Polymerase Chain Reaction (PCR) is a Useful and Low-Cost Tool for Molecular Sexing Psittaciformes under Human Care: An Example of a Collaborative Approach in Mexico.

Sex determination in monomorphic birds is a precondition for captive breeding programs and management and conservation strategies for threatened species. Most species of the order Psittaciformes often present complications since these birds lack external sexual phenotypic traits, making it impossible to differentiate males and females. In the present study, we used molecular techniques to determine the sex of 31 individuals belonging to nine species of the order Psittaciformes kept under human care at the Akumal Monkey Sanctuary & Rescued Animals in Quintana Roo, Mexico. This is a useful and low-cost methodology based on the analysis of the conserved region of the CHD1 gene, which was amplified by PCR with two sets of primers: P8/P2 and 2550F/2718 R. All individuals were successfully sexed with the first set of primers, while only 28 out of 31 samples (90%) could be amplified with the second set. Out of the 31 individuals analyzed, fifteen are female, and seventeen are male. This information represents a handy tool for adequately managing birds under human care, resulting in their reproduction and eventual reintegration into their natural habitat.

Comparação de métodos de sexagem em filhotes de serpentes da espécie Python brongersmai / Comparing methods of sex identification in Python brongersmai snakelets

Com a ascensão de animais exóticos no mercado pet, observou-se a necessidade de maiores estudos nesta área. Este estudo teve como objetivo comparar diferentes métodos de sexagem em filhotes de serpentes da espécie Python brongersmai (Bloody Python), sendo utilizados 14 filhotes com aproximadamente 1 ano e 9 meses de vida, oriundos do Criadouro Comercial de Fauna Silvestre e Exótica ­ CCF, autorização de manejo N° 414064, localizado no município de Cornélio Procópio ­ PR. Foi utilizado a introdução da probe metálica de sexagem para contagem de escamas, mensurações do Comprimento Rostro-Cloacal (CRC), Comprimento Pós-Cloacal (CPC), Comprimento Total (CT); avaliação ultrassonográfica dos órgãos reprodutivos e perfil genético (DNA), indicando a fidedignidade de cada um. Observou-se uma eficácia de 100% na determinação do sexo através das amostras de DNA, enquanto a sexagem a partir da contagem de escamas via probe metálica e o dimorfismo sexual por mensurações corporais permitiram apenas uma classificação sexual prévia, sofrendo variações quando comparadas, mostrando-se como métodos inconclusivos. Já a ultrassonografia não foi eficaz para o processo de sexagem em serpentes filhotes de até aproximadamente 1 ano e 9 meses de idade da espécie Python brongersmai.(AU)

With the increment of exotic animal's trade in the pet business, the necessity of more studies in this area was observed. This study aimed at comparing different methods of sex identification in Python brongersmai snakelets (Bloody Python), using 14 baby snakes aged 1 year and 9 months approximately, from commercial breeding of wild and exotic fauna, situated in Cornélio Procópio ­ PR. Methods used were the probing technique introduction, measurement of snout-vent length, post-vent length, total length; ultrasound evaluation of reproductive organs and genetic profile exam (DNA samples), denoting the veracity of each one. A 100% efficacy was observed in the study of sexual determination through DNA samples, while the other methods were shown to be inconclusive, whilst the sexing scale count via the probing technique introduction and sexual dimorphism by bodily measurements permitted only a previous sexual classification, suffering variations when compared, showing to be inconclusive methods. The ultrasound evaluation was not efficient for the sexing process in snakelets aged approximately 1 year and 9 months in Python brongersmai.(AU)

A citogenética da sexagem molecular de aves selvagens monomórficas e a influência negativa de anomalias pigmentares: revisão de literatura / The cytogenetics of the molecular sexage of wild birds monomorphics and the negative influence of anomalies pigmentary: literature review

O Brasil apresenta a segunda maior biodiversidade de aves do mundo, entretanto, lidera o ranking de aves ameaçadas de extinção, sobretudo, devido às ações antropológicas sobre as aves e seu habitat. Logo, a sexagem citogenética, através da técnica de PCR e estudo de cariótipos, possibilita a identificação e manutenção de espécies ameaçadas. Outrossim, existem anomalias pigmentares que modificam os fenótipos das aves e, consequentemente, prejudicam a identificação de espécies. Assim, esse trabalho objetivou, através de uma revisão de literatura, discorrer sobre a importância da citogenética na sexagem molecular de aves selvagens monomórficas e evidenciar a influência negativa de anomalias pigmentares.

