Human globozoospermia-related genes and their role in acrosome biogenesis.

The mammalian acrosome is a secretory vesicle attached to the sperm nucleus whose fusion with the overlying plasma membrane is required to achieve fertilization. Acrosome biogenesis starts during meiosis, but it lasts through the entire process of haploid cell differentiation (spermiogenesis). Acrosome biogenesis is a stepwise process that involves membrane traffic from the Golgi apparatus, but it also seems that the lysosome/endosome system participates in this process. Defective sperm head morphology is accompanied by defective acrosome shape and function, and patients with these characteristics are infertile or subfertile. The most extreme case of acrosome biogenesis failure is globozoospermia syndrome, which is primarily characterized by the presence of round-headed spermatozoa without acrosomes with cytoskeleton defects around the nucleus and infertility. Several genes participating in acrosome biogenesis have been uncovered using genetic deletions in mice, but only a few of them have been found to be deleted or modified in patients with globozoospermia. Understanding acrosome biogenesis is crucial to uncovering the molecular basis of male infertility and developing new diagnostic tools and assisted reproductive technologies that may help infertile patients through more effective treatment techniques. This article is categorized under: Reproductive System Diseases > Environmental Factors Infectious Diseases > Stem Cells and Development Reproductive System Diseases > Molecular and Cellular Physiology.

Morfologia espermática em touros: quais os principais defeitos e o porquê ocorrem / Sperm morphology in bulls: which are the main defects and why they occur

A morfologia espermática é uma característica seminal que está associada à fertilidade e é, portanto, um componente importante na rotina do controle de qualidade em Centros de Coleta e Processamento de Sêmen (CCPS). É utilizada para caracterizar e quantificar os vários tipos de anormalidades nas células espermáticas do touro, usando preparação em montagem úmida para microscopia de Contraste de Interferência Diferencial (DIC), Contraste de Fase (CF) e Lâmina Corada (LC). O perfil da morfologia espermática permite a tomada de decisão sobre o aproveitamento ou descarte de um ejaculado para criopreservação e predizer a fertilidade de uma amostra de sêmen. Alterações no espermograma, com evidências do histórico e exame físico do touro, levam a interpretação da função testicular anormal, e consequentemente, ao diagnóstico, tratamento e prognóstico, se for o caso. As causas mais comuns de uma espermatogênese anormal nos touros incluem: termorregulação testicular anormal, desequilíbrios hormonais, estresse de manejo, ambiental e nutricional, efeitos de toxinas ou expressão de genes deletérios, além de defeitos de origem genética. Conhecendo-se a estrutura do espermatozoide, torna-se mais fácil a identificação das anormalidades espermáticas bem como a descrição das mesmas e uma melhor compreensão de sua origem.(AU)

Sperm morphology is a seminal trait that is associated with fertility and is therefore an important component of routine quality control in Semen Collection and Processing Centers (SCPC). It is used to characterize and quantify the various types of abnormalities in bull sperm cells, using wet mount preparation for Differential Interference Contrast (DIC), Phase Contrast (PC) and Slides Smear (SS) microscopy. The sperm morphology profile allows decision making on the use or disposal of an ejaculate for cryopreservation and predicts the fertility of a semen sample. Changes in sperm morphology may indicate that fertility may be impacted and therefore it is important to routinely monitor ejaculates. An abnormal spermogram with evidence from a history and physical examination of the bull can lead to the interpretation of abnormal testicular function, and consequently, to the diagnosis, treatment and prognosis, if any. The most common causes of abnormal spermatogenesis in bulls include: abnormal testicular thermoregulation, hormonal imbalances, management, environmental and nutritional stress, effects of toxins or expression of deleterious genes, in addition to defects of genetic origin. Knowledge in the structure of the sperm makes easier the identification of sperm abnormalities, as well as their description and provides a better understanding of their origin.(AU)

Caracterización de la calidad del semen en hombres atendidos en un centro de reproducción asistida en Guayaquil, Ecuador / Description of the semen quality from men treated in an assisted reproduction center in Guayaquil, Ecuador

RESUMEN Con el objetivo de caracterizar la calidad seminal de hombres en un centro de reproducción asistida de la ciudad Guayaquil (Ecuador), se colectaron 204 muestras de semen de pacientes con problemas de fertilidad de entre 20 y 57 años, atendidos entre mayo de 2017 y septiembre de 2018. Se realizó un espermograma básico a cada muestra, siguiendo las recomendaciones del manual para la examinación y procesamiento de semen humano. El 27,4% de las muestras presentó normozoospermia. Dentro de las alteraciones la teratozoospermia fue de 27,9%, oligoteratozoospermia del 8,8%, evidenciándose mayor número en pacientes de 30 a 39 años. Un alto porcentaje de pacientes presentan una calidad del semen y morfología espermática por debajo los limites de referencia establecidos por la Organización Mundial de la Salud.

