Tuberculous epididymitis:a case report and literature review

Tuberculous epididymitis is a rare urological disease difficult to diagnose. The conventional methods for diagnosis are often time-consuming and invasive. The combined use of scrotal magnetic resonance imaging （MRI） and urinary polymerase chain reaction （PCR）-based assay for mycobacterial DNA （the latter because of its high sensitivity and specificity to demonstrate mycobacterial DNA） is a valuable method for rapid diagnosis of tuberculous epididymitis. We report a 79-year-old man who was admitted with the chief complaints of bilateral scrotal swelling and pain. The combined use of scrotal MRI and urinary PCR allowed prompt diagnosis of tuberculous epididymitis and adequate antituberculous therapy. （Asian J Androl 2005 Sep; 7： 329-332）

Chronic epididymitis and Grade III varicocele and their associations with semen characteristics in men consulting for couple infertility

Chronic epididymitis and varicocele are frequently observed genital disorders in men consulting for couple infertility, but their impact on semen characteristics at the time of infertility consultation is still a matter of debate. We investigated 652 male partners of couples who had their first infertility consultation between 1999 and 2015 in Argentina. Men with chronic epididymitis （n = 253）, Grade III varicocele （n = 106）, and both conditions （n = 125） were compared with a control group （n = 168） composed of men without these disorders or any other recognized causes of male infertility. We showed that men who presented isolated chronic epididymitis were more likely to have high percentages of low sperm motility and abnormal sperm morphology as well as a high number of white blood cells. Men with isolated Grade III varicocele had low sperm production and motility and an increased percentage of abnormal sperm morphology. Finally, men who simultaneously presented chronic epididymitis with Grade III varicocele had a low sperm motility and increased percentage of abnormal sperm morphology as well as a high number of white blood cells. Physical examination of the genital organs may identify common disorders, potentially involved as causal factors of patient＇s infertility. These disorders are associated with specific seminal profiles that should help in identifying the best treatment from the available therapeutic options, effectiveness, safety, and allowing as much as possible natural conception.

Damaged male germ cells induce epididymitis in mice

Epididymitis can be caused by infectious and noninfectious etiological factors.While microbial infections are responsible for infectious epididymitis,the etiological factors contributing to noninfectious epididymitis remain to be defined.The present study demonstrated that damaged male germ cells(DMGCs)induce epididymitis in mice.Intraperitoneal injection of the alkylating agent busulfan damaged murine male germ cells.Epididymitis was observed in mice 4 weeks after the injection of busulfan and was characterized by massive macrophage infiltration.Epididymitis was coincident with an accumulation of DMGCs in the epididymis.In contrast,busulfan injection into mice lacking male germ cells did not induce epididymitis.DMGCs induced innate immune responses in epididymal epithelial cells(EECs),thereby upregulating the pro-inflammatory cytokines such as tumor necrosis factor-a(7/VF-a),interleukin-6(/L-6),and interleukin-ip(IL-ip) as well as the chemokines such as monocyte chemotactic protein-1(MCP-1),monocyte chemotactic protein-5(MCP-5),and chemokine ligand-10(CXCL10).These results suggest that male germ cell damage may induce noninfectious epididymitis through the induction of innate immune responses in EECs.These findings provide novel insights into the mechanisms underlying noninfectious epididymitis,which might aid in the diagnosis and treatment of the disease.

Comprehensive transcriptome analysis based on RNA sequencing identifies critical genes for lipopolysaccharide-induced epididymitis in a rat model