Brazil has the second largest bird biodiversity in the world, however, it leads the ranking of endangered birds, mainly due to anthropological actions on birds and their habitat. Therefore, cytogenetic sexing, through the PCR technique and the study of karyotypes, enables the identification and maintenance of endangered species. Furthermore, there are pigmentary anomalies that modify the phenotypes of birds and, consequently, hinder the identification of species. Thus, this study aimed, through a literature review, to discuss the importance of cytogenetics in the molecular sexing of monomorphic wild birds and to highlight the negative influence of pigmentary anomalies.

Macho ou fêmea? Como o sexo dos vertebrados é determinado / Male or female? How the vertebrate sex are determined / ¿Macho o hembra? Cómo se determina el sexo de los vertebrados

La reproducción sexual es la forma de propagación más antigua y universal utilizada por los vertebrados. Los mecanismos que controlan la determinación sexual y la diferenciación en estos animales son diversos y dependen de una amplia variedad de factores genéticos, así como en algunos casos de factores ambientales. El sexo genético puede definirse por factores genéticos hereditarios que se determinan en la fertilización. Por otro lado, la diferenciación gonadal depende de la activación de factores transcripcionales que se expresan durante la ventana de diferenciación sexual. Dichos factores pueden tener su expresión alterada por condiciones ambientales como la temperatura y la osmolaridad, entre otros. Estos procesos sexuales se dividen clásicamente en determinación y diferenciación sexual, respectivamente. Con base en tales hechos, esta revisión tiene como objetivo mostrar los fundamentos básicos de los procesos de determinación y diferenciación sexual en vertebrados, enfatizando el grupo de peces teleósteos.(AU)

Sexual reproduction is the oldest and universal form of propagation used by vertebrates. The mechanisms that control sexual determination and differentiation in these animals are diverse and depend on a wide variety of genetic factors as well as in some cases environmental factors. Genetic sex can be define by hereditary genetic factors that are determined in fertilization. On the other hand, gonadal differentiation depends on the activation of transcriptional factors that are expressed during the sexual differentiation window. Such factors may have their expression altered by environmental conditions such as temperature and osmolarity, among others. These sexual processes are classically divided into sexual determination and differentiation, respectively. Based on such facts, this review aims to show the basic theoretical reasoning of the processes of sexual determination and differentiation in vertebrates, emphasizing the group of teleost fishes.(AU)

A reprodução sexual é a forma de propagação mais antiga e universal utilizada pelos vertebrados. Os mecanismos que controlam a determinação e diferenciação sexual nestes animais são diversos e dependem de uma grande variedade de fatores genéticos bem como em alguns casos de fatores ambientais. O sexo genético pode ser definido por fatores genéticos hereditários que são determinados na fecundação. Por outro lado, a diferenciação gonadal depende da ativação de fatores transcricionais que são expressos durante a janela de diferenciação sexual. Tais fatores podem ter sua expressão alterada por condições ambientais como a temperatura e a osmolaridade dentre outros. Estes processos sexuais são classicamente divididos em determinação e diferenciação sexual, respectivamente. Baseados em tai fatos, esta revisão tem como objetivo mostrar a fundamentação básica dos processos de determinação e diferenciação sexual em vertebrados com ênfase no grupo dos peixes teleósteos.(AU)

Sex identification of the ornamental amazon fish Astronotus ocellatus by videoceloscopy and gonadal biopsy.

This study was conducted to evaluate and validate the efficacy and safety of videoceloscopy and gonadal biopsy as sexing methods for the A. ocellatus. A total of 31 adult individuals were used. Florfenicol (50 mg/kg) and morphine (5 mg/kg) were administered intramuscularly during the pre-surgical period. Animals were maintained in a supine position preceding a ventral midline incision and endoscope optics were then utilized for gonad visualization and sex identification. A gonadal fragment was collected using laparoscopic forceps and conditioned in 10 % formalin. To suture the cavity, polyamide yarn was used in a simple and continuous pattern. At 15 days subsequent to surgery, healing was evaluated, and the stitches were removed. Videoceloscopy accuracy and gonadal biopsy effectiveness were 97 % and 83 %, respectively. Total time devoted in the videoceloscopy, gonadal biopsy and surgery was longer for animals identified as males compared to females The survival rate was 100 %. There were differences regarding food consumption at 24 and 36 h post-surgery when compared to control specimens (pre-surgical) Regarding position in the water column, differences were observed at 24 and 72 h after surgery when compared individually to the control specimens. There were differences for interaction behavior at 24, 36 and 60 h, and regarding search for hiding places at 12 and 24 h after surgery in relation to the control specimens. The applied videoceloscopy and gonadal biopsy surgical techniques are, therefore, effective and safe for A. ocellatus sexing procedures.