ABSTRACT In order to characterize the quality of semen from men in an assisted reproduction center in the city of Guayaquil (Ecuador), 204 semen samples were collected from patients with fertility disorders aged 20 to 57 years, who were admitted between May 2017 and September 2018. A basic spermogram was performed on each sample, following the fabricant recommendations for the examination and processing of human semen. It was found that 27.4% of the samples presented normozoospermia. Among the disorders, it was found that 27.9% had teratozoospermia, 8.8% had oligoteratozoospermia and a higher number of patients were found to be between 30 and 39 years old. A high percentage of patients presented sperm morphology and quality values below the reference limits established by the World Health Organization.

Recategorisation of body mass index to achieve andrological predictive power: a study in more than 20 000 patients.

The aim of this study was to recategorise body mass index (BMI) in order to classify patients according to their risk of semen abnormalities. Patients (n=20563) presenting at an andrology laboratory were classified into five groups according to BMI: underweight (BMI <20kg m-2), normal weight (BMI 20-24.9kg m-2), overweight (BMI 25-29.9kg m-2), obese (BMI 30-39.9kg m-2) and morbidly obese (BMI >40kg m-2). Semen quality was evaluated to determine: (1) differences between groups using analysis of variance (ANOVA); (2) the chances of semen abnormalities (using generalised linear models, Chi-squared tests and odds ratios); (3) reference BMI values with andrological predictive power (multivariate conglomerate analyses and multivariate analysis of variance (MANOVA)); and (4) expected values of abnormalities for each new group resulting from BMI recategorisation. Morbidly obese and underweight patients exhibited the highest decrease in semen quality and had higher chances of semen abnormalities. The smallest number of sperm abnormalities was found at a BMI of 27kg m-2. Four reference values were identified, recategorising BMI into four groups according to their risk of semen abnormalities (from lowest to highest risk): Group1,BMI between 20 and 32kg m-2; Group2, BMI <20 and BMI >32-37kg m-2; Group3, BMI >37-42kg m-2; and Group4, BMI >42kg m-2. A BMI <20 or >32kg m-2 is negatively associated with semen quality; these negative associations on semen quality increase from a BMI >37kg m-2 and increase even further for BMI >42kg m-2. The BMI recategorisation in this study has andrological predictive power.

Macrozoospermia associated with mutations of AURKC gene: First case report in Latin America and literature review.

A Chilean 35-year-old male patient with a history of primary infertility made an appointment at the Unit of Reproductive Medicine at Clínica Las Condes, Santiago, Chile. Multiple semen analyses revealed abnormal sperm morphology as the most prevalent finding. Multiflagellated and macrocephalic spermatozoa were observed and indicated a possible macrozoospermic phenotype. The constant presence of abnormal sperm morphology led the scope of the study to include Aurora Kinase C (AURKC) gene sequencing. The patient was diagnosed with a homozygous mutation of this gene. The mutation was detected in exon 6, type c.744C>G+/+ (P.Y248*) variant. As previously described in the Human Gene Mutation Database (HGMD), this pathogenic variant is associated with macrozoospermia. Although this mutation is not the most frequently observed, it is the first of its kind reported in Latin America.

Análise morfométrica da cabeça espermática em Saimiri cassiquiarensis / Morphometric analysis of the sperm head in Saimiri cassiquiarensis

The objective was to evaluate the sperm morphometry between normal and pathological cells in Saimiri cassiquiarensis aiming at the future use of data in CASA (Computer Assisted Sperm Analysis). Semen was collected from a male (S. cassiquiarensis) by electroejaculation. After collection, a smear in the proportion of 1:1 (semen and eosin-nigrosin stain) was performed, and 100 sperm were measured and morphologically classified as normal and pathological defects (major and minor). Of the total sperm analyzed, 48% were classified as normal and 52% pathological. Of the pathologies, the most frequent was a folded tail (40%), followed by a strongly folded tail (5%), curled tail (2%) and isolated head (5%). The morphometric data showed no statistical difference (p<0.05) between normal and pathological defects. This is the first description for the sperm morphometry in Saimiri cassiquiarensis, therefore, from this database, future assessments at CASA can be conducted for this species.(AU)

Análise morfométrica da cabeça espermática em Saimiri cassiquiarensis / Morphometric analysis of the sperm head in Saimiri cassiquiarensis

The objective was to evaluate the sperm morphometry between normal and pathological cells in Saimiri cassiquiarensis aiming at the future use of data in CASA (Computer Assisted Sperm Analysis). Semen was collected from a male (S. cassiquiarensis) by electroejaculation. After collection, a smear in the proportion of 1:1 (semen and eosin-nigrosin stain) was performed, and 100 sperm were measured and morphologically classified as normal and pathological defects (major and minor). Of the total sperm analyzed, 48% were classified as normal and 52% pathological. Of the pathologies, the most frequent was a folded tail (40%), followed by a strongly folded tail (5%), curled tail (2%) and isolated head (5%). The morphometric data showed no statistical difference (p<0.05) between normal and pathological defects. This is the first description for the sperm morphometry in Saimiri cassiquiarensis, therefore, from this database, future assessments at CASA can be conducted for this species.

