Testis Size Research Articles

House sparrows do not show a diel rhythm in double-strand DNA damage in erythrocytes.

DNA damage can be caused by a number of intrinsic and extrinsic factors. A recent study showed that free-living house sparrows (Passer domesticus) have higher DNA damage in the summer than the winter across five different tissues. This result was consistent when house sparrows were brought into captivity and exposed to comparable light cycles, with all other variables held constant. These results generated two hypotheses: (1) seasonal variation in DNA damage is related to circadian regulation and (2) seasonal variation in DNA damage is related to the total number of active hours. To investigate these hypotheses, we first quantified erythrocyte DNA damage in wild-caught house sparrows held in captivity on a 12L:12D light cycle at six points during the day to assess a diel or circadian rhythm but did not find one. We then performed a resonance experiment, in which birds experienced unnatural light cycles, and compared DNA damage in birds held on 6L:6D and 4.5L:7.5D resonance light cycles with their natural counterparts, 12L:12D and 9L:15D, respectively. We assessed corticosterone levels and DNA damage in blood before and after the resonance light cycles and DNA damage in abdominal fat, hippocampus, hypothalamus, and liver after the resonance light cycles. While our second experiment was not able to effectively test our hypotheses, we were able to demonstrate some interesting patterns. Throughout the resonance experiment, baseline corticosterone and testes size increased, consistent with the birds being photostimulated and preparing to breed. Surprisingly, the direction of change of DNA damage throughout the resonance photoperiod differed with tissue, which is not consistent with patterns during the breeding season in the wild. Our data indicate a potential uncoupling of the breeding physiology with the effect on DNA damage due to exposure to a resonance light cycle, which the birds may have interpreted as a skeleton photoperiod. Finally, though we were unable to fully disentangle the dynamics underlying seasonal DNA damage, we show that the previously documented patterns are not simply due to diel changes or the total amount of light exposure within a 24-hour period.

Rapid detection of mouse spermatogenic defects by testicular cellular composition analysis via enhanced deep learning model.

Histological analysis of the testicular sections is paramount in infertility research but tedious and often requires months of training and practice. Establish an expeditious histopathological analysis of mutant mice testicular sections stained with commonly available hematoxylin and eosin (H&E) via enhanced deep learning model MATERIALS AND METHODS: Automated segmentation and cellular composition analysis on the testes of six mouse reproductive mutants of key reproductive gene family, DAZ and PUMILIO gene family via H&E-stained mouse testicular sections. We improved the deep learning model with human interaction to achieve better pixel accuracy and reduced annotation time for histologists; revealed distinctive cell composition features consistent with previously published phenotypes for four mutants and novel spermatogenic defects in two newly generated mutants; established a fast spermatogenic defect detection protocol for quantitative and qualitative assessment of testicular defects within 2.5-3h, requiring as few as 8 H&E-stained testis sections; uncovered novel defects in AcDKO and a meiotic arrest defect in HDBKO, supporting the synergistic interaction of Sertoli Pum1 and Pum2 as well as redundant meiotic function of Dazl and Boule. Our testicular compositional analysis not only could reveal spermatogenic defects from staged seminiferous tubules but also from unstaged seminiferous tubule sections. Our SCSD-Net model offers a rapid protocol for detecting reproductive defects from H&E-stained testicular sections in as few as 3h, providing both quantitative and qualitative assessments of spermatogenic defects. Our analysis uncovered evidence supporting the synergistic interaction of Sertoli PUM1 and PUM2 in maintaining average testis size, and redundant roles of DAZ family proteins DAZL and BOULE in meiosis.

Microcotyle Tazeroutii n. sp. (Monogenea: Microcotylidae) from the Gills of the Boarfish Capros aper Linnaeus, 1758 (Teleostei: Caproidae) off the Algerian Coast, Western Mediterranean.

