg de alimento durante 21 días. Un grupo control recibió la misma dieta, sin MT. A los 150 días pos-eclosión, 30 peces de cada tratamiento fueron eutanasiados para evaluación gonadal mediante técnicas histológicas. Resultados: La MT afectó significativamente la diferenciación de las gónadas femeninas en las dosis de 60 y 80 mg MT/kg de alimento. El cambio de sexo se observó en los tratamientos con las dosis de 60, 80 y 100 mg MT/kg alimento, con 50, 40 y 20% de neomachos, respectivamente. En los tratamientos de masculinización se observaron gónadas intersexuales. En las dosis más altas de MT se observó inhibición del desarrollo gonadal de hembras y machos. Conclusiones: El suministro dietario de MT masculinizó las larvas de R. quelen. Se recomienda usar 60 mg/kg, ya que dosis mayores tienen efectos inhibidores en el desarrollo gonadal para ambos sexos.

Resumo Antecedentes: O cultivo monossexo feminino é desejável na aquicultura comercial de determinadas espécies devido à maior taxa de crescimento. Idealmente, as fêmeas devem ser livres de hormônios exógenos. O passo inicial para gerar descendências femininas livres destes hormônios é a masculinização de fêmeas normais para produzir animais revertidos sexualmente, os chamados neomachos. Os neomachos podem então ser cruzados com fêmeas normais para a produção de descendências femininas. Objetivo: Masculinizar larvas de R. quelen utilizando o hormônio 17α-metiltestosterona (MT) incorporado no alimento. Métodos: Larvas de R. quelen foram alimentadas com dietas suplementadas com MT nas doses de 60, 80 ou 100 mg/kg de alimento durante 21 dias. Um grupo controle foi alimentado com dieta similar livre de MT. Aos 150 dias pós-eclosão, 30 peixes de cada grupo de tratamento foram eutanasiados para avaliação gonadal através de técnicas histológicas. Resultados: O uso de MT afetou significativamente a diferenciação das gônadas femininas nas doses 60 e 80 mg/kg de alimento. A reversão sexual foi observada em todos os grupos tratados com MT, gerando 50, 40 e 20% de neomachos nas doses 60, 80 e 100 mg MT/kg de alimento, respectivamente. Gônadas intersexuais foram observadas somente nos tratamentos masculinizantes. Nas maiores doses de MT, efeitos inibitórios de desenvolvimento gonadal foram observados em fêmeas e machos. Conclusão: A administração dietética de MT efetivamente masculinizou larvas de R. quelen. No entanto, a dose mais baixa de 60 mg/kg de alimento é recomendada devido aos efeitos inibitórios das doses mais elevadas de MT no desenvolvimento gonadal de ambos os sexos.

Complexes between methyltestosterone and ß-cyclodextrin for application in aquaculture production.

The inclusion complexes between 17-α-methyltestosterone (MT) and ß-cyclodextrin (bCD) were prepared and characterized in dissolution and solid phase. The complex promoted a sixfold increment in solubility of the hormone. It has a limited solubility and stoichiometry of 2:1 (bCD:MT) determined by DSC, NMR and solubility experiments, the association constant Ka=2846Lmol-1 and complex fraction of 76% (assessed by DOSY-NMR, in (1:3) DMSO/D2O). The association constant obtained in water by the solubility isotherms is 7540Lmol-1. 2D-ROESY experiments indicate the intermolecular orientation (complete inclusion of the hormone in the cavity). Simulations by molecular dynamics agreed with the formation of the inclusion complex 2:1. Release tests showed the slower release for the complexes, with 50% for lyophilization and 56% for malaxation. These results clearly demonstrate the complexation of MT in bCD, which formulations are promising for further applications involving this steroid in aquaculture, both for sexual reversal and in technologies of hormone in water sequestration.

Populações monosexo em peixes nativos brasileiros: iniciando o futuro / Monosex population in Brazilian native fish: the start of the future

Técnicas de controle e manipulação do sexo fenotípico têm sido amplamente utilizadas na piscicultura mundial (como atividade pecuária) e em estudos científicos acerca da fisiologia reprodutiva de peixes. A indução do sexo desejado é possível graças à alta flexibilidade do processo de diferenciação sexual de peixes e seus variados sistemas de determinação sexual. Atualmente, são produzidas populações monosexo em mais de 20 espécies de peixes de importância comercial em diferentes países. Se nos países mais avançados a produção monosexuada de peixes já é prática consolidada, no Brasil a única espécie produzida comercialmente em lotes monosexo é africana (tilápia Nilótica), ou seja, exótica. Entretanto, recentes investigações sobre desempenho zootécnico comparativo entre machos e fêmeas têm sido desenvolvidas nos peixes nativos brasileiros. Essa revisão aborda as finalidades e métodos para produção de populações monosexo em peixes, ressaltando a sua ampla disseminação na aquicultura mundial, e traz à tona as primeiras espécies nativas brasileiras em que esse tipo de estudo tem sido realizado.(AU)