Epididymitis is a comm only diagnosed disease associated with male infertility.However,little is known about the molecules that are involved in its development.This study was to identify critical genes associated with lipopolysaccharide-induced epididymitis and an a lyze the molecular mecha nism of epididymitis through RNA sequencing.Experime ntal epididymitis models were generated by administering male Sprague-Dawley rats'lipopolysaccharide.A total of 1378 differentially expressed genes,including 531 upregulated and 847 down regulated gen es,were identified in the epididymitis model rats compared with those in sham-operated rats by RNA seque ncing.Fun ctional enrichme nt an a lyses suggested that the upregulated genes were markedly enriched in inflammati on.related biological processes,as well as in the tumor necrosis factor(TNF)signaling pathway,cytokine-cytokine receptor interactions,complement and coagulation cascades,and in the chemokine signalipathway.Four downregulated genes(collagen type XXVⅢalpha 1 chain[Col28α1],cyclirndependent kinase-like 1[Cdkl1],phosphoserine phosphatase[Psph],and fatty acid desaturase 2[Fads2])and ten upregulated genes(CCAAT/enhancer-binding protein beta[Cebp0],C-X-C motif chemokine receptor 2[Cxcr2],interleukin 11[ll11],C-C motif chemokine ligand 20[Ccl20],nuclear factor-kappa-B inhibitor alpha[NfKbia],claudin 4[Cldn4],matrix metallopeptidase 9[Mmp9],heat shock 70 kDa protein 8[Hspa8],intercellular cell adhesion molecule-1[Icam1],and Jun)were successfully confirmed by real-time polymerase chai n reaction.Wester n blot dem on strated that CDKL1 was decreased,while MMP9 and NFKBIA were increased in the experimental model group compared with those in the sham-operated group.Our study sheds new light on the understand!ng of the early response of the epididymis during bacterial epididymitis.

Aggressive angiomyxoma of the epididymis: A case report

BACKGROUND Aggressive angiomyolipoma is an extremely rare benign mesenchymal tumor that was originally described as a locally recurrent mucinous spindle cell tumour.Agg-ressive angiomyolipoma originates from myofibroblasts,vascular smooth muscle cells,or fibroblasts,and displays various phenotypes of myofibroblasts and abnor-mal muscle arteries.Aggressive angiomyolipoma was first identified in 1983 and fewer than 50 male patients have been reported to date.It is an extremely rare mesenchymal tumour and often confused with other diseases.Patients with epididymal aggressive angiomyolipoma lack typical symptoms,most of which occur incidentally,although some patients may experience mild pain,discomfort,and swelling.Pain may be exacerbated by pressure from the mass.CASE SUMMARY A 66-year-old male was admitted to the hospital on January 14,2022 with chief complaint of swelling in the left scrotum for one year.There was no apparent cause for the swelling.The patient did not consult with any doctor or receive any treatment for the swelling.The enlarged scrotum increased in size gradually until it reached approximately the size of a goose egg,and was accompanied by discom-fort and swelling of the left cavity of the scrotum.The patient had no history of any testicular trauma,infection,or urinary tract infection.The patient urinated freely,1-2 times at night,without urgency,dysuria(painful urination),or haematuria.There was no significant family history of malignancy.The patient underwent excision of the enlarged tumour and the left epididymis under general anaes-thesia on January 18,2022.Twelve months of follow-up revealed no recurrence.The patient was satisfied with the treatment.CONCLUSION Aggressive angiomyolipoma is extremely rare clinically and often confused with other diseases.The pathogenesis of aggressive angiomyolipoma is unclear and the clinical presentation is mostly a painless enlarged mass.The diagnosis of aggressive angiomyolipoma requires a combination of medical history,preoperative imaging such as computed tomography and magnetic resonance imaging,cytological examination and preoperative and postoperative pathological biopsy.The preferred treatment is surgery,with the possibility of a new alternative treatment option after hormonal therapy.Aggressive angiomyolipoma should be considered in the differential diagnosis of parametrial tumors of the male genital area that present as clinically significant masses.The high recurrence rate of aggressive angiomyolipoma may be related to incomplete tumor resection,and patients with aggressive angiomyolipoma are advised to undergo annual postoperative follow-up and imaging for recurrence.

Assessment of the Quality of Frozen-Thawed Semen or Epididymal Sperm in Three Native Vietnamese Pig Breeds

Our aim was to evaluate the quality of ejaculated and epididymal frozen-thawed pig sperm of endangered Vietnam native pig breeds. Ejaculated sperm was collected from live boars and epididymal sperm was collected from slaughtered boars of the MuongTe, Kieng Sat and Co BinhThuan breeds and frozen in 0.25 ml straws using a protocol established earlier for modern pig breeds. We evaluated the sperm quality after thawing in terms of motility and rates of viable and abnormal spermatozoa. Our results revealed that the sperm motility and rates of viable and abnormal frozen-thawed sperm were >30%, >44%, and <14%, respectively. The origin of sperm had an effect on the production of pig embryos in vitro. In the Co BinhThuan breed, ejaculated sperm generated higher cleavage, blastocyst and hatching rates than did the epididymal sperm (60.11% vs 56.02%, 17.23% vs 14.31%, 3.78% vs 2.34%, respectively, P < 0.05). Although no difference in cleavage rate, blastocyst formation rate and the average number of cells/blastocysts, the hatching blastocyst rate was different between the breeds (P > 0.05). In the Co BinhThuan breed, the rate of pregnancy of ejaculated groups was similar to that of the epididymal group. In conclusion, the ejaculated and epididymal sperm of native Vietnamese pigs were successfully frozen. We succeeded in creating embryos in vitro and pregnant pigs after artificial insemination from frozen-thawed semen in three native Vietnamese pig breeds for the first time. The use of the ejaculated sperm improved the production of native pig embryos in vitro efficiency.