In this study we describe a new species Microcotyle tazeroutii n. sp. (Monogenea: Microcotylidae) found on the gills and operculum of the boarfish Capros aper (Caproidae) off the Algerian coast of the Western Mediterranean. Monogeneans were observed alive or recently dead on the operculum and gills using a dissecting microscope, measured and drawn for morphological study. Furthermore, a molecular analysis was conducted using a partial fragment of the mitochondrial cytochrome c oxidase subunit 1 (cox1) of two specimens of monogeneans and a tissue sample of the fish's gills in which the parasites were found to confirm the identity of fish. The new species Microcotyle tazeroutii n. sp., exhibits a combination of morphological features that differentiate it from all other known species within the genus, such as the shape and the size of body, the haptor length, the number and the size of clamps and testes, the number of spines of the genital atrium and the size of eggs. Additionally, a molecular analysis of the mitochondrial cytochrome c oxidase subunit 1 (cox1 gene) revealed significant interspecific differences between Microcotyle tazeroutii n. sp. and previously published sequences of other Microcotyle species. The morphological and molecular analyses revealed that Microcotyle tazeroutii n. sp. has unique characteristics that distinguish it from all previously identified species and confirmed the presence of Microcotyle within the Caproidae family for the first time.

Dipeptide metabolite, glutamyl-glutamate mediates microbe-host interaction to boost spermatogenesis

The decrease in sperm count and infertility is a global issue that remains unresolved. By screening environmental bacterial isolates, we have found that a novel lactic acid bacterium, Lactiplantibacillus plantarum SNI3, increased testis size, testosterone levels, sperm count, sexual activity and fertility in mice that have consumed the bacteria for four weeks. The abundance of L. plantarum in the colon microbiome was positively associated with sperm count. Fecal microbiota transplantation (FMT) from L. plantarum SNI3-dosed mice improved testicular functions in microbiome-attenuated recipient animals. To identify mediators that confer pro-reproductive effects on the host, untargeted in situ mass spectrometry metabolomics was performed on testis samples of L. plantarum SNI3-treated and control mice. Enrichment pathway analysis revealed several perturbed metabolic pathways in the testis of treated mice. Within the testis, a dipeptide, glutamyl-glutamate (GluGlu) was the most upregulated metabolite following L. plantarum SNI3 administration. To validate the pro-reproductive feature of GluGlu, systemic and local injections of the dipeptide have been performed. γ-GluGlu increased sperm count but had no effect on testosterone. These findings highlight the role of γ-GluGlu in mediating spermatogenetic effects of L. plantarum on the male mouse host and –following relevant human clinical trials- may provide future tools for treating certain forms of male infertility.

Photoperiodism, testosterone and adult neurogenesis in canaries (Serinus canaria).

Domestic strains of canaries (Serinus canaria) variably respond to photoperiod changes and apparently stay in breeding state for extended periods. Fife Fancy canaries are supposed to be similar to the native species living at 27-39° north where photoperiod significantly changes across the year. Our birds showed reproductive cycles when exposed to light regimes mimicking the annual cycle of photoperiod. However after 6 months in short days (SD: 8L:16D), males developed large testes, as observed by X-ray tomography, and intense singing. Switching to long days (LD: 16L:8D) did not further increase song rate nor testes size but increased song duration, number of syllables per song, and trill occurrence frequency. No sign of regression was observed after 12 weeks in LD but return to SD produced a rapid decrease in testes size and singing activity below values in birds maintained throughout in SD. Fife Fancy thus does not seem to develop absolute but only relative refractoriness. The relatively high singing activity expressed by SD-photosensitive males does not seem to depend on high testosterone (T) concentrations. Singing did not correlate with plasma testosterone (T). Treatment with ATD + Flutamide only marginally decreased song rate and did not affect song quality nor song control nuclei volume. These birds are either supersensitive to low T levels or their reproductive physiology is activated by other mechanisms. Neurogenesis is increased by T and by LD but the function of new neurons incorporated in HVC is poorly understood. We developed a procedure based on X-ray focal irradiation to deplete neural progenitors adjacent to HVC and study the functional consequences. The decrease in neurogenesis increased the variability of T-induced songs in females and decreased their bandwidth. Neurogenesis in HVC thus plays a role in song production and X-ray focal irradiation represents an excellent tool to analyze adult neurogenesis.

Utility of diffusion weighted Magnetic Resonance Imagining to detect non-palpable undescended testis.