Techniques for controlling and manipulating phenotypic sex have been widely used in fish farming worldwide (as livestock activity) and in scientific studies of fish reproductive physiology. The induction of a desired sex is possible due to the high flexibility of the process of fish sex differentiation and the different systems of fish sex determination. Currently, monosex populations are produced in at least 20 economically important fish species in different countries. While in the most advanced countries the monosex production of fish is already consolidated, in Brazil the only species produced commercially in monosex batches is African (Nile tilapia), i.e. exotic. However, recent research on the comparative production between males and females has been developed with native Brazilian fish. This review addresses the purposes and methods for producing monosex population in fish, highlighting their wide spread use in the world and brings to light the first native Brazilian species in which this type of study has been already conducted.(AU)

Populações monosexo em peixes nativos brasileiros: iniciando o futuro / Monosex population in Brazilian native fish: the start of the future

Técnicas de controle e manipulação do sexo fenotípico têm sido amplamente utilizadas na piscicultura mundial (como atividade pecuária) e em estudos científicos acerca da fisiologia reprodutiva de peixes. A indução do sexo desejado é possível graças à alta flexibilidade do processo de diferenciação sexual de peixes e seus variados sistemas de determinação sexual. Atualmente, são produzidas populações monosexo em mais de 20 espécies de peixes de importância comercial em diferentes países. Se nos países mais avançados a produção monosexuada de peixes já é prática consolidada, no Brasil a única espécie produzida comercialmente em lotes monosexo é africana (tilápia Nilótica), ou seja, exótica. Entretanto, recentes investigações sobre desempenho zootécnico comparativo entre machos e fêmeas têm sido desenvolvidas nos peixes nativos brasileiros. Essa revisão aborda as finalidades e métodos para produção de populações monosexo em peixes, ressaltando a sua ampla disseminação na aquicultura mundial, e traz à tona as primeiras espécies nativas brasileiras em que esse tipo de estudo tem sido realizado.

Techniques for controlling and manipulating phenotypic sex have been widely used in fish farming worldwide (as livestock activity) and in scientific studies of fish reproductive physiology. The induction of a desired sex is possible due to the high flexibility of the process of fish sex differentiation and the different systems of fish sex determination. Currently, monosex populations are produced in at least 20 economically important fish species in different countries. While in the most advanced countries the monosex production of fish is already consolidated, in Brazil the only species produced commercially in monosex batches is African (Nile tilapia), i.e. exotic. However, recent research on the comparative production between males and females has been developed with native Brazilian fish. This review addresses the purposes and methods for producing monosex population in fish, highlighting their wide spread use in the world and brings to light the first native Brazilian species in which this type of study has been already conducted.

Identification of neomales in South American catfish Rhamdia quelen on the basis of the sex ratio in the progeny

In the present study, we aimed to identify masculinized genotypic females of Rhamdia Quelen on the basis of the sex ratio of the progeny. Masculinizing diets containing 3 levels of 17α-methyltestosterone (MT; 60, 90, or 120 mg kg-1) were administered to R. quelenfry. Thereafter, 5 phenotypic males from each MT treatment were crossed with normal females, and their progenies were sexed. At least 1 male from each treatment group generated progeny with a higher female:male ratio. These males, designated M60, M90, and M120, were crossed again with 3 other normal females to re-evaluate the sex ratio of the progeny. Moreover, a normal male was used as a control. Again, we found a higher female:male ratio in the progeny of M60, M90, and M120. The control male produced 2sets of balanced progeny and 1 with a lower female:maleratio. Although these breeders did not generate all- female progeny (79.75 ± 7.20% of females), our findingsindicate that M60, M90, and M120 can be considered masculinized genotypic females of R. quelen, suggesting the involvement of autosomal genes or polygenic interactions in sex determination.