Infectious Pathology of the Scrotum in Abidjan: Ultrasound Features of 80 Cases

Objectives: The aim of this study was to determine the epidemiological-clinical profile of patients with scrotal infectious pathology in Abidjan and describe the ultrasound features of this scrotal infectious pathology. Methods: This was a prospective study of 80 cases of scrotal infectious pathology objectified by ultrasound at Yopougon University Hospital from 1 January 2015 to 31 December 2015. Ultrasounds were performed using a high-frequency linear probe in B and Color Doppler modes by senior radiologists. The epidemiological-clinical data were recorded from the ultrasound request form and the interrogation of the patient. Results: The average age was 23 years with extreme ranging from 16 to 40 years. Soldiers were the most concerned (40%) followed by students (30%). The painful large bursa was the quasi constant presenting feature (95% of cases) and fever was associated in less than half of the cases (45% of cases). The scrotal involvement was most often unilateral (85% of cases) and the left side was involved in 70% of the cases. Epididymitis was the most frequent pathology (60%) followed by orchiepididymitis (30%) and orchitis (10%). The most commonly encountered accompanying ultrasound findings were envelope thickening (100%), intravaginal fluid effusion (60%), and Doppler Hypervascularization (30%). Conclusion: In Abidjan Scrotal infectious pathology is most often encountered among young soldiers or students most often with a ± febrile large bursa. The most common pathology is left unilateral epididymitis.

Coccidioidomycosis of the Testis and Epididymis

This report describes an unusual presentation of a man with a testicular mass who presented in diabetic ketoacidosis to the emergency department. Initial diagnosis was a suspected testicular malignancy based on history, physical exam, and available laboratory and radiological imaging. Due to the possibility of a testicular malignancy, the patient was taken for immediate orchiectomy. Histology revealed coccidioido-mycosis of the left testicle and epididymis. Treatment with the appropriate antifungals was initiated. Despite aggressive multi-disciplinary therapy the patient continued to deteriorate and eventually expired as a result of the massive systemic infection. Literature review revealed the presentation of disseminated genitourinary coccidioidomycosis is rare and seldom reported.

Sperm maturation in the epididymis： a new look at an old problem

The osmotic challenges facing maturing spermatozoa and their responses to them are discussed in relation to the concept of sperm maturation, defined as the increased ability of more distally recovered epididymal spermatozoa to fertilize eggs when inseminated into the female tract. One explanation could be that the more distal cells are better able to regulate their volume, and reach the oviducts, as a consequence of uptake of epididymal osmolytes. Increased motility, zona binding and oolemma fusion capacities are also acquired within the epididymis and are necessary for those cells that finally arrive at the site of fertilization. （Asian J Androl 2007 July; 9： 533-539）

Effect of WFDC 2 silencing on the proliferation,motility and invasion of human serous ovarian cancer cells in vitro

Objective:To investigate effect and possible mechanisms of silencing human WFDC2（HE4） gene on biological behavior changes as cell proliferation,apoplosis,movement and invasion of human serous ovarian cancer cell line SKOV3.Methods:Lentiviral WFDC2 gene sequence of small interfering siRNA was stablely transfected into SKOV3 identified by Q-PCR and western-blot. Obtained SKOV3 stable strains with silenced HE4 were measured by proliferation,apoplosis, migration,and invasion.Results:Gene sequencing showed that the oligonucleotides were successfully inserted into the expected site.After silencing HE4 in the SKOV3,proliferation was significandy inhibited（P【0.05）.G0/G1 phase was arrested by the cell cycle（P【0.01） and capacity of the migration and invasion decreased significandy（P【0.01）.Slight early apoptosis ratio and no change of late apoplosis were found without change of Caspase-3 or Bcl-2 protein.Proteins involed in ERK pathway as phosphorylated protein as p-EGFR,p- ERK decreased and protease protein involved in tissue remoding as matrix metalloproteinases MMP-9,MMP-2 and cathepsin B decreased compared with control group.Conclusions:HE4 gene plays an important role in regulating proliferation,apoptosis,migration,invasion of serous ovarian cancer cells by ERK pathway and protease system.Its role in apoptosis needs to be further explored,and it may be a potential target for serous ovarian cancer.