To assess the effectiveness of diffusion-weighted magnetic resonance imaging (DW-MRI) in the detection of non-palpable undescended testis (NPUT) and to compare DW-MRI results with surgical findings. This descriptive, cross-sectional study was carried out at Dow Institute of Radiology, Dow University of Health Sciences. Karachi on a cohort of patients who underwent DW-MRI for suspected NPUT between 15th September, 2022 to 16th March, 2023. The study included 175 boys below the age of 16 years with history of clinically non-palpable testes. MRI scans were acquired using additional DWI sequence. Two radiology faculty of more than five years of experience independently evaluated the DW-MRI images for the presence or absence of testes in its normal anatomical position, abnormal location, side and size of testes. Out of the 175 patients, DW-MRI successfully detected 128 (73.1%) non-palpable undescended testes. Statistical analysis in clinically detected cases of showed sensitivity of NPTU 0.8%, specificity of 92.5%, diagnostic accuracy 94.29%, positive predictive value 97.7%, and negative predictive value 84.1% for localizing undescended testes with Diffusion Weighted DW-MRI taking surgical findings as gold standard. DWI sequences complement the conventional MRI, increasing its sensitivity and diagnostic accuracy. By facilitating early and accurate diagnosis, DW-MRI has the potential to streamline patient management, reduce unnecessary surgical exploration, and ultimately improve the long-term reproductive health and quality of life for individuals with undescended testes.

388 Effects of maternal nutrient restriction during late gestation on pre-pubertal beef calf testis size and histology

388 Effects of maternal nutrient restriction during late gestation on pre-pubertal beef calf testis size and histology

Contraceptive effect of a gonadotropin-releasing hormone vaccine on captive male brown bears (Ursus arctos).

Fertility control has traditionally been applied in zoos to control captive populations, and reversible contraception is important. However, contraceptive methods for male bears have not been reported. We aimed to establish a reversible contraceptive for male brown bears by investigating the effects of a gonadotropin-releasing hormone (GnRH) vaccine (Improvac®) that was developed for the immune castration of pigs. We vaccinated six bears with two sequential doses of 400 (n = 2) or 600 μg Improvac® (n = 4) with a 1-month interval during the pre-breeding season (February to April). We compared the reproductive parameters (testosterone levels and semen parameters) of the six vaccinated and four non-vaccinated (control) bears once during the breeding season (May or June). To investigate whether the reproductive performance could be restored in the following year of contraception, we also compared the reproductive parameters once during the breeding season in two bears between the year with GnRH vaccination and the following year without vaccination. Vaccination treatments suppressed reproductive parameters in 5 bears, although vaccination with 400 μg of Improvac® was not effective in one bear. Testosterone levels and the rate of progressive sperm motility were significantly lower, and total sperm count and testis size tended to be lower in vaccinated bears, compared with the controls. Blood biochemical findings and direct observations after Improvac® vaccination did not reveal side effects. Moreover, testosterone levels and spermatogenic scores of two bears were restored in the following year. We confirmed that the Improvac® vaccine elicited a reversible contraceptive effect in male brown bears.

Effects of female-specific selection for reproductive investment on male fertility traits.

Despite sharing an autosomal genome, the often divergent reproductive strategies of males and females cause the selection to act in a sex-specific manner. Selection acting on one sex can have negative, positive, or neutral fitness consequences on the opposite sex. Here, we test how female-limited selection on reproductive investment in Japanese quail (Coturnix japonica) affects male fertility-related traits. Despite there being no difference in the size of males' testes from lines selected for high female reproductive investment (H-line) or low female reproductive investment (L-line), in both lines, the left testis had a greater volume of sperm-producing tissue. Since H-line females have a larger left-side restricted oviduct, this suggests a positive genetic correlation between male and female gonad function and that internal testis structure is a target of sexual selection. However, despite H-line males having previously been found to have greater fertilization success in a competitive scenario, we found little evidence of a difference between the lines in sperm number, motility, velocity, length, or the number of sperm that reached the ova. Precopulatory cues and/or the role of seminal fluid in sperm motility may thus be more likely to contribute to the H-line male fertilization advantage in this species.

Use of a slow-release GnRH implant in an adult billy goat.