Reference values (RV), MNS and MTS for morphological characteristics of normal and abnormal human spermatozoon describing Teratozoospermic Index (TZI) & Sperm Deformity Index (SDI) in Sudanese infertile couples using CASA System / Valores de referencia (RV), MNS y MTS para las características morfológicas de espermatozoides humanos normales y anormales que describen el Índice Teratozoospérmico (TZI) y el Índice de Deformidad del Esperma (SDI) en parejas infértiles de Sudán que utilizan el sistema CASA

A scientific determination of fertilization ability of the sperm can be made by motility, viability and morphological examinations that are called as potential fertility criteria. Some previous studies documented only the total morphological defect rates without including the morphologic subjects. As it is recorded in many studies, the success of IUI, ICSI and IVF depends mainly on the quality of the collected semen. 1) Determine and classify the common morphological defects and rates of sperms. 2) Analyze the effect of age on the sperm abnormalities and to assess the impact of environment on changing normal sperm characteristics. 3) Determine the common types of semen abnormalities (Asthenoterato-zoospermia, Asthenozoospermia, Azoopyospermia, Azoospermia, Hypospermia, Oligoasthenoteratozoospermia, Oligoasthenozoopyospermia, Oligoasthenozoospermia and Teratozoospermia). 4) Determine the range of teratozoospermic index (TZI) and sperm deformity index (SDI). A prospective case series study for 566 men of infertile couples who were requesting semen analysis was applied to those came to the ULTRALAB laboratory center main campus and ULTRALAB branch of the Sudan Assisted Reproduction Center (SARC), Khartoum, Sudan. Data collection was done for 20 months from April 1st, 2010 to December 31st, 2011. analysis of semen samples was done using Computer Assisted Semen Analysis (CASA). 1) The study demonstrates that there are differences in normality and abnormality of sperm morphology parameters of sperm between Sudanese population and other studies including WHO standards. 2) SDI and TZI were higher in overall semen as well as in abnormal semen samples. 3) Common semen abnormalities were oligoasthenoteratozoospermia, asthenoteratozoospermia and asthenozoospermia. There are differences in sperm morphology of both normal and abnormal parameters between Sudanese population and other studies including WHO standards.

Se realizó una determinación científica de la capacidad de fertilización de los espermatozoides mediante motilidad, viabilidad y exámenes morfológicos denominados criterios de fertilidad potencial. Algunos estudios previos documentan solamente el total de las tasas de defectos morfológicos sin incluir a los sujetos morfológicos. Como se registra en muchos estudios, el éxito de IUI, ICSI y FIV depende principalmente de la calidad del semen recolectado. Los objetivos de este trabajo fueron: 1) Determinar y clasificar los defectos morfológicos comunes y las tasas de espermatozoides; 2) Analizar el efecto de la edad en las anomalías de los espermatozoides y evaluar el impacto del medio ambiente en el cambio de las características normales de los espermatozoides; 3) Determinar los tipos comunes de anomalías en el semen (astenoterato-zoospermia, astenozoospermia, azoopiepermia, azoospermia, hipospermia, oligoastenoteratozoospermia, oligoastenozoopermia, oligoastenozoospermia y teratozoospermia); 4) Determinar el rango del índice teratozoospérmico (TZI) y el índice de deformidad del esperma (IDE). Se realizó un estudio prospectivo de series de casos en 566 hombres, de parejas infértiles, que solicitaban análisis de semen en laboratorios ULTRALAB y la sucursal de ULTRALAB del Centro de Reproducción Asistida de Sudán (SARC), Jartum, Sudán. La recolección de datos se realizó durante 20 meses, desde el 1 de abril de 2010 hasta el 31 de diciembre de 2011. El análisis de las muestras de semen se realizó mediante el análisis de semen asistido por computadora (CASA). Existen diferencias en la normalidad y anormalidad de los parámetros de la morfología de los espermatozoides entre la población sudanesa y otros estudios, incluidas las normas de la Organización Mundial de la Salud. Los parámetros SDI y TZI fueron más altos en el semen general, así como en muestras de semen anormales. Las anomalías comunes del semen fueron oligoastenatoatoospermia, astenoteratozoospermia y astenozoospermia. Existen diferencias en la morfología de los espermatozoides de los parámetros normales y anormales entre la población sudanesa y otros estudios que incluyen las normas de la Organización Mundial de la Salud.