Macho ou fêmea? Como o sexo dos vertebrados é determinado / Male or female? How the vertebrate sex are determined / ¿Macho o hembra? Cómo se determina el sexo de los vertebrados

La reproducción sexual es la forma de propagación más antigua y universal utilizada por los vertebrados. Los mecanismos que controlan la determinación sexual y la diferenciación en estos animales son diversos y dependen de una amplia variedad de factores genéticos, así como en algunos casos de factores ambientales. El sexo genético puede definirse por factores genéticos hereditarios que se determinan en la fertilización. Por otro lado, la diferenciación gonadal depende de la activación de factores transcripcionales que se expresan durante la ventana de diferenciación sexual. Dichos factores pueden tener su expresión alterada por condiciones ambientales como la temperatura y la osmolaridad, entre otros. Estos procesos sexuales se dividen clásicamente en determinación y diferenciación sexual, respectivamente. Con base en tales hechos, esta revisión tiene como objetivo mostrar los fundamentos básicos de los procesos de determinación y diferenciación sexual en vertebrados, enfatizando el grupo de peces teleósteos.

Sexual reproduction is the oldest and universal form of propagation used by vertebrates. The mechanisms that control sexual determination and differentiation in these animals are diverse and depend on a wide variety of genetic factors as well as in some cases environmental factors. Genetic sex can be define by hereditary genetic factors that are determined in fertilization. On the other hand, gonadal differentiation depends on the activation of transcriptional factors that are expressed during the sexual differentiation window. Such factors may have their expression altered by environmental conditions such as temperature and osmolarity, among others. These sexual processes are classically divided into sexual determination and differentiation, respectively. Based on such facts, this review aims to show the basic theoretical reasoning of the processes of sexual determination and differentiation in vertebrates, emphasizing the group of teleost fishes.

A reprodução sexual é a forma de propagação mais antiga e universal utilizada pelos vertebrados. Os mecanismos que controlam a determinação e diferenciação sexual nestes animais são diversos e dependem de uma grande variedade de fatores genéticos bem como em alguns casos de fatores ambientais. O sexo genético pode ser definido por fatores genéticos hereditários que são determinados na fecundação. Por outro lado, a diferenciação gonadal depende da ativação de fatores transcricionais que são expressos durante a janela de diferenciação sexual. Tais fatores podem ter sua expressão alterada por condições ambientais como a temperatura e a osmolaridade dentre outros. Estes processos sexuais são classicamente divididos em determinação e diferenciação sexual, respectivamente. Baseados em tai fatos, esta revisão tem como objetivo mostrar a fundamentação básica dos processos de determinação e diferenciação sexual em vertebrados com ênfase no grupo dos peixes teleósteos.

Correlation of maternal concentrations of plasma testosterone with fetal sex in horses / Correlação das concentrações plasmáticas de testosterona materna com o sexo fetal em equinos

The objectives of this study were to evaluate the correlation of fetal sex and plasma testosterone concentrations between the 5th and 8th months of pregnancy in mares and to verify the applicability of this test to predict fetal sex. Blood samples were collected from 21 mares at 30-day intervals of between 150 and 240 days of pregnancy. Plasma testosterone was determined by radioimmunoassay and the sex of the foals confirmed at birth. The levels of maternal testosterone were higher in mares carrying female fetuses at months 5 and 8 (P 0.05). Limit values were determined by analyzing the receiver operating characteristic (ROC) estimates: 35.5 pg/mL and 40 pg/mL for the 5th and 8th month, respectively. For the mares with plasma testosterone values equal to or above the threshold, gestation of female foals was predicted, and for those with plasma testosterone below the threshold values pregnancy of male foals was predicted. In the 5th month, the predictive values for male and female fetuses were 70% and 88.9%, respectively; the detection rates were 87.5% and 72.7%, and the total accuracy of the examination was 78.9%. In the 8th month, the predictive values for male and female fetuses were 80% and 90%, respectively; the detection rates were 88.9% and 81.8%, and the total accuracy of the examination was 85%. It was concluded that there was a correlation between fetal sex and plasma testosterone concentrations in pregnant mares. Prediction of fetal sex based on plasma concentrations of maternal testosterone can be performed in months 5 and 8 with 78.9% and 85% accuracy, respectively.(AU)