Can inhibin-B predict the outcome of microsurgical epididymal sperm aspiration in patients with suspected primary obstructive azoospermia？

Aim： To evaluate whether inhibin-B can predict the outcome of a microsurgical epidymal sperm aspiration （MESA） procedure in patients with suspected primary obstructive azoospermia （OA） and if inhibin-B can replace testicular biopsy in the diagnostic work-up of these patients. Methods： Inhibin-B levels and testicular biopsy scores were related to the outcome of MESA in 43 patients with suspected primary OA. MESA was considered to be successful when epididymal sperm could be identified during the procedure. Results： Spermatozoa were present in the epididymal aspirate in 28 out of the 43 patients （65%）. lnhibin-B values were not significantly different in patients with successful or unsuccessful MESA. The modified Johnsen score, however, was significantly lower in patients with unsuccessful MESA （P = 0.003）. A rete testis obstruction or epididymal malfunctioning was found in 15% of patients with suspected primary OA, reflected by unsuccessful MESA despite normal inhibin-B levels and normal testicular histology. Conclusion： Inhibin-B cannot replace testicular biopsy as a diagnostic tool in the work-up of patients with suspected primary OA. Testicular biopsy is useful in identifying patients with spermatogenic arrest, who might have normal inhibin-B values.

Human ribonuclease 9,a member of ribonuclease A superfamily,specifically expressed in epididymis,is a novel sperm-binding protein

To explore the functions of human ribonuclease 9(RNase 9),we constructed a mammalian fusion expression vector pcDNA-hRNase9,prepared recombinant human RNase 9-His fusion protein from HEK293T cells and determined its N-terminal amino acid sequences.According to the determined mature protein,recombinant human RNase 9 was prepared in E.coli.Ribonucleolytic activity and antibacterial activity of recombinant human RNase 9 were detected,and the distribution of human RNase 9 on tissues and ejaculated spermatozoa and in vitro capacitated spermatozoa were analyzed via indirect immunofluorescence assay.The results showed that recombinant human RNase 9 did not exhibit detectable ribonucleolytic activity against yeast tRNA,but exhibited antibacterial activity,in a concentration/time dependent manner,against E.coli.Immunofluorescent analyses showed that the predicted human RNase 9 was present throughout the epididymis,but not present in other tissues examined,and human RNase 9 was also present on the entire head and neck regions of human ejaculated spermatozoa and in vitro capacitated spermatozoa.These results suggest that human RNase 9 may play roles in host defense of male reproductive tract.

Successful pregnancy and birth after intrauterine insemination using caput epididymal sperm by percutaneous aspiration

<abstract>Aim: To manage male infertility with obstructive azoospermia by means of percutaneous epididymal sperm aspiration (PESA) and intrauterine insemination (IUI). Methods: Ninety azoospermic patients with congenital bilateral absence of the vas deferens (BAVD, n=58) or bilateral caudal epididymal obstruction (BCEO, n=32) requesting for fine needle aspiration (FNA), PESA and IUI were recruited. The obstruction was diagnosed by vasography and determination of the fructose, carnitine and alpha-glucosidase levels in the seminal fluid. Results: The mean sperm motility, density, abnormal sperm and total sperm count of the caput epdidymis were 16 %±22 %, (12±31) ×106/mL, 55 %±36 % and (16±14)×106, respectively. In the 90 couples, a total of 74 PESA procedures and 66 cycles of IUI were performed. Three pregnancies resulted, including one twin pregnancy giving birth to two healthy boys, one single pregnancy with a healthy girl and another single pregnancy aborted at week 6 of conception. The pregnancy rate per IUI cycle was 4.5 %. Conclusion: The birth of normal, healthy infants by IUI using PESA indicates that the caput epididymal sperm possess fertilization capacity. The PESA-IUI programme is a practical and economical procedure for the management of patients with obstructive azoospermia.