A 9.4 mg deslorelin slow-release implant was inserted into an adult, healthy billy goat to achieve temporary infertility and a reduction in sexual behavior. The implant was inserted in late autumn. No significant change in testis size was observed over the following 6 weeks. The endocrine function of the testis, which was examined by stimulation with human chorionic gonadotropin, was also unchanged after 6 weeks compared to the initial examination. Histological examination revealed a preserved spermatogenesis.In conclusion, the application of a GnRH analogue implant in the adult male goat has no influence on the investigated parameters - and thus probably also on its fertility.

Indocyanine green fluorescence imaging as a predictor of long-term testicular atrophy in testicular torsion: a pilot study.

This pilot study evaluated indocyanine green-guided near-infrared fluorescence (ICG-NIRF) imaging of testicular blood flow to predict long-term testicular atrophy after testicular torsion (TT) surgery. The subjects of this retrospective study were patients who underwent surgery for TT at our hospital between December, 2020 and July, 2022. After detorsion, testicular blood flow was evaluated by ICG-NIRF imaging and classified into three categories: fluorescence detected, no fluorescence detected, and fluorescence detected only in the tunica albuginea vessels. Testicular volume was measured by ultrasonography up to 12months after surgery to evaluate long-term outcomes. Twelve patients were included in this analysis. We found a 100% correlation between the absence of ICG-NIRF signals and subsequent testicular atrophy. In three patients without an ICG-NIRF signal, the median testis size 12months postoperatively was significantly smaller (16.5% of the contralateral testis; range 13-20%) than that in six patients with an ICG-NIRF signal (96%; 89-115%) (p = 0.013). Mild atrophy (74.5%; 73-76%) was also observed in the three patients for whom an ICG-NIRF signal was detected only in the tunica albuginea vessels. Our pilot study highlights the potential of ICG-NIRF imaging as a prognostic tool for guiding surgical decision-making for patients with TT, by predicting postoperative testicular atrophy.

Resource availability alters breeding strategies in a small mammal community.

Following a resource pulse, animals may finance reproduction by consuming concurrently available resources (income breeding) or by storing resources for future reproduction (capital breeding). Understanding how these reproductive strategies are used is important for determining the ecological mechanisms that structure timing of reproduction and that drive interannual population fluctuations in animals. We gathered a reproductive dataset for five small mammal species over a 12-year period in Northeastern USA during which six masting events of American beech (Fagus grandifolia) and eastern hemlock (Tsuga canadensis) occurred. Masting created alternate years where seeds were either available late (masting year) or early (cached from the previous year) in the breeding season. The small mammal species differed in reliance on seeds and overwintering strategies. We quantified the diet using stable isotopes and recorded reproduction timing, proportion breeding and litter size in females and testes size in males. Timing of seed availability minimally affected litter size but strongly affected proportion breeding and timing of reproduction. During masting years (late seed availability), a higher proportion of females reproduced, with breeding taking place later in the season (lactation timed with peak seed availability), although the delay was restricted in Napaeozapus insignis, an obligate hibernator. After a fall mast, cached seeds were used as capital in the following spring (early seed availability) to support a litter that, depending on the species, occurred 24-79 days sooner than a mast year. No late-season reproduction occurred in years with early seed availability except for Myodes gapperi which produced a second litter, likely financed by fungal consumption. Males also showed strong responses to seed availability, mirroring female reproduction with testes size staying constant in years with late seed availability and sharply decreasing over the breeding season in years with early seed availability. Our results highlight that although photoperiod and temperature broadly set bounds of the breeding season in temperate environments, resource availability influences the reproductive strategies that species use, which in turn alters reproductive timing and can drive large inter-annual population fluctuations. Differences in overwintering strategies and diet may further modulate reproductive timing and output relative to resource pulses.