Identification of neomales in South American catfish Rhamdia quelen on the basis of the sex ratio in the progeny

In the present study, we aimed to identify masculinized genotypic females of Rhamdia Quelen on the basis of the sex ratio of the progeny. Masculinizing diets containing 3 levels of 17α-methyltestosterone (MT; 60, 90, or 120 mg kg-1) were administered to R. quelenfry. Thereafter, 5 phenotypic males from each MT treatment were crossed with normal females, and their progenies were sexed. At least 1 male from each treatment group generated progeny with a higher female:male ratio. These males, designated M60, M90, and M120, were crossed again with 3 other normal females to re-evaluate the sex ratio of the progeny. Moreover, a normal male was used as a control. Again, we found a higher female:male ratio in the progeny of M60, M90, and M120. The control male produced 2sets of balanced progeny and 1 with a lower female:maleratio. Although these breeders did not generate all- female progeny (79.75 ± 7.20% of females), our findingsindicate that M60, M90, and M120 can be considered masculinized genotypic females of R. quelen, suggesting the involvement of autosomal genes or polygenic interactions in sex determination. (AU)

Síndrome PAGOD y anomalías vasculares: ¿es un defecto de la angiogénesis embrionaria? Un nuevo caso y revisión / PAGOD syndrome and vascular anomalies: is a defect embryonic angiogenesis? A case report and review

El Síndrome PAGOD es un acrónimo de hipoplasia de pulmón y arterias pulmonares, agonadismo, onfalocele / defecto diafragmático y dextrocardia. Se describe una serie de 21 pacientes, en la cual, 90,5 % presentó un cariotipo 46,XY y solo dos casos 46,XX; el 66,6 % exhibió un fenotipo femenino y 28,6 % genitales ambiguos. La ocurrencia de dos paciente 46,XX excluye al cromosoma Y como portador del defecto genético y plantea la posibilidad de una herencia recesiva ligada al cromosoma X, sin descartar que los casos observados en hermanos puedan deberse a mutaciones en otros genes como STRA6, VEGFA, VEGFB, VEGFC, transcritos de empalmes alternativos de VEGFA, HIF1, HIF2, entre otros. Las malformaciones congénitas observadas en los pacientes fueron: genitales y gónadas 85,7 %, diafragma y pared 66,6 %, cardíaco 80,9 %, pulmonar 71,4 %, vascular 80,9 % y abdomen 42,8 %. La revisión de los pacientes ha demostrado un alto grado de variabilidad en la expresividad de malformaciones de órganos, aparatos o sistemas. Las malformaciones vasculares representan un componente importante y característico del síndrome PAGOD y cuya base morfogenética del síndrome pueda deberse a un defecto de la angiogénesis embrionaria temprana con repercusión en la organogénesis de aparatos y sistemas. Dentro de los genes relacionados con el remodelamiento vascular durante la embriogénesis, regeneración tisular y carcinogénesis está el Factor de Crecimiento del Endotelio Vascular D (VEGFD), localizado en Xp22.31, con expresión en pulmón, corazón, intestino delgado, pulmón fetal, útero, mamas, tejido neural y neuroblastoma, el cual representa un fuerte candidato para su análisis molecular como una de las posibles causa del síndrome.

PAGOD Syndrome is an acronym for lung and pulmonary arteries hypoplasia, agonadism, omphalocele / diaphragmatic defect and dextrocardia. A series of 21 patients is described, where 90.5% had a 46,XY karyotype and only two cases 46,XX; 66.6% exhibited a female phenotype and 28.6% ambiguous genitalia. The occurrence of two patients 46,XX excludes the Y chromosome as a carrier of the genetic defect and raises the possibility of a recessive X-linked inheritance, without ruling out that the observed cases in siblings may be due to mutations in other genes as Stra6, VEGFA, VEGFB, VEGFC, and alternative splicing of transcripts VEGFA, HIF1, HIF2, among others. Congenital malformations were observed in patients’ genitals and gonads 85.7%, 66.6% in diaphragm and abdominal wall , heart 80.9%, 71.4% lungs, blood vessels 80.9% and 42.8% in abdomen. The review of patients has demonstrated a high degree of variability in the expression of malformations of organs and organ systems. Vascular malformations represent an important and characteristic component of PAGOD syndrome and whose base morphogenetic syndrome may be due to a defect in early embryonic angiogenesis with impact on organogenesis and system development. Among genes related to vascular remodeling during embryogenesis, tissue regeneration and carcinogenesis, the Endothelial Growth Factor D Vascular (VEGFD), located in the Xp22.31 region, with expression in lung, heart, small intestine, uterus, breast, neuroblastoma and neural tissue, represents a strong candidate for molecular analysis as a cause of the syndrome.