Os objetivos do estudo foram avaliar a correlação do sexo fetal com as concentrações plasmáticas de testosterona entre o 5° e o 8º mês de gestação na égua e verificar a aplicabilidade deste exame para a predição do sexo fetal. Amostras de sangue foram coletadas de 21 éguas, com intervalos de 30 dias, entre 150 e 240 dias de gestação. A testosterona plasmática foi determinada por radioimunoensaio e o sexo dos potros foi confirmado ao nascimento. Os valores de testosterona materna foram superiores nas éguas gestando fetos fêmeas aos cinco e oito meses (P 0.05). Através da análise da curva ROC (receiver operating characteristic) foram determinados valores limites de 35,5 pg/mL e 40 pg/mL para o 5º e o 8° mês, respectivamente. Éguas com testosterona plasmática igual ou acima dos valores limites foram preditas como gestando fêmeas e éguas com testosterona plasmática abaixo dos valores limites foram preditas como gestando machos. Aos cinco meses, os valores preditivos para fetos machos e fêmeas foram 70% e 88,9%, respectivamente; as taxas de detecção foram 87,5% e 72,7% e a acurácia total do exame foi de 78,9%. Aos oito meses, os valores preditivos para fetos machos e fêmeas foram 80% e 90%, respectivamente; as taxas de detecção foram 88,9% e 81,8% e a acurácia total do exame foi de 85%. Conclui-se que houve correlação entre o sexo fetal e as concentrações de testosterona plasmática em éguas prenhes. A predição do sexo fetal baseada nas concentrações plasmáticas de testosterona materna pode ser realizada aos cinco e oito meses de gestação com 78,9% e 85% de acurácia, respectivamente.(AU)

Sêmen ovino e caprino imunossexado e diluído em meio de conservação à base de água de coco em pó (ACP101/102c) / Ram and goat semen immunosexed and diluted in powdered coconut water-based preservation medium (ACP101/102c)

Sperm sexing aims to separate sperm populations in carriers of the "X" or "Y" chromosome. Currently, flow cytometry is a technique that allows greater accuracy; however, it causes structural changes in sperm, reduces viability, and has a high cost. As a result, other methods have been researched, including immunosexing, which uses monoclonal antibodies to detect sex-specific surface antigens. Thus, the objective of this study was to evaluate the immunosexing technique using a monoclonal antibody against sex-specific protein (HY) in the conservation of ram and goat semen in ACP101/102c. Ejaculates from five rams and five goats were collected with the aid of an artificial vagina; they were evaluated and submitted to the immunosexing protocol, according to the manufacturer's recommendations, using the Monoclonal Antibody Kit specific for mammalian sperm with "Y" chromosomes (HY; HY Biotechnology, Rio de Janeiro, RJ, Brazil). After sexing, the supernatant was resuspended in the cryopreservation diluent: ACP ram (ACP101/102c + 20% egg yolk + 7% glycerol) and ACP goat (ACP101/102c + 2.5% egg yolk + 7% glycerol), packaged in 0.25 mL straws, refrigerated at 4°C, stabilized for 30 min, frozen in liquid nitrogen vapor (-60°C) for 15 min, immersed in liquid nitrogen, and stored in cryogenic cylinders. The samples were evaluated in natura (T1), after immunosexing (T2) and after thawing (T3) for sperm motility subjectively using conventional microscopy (40x). Plasma membrane integrity (IMP) and sperm cell morphology were evaluated by the smear staining technique using eosin-nigrosine dye, and the percentages of healthy and morphologically defect spermatozoa were determined. In the evaluation of ram semen regarding sperm motility and IMP, no statistically significant differences were observed between treatments after sexing in the evaluation of absolute data (P > 0.05), with the difference being observed only between T1 and T2, and T3 (P < 0.05). Regarding the relative percentage and sperm morphology, no statistically significant differences were observed (P > 0.05). Regarding the evaluation of goat semen samples, the motility parameters were consistent with the technique submitted; however, the IMP data did not appear as expected, requiring further evaluation for a better assessment of the technique for this species. The data obtained from ram semen submitted to the immunosexing protocol, regarding the absolute evaluation of motility and IMP, demonstrated that the non-sexed semen (T1) was superior to the sexed treatments (T2 and T3); however, it is noteworthy that freezing started with approximately 50% of the cells, since the immunosexing technique results in a loss of viability of approximately 50% of the sperm, which corresponds to the ratio of sperm carrying the X chromosome. In addition, when the data in this study were transformed into relative values, no statistical differences were observed, indicating that the immunosexing protocol, as well as the freezing protocol, did not significantly affect the quality of ram sperm cells. In relation to the immunosexing of goat semen, future studies should be conducted in vitro to define a more appropriate protocol for the species and, in addition, in vivo studies should be performed to prove the quality of the technique. It was concluded that the immunosexing process using a monoclonal antibody against sex-specific protein (HY) associated with the use of powdered coconut water diluent (ACP101/102c) in the cryopreservation of semen proved to be efficient in the in vitro evaluation of ovine species.(AU)

Quantification of immunoreactive testosterone and estradiol-17ß metabolites to identify the sex of Neotropical otters (Lontra longicaudis annectens) in the field.