Unraveling mate choice evolution through indirect genetic effects

Abstract Attractiveness is not solely determined by a single sexual trait but rather by a combination of traits. Because the response of the chooser is based on the combination of sexual traits in the courter, variation in the chooser’s responses that are attributable to the opposite-sex courter genotypes (i.e., the indirect genetic effects [IGEs] on chooser response) can reflect genetic variation in overall attractiveness. This genetic variation can be associated with the genetic basis of other traits in both the chooser and the courter. Investigating this complex genetic architecture, including IGEs, can enhance our understanding of the evolution of mate choice. In the present study on the field cricket Gryllus bimaculatus, we estimated (1) genetic variation in overall attractiveness and (2) genetic correlations between overall attractiveness and other pre- and postcopulatory traits (e.g., male latency to sing, female latency to mount, male guarding intensity, male and female body mass, male mandible size, and testis size) within and between sexes. We revealed a genetic basis for attractiveness in both males and females. Furthermore, a genetic variance associated with female attractiveness was correlated with a genetic variance underlying larger male testes. Our findings imply that males that mate with attractive females can produce offspring that are successful in terms of precopulatory sexual selection (daughters who are attractive) and postcopulatory sexual selection (sons with an advantage in sperm competition), potentially leading to runaway sexual selection. Our study exemplifies how the incorporation of the IGE framework provides novel insights into the evolution of mate choice.

Exosomes of mesenchymal stem cells and PRP restore spermatogenesis in the rat model of non-obstructive azoospermia.

Since available therapeutic approaches for chemotherapy-induced non-obstructive azoospermia (NOA) patients are not enough efficient, an urgent need for treatment alternatives is felt. This study shows that adipose tissue-derived mesenchymal stem cells-derived exosome (AD-Exo) treatment is more effective in ameliorating busulfan-induced NOA rat models compared to platelet-rich plasma (PRP). Patients with non-obstructive azoospermia (NOA) are unable to have their children. Therefore, there is an urgent need for additional treatment alternatives for these patients. Recently, novel treatments based on the exosomes derived from mesenchymal stem cells (MSCs) as the agents responsible for exerting the paracrine effects and consequently biological functions of MSCs are proposed. Besides, platelet-rich plasma (PRP) as a significant blood byproduct has been therapeutically applied in several male infertility studies. In this study, we compared the effects of PRP and exosome treatment on spermatogenesis restoration in NOA rat models. Exosomes and PRP were isolated from the adipose tissue-derived MSCs (AD-MSCs) collected from conditioned medium and peripheral blood of human volunteers, respectively. Non-obstructive azoospermia (NOA) induction was done through two doses of busulfan at a 21-day interval. Thirty-five days after NOA induction, intratesticular injection of AD-MSCs-derived exosome (AD-Exo), PRP, and PBS was performed. The control group did not receive any treatment. Two months later, the rats were euthanized for further analysis. Our results revealed that both AD-Exo and PRP treatments improved the size and weight of testis, modulated the expression level of Dazl, Ddx4, Stra8, Pwil1, and Ccna1, and ameliorated the serum level of LDH, SOD, and GR enzymes in NOA rats. Moreover, the AD-Exo group showed improved testosterone, GPx, MAD, and CAT serum levels, sperm motility, and protein levels of DAZL and DDX4. This investigation verified the more efficient effects of AD-Exo treatment in comparison to PRP in ameliorating busulfan-induced NOA rat models.

Lead and calcium crosstalk tempted acrosome damage and hyperpolarization of spermatozoa: signaling and ultra-structural evidences

BackgroundExposure of humans and animals to heavy metals is increasing day-by-day; thus, lead even today remains of significant public health concern. According to CDC, blood lead reference value (BLRV) ranges from 3.5 µg/dl to 5 μg/dl in adults. Recently, almost 2.6% decline in male fertility per year has been reported but the cause is not well established. Lead (Pb2+) affects the size of testis, semen quality, and secretory functions of prostate. But the molecular mechanism(s) of lead toxicity in sperm cells is not clear. Thus, present study was undertaken to evaluate the adverse effects of lead acetate at environmentally relevant exposure levels (0.5, 5, 10 and 20 ppm) on functional and molecular dynamics of spermatozoa of bucks following in vitro exposure for 15 min and 3 h.ResultsLead significantly decreased motility, viable count, and motion kinematic patterns of spermatozoa like curvilinear velocity, straight-line velocity, average path velocity, beat cross frequency and maximum amplitude of head lateral displacement even at 5 ppm concentration. Pb2+ modulated intracellular cAMP and Ca2+ levels in sperm cells through L-type calcium channels and induced spontaneous or premature acrosome reaction (AR) by increasing tyrosine phosphorylation of sperm proteins and downregulated mitochondrial transmembrane potential. Lead significantly increased DNA damage and apoptosis as well. Electron microscopy studies revealed Pb2+ -induced deleterious effects on plasma membrane of head and acrosome including collapsed cristae in mitochondria.ConclusionsPb2+ not only mimics Ca2+ but also affects cellular targets involved in generation of cAMP, mitochondrial transmembrane potential, and ionic exchange. Lead seems to interact with Ca2+ channels because of charge similarity and probably enters the sperm cell through these channels and results in hyperpolarization. Our findings also indicate lead-induced TP and intracellular Ca2+ release in spermatozoa which in turn may be responsible for premature acrosome exocytosis which is essential feature of capacitation for fertilization. Thus, lead seems to reduce the fertilizing capacity of spermatozoa even at 0.5 ppm concentrations.Graphical