Sex revesal of Nile tilapia (Oreochromis niloticus) Supreme variety, fingerlings submitted to different temperatures for sexual differentiation phase / Inversão sexual de alevinos de tilápias do Nilo (Oreochromis niloticus) variedade Supreme, submetidos a diferentes temperaturas durante fase de diferenciação sexual

This experiment evaluated the effects of temperature on sex inversion survival and presence of deformities in larvae of tilapia subjected to the following treatments control (28ºC + diet 60 mg kg-1 of 17 ?-methyltestosterone), 28, 30, 32 and 34ºC. The results showed a statistical difference between the proportion of males, with temperatures control, 32 and 34ºC (98, 91, 96%, respectively) showed better results than those obtained for treatments 28 and 30ºC (71 and 82%). The survival observed in different treatments were 90.74, 90.49, 88.20, 85.43 and 82.16 for the control, 28, 30, 32 and 34ºC, respectively, and there was statistical difference between treatments 32 and 34 ºC, only when these were compared with the control. In the analysis of the radiographs was not possible to observe the presence of morphological changes in fish subjected to different treatments. With this experiment, we concluded that the temperatures of 32 and 34C were able to genetically larvae masculinizing females, and that there was no increase in mortality and the presence of deformities could be attributed to treatment. This technique is an alternative to use of steroid hormones.

Este experimento avaliou os efeitos da temperatura na inversão sexual, sobrevivência e presença de deformidades em larvas de tilapia submetidas aos seguintes tratamentos controle (28ºC + ração 60 mg kg-1 de 17 ?-metiltestosterona), 28, 30, 32 e 34ºC. Os resultados demonstraram diferença estatística entre a proporção de machos, sendo que as temperaturas controle, 32 e 34ºC (98; 91; 96 %, respectivamente) apresentaram resultados superiores aos obtidos para os tratamentos 28 e 30ºC (71 e 82 %). A sobrevivência observada nos diferentes tratamentos foram 90,74; 90,49; 88,20; 85,43 e 82,16 para o controle, 28, 30, 32 e 34ºC, respectivamente, sendo que houve diferença estatística entre os tratamentos 32 e 34oC, somente quando estes foram comparados com o controle. Na análise das radiografias não foi possível observar presença de alterações morfológicas nos peixes submetidos aos diferentes tratamentos. Com este experimento, concluiu-se que as temperaturas de 32 e 34ºC foram capazes de masculinizar larvas geneticamente fêmeas, e que não houve incremento na mortalidade e na presença de deformidades que possam ser atribuídas aos tratamentos. Essa técnica é uma alternativa para a utilização de hormônios esteroides.

Hypervitaminosis induced by vitamin A supplementation in ration for post larvae of Nile tilapia / Hipervitaminose induzida pela suplementação de vitamina A em rações para pós-larvas de tilápia do Nilo

The present study was carried out to evaluate the effect of the hypervitaminosis by supplementation of vitamin A in balanced ration, on the performance of Nile tilapia (Oreochromis niloticus) during sex reversal phase. The experiment was carried out during 30 days in a randomized experimental design with six treatments and five repetitions. Was considered an experimental unit an aquarium of 50L contends 70 post larvae. The first treatment was consisted by a ration where was added only commercial premix how a vitamin A (30 KUI) source. The others had been supplemented with 1.030, 2.030, 3.030, 4.030 e 5.030 KUI of vitamin A. At the end, the final average weight (FAW), the standard (SL) and total length (TL), the weight gain (WG), the biomass gain (BG), the apparent feed conversion (FA), the condition factor (CF) and the survival (SU) were assessed. The results of FAW, SL, WG and BG showed a negative linear effect (P 0,05) by the increase of the vitamin A in the ration. The hipervitaminosis of vitamin A above of 30 KUI damaged the post larvae Nile tilapia growth.

O presente trabalho foi realizado para avaliar os efeitos da hipervitaminose por meio de suplementação de diferentes níveis de vitamina A em rações balanceadas, sobre o desempenho da tilápia do Nilo (Oreochromis niloticus) durante a fase de reversão sexual. O período experimental foi de 30 dias, com um delineamento inteiramente casualizado com seis tratamentos e cinco repetições. Foi considerado como unidade experimental um aquário de 50L contendo 70 pós-larvas. O primeiro tratamento constituiu de uma ração onde foi adicionado apenas o premix comercial como fonte de vitamina A (30 KUI). Os outros foram suplementados com 1.030, 2.030, 3.030, 4.030 e 5.030 KUI de vitamina A. Ao final do experimento os peixes foram avaliados quanto ao peso médio final (PMF), aos comprimentos total final (CT) e padrão final (CP), ao ganho de peso médio (GPM), ao ganho de biomassa (GB), a conversão alimentar aparente (CAA), ao fator de condição final (FC) e à sobrevivência (%). Os resultados de PMF, CP, GPM e GB mostraram um efeito linear negativo (P 0,05) em relação ao aumento dos níveis de vitamina A na ração. Conclui-se que a inclusão de vitamina A em níveis acima de 30 KUI prejudicam o crescimento das pós larvas de tilápia do Nilo.