Before there was use of ultrasonographic imaging, determination of the ratio of estrogens to androgens in the same individual was a technique used for differentiating the sex of monomorphic animals in captivity, with larger estrogen concentrations in the females. Due to species-specific differences in both concentration and changes throughout the year of these hormones, corroboration of the method is needed in each case. In this study, there was use of a chemo-immuno assay to quantify sex steroids in fecal samples collected from seven (five females and two males) Neotropical otters, Lontra longicaudis. The reproductive season for this species was determined to be between October and March, with increased estradiol in the females and relatively greater concentrations of testosterone in the males as compared with other seasons of the year. Results from utilization of a k-means analysis procedure indicated that the use of steroid ratios in fecal samples to differentiate otter sex is an effective technique when there are evaluations during the breeding season. The estrogen to androgen ratios during this period, however, are the inverse of what was expected, with there being larger testosterone concentrations in the female otters. The ratio of estrogens to androgens in feces of captive otters can be effectively used to determine the sex of otters in the field. We propose this method is reliable for sex determination in wild otter populations during the reproductive season.

Characterization of carcasses of Zebu cattle raised in a semiarid region according to sex

The objective was to group and characterize Zebu cattle carcasses according to sex. Data from 15,002 carcasses of cattle raised in the semiarid region of the state of Minas Gerais, Brazil, were used. The carcass characteristics analyzed were weight, conformation, subcutaneous fat, number of permanent incisor teeth (PIT), and sex (uncastrated males, castrated males, females (up to six PIT), and cows (eight PIT)). Cluster analysis was applied to establish the relationship between sex and carcass characteristics. Four clusters were identified according to sex, and 60% of the total variance in the data set is explained by the clusters. Uncastrated males appear together in a single group (Cluster 1), which demonstrates homogeneity in their carcass characteristics. The heaviest group was Cluster 1. The castrated males appear in three groups, some of them (33.58%) grouped with the majority of cows (92.85%), which indicates that these carcasses did not achieve the quality required by the industry. Another part of the castrated males (41.84%) presented characteristics required by the industry. The females appear in all clusters. Except for uncastrated males and cows, the effect of sex (castrated males and females) on the carcass characteristics of Zebu cattle from the semiarid region of the Minas Gerais does not assure similar characteristics. Therefore, the improvement of carcass quality, using castration as the central grading criterion, should be reviewed not to overemphasize this item.(AU)

Application of embryo biopsy and sex determination via polymerase chain reaction in a commercial equine embryo transfer program in Argentina.

Embryo biopsy for fetal sexing has clinical application, but few reports are available of its use within an active embryo transfer program. We evaluated results on biopsy of 459 embryos over one breeding season. There were no significant differences in pregnancy rate between biopsied and non-biopsied embryos (72% vs 73%) or for biopsied embryos recovered at the centre (73%) compared with those shipped overnight (72%). However, the pregnancy rate decreased significantly in shipped embryos biopsied ≥20h after collection. Overall, 86% of biopsies provided a sex diagnosis. The likelihood of a positive genomic (g) DNA result was significantly higher for biopsies from large blastocysts (96%) than from smaller embryos (70-85%). In total, 38% of biopsies were positive for Y chromosome DNA (Y-DNA) and were diagnosed as male. Subsequently, 95% of Y-DNA-positive embryos were confirmed as male and 78% of Y-DNA-negative embryos were confirmed as female. The accuracy of prediction of female (Y-DNA negative) was significantly higher when the biopsy sample was probed for Y-DNA only compared with probing for both gDNA and Y-DNA. We estimate that by transferring only Y-DNA-negative embryos, 3% of potential female pregnancies may have been lost, and production of male pregnancies was reduced by 72%.