P-064 Adolescent varicocele: clinical profile and impact of treatment

Abstract Study question What is the clinical presentation of adolescent varicocele and the impact of its repair on semen quality? Summary answer Adolescent varicocele usually presents as testicular pain and does not influence semen quality. Varicocele ligation does not impact postoperative semen results in this patient population. What is known already Varicocele is a common condition characterized by the abnormal dilation of the pampiniform plexus of veins resulting in testicular dysfunction and impaired semen quality. While the effect of varicocelectomy on the fertility potential of adult men has been commonly explored, its impact on semen parameters of adolescents is less commonly investigated. Study design, size, duration The charts of 2171 patients who underwent microsurgical subinguinal varicocelectomy for clinically palpable disease between 2011-2023 were retrospectively reviewed. Patients <19 years of age were included in the analysis. Participants/materials, setting, methods The patients’ medical charts were reviewed to include demographic and clinical characteristics; indication of surgery, body mass index, testis size, grade of clinical disease, vein diameter (assessed with scrotal ultrasound) and semen analysis results (WHO 2010). Data were analyzed using Wilcoxon Signed Ranked. Mean ± SD and median (IQR) were used to report normally and non-normally distributed data, respectively. A p value <0.05 was considered significant. Main results and the role of chance A total of 94 adolescent patients were included in the study. Their mean BMI was 22.14±5 Kg/m2, mean left testis size was 12.26 ± 3.05 cm3 and right testis size 13.26±3.94 cm3. The maximum vein diameter 4.7±1.04 mm and right vein diameter 2.21±0.83 mm. 83 patients underwent unilateral Microsurgical Varicocelectomy while 5 patients underwent bilateral Microsurgical Varicocelectomy. Left varicocele was of grades 3, 2 and 1 in 65, 18 and 11 patients, respectively. Surgery was indicated for testis size discrepancy in 36.2% of cases and on elective basis (prior to army recruitment) in 63.8% of cases. Table 1 presents the pre- and post-operative semen parameter results. Patients had normal pre-operative medians of sperm count, total motility and normal morphology. No significant post-operative changes were observed in the semen quality of adolescents. Limitations, reasons for caution Results were obtained from a relatively small sample size. However, varicocele is less commonly performed on adolescents necessitating further studies on this patient population. Wider implications of the findings Results of this study shed the light on the characteristics of adolescents presenting with varicocele. Trial registration number NA

P-063 Effect of varicocelectomy on serum testosterone levels of hypogonadal men above 40 years of age