Proteomics and Leishmaniasis: Potential Clinical Applications.

Leishmaniases are diseases caused by protozoan parasites of the genus Leishmania. They are endemic in 98 countries, affect around 12 million people worldwide and may present several distinct clinical forms. Unfortunately, there are only a few drugs available for treatment of leishmaniasis, which are toxic and not always effective. Different parasite species and different clinical forms require optimization of the treatment or more specific therapies, which are not available. The emergence of resistance is also a matter of concern. Besides, diagnosis can sometimes be complicated due to atypical manifestations and associations with other pathologies. In this review, proteomic data are presented and discussed in terms of their application in important issues in leishmaniasis such as parasite resistance to chemotherapy, diagnosis of active disease in patients and dogs, markers for different clinical forms, identification of virulence factors, and their potential use in vaccination. It is shown that proteomics has contributed to the discovery of potential biomarkers for prognosis, diagnosis, therapeutics, monitoring of disease progression, treatment follow-up and identification of vaccine candidates for specific diseases. However, the authors believe its capabilities have not yet been fully explored for routine clinical analysis for several reasons, which will be presented in this review.

Microscopic sperm head damage and abnormalities as heat stress indicators in Australian Merino rams (Ovis aries) in Northern Patagonia, Argentina / Danos e anormalidades microscópicas das cabeças espermáticas como indicadores de estresse por calor em carneiros Merino Australiano (Ovis aries) da Patagônia Norte, Argentina

In Northern Patagonia, the mating season starts on March 15th, when rams are submitted to summer temperatures. Exposure of rams to heat stress increases the prevalence of microscopic damage to spermatozoa, morphological abnormalities, and reductions in fertility. This study assesses the adaptive capabilities of six unshorn and six shorn Australian Merino rams, half of which were treated in a heat chamber for eight hours for five days, gradually reaching a temperature of up to 40 °C. Microscopic damage, abnormalities and ultramicroscopic alterations of the plasma membrane and the acrosome of sperm head were analysed. There were significant differences in the percentage of tailless spermatozoa and proximal cytoplasmic droplets between post-treatment periods. Temperature primarily affected the shorn rams and the sperm heads during spermiogenesis. Submicroscopic alterations were observed when the plasma membrane was present in the anterior segment. These alterations can be intact, waved, or dilated. When the plasma membrane was absent, the acrosome might be intact, dilated, and waved. In addition, the outer acrosomal membrane may completely lose its contents or have a nude nucleus. The plasma membrane assumes a waved shape as a result of the effect of temperature on the epididymis. According to this study, the tailless head, proximal cytoplasmic droplets, and the ultramicroscopic categories studied were robust indicators of semen heat stress. After ten weeks, the sperm head recovered its normal shape. Unshorn rams are better adapted to summer heat stress than shorn ones. Microscopy and transmission electron microscopy alterations have been shown to be excellent indicators of thermal stress in Australian Merino rams and may be useful tools to help sheep farmers choose when to begin the mating season, which will vary depending on the environmental conditions of the summer.(AU)

Na Patagônia Norte, os ovinos têm sua estação de acasalamento iniciada em 15 de março, portanto, ficam sujeitos às temperaturas do verão. A exposição de carneiros a estresse térmico aumenta a prevalência de danos microscópicos e anomalias morfológicas nos espermatozoides, que implica uma redução na fertilidade. Este trabalho avaliou a capacidade adaptativa de carneiros Merino Australiano com lã (N = 6) e tosquiados (N = 6): metade ficou ao ar livre e outra metade foi mantida em uma câmara climática por oito horas, durante cinco dias, chegando gradualmente a uma temperatura máxima de 40 °C. Foram analisados danos microscópicos, anormalidades e alterações ultramicroscópicas da membrana plasmática e do acrossoma da cabeça dos espermatozoides. Os resultados microscópicos confirmaram a existência de diferença significativa na porcentagem de espermatozoides sem cauda e com gota citoplasmática proximal, entre os ejaculados pós-tratamento. A temperatura afetou os carneiros tosquiados, principalmente a cabeça de seus espermatozoides, durante a espermatogênese. Alterações submicroscópicas foram observados na membrana plasmática quando ela estava presente no segmento anterior: quando não intacta, ficava ondulada ou dilatada. Quando a membrana plasmática estava ausente, o acrossoma podia se apresentar ondulado ou dilatado. Além disso, sob efeito do calor, a membrana acrossomal externa pode perder completamente seu conteúdo ou apresentar núcleo desnudo. A membrana plasmática assume uma forma ondulada pelo efeito da temperatura no epidídimo. Depois de dez semanas, a cabeça dos espermatozoides recuperou sua forma normal. Como demonstrado neste estudo, a cabeça sem cauda, as gotas citoplasmáticas proximais e as categorias ultramicroscópicas estudadas são indicadores do efeito do estresse térmico no sêmen, e os carneiros com maior cobertura de lã se adaptam melhor ao estresse por calor. Alterações de microscopia e de microscopia eletrônica de transmissão têm se mostrado excelentes indicadores de estresse por calor em carneiros Merino Australiano e podem ser ferramentas úteis para ajudar criadores de ovelhas a escolher quando começar a época de acasalamento, o que irá variar de acordo com as condições ambientais do verão.(AU)