Sexagem em tamanduá-bandeira (Myrmecophaga tridactyla) por meio do teste da reação em cadeia da polimerase / Polymerase chain reaction for sexing in giant anteater's (Myrmecophaga tridactyla)

Em tamanduá-bandeira (Myrmecophaga tridactyla) não há dimorfismo sexual, tornando-se necessária a diferenciação entre machos e fêmeas, em especial naqueles indivíduos com finalidade reprodutiva. Entre as diversas técnicas empregadas para a caracterização sexual, a reação em cadeia da polimerase (PCR) é utilizada em mamíferos para identificar uma sequência genética especifica do cromossomo Y (SRY), sendo considerado um meio moderno e eficaz de determinação sexual. O objetivo deste trabalho é padronizar um protocolo para determinação sexual de tamanduá-bandeira por meio da técnica de PCR, utilizando material genético extraído do bulbo capilar desses animais. Mediante esse protocolo, foi possível determinar o sexo de sete animais testados, sendo compatível com o sexo de cada indivíduo. Conclui-se que o protocolo padronizado apresentou total eficácia, sendo possível determinar o sexo de tamanduás-bandeira utilizando material genético extraído do bulbo capilar.(AU)

There is no sexual dimorphism in the giant anteater (Myrmecophaga tridactyla), so the distinction between males and females become necessary, especially in animals with reproductive purpose. The Polymerase Chain Reaction (PCR), among the various techniques used for characterization, is considered a modern and effective means of sex determination and used in mammals to identify the Y chromosome (SRY) specifies genetic sequence. The objective of this work is to standardize a protocol for sex determination of giant anteater by PCR technique, using genetic material extracted from the capillary bulb of these animals. With this protocol was possible the sex determination of seven tested animals, being compatible with the sex of each individual. In conclusion, this protocol showed total effectiveness, being possible to determine the giant anteater sex using genetic material extracted from the capillary bulb.(AU)

Sexagem em tamanduá-bandeira (Myrmecophaga tridactyla) por meio do teste da reação em cadeia da polimerase / Polymerase chain reaction for sexing in giant anteater's (Myrmecophaga tridactyla)

Em tamanduá-bandeira (Myrmecophaga tridactyla) não há dimorfismo sexual, tornando-se necessária a diferenciação entre machos e fêmeas, em especial naqueles indivíduos com finalidade reprodutiva. Entre as diversas técnicas empregadas para a caracterização sexual, a reação em cadeia da polimerase (PCR) é utilizada em mamíferos para identificar uma sequência genética especifica do cromossomo Y (SRY), sendo considerado um meio moderno e eficaz de determinação sexual. O objetivo deste trabalho é padronizar um protocolo para determinação sexual de tamanduá-bandeira por meio da técnica de PCR, utilizando material genético extraído do bulbo capilar desses animais. Mediante esse protocolo, foi possível determinar o sexo de sete animais testados, sendo compatível com o sexo de cada indivíduo. Conclui-se que o protocolo padronizado apresentou total eficácia, sendo possível determinar o sexo de tamanduás-bandeira utilizando material genético extraído do bulbo capilar.(AU)

There is no sexual dimorphism in the giant anteater (Myrmecophaga tridactyla), so the distinction between males and females become necessary, especially in animals with reproductive purpose. The Polymerase Chain Reaction (PCR), among the various techniques used for characterization, is considered a modern and effective means of sex determination and used in mammals to identify the Y chromosome (SRY) specifies genetic sequence. The objective of this work is to standardize a protocol for sex determination of giant anteater by PCR technique, using genetic material extracted from the capillary bulb of these animals. With this protocol was possible the sex determination of seven tested animals, being compatible with the sex of each individual. In conclusion, this protocol showed total effectiveness, being possible to determine the giant anteater sex using genetic material extracted from the capillary bulb.(AU)

Potencial biotecnológico da sexagem espermática na produção animal / Biotechnological potential of sex-sorting sperm in animal production

A predeterminação do sexo da progênie é um desejo entre os criadores, uma vez que permite o direcionamento do sexo dos animais nascidos, segundo a finalidade do sistema de produção. Com a descoberta dos cromossomos sexuais X e Y, estudos para a pré-seleção do sexo seguiram um direcionamento científico, a fim de desenvolver técnicas para a separação das populações de espermatozoides portadores destes cromossomos. Com esta finalidade foi desenvolvido e aprimorado o método de separação em citômetro de fluxo, que é de alta precisão, embora apresente custo elevado e cause injúrias aos espermatozoides. Por conseguinte, protocolos alternativos vêm sendo buscados para viabilizar a sexagem espermática, sem maiores prejuízos estruturais e funcionais aos gametas, no que se destacam os gradientes de densidade de Percoll®. Em decorrência do potencial biotecnológico da sexagem espermática, visando maximizar a produção animal, foi objetivado com esta revisão expor os pontos positivos e negativos das duas principais técnicas usadas para este fim.

The predetermination of progeny sex is a desire among breeders, since it allows the sexing of born animals according the purpose of the production system. With the discovery of the sex chromosomes X and Y, the sex pre-selection studies followed a scientific direction, in order to develop techniques for the separation of sperm populations with these chromosomes. For this purpose it was developed and improved the flow cytometer separation method, which is highly accurate, although presenting a high cost and causing sperm injuries. Therefore, alternative protocols have been sought to enable sperm sexing,without major structural and functional damage to gametes, with emphasis on Percoll® density gradients. Due to the biotechnological potential of sperm sexing, in order to maximize the animal production, it was objectified in this review expose the positive and negative points of the two main techniques used for this purpose.