Abstract Study question Can varicocelectomy be indicated for the treatment of hypogonadism in men above 40 years of age? Summary answer Varicocelectomy improves serum testosterone (T) levels in men with preoperative hypogonadism. This improvement can be anticipated in men above the age of 40 years. What is known already Varicocele ligation is a common intervention used to restore male fertility potential and enhance conception rates. Few studies reported a favorable effect for varicocelectomy on serum T levels stirring some scientists to indicate treatment for men with late onset hypogonadism. Nonetheless, data is still scarce for such a recommendation highlighting the importance of this work Study design, size, duration The charts of 1696 patients who underwent microsurgical subinguinal varicocelectomy for clinically palpable disease between 2011-2023 were retrospectively reviewed. Patients with available pre- and post-operative serum hormone levels were included in the study while those receiving any form of androgen replacement or induction treatment or with known secondary causes of hypogonadism were excluded. Participants/materials, setting, methods Medical charts were reviewed to collect demographic and clinical data. Patients were classified into 2 groups according to preoperative T levels: hypogonadism group (serum T < 10.4 nmol/L) (n = 226) and eugonadal group (serum T ≥ 10.4 nmol/L) (n = 1469). The hypogonadism group was subclassified according to age into less (n = 161) or ≥ (n=66) 40 years of age. Changes in hormone levels were analyzed using Wilcoxon Signed Ranked. A p value <0.05 was considered significant. Main results and the role of chance The patients mean age was 33.6 ± 8.5 years. Their mean BMI was 27.2 ± 5.8 Kg/m2, mean left testis size was 13.4 ± 3.5 cm3 and right testis size 14.4 ± 4.5 cm3. The maximum left and right vein diameters was 3.9 ± 1.3 mm and 2.46 ± 0.73 mm. Unilateral and bilateral microsurgical varicocelectomy were performed in 82% and 18% of cases, respectively. Post-operatively, no significant changes were observed in hormone levels in comparison to preoperative values in the eugonadal group. However, patients with preoperative hypogonadism had significant increase in serum T (7.7±2.2 vs 11.7±6.6, p < 0.001) and E2 (72.5±31.3 vs 94.8±42, p < 0.001) levels following the intervention. These significant improvements were observed in both men < 40 years of age (p < 0.001 for both T and E2) and ≥ 40 years of age (T: p = 0.027, E2: p = 0.024). Limitations, reasons for caution Results were obtained from a retrospective chart review. The majority of these patients performed surgery for fertility reasons and data regarding hypogonadism symptoms is lacking. Wider implications of the findings Results of this study further confirm that an increase in serum testosterone is likely to be anticipated in patients undergoing varicocelectomy who have low serum testosterone levels pre-operatively Trial registration number not applicable

O-137 Functional characterisation of three human male infertility associated X-linked genes using Drosophila melanogaster as model organism

Abstract Study question What is the functional relevance of GLUD2, FAM47A, and TAF7L in spermatogenesis and male infertility? Summary answer Knockdown of orthologues leads to infertility in male flies substantiating GLUD2, FAM47A, and TAF7L as candidate genes for human male infertility. What is known already Non-obstructive azoospermia (NOA) is clinically the most severe form of spermatogenic failure and male infertility. Despite advances in the genetic diagnostics, the precise cause and molecular diagnosis remains elusive for the majority of affected men. GLUD2, FAM47A, and TAF7L are X-linked and testis-enriched genes, with increasing evidence of their relevance in male infertility. However, so far, no functional study or animal model supporting their contribution to the disease exist. Study design, size, duration We queried exome/genome data of more than 2, 300 infertile men with severe quantitative spermatogenic failure from the Male Reproductive Genomics (MERGE) cohort for variants in GLUD2, FAM47A, and TAF7L. To assess the impact of these three genes on male infertility we performed functional studies using Drosophila melanogaster as a model organism. Participants/materials, setting, methods Exome/genome data was filtered for rare (MAF <0.001, gnomAD), hemizygous loss-of-function (LoF) and potentially pathogenic missense variants (CADD score >20) in GLUD2 (NM_012084.4), FAM47A (NM_203408.3), and TAF7L (NM_024885.4). Depending on sample availability, the X-linked inheritance pattern was confirmed by segregation analysis. To investigate the relevance of these genes in male infertility, we generated and functionally characterised testis-specific knockdown (KD) of orthologues in Drosophila melanogaster using GAL4-UAS system. Main results and the role of chance In GLUD2, we identified four missense and one LoF variant in five azoospermic men. All variant carriers revealed impaired spermatogenesis with predominant meiotic arrest (MeiA). In FAM47A, we identified three missense and one LoF variant in five azoospermic men, four of whom consistently exhibited a testicular phenotype of Sertoli cell-only (SCO). In TAF7L, we identified four missense variants in three azoospermic men. One of them was a carrier of two variants. Notably, all the identified variants were clustered in the mutation hotspot region within exons 9, 10, and 13. Testis-specific KD of GLUD2, FAM47A, and TAF7Lorthologues consistently resulted in complete sterility in male flies. Compared to controls, Glud2-KD flies had normal testicular morphology but revealed small seminal vesicles without mature sperm. Testicular squash analysis showed germ cell maturation arrest at the elongating spermatid stage, leading to individualisation complex ablation. Immunofluorescence staining revealed a lack of cystic bulges and waste bags, indicating disrupted spermatogenesis. In contrast, Fam47a-KD and Taf7l-KD flies were infertile due to total germ cell loss in the testis, resulting in an extremely small testis size compared with controls, consistent with the SCO testicular phenotype observed in infertile men with FAM47A and TAF7L variants. Limitations, reasons for caution The main limitation is that the study does not analyse a gene-specific genotype-phenotype correlation of the missense variants identified. Furthermore, extensive research is required to elucidate the underlying molecular mechanisms by which GLUD2, FAM47A, and TAF7L regulate male fertility in humans. Wider implications of the findings This study highlights the utility of Drosophila for studying the role of human male fertility genes, underlining the importance of validating genetic findings. Additionally, it contributes significantly to advancing our understanding of the genetic basis of azoospermia, offering potential targets for research aimed at addressing male infertility. Trial registration number not applicable

