TiO2 nanoparticles affect spermatogenesis and adhesion junctions via the ROS-mediated mTOR signalling pathway in Eriocheir sinensis testes.

Recent findings found that TiO2 nanoparticles (TiO2-NPs) have male reproductive toxicity. However, few reports have studied the toxicity of TiO2-NPs in crustaceans. In this study, we first chose the freshwater crustacean Eriocheir sinensis (E. sinensis) to explore the male toxicity of TiO2-NP exposure and the underlying mechanisms. Three nm and 25 nm TiO2-NPs at a dose of 30 mg/kg bw induced apoptosis and damaged the integrity of the haemolymph-testis-barrier (HTB, a structure similar to the blood-testis-barrier) and the structure of the seminiferous tubule. The 3-nm TiO2-NPs caused more severe spermatogenesis dysfunction than the 25-nm TiO2-NPs. We initially confirmed that TiO2-NP exposure affected the expression patterns of adherens junctions (α-catenin and ß-catenin) and induced tubulin disorganization in the testis of E. sinensis. TiO2-NP exposure caused reactive oxygen species (ROS) generation and an imbalance of mTORC1-mTORC2 (mTORC1/rps6/Akt levels were increased, while mTORC2 activity was not changed). After using the ROS scavenger NAC to inhibit ROS generation, both the mTORC1-mTORC2 imbalance and alterations in AJs were rescued. More importantly, the mTORC1 inhibitor rapamycin abolished mTORC1/rps6/Akt hyperactivation and partially restored the alterations in AJs and tubulin. Collectively, the mTORC1-mTORC2 imbalance induced by TiO2-NPs was involved in the mechanism of AJ and HTB disruption, resulting in spermatogenesis in E. sinensis.

Kinesin 12 (KIF15) contributes to the development and tumorigenicity of prostate cancer.

In Asia, prostate cancer is becoming a growing concern, impacting both socially and economically, compared with what is seen in western countries. Hence, it is essential to know the mechanisms associated with the development and tumorigenesis of PCa for primary diagnosis, risk management, and development of therapy strategies against PCa. Kinesin family member 15 (KIF15), a kinesin family member, is a plus-end-directed kinesin that functions to form bipolar spindles. There is emerging evidence indicating that KIF15 plays a significant role in several malignancies, such as pancreatic cancer, hepatocellular carcinoma, lung adenocarcinoma, and breast cancer. Still, the function of KIF15 remains unclear in prostate cancer. Here, we study the functional importance of KIF15 in the tumorigenesis of PCa. The bioinformatic analysis from PCa patients revealed high KIF15 expression compared to normal prostate tissues. High expression hinting at a possible functional role of KIF15 in regulating cell proliferation of PCa, which was demonstrated by both in vitro and in vivo assays. Downregulation of KIF15 silenced the expression of CDK2, p-RB, and Cyclin D1 and likewise blocked the cells at the G1 stage of the cell cycle. In addition, KIF15 downregulation inhibited MEK-ERK signaling by significantly silencing p-ERK and p-MEK levels. In conclusion, this study confirmed the functional significance of KIF15 in the growth and development of prostate cancer and could be a novel therapeutic target for the treatment of PCa.

Antitumor Activity of Small Activating RNAs Induced PAWR Gene Activation in Human Bladder Cancer Cells.

Small double-stranded RNAs (dsRNAs) have been proved to effectively up-regulate the expression of particular genes by targeting their promoters. These small dsRNAs were also termed small activating RNAs (saRNAs). We previously reported that several small double-stranded RNAs (dsRNAs) targeting the PRKC apoptosis WT1 regulator (PAWR) promoter can up-regulate PAWR gene expression effectively in human cancer cells. The present study was conducted to evaluate the antitumor potential of PAWR gene induction by these saRNAs in bladder cancer. Promisingly, we found that up-regulation of PAWR by saRNA inhibited the growth of bladder cancer cells by inducing cell apoptosis and cell cycle arrest which was related to inhibition of anti­apoptotic protein Bcl-2 and inactivation of the NF-κB and Akt pathways. The activation of the caspase cascade and the regulation of cell cycle related proteins also supported the efficacy of the treatment. Moreover, our study also showed that these saRNAs cooperated with cisplatin in the inhibition of bladder cancer cells. Overall, these data suggest that activation of PAWR by saRNA may have a therapeutic benefit for bladder cancer.

Inhibition of kinesin motor protein KIFC1 by AZ82 induces multipolar mitosis and apoptosis in prostate cancer cell.