Potencial biotecnológico da sexagem espermática na produção animal / Biotechnological potential of sex-sorting sperm in animal production

A predeterminação do sexo da progênie é um desejo entre os criadores, uma vez que permite o direcionamento do sexo dos animais nascidos, segundo a finalidade do sistema de produção. Com a descoberta dos cromossomos sexuais X e Y, estudos para a pré-seleção do sexo seguiram um direcionamento científico, a fim de desenvolver técnicas para a separação das populações de espermatozoides portadores destes cromossomos. Com esta finalidade foi desenvolvido e aprimorado o método de separação em citômetro de fluxo, que é de alta precisão, embora apresente custo elevado e cause injúrias aos espermatozoides. Por conseguinte, protocolos alternativos vêm sendo buscados para viabilizar a sexagem espermática, sem maiores prejuízos estruturais e funcionais aos gametas, no que se destacam os gradientes de densidade de Percoll®. Em decorrência do potencial biotecnológico da sexagem espermática, visando maximizar a produção animal, foi objetivado com esta revisão expor os pontos positivos e negativos das duas principais técnicas usadas para este fim.(AU)

The predetermination of progeny sex is a desire among breeders, since it allows the sexing of born animals according the purpose of the production system. With the discovery of the sex chromosomes X and Y, the sex pre-selection studies followed a scientific direction, in order to develop techniques for the separation of sperm populations with these chromosomes. For this purpose it was developed and improved the flow cytometer separation method, which is highly accurate, although presenting a high cost and causing sperm injuries. Therefore, alternative protocols have been sought to enable sperm sexing,without major structural and functional damage to gametes, with emphasis on Percoll® density gradients. Due to the biotechnological potential of sperm sexing, in order to maximize the animal production, it was objectified in this review expose the positive and negative points of the two main techniques used for this purpose.(AU)

A new chicken molecular sexing assay based on the Z chromosome dose and the MHM region.

Birds have a ZZ and ZW sex chromosome system (male and female, respectively). On the short arm of the Z chromosome of Gallus gallus domesticus there is a repetitive region called MHM region, which is absent on the W chromosome, that causes a natural copy number difference of the MHM region between the sexes, making possible the development of a quantitative PCR (qPCR) sexing assay, based on the Z chromosome double dose. Twenty-seven samples of tissues from eight adult Gallus gallus domesticus (four males and four females) were used to establish the parameters of the MHM copy-number sexing assay. We blinded sexed 20 chicks using 140 samples from different tissues (heart, brain, gonad, kidney, lung, muscle, and blood). The success rate of the assay was 100% (140/140). It required small amounts of DNA (0.39 ng), opening the perspective to the use of the assay in studies in which the amount of available DNA is limited.

Biopsy of bovine embryos produced in vivo and in vitro does not affect pregnancy rates.

Assisted reproductive techniques have significantly contributed to animal breeding programs. Similarly, genomics has provided important information and tools to improve the accuracy of selection. However, the greatest benefits of those tools can only be expected when they are combined, allowing animals to be selected accurately early in life. Therefore, obtaining DNA samples from embryos without compromising their viability is essential for the consolidation of preimplantation genomic selection. We aimed to evaluate the effect on the gestation rate of conducting a biopsy of in vivo (VV) and in vitro-produced (IVP) bovine embryos. The VV and IVP embryos were distributed into two groups: VV-B (biopsied embryos; n = 380) and VV-C (intact embryos-controls; n = 229) and IVP-B (biopsied embryos; n = 91) and IVP-C (intact embryos-controls; n = 227), respectively. After biopsy, embryos from both groups VV-B and IVP-B were cultured for an additional 3 hours before being transferred to synchronized recipients. To evaluate the quality of the DNA obtained in the biopsies, this was used to determine the sex of embryos by polymerase chain reaction. No effect (P > 0.05) of the biopsy was observed for any of the treatments, the pregnancy rate at D 60 post-transfer being similar for VV-B: 206/380 (54.21%) and VV-C: 128/229 (55.89%) and for IVP-B: 24/91 (26.37%) and IVP-C: 45/227 (19.82%). Also, no effect (P > 0.05) of the embryo's stage of development was detected on percentage of pregnant recipients when in vitro embryos were transferred. From the biopsies analyzed, about 90% had the sex determined, confirming that DNA was there and it was efficiently amplified. The results indicated that biopsy does not affect the viability of IVV and IVP bovine embryos and can be used in commercial programs to associate assisted reproductive technologies with genomic selection.