Microsurgical epididymal sperm aspiration： indications, techniques and outcomes

Microsurgical epididymal sperm aspiration （MESA） refers to retrieval of sperm-containing fluid from optimal areas of the epididymis that are selected and sampled using high-power optical magnification provided by an operating microscope. Retrieved sperm are subsequently used for intracytoplasmic sperm injection （ICSI） to induce fertilization and pregnancy. MESA is considered by many experts to be the gold standard technique for sperm retrieval in men with obstructive azoospermia given its high yield of quality sperm, excellent reported fertilization and pregnancy rates, and low risk of complications. However, MESA must be performed in an operating room, requires microsurgical skills and is only useful for reproduction using ICSI. Herein we present an overview of the evaluation of candidate patients for MESA, the technical performance of the procedure and the outcomes that have been reported.

Clinical observation of loupe-assisted intussusception vasoepididymostomy in the treatment of obstructive azoospermia(analysis of 49 case reports)

To evaluate the clinical outcomes of loupe-assisted intussusception vasoepididymostomy(VE)in the treatment of epididymal obstructive azoospermia(EOA),we retrospectively analyzed data from 49 patients with EOA who underwent two-suture longitudinal intussusception vasoepididymostomy(LIVE)between 2000 and 2007.The data included the surgical method,postoperative motile sperm count per ejaculation,percentage of progressive motile sperm and patency and pregnancy outcomes.There were a total of 49 men undergoing scrotal exploration,and epididymal obstruction was found in all cases.Bilateral or unilateral anastomoses were performed in 40 and 6 men,respectively.The postoperative courses of 42 patients were followed up for more than 6 months,and the courses of 38 patients were followed up for more than 1 year.The overall patency and pregnancy rates were 71.4%and 26.3%,respectively.Moreover,progressive motile sperm was more frequently present in those patients who had undergone anastomosis at cauda than at corpus or caput.Pregnancy was achieved only in those patients who had undergone anastomosis at least on one side of the cauda epididymis.We think that the loupe-assisted method,with a lower overall cost and a simplified surgical procedure,can achieve satisfactory patency outcomes and pregnancy results.Data from this paper also suggest that paternity outcomes occur more frequently after anastomoses at cauda than at corpus or caput.

Expression of serum human epididymal secretory protein E4 at low grade and high grade serous carcinomas

Objective:To investigate the value of serum human epididymis protein 4(HE4) in differential diagnosis of patients with low-grade serous(LGSC) and high-grade serous carcinoma(HGSC) serous ovarian cancer.Methods:LGSC and HGSC serous ovarian cancer were diagnosed by the two-tier grade system,serum levels of HE4 and carbohydrate antigen 12S(CA125) were measured by ELBA and radioisotope method,respectively in 60 serous ovarian cancer patients. HE4 and TPS3 protein in cancer tissue were measured by immunohistochemical method. Results:The difference in density of HE4 and TP53 protein was significant between LGSC and HGSC tissue,while serum CA12S did not show significant difference between different serum samples.There was significant difference in serum HE4 levels between LGSC and HGSC and the result was different within FIGO(Ⅰ+Ⅱ) stage,suggesting HE4 was not a reliable biomarker for the discrimination between LGSC and HCSC.HE4 had potential as a biomarker for the discrimination between LGSC and HGSC but the role in early diagnosis was limited.Conclusions:HE4 may be a reliable marker for differential diagnosis of LGSC and HGSC.But its role in early diagnosis of LGSC and HGSC need to be confirmed from the perspective of two-tier grade system.

Age-dependent expression of the cystatin-related epididymal spermatogenic （Cres） gene in mouse testis and epididymis