Gubernaculum-sparing orchiopexy versus gubernaculum excision; A randomized trial on success and atrophy rates

Previous studies showed that extra blood supply can decrease testicular atrophy following laparoscopic orchiopexy. We evaluated the impact of preserving the gubernacular attachment (which contains blood supply from cremasteric artery and its anastomoses) on atrophy rates following open conventional orchiopexy. This double-blinded randomized trial was implemented from March 2022 to September 2023. Included boys with non-palpable testis, even with examination under anesthesia, underwent diagnostic laparoscopy to evaluate the testis's location and size. Nubbin testes and those with > 2-cm distance from the internal inguinal ring. Participants were assigned into two groups (gubernaculum sparing (GS) and excision (GE)) by permuted block randomization. Overall success was defined as achieving both morphologic success (atrophy <20% of the intraoperative size) and anatomical success (scrotal or high-scrotal locations). Boys were followed at three- and six-month post-surgery via ultrasound. Independent t-test, repeated ANOVA, and Friedman's tests were used where appropriate. Of 92 boys (105 UDTs overall), 75 testes (36 in GS, 39 in GE groups) were used in the analysis. The mean age of participants was 25±17 months (range 6-84). The mean testis size of cases intraoperatively was 460±226, 396±166, and 520±258mm3 among all participants, GS, and GE cases, respectively. Both groups showed a significant decrease in testicular volume on both follow-up checkpoints, but this decrement was significantly higher in the GE group (p<0.001). The anatomical success rate was significantly higher among GS boys (97.2% versus 82.1%; p=0.038). The overall success rate was significantly higher for the GS group (61.1% versus 25.6%; p=0.002). Although mean testicular volume decreased in both groups, we found superior morphologic and overall success rates among the GS group. The greatest size reduction was noted at the three-month post-surgery compared to the six-month checkpoint. https://irct.ir/trial/58842.

Experimental evolution under predation reduces body size in dung flies but courtship displays persist in males (Diptera: Sepsidae)

Exaggerated sexual traits, such as ornaments and courtship displays, are crucial for mate acquisition in many species and are often subject to directional runaway selection. However, in the face of high predation risk, natural selection can result in a reduction of conspicuous precopulatory displays to avoid detection by potential predators. Sexual selection may then favour increased investment in inconspicuous postcopulatory traits. Here, we investigated the transgenerational effects of predation on precopulatory male courtship and postcopulatory sexual traits (testes size, sperm length) in a dung fly, Sepsis punctum (Sepsidae). Behavioural assays prior to selection document a marked decrease in male courtship displays in the presence of a predator, the Asian Ant Mantis (Odontomantis planiceps). However, after ten generations of experimental evolution, flies exhibited a marked increase in courtship, both in the absence and presence of a predator. Additionally, under sustained predation pressure, male and female body size decreased but male postcopulatory traits were not significantly affected. These results suggest that precopulatory courtship can be under strong sexual selection even in the face of predation pressure. Larger flies were more susceptible to predation, and there could be canalisation of postcopulatory traits that are crucial for fertilisation.