SUN5 interacts with nuclear membrane LaminB1 and cytoskeletal GTPase Septin12 mediating the sperm head-and-tail junction.

Acephalic spermatozoa syndrome (ASS) is a severe teratospermia with decaudated, decapitated, and malformed sperm, resulting in male infertility. Nuclear envelope protein SUN5 localizes to the junction between the sperm head and tail. Mutations in the SUN5 gene have been identified most frequently (33-47%) in ASS cases, and its molecular mechanism of action is yet to be explored. In the present study, we generated Sun5 knockout mice, which presented the phenotype of ASS. Nuclear membrane protein LaminB1 and cytoskeletal GTPases Septin12 and Septin2 were identified as potential partners for interacting with SUN5 by immunoprecipitation-mass spectrometry in mouse testis. Further studies demonstrated that SUN5 connected the nucleus by interacting with LaminB1 and connected the proximal centriole by interacting with Septin12. The binding between SUN5 and Septin12 promoted their aggregation together in the sperm neck. The disruption of the LaminB1/SUN5/Septin12 complex by Sun5 deficiency caused separation of the Septin12-proximal centriole from the nucleus, leading to the breakage of the head-to-tail junction. Collectively, these data provide new insights into the pathogenesis of ASS caused by SUN5 deficiency.

[Clinical characteristics and genetic analysis of a patient with Acephalic spermatozoa syndrome due to variant of PMFBP1 gene].

OBJECTIVE: To analyze the clinical characteristics and genetic basis of a male patient with primary infertility caused by Acephalic spermatozoa syndrome. METHODS: A patient who had presented at the Henan Provincial People's Hospital on October 1, 2022 was selected as the study subject. Clinical data and results of laboratory exams and sperm electron microscopy were collected. The patient was subjected to whole exome sequencing (WES), and candidate variants were verified by Sanger sequencing and pathogenicity analysis. RESULTS: WES revealed that the patient has harbored compound heterozygous variants of the PMFBP1 gene, namely c.853del (p.Ala285Leufs*24) and c.1276A>T (p.Lys426X), which were both unreported previously. Sanger sequencing suggested that the c.853del (p.Ala285Leufs*24) variant has derived from his deceased mother, whilst the c.1276A>T (p.Lys426X) variant has derived from his father. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), both variants were classified as pathogenic (PVS1+PM2_Supporting+PP4). CONCLUSION: The compound heterozygous variants of the PMFBP1 gene probably underlay the Acephalic spermatozoa syndrome in this patient. The discovery of the novel variants has also enriched the mutational spectrum of Acephalic spermatozoa syndrome.

Genetic Causes of Qualitative Sperm Defects: A Narrative Review of Clinical Evidence.

Several genes are implicated in spermatogenesis and fertility regulation, and these genes are presently being analysed in clinical practice due to their involvement in male factor infertility (MFI). However, there are still few genetic analyses that are currently recommended for use in clinical practice. In this manuscript, we reviewed the genetic causes of qualitative sperm defects. We distinguished between alterations causing reduced sperm motility (asthenozoospermia) and alterations causing changes in the typical morphology of sperm (teratozoospermia). In detail, the genetic causes of reduced sperm motility may be found in the alteration of genes associated with sperm mitochondrial DNA, mitochondrial proteins, ion transport and channels, and flagellar proteins. On the other hand, the genetic causes of changes in typical sperm morphology are related to conditions with a strong genetic basis, such as macrozoospermia, globozoospermia, and acephalic spermatozoa syndrome. We tried to distinguish alterations approved for routine clinical application from those still unsupported by adequate clinical studies. The most important aspect of the study was related to the correct identification of subjects to be tested and the correct application of genetic tests based on clear clinical data. The correct application of available genetic tests in a scenario where reduced sperm motility and changes in sperm morphology have been observed enables the delivery of a defined diagnosis and plays an important role in clinical decision-making. Finally, clarifying the genetic causes of MFI might, in future, contribute to reducing the proportion of so-called idiopathic MFI, which might indeed be defined as a subtype of MFI whose cause has not yet been revealed.

BAG5 regulates HSPA8-mediated protein folding required for sperm head-tail coupling apparatus assembly.

Teratozoospermia is a significant cause of male infertility, but the pathogenic mechanism of acephalic spermatozoa syndrome (ASS), one of the most severe teratozoospermia, remains elusive. We previously reported Spermatogenesis Associated 6 (SPATA6) as the component of the sperm head-tail coupling apparatus (HTCA) required for normal assembly of the sperm head-tail conjunction, but the underlying molecular mechanism has not been explored. Here, we find that the co-chaperone protein BAG5, expressed in step 9-16 spermatids, is essential for sperm HTCA assembly. BAG5-deficient male mice show abnormal assembly of HTCA, leading to ASS and male infertility, phenocopying SPATA6-deficient mice. In vivo and in vitro experiments demonstrate that SPATA6, cargo transport-related myosin proteins (MYO5A and MYL6) and dynein proteins (DYNLT1, DCTN1, and DNAL1) are misfolded upon BAG5 depletion. Mechanistically, we find that BAG5 forms a complex with HSPA8 and promotes the folding of SPATA6 by enhancing HSPA8's affinity for substrate proteins. Collectively, our findings reveal a novel protein-regulated network in sperm formation in which BAG5 governs the assembly of the HTCA by activating the protein-folding function of HSPA8.