Kinesin 14 family member KIFC1 is a mitotic kinesin which contains a C-terminal motor domain and plays a vital role for clustering the amplified centrosomes. Overexpression of KIFC1 in prostate cancer (PCa) cells showed resistance to docetaxel (DTX). The present study revealed that small KIFC1 inhibitor AZ82 suppresed the transcription and translation of KIFC1 significantly in PCa cells. AZ82 inhibited the KIFC1 expression both in the cytoplasm and nucleus of PCa cells. Inhibition of KIFC1 by AZ82 caused multipolar mitosis in PCa cells via de-clustering the amplified centrosomes and decreased the rate of cancer cell growth and proliferation. Moreover, depletion of KIFC1 reduced cells entering the cell cycle and caused PCa cells death through apoptosis by increasing the expression of Bax and Cytochrome C. Thereby, KIFC1 silencing and inhibition decreased the PCa cells survival by inducing multipolar mitosis as well as apoptosis, suggesting inhibition of KIFC1 using AZ82 might be a strategy to treat PCa by controlling the cancer cell proliferation.

C-terminal kinesin motor KIFC1 participates in facilitating proper cell division of human seminoma.

C-terminus kinesin motor KIFC1 is known for centrosome clustering in cancer cells with supernumerary centrosomes. KIFC1 crosslinks and glides on microtubules (MT) to assist normal bipolar spindle formation to avoid multi-polar cell division, which might be fatal. Testis cancer is the most common human cancer among young men. However, the gene expression profiles of testis cancer is still not complete and the expression of the C-terminus kinesin motor KIFC1 in testis cancer has not yet been examined. We found that KIFC1 is enriched in seminoma tissues in both mRNA level and protein level, and is specifically enriched in the cells that divide actively. Cell experiments showed that KIFC1 may be essential in cell division, but not essential in metastasis. Based on subcellular immuno-florescent staining results, we also described the localization of KIFC1 during cell cycle. By expressing ΔC-FLAG peptide in the cells, we found that the tail domain of KIFC1 might be essential for the dynamic disassociation of KIFC1, and the motor domain of KIFC1 might be essential for the degradation of KIFC1. Our work provides a new perspective for seminoma research.

Myosin Va plays essential roles in maintaining normal mitosis, enhancing tumor cell motility and viability.

Myosin Va, a member of Class V myosin, functions in organelle motility, spindle formation, nuclear morphogenesis and cell motility. The purpose of this study is to explore the expression and localization of myosin Va in testicular cancer and prostate cancer, and its specific roles in tumor progression including cell division, migration and proliferation. We detected myosin Va in testicular and prostate tumor tissues using sqRT-PCR, western blot, and immunofluorescence. Tumor samples showed an increased expression of myosin Va, abnormal actin and myosin Va distribution. Immunofluorescence images during the cell cycle showed that myosin Va tended to gather at cytoplasm during anaphase but co-localized with nucleus during other phases, suggesting the roles of myosin Va in disassembly of spindle microtubule, movement of chromosomes and normal cytokinesis. In addition, multi-nucleation and aberrant nuclear morphology were observed in myosin Va-knockdown cells. Wounding assay and CCK-8-based cell counting were conducted to explore myosin Va roles in cell migration, viability and proliferation. Our results suggest that myosin Va plays essential roles in maintaining normal mitosis, enhancing tumor cell motility and viability, and these properties are the hallmark of tumor progression and metastasis development. Therefore, an increased understanding of myosin Va expression and function will assist in the development of future oncodiagnosis and -therapy.

A novel role of KIF3b in the seminoma cell cycle.

KIF3b is a protein of the kinesin-2 family which plays an important role in intraflagellar transport. Testis cancer is a common cancer among young men. Its diagnostic rate is increasing and over half of the cases are seminomas. Many aspects of the mechanism and gene expression background of this cancer remain unclear. Using western-blotting and semi-quantitative PCR we found high protein levels of KIF3b enrichment in seminoma tissue despite the mRNA levels remaining equivalent to that of normal testicular tissues. The distribution of KIF3b was mainly in cells with division potential. Wound-healing assays and cell counting kit assays showed that the knockdown of KIF3b significantly suppressed cell migration ability, viability and number in HeLa cells. Immunofluorescence images during the cell cycle revealed that KIF3b tended to gather at the spindles and was enriched at the central spindle. This indicated that KIF3b may also have direct impacts upon spindle formation and cytokinesis. By counting the numbers of nuclei, spindles and cells, we found that the rates of multipolar division and multi-nucleation were raised in KIF3b-knockdown cells. In this way we demonstrate that KIF3b functions importantly in mitosis and may be essential to seminoma cell division and proliferation as well as being necessary for normal cell division.