Efeito da sexagem e linhagens sobre o desempenho e rendimento de carcaça de frangos de corte / Effect of strains and sexing on performance and carcass yield of broilers

Realizou-se este trabalho com o objetivo de avaliar o desempenho produtivo e o rendimento de carcaça de diferentes linhagens e sexagens de frangos de corte. Foram avaliadas 576 aves das linhagens Cobb, Ross e Hubbard, dispostas nas sexagem macho, fêmea ou misto, abatidas aos 45 dias de idade. Utilizou-se o delineamento inteiramente casualizado (DIC), num bifatorial 3 x 3 (linhagens x sexagem), com quatro repetições e 16 aves em cada tratamento. O peso vivo, ganho de peso, consumo de ração e conversão alimentar apresentaram diferenças significativas no decorrer das fases avaliadas, porém, mostraram-se semelhantes ao final do período avaliado. O desempenho dos machos apresentou superioridade em comparação com as fêmeas e os mistos. No rendimento de carcaça, não foi possível observar diferenças significativas entre as linhagens e sexagens das aves; no entanto, em alguns cortes nobres a linhagens Cobb apresentou melhores resultados.

We carried out this study to evaluate the productive performance and carcass yield of different strains and sexing of broilers. We evaluated 576 birds of Cobb, Ross, and Hubbard strains, arranged in male, female or mixed sexing, slaughtered at 45 days of age. We used a completely randomized design (CRD), in a 3 X 3 factorial (strain X sex), with four replicates per treatment. Body weight, weight gain, feed intake, and feed conversion showed significant differences in the course of the phases evaluated; however, they were similar at the end of the study period. Males showed superior results compared to females and mixed sexing. Carcass yield showed no significant differences among strains and sexing of birds; however, in some prime cuts, Cobb presented the best results.

Efeito da sexagem e linhagens sobre o desempenho e rendimento de carcaça de frangos de corte / Effect of strains and sexing on performance and carcass yield of broilers

Realizou-se este trabalho com o objetivo de avaliar o desempenho produtivo e o rendimento de carcaça de diferentes linhagens e sexagens de frangos de corte. Foram avaliadas 576 aves das linhagens Cobb, Ross e Hubbard, dispostas nas sexagem macho, fêmea ou misto, abatidas aos 45 dias de idade. Utilizou-se o delineamento inteiramente casualizado (DIC), num bifatorial 3 x 3 (linhagens x sexagem), com quatro repetições e 16 aves em cada tratamento. O peso vivo, ganho de peso, consumo de ração e conversão alimentar apresentaram diferenças significativas no decorrer das fases avaliadas, porém, mostraram-se semelhantes ao final do período avaliado. O desempenho dos machos apresentou superioridade em comparação com as fêmeas e os mistos. No rendimento de carcaça, não foi possível observar diferenças significativas entre as linhagens e sexagens das aves; no entanto, em alguns cortes nobres a linhagens Cobb apresentou melhores resultados.(AU)

We carried out this study to evaluate the productive performance and carcass yield of different strains and sexing of broilers. We evaluated 576 birds of Cobb, Ross, and Hubbard strains, arranged in male, female or mixed sexing, slaughtered at 45 days of age. We used a completely randomized design (CRD), in a 3 X 3 factorial (strain X sex), with four replicates per treatment. Body weight, weight gain, feed intake, and feed conversion showed significant differences in the course of the phases evaluated; however, they were similar at the end of the study period. Males showed superior results compared to females and mixed sexing. Carcass yield showed no significant differences among strains and sexing of birds; however, in some prime cuts, Cobb presented the best results.(AU)

Influência do ciclo lunar na determinação do sexo de cordeiros / Influence of lunar cycle in the parturition of the Dorper sheep breed

The aim of this study was to evaluate the influence of lunar phases in Dorper sheep, according to theproportion of births (single: double). Twenty were used two sheep from a breeding season. For the evaluation oflunar phases sheep were grouped proportionally according to the type of delivery (single: double). The analysisof the types of delivery were obtained according to the moon phases in place by the Brazilian NationalObservatory, being considered corresponding to the lunar phase where the maximum headquarters was up totwo days before and after the date of interest after being compared by the test chi-square test (P <0.05). It wasfound that there was a greater proportion of births in the crescent moon (P <0.05) compared to other lunarphases. The conclusion of this research that the crescent moon of the lunar phases, seems to affect the types ofdelivery of Dorper sheep.