Novel variations in TENT5D lead to teratozoospermia in infertile patients.

PURPOSE: Teratozoospermia is the main pathogenic factor of male infertility. However, the genetic etiology of teratozoospermia is largely unknown. This study aims to clarify the relationship between novel variations in TENT5D and teratozoospermia in infertile patients. MATERIALS AND METHODS: Two infertile patients were enrolled. Routine semen analysis of patients and normal controls was conducted with the WHO guidelines. Whole-exome sequencing (WES) was conducted to identify pathogenic variants in the two patients. Morphology and ultrastructure analysis of spermatozoa in the two patients was determined by Papanicolaou staining, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The functional effect of the identified variants was analyzed by immunofluorescence staining and western blotting. The expression of TENT5D in different germ cells was detected by immunofluorescence staining. RESULTS: Two new hemizygous variations, c.101C > T (p.P34L) and c.125A > T (p.D42V), in TENT5D were detected in two patients with male infertility. Morphology analysis showed abnormalities in spermatozoa morphology in the two patients, including multiple heads, headless, multiple tails, coiled, and/or bent flagella. Ultrastructure analysis showed that most of the spermatozoa exhibited missing or irregularly arranged '9+2' structures. Further functional experiments confirmed the abrogated TENT5D protein expression in patients. In addition, both p.P34L and p.D42V substitutions resulted in a conformational change of the TENT5D protein. We precisely analyzed the subcellular localization of TENT5D in germ cells in humans and mice. And we found that TENT5D was predominantly detected in the head and flagellum of elongating spermatids and epididymal spermatozoa. CONCLUSIONS: Our results showed further evidence of a relationship between TENT5D mutation and human male infertility, providing new genetic insight for use in the diagnosis and treatment of male infertility.

Splicing Mutation in DNALI1 Causes Male Infertility with Severe Oligoasthenoteratozoospermia in Humans.

Oligo-astheno-teratozoospermia (OAT), which is a common cause of male infertility, can be caused by genetic factors. This study reports on a case of a male patient suffering from infertility concomitant with OAT. Whole-exome sequencing (WES) confirmed the presence of a homozygous variant (NM_003462: c.464-1G > A) in the DNALI1 gene via Sanger sequencing. Immunofluorescence staining demonstrated that the DNALI1 signal was nearly undetectable in the patient's sperm. Bioinformatics analysis revealed that this mutation could reverse the splicing of the exon 4 acceptor splice site. A minigene experiment was performed to verify the mutation and the results confirmed that the mutation disrupted the splicing. Our findings show that this rare mutation in DNALI1 contributes to male infertility and OAT in humans, thereby expanding our understanding of the causes and pathogenesis of male infertility. This knowledge facilitates genetic counseling, clinical diagnosis, and therapeutic development of male infertility.

Characterization of the semen microbiota of healthy stud dogs using 16S RNA sequencing.

The reproductive microbiota of male dogs has never been investigated using culture-independent sequencing techniques. The purpose of the present study was to get seminal knowledge on the microbiota of the ejaculate. Specifically, factors as the fraction of the ejaculate, the sperm quality (normospermia, teratozoospermia), and the living environment were evaluated. The sperm-rich and the prostatic fractions of the ejaculate were collected from healthy stud dogs. Following the sperm analysis, samples from twenty animals (normospermic n = 10 and teratozoospermic n = 10) were stored at - 80 °C until further processing including DNA extraction and 16S rRNA sequencing. Alpha- (Shannon index) and beta- (Bray-Curtis, Unweighted UniFrac) diversities were assessed and compared (PERMANOVA) based on the group of samples (biological samples from the ejaculate and controls), the fraction of the ejaculate (sperm-rich and prostatic fractions), the animal group (normospermia and teratozoospermia), and the living environment of the animal (kennel or pet living in-house). The most abundant bacterial phyla in canine semen samples were Proteobacteria, Firmicutes, and Actinobacteria. Overall, the dominant bacterial family was that of Pasteurellaceae The genus Mycoplasma was never detected. No differences in terms of bacterial composition were found based on the fraction of the ejaculate and based on the animal group (P > 0.05). On the other hand, differences in alpha and beta diversities were highlighted based on the living environment (P = 0.001). Overall, the results of the present study provide preliminary insights on dog semen microbiota, opening a new chapter in the field of canine andrology. Our results suggest that the environment may play a role in influencing the reproductive microbiota of male dogs and that the prostatic fraction of the ejaculate can be used for further research as a representative of the semen microbiota.

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.

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.

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)

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