Microscopic sperm head damage and abnormalities as heat stress indicators in Australian Merino rams (Ovis aries) in Northern Patagonia, Argentina / Danos e anormalidades microscópicas das cabeças espermáticas como indicadores de estresse por calor em carneiros Merino Australiano (Ovis aries) da Patagônia Norte, Argentina

In Northern Patagonia, the mating season starts on March 15th, when rams are submitted to summer temperatures. Exposure of rams to heat stress increases the prevalence of microscopic damage to spermatozoa, morphological abnormalities, and reductions in fertility. This study assesses the adaptive capabilities of six unshorn and six shorn Australian Merino rams, half of which were treated in a heat chamber for eight hours for five days, gradually reaching a temperature of up to 40 °C. Microscopic damage, abnormalities and ultramicroscopic alterations of the plasma membrane and the acrosome of sperm head were analysed. There were significant differences in the percentage of tailless spermatozoa and proximal cytoplasmic droplets between post-treatment periods. Temperature primarily affected the shorn rams and the sperm heads during spermiogenesis. Submicroscopic alterations were observed when the plasma membrane was present in the anterior segment. These alterations can be intact, waved, or dilated. When the plasma membrane was absent, the acrosome might be intact, dilated, and waved. In addition, the outer acrosomal membrane may completely lose its contents or have a nude nucleus. The plasma membrane assumes a waved shape as a result of the effect of temperature on the epididymis. According to this study, the tailless head, proximal cytoplasmic droplets, and the ultramicroscopic categories studied were robust indicators of semen heat stress. After ten weeks, the sperm head recovered its normal shape. Unshorn rams are better adapted to summer heat stress than shorn ones. Microscopy and transmission electron microscopy alterations have been shown to be excellent indicators of thermal stress in Australian Merino rams and may be useful tools to help sheep farmers choose when to begin the mating season, which will vary depending on the environmental conditions of the summer.(AU)

Na Patagônia Norte, os ovinos têm sua estação de acasalamento iniciada em 15 de março, portanto, ficam sujeitos às temperaturas do verão. A exposição de carneiros a estresse térmico aumenta a prevalência de danos microscópicos e anomalias morfológicas nos espermatozoides, que implica uma redução na fertilidade. Este trabalho avaliou a capacidade adaptativa de carneiros Merino Australiano com lã (N = 6) e tosquiados (N = 6): metade ficou ao ar livre e outra metade foi mantida em uma câmara climática por oito horas, durante cinco dias, chegando gradualmente a uma temperatura máxima de 40 °C. Foram analisados danos microscópicos, anormalidades e alterações ultramicroscópicas da membrana plasmática e do acrossoma da cabeça dos espermatozoides. Os resultados microscópicos confirmaram a existência de diferença significativa na porcentagem de espermatozoides sem cauda e com gota citoplasmática proximal, entre os ejaculados pós-tratamento. A temperatura afetou os carneiros tosquiados, principalmente a cabeça de seus espermatozoides, durante a espermatogênese. Alterações submicroscópicas foram observados na membrana plasmática quando ela estava presente no segmento anterior: quando não intacta, ficava ondulada ou dilatada. Quando a membrana plasmática estava ausente, o acrossoma podia se apresentar ondulado ou dilatado. Além disso, sob efeito do calor, a membrana acrossomal externa pode perder completamente seu conteúdo ou apresentar núcleo desnudo. A membrana plasmática assume uma forma ondulada pelo efeito da temperatura no epidídimo. Depois de dez semanas, a cabeça dos espermatozoides recuperou sua forma normal. Como demonstrado neste estudo, a cabeça sem cauda, as gotas citoplasmáticas proximais e as categorias ultramicroscópicas estudadas são indicadores do efeito do estresse térmico no sêmen, e os carneiros com maior cobertura de lã se adaptam melhor ao estresse por calor. Alterações de microscopia e de microscopia eletrônica de transmissão têm se mostrado excelentes indicadores de estresse por calor em carneiros Merino Australiano e podem ser ferramentas úteis para ajudar criadores de ovelhas a escolher quando começar a época de acasalamento, o que irá variar de acordo com as condições ambientais do verão.(AU)