[Penile necrosis resulting from post-circumcision microwave diathermy: A report of 9 cases].

OBJECTIVE: To investigate the pathogenesis and treatment of penile necrosis resulting from microwave diathermy following circumcision. METHODS: We retrospectively analyzed the clinical data about 9 cases of penile necrosis resulting from postoperative microwave diathermy following circumcision. The 9 males, aged 20 - 39 (mean 26) years, underwent traditional circumcision for redundant prepuce or phimosis in other hospitals, followed by microwave diathermy for 30 - 60 minutes daily, which resulted in penile necrosis. With no response to conservative therapy, the patients were referred to our hospital at 3 -30 days postoperatively. Of the 9 patients, 5 presented with dry gangrene and 4 with moist gangrene. Six of the patients underwent partial penectomy, including 1 that received penis lengthening.3 months later, while the other 3 underwent total penectomy for total penile necrosis followed by penile reconstruction 3 months later, with deep inferior epigastric perforator (DIEP) flaps and by implantation of the 12th costal cartilage in 2 cases and with epigastric groin island flaps and by urethroplasty in the other. RESULTS: The patients were followed up for 2 - 8 years, and all could urinate smoothly in the standing position. Of the 6 men treated by partial penectomy, 1 received penis lengthening and achieved a penile length of 7 cm and 5 had the remaining penile length of 3 -5 cm, 4 with erectile function and the other 2 capable of sexual intercourse. The 3 men treated by total penectomy achieved nearly normal external appearance of the penis, with a finalized length of (11.7 ± 1.3) cm, a circumference of (11.4 ± 2.1) cm, and a normal feel of the skin. Of the 3 cases of penile reconstruction, 2 achieved sufficient erectile hardness of the penis (grade 3) for sexual intercourse, while the other 1 remained impotent. CONCLUSION: Post-circumcision microwave diathermy may result in penile necrosis, for the management of which, early debridement is necessitated and penile lengthening or reconstruction can be performed according to the severity of the lesion and needs of the patient.

The expression pattern of the C-terminal kinesin gene kifc1 during the spermatogenesis of Sepiella maindroni.

In this study, we investigated the gene sequence and characteristic of kifc1 in Sepiella maindroni through PCR and RACE technology. Our research aimed particularly at the spatio-temporal expression pattern of kifc1 in the developmental testis through in situ hybridization. The particular role of kifc1 in the spermatogenesis of S. maindroni was our particular interest. Based on multiple protein sequence alignments of KIFC1 homologues, kifc1 gene from the testis of S. maindroni was identified, which consisted of 2432bp including a 2109 in-frame ORF corresponding to 703 continuous amino acids. The encoded polypeptide shared highest similarity with Octopus tankahkeei. Through the prediction of the secondary and tertiary structures, the motor domain of KIFC1 was conserved at the C-terminal, having putative ATP-binding and microtubule-binding motifs, while the N-terminal was more specific to bind various cargoes for cellular events. The stalk domain connecting between the C-terminal and N-terminal determined the direction of movement. According to RT-PCR results, the kifc1 gene is not tissue-specific, commonly detected in different tissues, for example, the testis, liver, stomach, muscle, caecum and gills. Through an in situ hybridization method, the expression pattern of KIFC1 protein mimics in the spermatogenesis of S. maindroni. During the primary stage of the spermatogenesis, the kifc1 mRNA signal was barely detectable. At the early spermatids, the signal started to be present. With the elongation of spermatids, the signals increased substantially. It peaked and gathered around the acrosome area when the spermatids began to transform to spindle shape. As the spermatids developed into mature sperm, the signal vanished. In summary, the expression of kfic1 at specific stages during spermiogenesis and its distribution shed light on the potential functions of this motor in major cytological transformations. The KIFC1 homologue may provide a direct shaping force to the nucleus or influence the shaping process through indirect regulation.

Regulation of paracellular permeability: factors and mechanisms.

Epithelial permeability is composed of transcellular permeability and paracellular permeability. Paracellular permeability is controlled by tight junctions (TJs). Claudins and occludin are two major transmembrane proteins in TJs, which directly determine the paracellular permeability to different ions or large molecules. Intracellular signaling pathways including Rho/Rho-associated protein kinase, protein kinase Cs, and mitogen-activated protein kinase, modulate the TJ proteins to affect paracellular permeability in response for diverse stimuli. Cytokines, growth factors and hormones in organism can regulate the paracellular permeability via signaling pathway. The transcellular transporters such as Na-K-ATPase, Na(+)-coupled transporters and chloride channels, can interact with paracellular transport and regulate the TJs. In this review, we summarized the factors affecting paracellular permeability and new progressions of the related mechanism in recent studies, and pointed out further research areas.