Aim： To investigate the spatial and temporal expression of the cystatin-related epididymal spermatogenic （Cres） gene in mouse testis and epididymis during postnatal development. Methods： The QuantiGene assay and indirect immunofluorescence technique were used to examine the Cres mRNA and Cres protein level in mouse testis and epididymis on postnatal days 14, 20, 22, 28, 35, 49, 70 and 420. Results： （1） In both the testis and epididymis, Cres mRNA was fast detected on day 20, then it increased gradually from day 20 to day 70, and the high expression level maintained till day 420. （2） In the testis, the Cres protein was exclusively localized to the elongating spermatids and was first detected on day 22. The number of Cres-positive spermatids increased progressively till day 49. From day 49 to day 420, the number of Cres-positive cells was almost stable. （3） The Cres protein was first detected on day 20 in the proximal caput epididymal epithelium. By day 35, the expression level of the Cres protein increased dramatically and the high level was maintained till day 420. Moreover, the luminal fluid of the midcaput epididymis was also stained Cres-positive from day 35 on. No Cres-positive staining was observed in distal caput, corpus and cauda epididymis throughout. Conclusion： The Cres gene displays a specific age-dependent expression pattern in mouse testis and epididymis on both the mRNA and protein level.

Omental mass combined with indirect inguinal hernia leads to a scrotal mass: A case report

BACKGROUND Primary omental tumors are uncommon,and omental fibromas account for 2%of these tumors.Due to the low incidence of omental fibromas and the limited relevant literature,it is challenging for clinicians to make an accurate diagnosis of this condition,especially before surgery.CASE SUMMARY A 30-year-old man was admitted to the hospital because of a left epididymal mass with vague discomfort for more than 1 mo.A physical examination was performed,and the findings showed that the epididymal mass may have entered the abdominal cavity.Pelvic computed tomography was performed in our hospital and revealed a left inguinal hernia with a mass in the hernial contents,and no masses were found in the left epididymis.A traditional inguinal hernia incision was made.Intraoperative hernia contents were found to be of the greater omentum,and a 2.5 cm-diameter mass was found at the distal end of the greater omentum.The scrotum and epididymis did not exhibit other masses.Then,the mass of the greater omentum was excised.Intraoperative frozen pathological examination suggested a spindle cell tumor.The postoperative pathological examination suggested that the mass was an omental angiofibroma.Postoperatively,the patient recovered well and was discharged.Outpatient re-examinations were performed at 1 mo and half a year after the operation and showed no obvious abnormalities.CONCLUSION Due to the low morbidity rate associated with and latent nature of omental tumors,these tumors are difficult to diagnose preoperatively;thorough medical history taking,detailed physical examinations,and necessary imaging auxiliary examinations can help clinicians diagnose and treat these cases.

Inductively coupled plasma emission spectroscopic and flame photometric analysis of goat epididymal fluid

Aim: The elemental composition of the epididymal luminal fluid (ELF) in adult goat ( Capra indica) was investigat-ed. Methods: ELF was collected by micropuncture from twelve sites along the epididymal duct. The elementalcontents was analyzed with inductively coupled plasma (ICP) emission spectroscopy, a microanalytical technique thatcan simultaneously measure many elements in minute volumes of sample. The Na and K concentrations were determinedby flame photometry. Results: ICP spectroscopy showed the presence of copper, calcium, nickel, iron, magne-sium, chromium, titanium and zinc in ELF, with fluctuating levels at different sites along the length of the epididymis.Cadmium, cobalt, lead and manganese were not fotmd. The Na^+ / K^+ ratio was seen to be higher at the initial seg-ments of the epididymis and lower at the distal. Conclusion: It is proposed that the observed characteristic distribu-tion of elements in ELF may have far reaching implications in sperm maturation and storage known to occur in the epi-didymis. (Asian J Androl 2000 Dec; 2: 288-292)

Vlouse sperm acquire a new structure on the apical hoo Juring epididymal maturation

Spermatozoa emerging from the testis undergo a maturation process in the epididymis during which they change morphologically, biochemically and physiologically to gain motility and the ability to fertilize ova. We examined mouse epididymal sperm with immunostaining and transmission electron microscopy （EM） and identified a previously unknown structure on the apical hook. The structure has a coiled configuration around 11 nm in thickness and is present at the tip of each corner of the triangular-rod shaped perforatorium. Surveying sperm isolated from various regions of the epididymis indicated that mouse sperm acquire the hook rim （HR） structure during its passage through the proximal two-thirds of the caput epididymidis. The structure withstands vigorous sonication and harsh chemical treatments and remains intact after the acrosome reaction. Its location and sturdiness suggest a function in protecting the apical hook from mechanical wear during fertilization. Our EM images of epididymal sperm also revealed additional novel structures as well as lateral asymmetry of the sperm head, indicating that mouse sperm head has a structure more complex than previously recognized.