Peça intermediária de espermatozoides bovinos: funções e anormalidades / Midpiece of bovine spermatozoa: functions and abnormalities

O reprodutor tem grande importância na cadeia produtiva por possuir maior potencial de difusão do seu material genético dentro do rebanho do que as fêmeas que produzem apenas uma cria por ano, em manejo de monta natural. Entretanto, este potencial somente se torna real quando os machos apresentam boa qualidade seminal, resultando em menores taxas de retorno ao estro. No entanto, apesar das características reprodutivas apresentarem baixa herdabilidade, é consensual que algumas patologias espermáticas possam apresentar características hereditárias e neste caso podem permanecer disseminadas nos rebanhos. Entre as anomalias espermáticas identificadas nos ejaculados de bovinos, as patologias de peça intermediária são classificadas como defeitos espermáticos maiores, comprometendo a fertilidade dos reprodutores, porém estas têm recebido pouca atenção. O objetivo deste trabalho de revisão é apresentar os principais estudos sobre a formação da peça intermediária, sua importância e como esta pode sofrer anormalidades, visto que ejaculados com presença destas anomalias apresentam baixa motilidade espermática e fertilidade.(AU)

Bulls are of immense importance in the productive chain because they have a greater potential of diffusion of genetic material within the herd than females that produce only one calf per year in natural mating management. However, this potential is only achieved when males present good seminal quality, resulting in lower rates of return to estrus. Although the reproductive traits have low heritability, it is consensual that some sperm pathologies may present hereditary characteristics and in this case they can remain disseminated in the herds. Among the sperm abnormalities identified in bovine ejaculates, the midpiece pathologies are classified as a major sperm defect, compromising bull fertility, but these pathologies have received little attention. The objective of this review is to present the main studies on the midpiece formation, its importance and how it can undergo abnormalities, since ejaculates with the presence of this pathology present low sperm motility and fertility.(AU)

Peça intermediária de espermatozoides bovinos: funções e anormalidades / Midpiece of bovine spermatozoa: functions and abnormalities

O reprodutor tem grande importância na cadeia produtiva por possuir maior potencial de difusão do seu material genético dentro do rebanho do que as fêmeas que produzem apenas uma cria por ano, em manejo de monta natural. Entretanto, este potencial somente se torna real quando os machos apresentam boa qualidade seminal, resultando em menores taxas de retorno ao estro. No entanto, apesar das características reprodutivas apresentarem baixa herdabilidade, é consensual que algumas patologias espermáticas possam apresentar características hereditárias e neste caso podem permanecer disseminadas nos rebanhos. Entre as anomalias espermáticas identificadas nos ejaculados de bovinos, as patologias de peça intermediária são classificadas como defeitos espermáticos maiores, comprometendo a fertilidade dos reprodutores, porém estas têm recebido pouca atenção. O objetivo deste trabalho de revisão é apresentar os principais estudos sobre a formação da peça intermediária, sua importância e como esta pode sofrer anormalidades, visto que ejaculados com presença destas anomalias apresentam baixa motilidade espermática e fertilidade.

Bulls are of immense importance in the productive chain because they have a greater potential of diffusion of genetic material within the herd than females that produce only one calf per year in natural mating management. However, this potential is only achieved when males present good seminal quality, resulting in lower rates of return to estrus. Although the reproductive traits have low heritability, it is consensual that some sperm pathologies may present hereditary characteristics and in this case they can remain disseminated in the herds. Among the sperm abnormalities identified in bovine ejaculates, the midpiece pathologies are classified as a major sperm defect, compromising bull fertility, but these pathologies have received little attention. The objective of this review is to present the main studies on the midpiece formation, its importance and how it can undergo abnormalities, since ejaculates with the presence of this pathology present low sperm motility and fertility.

Relationship between morphological abnormalities in commercial bull frozen semen doses and conception rate.

Commercial doses of frozen bull semen for artificial insemination may have a certain percentage of morphological defects, despite being subject to prior selection. The aims of this study were to determine the prevalence of morphological abnormalities in commercial doses (n = 55, r = 2) of dairy and beef bulls, from AI Centers and to determine the possible existence of differences between them, regarding the percentage of abnormal spermatozoa. At least 200 spermatozoa per sample were evaluated using Bengal Rose stain (3% m/v) and light microscopy (×1000 magnification). The mean percentage of abnormal sperm samples from dairy breeds was 7.19% ± 4.91% and from beef breeds was 15.83% ± 9.28%. Significant differences between biotypes were found in the proportion of abnormal spermatozoa, abnormal heads and abnormal midpieces; it could be due to different selection pressure. It was observed that the percentage of abnormal spermatozoa was not a good fertility level predictor for the commercial samples of frozen bovine semen used in this study. In both biotypes, the midpiece abnormalities were the most frequent, mainly its distal flexion (compensable defect). This could be as a result of the effects of freezing and thawing on spermatozoa.

Normozoospermic versus teratozoospermic domestic cats: differential testicular volume, sperm morphometry, and subpopulation structure during epididymal maturation.

Teratozoospermia (<40% morphologically normal spermatozoa/ejaculate) is a frequent phenomenon in feline species. This research was carried out to study the possible differences in testicular volume, differential sperm morphometric traits, and potential differences regarding the sperm subpopulational structure during epididymal sperm maturation in teratozoospermic feline donors. Epididymal sperm samples were collected from the caput (R1), corpus (R2), and cauda (R3) epididymidis in two donor groups (N: normozoospermic; T: teratozoospermic). Aliquots were assessed for concentration, viability, motility, and acrosomal integrity. Sperm morphometric descriptors from CASA-Morph analysis were analyzed by the Principal Component Analysis (PCA) and clustering analyses. Irrespective of the group analyzed, PCA revealed two Principal Components (PCs) for each epididymal region explaining more than the 93% of the variance. Surprisingly, the number of subpopulations remained constant in regions R1-R2-R3 irrespective of the donor group analyzed. However, the distribution of these subpopulations was found to be structurally different and strongly influenced by the epididymal region and the donor group. In conclusion, testicular morphometry and the sperm subpopulation structure were different in N and T donors. The alterations in subpopulations during epididymal maturation could be used as a potential clinical indicator of teratozoospermic individuals since an important influence of teratozoospermia on sperm subpopulation structure has been demonstrated.

Systematic tracking of altered modules identifies disrupted pathways in teratozoospermia.

The objective of this study was to identify disrupted pathways in teratozoospermia by systematically tracking dysregulated modules in reweighted protein-protein interaction (PPI) networks. We inferred and reweighted the PPI networks of normal and teratozoospermia groups based on Spearman correlation coefficients. Modules in the PPI networks were explored via a clique-merging algorithm and altered modules were identified based on maximum weight bipartite matching. Furthermore, pathway-enrichment analyses of genes in altered modules were performed by Database for Annotation, Visualization, and Integrated Discovery (DAVID) to illuminate the biological pathways in teratozoospermia. A total of 20,102 genes were screened from the expression profile. We explored 2406 and 2101 modules in normal and disease PPI networks, respectively. Moreover, we obtained 875 altered modules by comparing modules in normal and teratozoospermia PPI networks. At P < 0.01, the genes involved in 2855 interactions with score changes >1 were mainly enriched in 66 pathways and the genes in altered modules were enriched in 71 pathways. The activity genes (missed and added genes in the disrupted modules) were enriched in 41 common pathways. There were 36 mutual enriched pathways under the five different conditions. Moreover, the cell cycle pathway was disrupted in the first 10 pathways of each condition. This study provides a powerful biomarker discovery platform to better understand the progression of teratozoospermia by systematically tracking dysregulated modules. This method uncovered potential diagnostic and therapeutic targets of teratozoospermia. This information might lead to improved monitoring and treatment of teratozoospermia.

Domestic cat testicular aromatase activity as assessed by the tritiated water-release assay

Lower testicular tetosterone:17β-estradiol (T:E2) ratio was found in teratospermic domestic cats (<40% morphologically normal sperm). The aim of this study was to assess the reliability of the tritiated water-release assay (TWRA) to measure aromatase activity in domestic cat testes. Testicular T and E2 concentrations, measured by enzyme immunoassay, and sperm morphology were evaluated to verify the relationship between them. Aromatase activity was measured in microsomal fraction and in homogenates of cat testes. Rat ovaries and piglet testes were used for assay validation. Aromatase activity was not detected in cat testes microsomal fraction (n = 8), not even when the protein amount added to the assay was increased from 50 to 200 μg. In homogenates, however, it was detected (3.5 ± 0.5 pmol.g-1.h-1; n = 7), although in such low levels that no activity inhibition was detectedwhen homogenates were incubated with increasing fadrazole concentrations. Although none of the cats in this study were classified as teratospermic, some sperm defects were correlated with testicular T:E2 ratio (abnormal acrosome, r = -0.76) and with E2 concentration (proximal cytoplasmic droplet, r = 0.77). However, we did not find any correlation between aromatase activity and hormonalor sperm morphology data. To our knowledge this is the first demonstration of testicular aromatase activity in domestic cats. Despite that, due to the low aromatase activity measured and the lack of correlation with other reproductive data, we could not infer that TWRA is a reliable method to detect differences in testicular aromatase activity in normospermic cats. Perhaps this method could be used in teratospermic individuals that probably havean increased aromatase activity. As an alternative, we suggest that more sensitive techniques should be used to compare aromatase activity between normospermic and teratospermic cats.

Domestic cat testicular aromatase activity as assessed by the tritiated water-release assay

Lower testicular tetosterone:17β-estradiol (T:E2) ratio was found in teratospermic domestic cats (<40% morphologically normal sperm). The aim of this study was to assess the reliability of the tritiated water-release assay (TWRA) to measure aromatase activity in domestic cat testes. Testicular T and E2 concentrations, measured by enzyme immunoassay, and sperm morphology were evaluated to verify the relationship between them. Aromatase activity was measured in microsomal fraction and in homogenates of cat testes. Rat ovaries and piglet testes were used for assay validation. Aromatase activity was not detected in cat testes microsomal fraction (n = 8), not even when the protein amount added to the assay was increased from 50 to 200 μg. In homogenates, however, it was detected (3.5 ± 0.5 pmol.g-1.h-1; n = 7), although in such low levels that no activity inhibition was detectedwhen homogenates were incubated with increasing fadrazole concentrations. Although none of the cats in this study were classified as teratospermic, some sperm defects were correlated with testicular T:E2 ratio (abnormal acrosome, r = -0.76) and with E2 concentration (proximal cytoplasmic droplet, r = 0.77). However, we did not find any correlation between aromatase activity and hormonalor sperm morphology data. To our knowledge this is the first demonstration of testicular aromatase activity in domestic cats. Despite that, due to the low aromatase activity measured and the lack of correlation with other reproductive data, we could not infer that TWRA is a reliable method to detect differences in testicular aromatase activity in normospermic cats. Perhaps this method could be used in teratospermic individuals that probably havean increased aromatase activity. As an alternative, we suggest that more sensitive techniques should be used to compare aromatase activity between normospermic and teratospermic cats.(AU)

Calidad del semen de obreros expuestos laboralmente a hidrocarburos / Semen quality of workers exposed to hydrocarbons

Se realizó un estudio comparativo entre dos grupos de trabajadores de la industria hulera mexicana. El primer grupo de estudio estuvo conformado por 48 obreros expuestos laboralmente a hidrocarburos aromáticos durante 2 a 24 años; el otro grupo lo integraron 42 trabajadores de áreas administrativas, no expuestos a hidrocarburos ni a otros tóxicos. Nuestro objetivo fue describir y comparar las características del semen de ambos grupos para conocer algunos de los efectos adversos que tiene la exposición crónica a hidrocarburos sobre la reproducción masculina manifestados a través de los cambios en la calidad del semen. La concentración de los hidrocarburos del ambiente laboral fue cuantificada por monitoreo continuo de todas las áreas de la fábrica durante las jornadas de trabajo. El estudio de las muestras de semen de ambos grupos se realizó de acuerdo con los criterios establecidos por la Organización Mundial de la Salud. Los hidrocarburos encontrados en el ambiente laboral fueron etilbenceno (220.7-234 mg/m3 ), benceno (31.9-47.8 mg/m3), tolueno (189.7-212.5 mg/m3) y xileno (47-56.4 mg/m3). El análisis de las características del semen de ambos grupos demostró mayor porcentaje de varones normozoospérmicos (76%) en el grupo de trabajadores no expuestos respecto del grupo de trabajadores expuestos, en el que sólo el 17% presentó normozoospermia. En la mayoría de los trabajadores expuestos encontramos anormalidad en la viscosidad del semen, en su capacidad de licuefacción, recuento espermático bajo, motilidad espermática disminuida o no observable y una gran cantidad de espermatozoides con alteraciones en su morfología. Algunas de estas características anormales del semen se asociaron con los años de exposición a los hidrocarburos. En el semen de los obreros expuestos a hidrocarburos encontramos una cantidad significativamente mayor de células germinales inmaduras con alteraciones morfológicas nucleares, micronúcleos, en comparación con el grupo de individuos que no tuvieron contacto con estos tóxicos. Además, en el grupo de expuestos se observó que el porcentaje de células germinales inmaduras con micronúcleos tuvo asociación con la edad del individuo y los años de exposición, así como con la morfología espermática. A manera de conclusión, podría decirse que la exposición crónica a hidrocarburos aromáticos potencialmente afecta el proceso de espermatogénesis y se refleja en una mala calidad del semen de los individuos expuestos a estos tóxicos