Expression and function analysis of metallothionein in the testis of Portunus trituberculatus exposed to cadmium.

Metallothioneins (MTs) possess a unique molecular structure that provides metal-binding and redox capabilities. These capabilities include the maintenance of metal equilibria that protect against heavy metals (especially cadmium) and oxidative damage. Past studies have focused on the function of MTs in vertebrates. However, the functions of MTs during spermiogenesis in invertebrates remain unclear. In order to investigate the function of MTs during spermiogenesis in Portunus trituberculatus, we used RT-PCR and RACE to identify two MT complete cDNA sequences in the total RNA from the P. trituberculatus testis. The 450 bp MT-1 cDNA consists of a 77 bp 5' untranslated region, a 196 bp 3' untranslated region, and a 177 bp open reading frame that encodes 58 amino acids including 19 cysteines. The 581 bp MT-2 cDNA consists of 73 bp 5' untranslated region, a 328 bp 3' untranslated region, and a 180 bp open reading frame that encodes 59 amino acids including 18 cysteines. MT-1 and MT-2 of P. trituberculatus more closely resemble invertebrate (especially crab) MT homologues than vertebrate MT homologues as indicated by protein alignment comparisons and phylogenetic tree analysis. MT-1 and MT-2 were detected in the heart, testis, muscle, hepatopancreas, and gill of P. trituberculatus by tissue expression analysis. In addition, MT-1 and MT-2 are present during the entire process of spermiogenesis in P. trituberculatus as indicated by H&E staining and in situ hybridization. MT-1 and MT-2 expression levels significantly increase after cadmium (Cd) exposure as measured by real-time quantitative PCR analysis. Therefore, we suggest that MT-1 and MT-2 perform important functions in spermiogenesis and testis detoxification in P. trituberculatus.

[Valuable experiences and analysis of causes of urine-induced sepsis].

OBJECTIVE: To explore the characteristics, early symptoms and valuable experiences in the diagnosis and treatment of urine-induced sepsis. METHODS: The clinical data of 30 cases of urine-induced sepsis between August 2008 and April 2012 were reviewed retrospectively. Among them, YAG laser lithotripsy (n = 3) and transurethral prostatic resection (TURP) (n = 2) were performed. One case was after transurethral resection of bladder (TURB). There were 3 cases after cystectomy and Bricker and another 18 during and after percutaneous nephrolithotomy (PCNL). RESULTS: A total of 12 PCNL cases have significant drop in blood pressure during operation with non-bleed causes. A total of 26 cases developed symptoms of chills and high fever after 2 hours of surgery. The earliest symptoms of urine-induced sepsis were decline in blood pressure and high fever. After resistance to infection and symptomatic treatment actively, 27 patients were rescued successful (90%), 3 patients died (10%). Among the 3 deceased patients, 1 case was after YAG laser lithotripsy under ureteroscope, 1 case was after PCNL, 1 case was after TURP. CONCLUSIONS: The onset of urine-induced sepsis onset may be insidious. But this condition deteriorates rapidly and it is rather difficult to reverse. Most cases could be managed when the onset characteristics were recognized early. Prevention and early treatment are keys of lowering the mortality.

Inguinoscrotal hernia of the ureter combined with renal pelvic carcinoma.

Inguinoscrotal herniation of the ureter is a rare finding, with the potential for serious surgical complications. Here we report an extremely rare case of inguinoscrotal hernia of the ureter combined with renal pelvic carcinoma. This 61-year-old man was diagnosed with right renal pelvic tumor, bilateral hydronephrosis with inguinoscrotal hernia of the right ureter, and left ureteral calculus. He was successfully treated with right nephroureterectomy, inguinoscrotal hernia repair, and left ureterolithotomy. Pathologic examinations revealed a high-grade transitional cell carcinoma.

[Transurethral vapor enucleation and resection of prostate with TURis button electrode].

OBJECTIVE: To describe an efficient and effective method of using Olympus TURis button plasma vaporization electrode plus loop electrode for transurethral vapor enucleation and resection of prostate. METHODS: Between July 2011 and October 2011, the investigators performed transurethral vapor enucleation and resection of prostate using Olympus TURis button plasma vaporization electrode plus loop electrode in 16 consecutive patients at our institution. The parameters of prostate weight, International Prostate Symptom Score (IPSS), quality of life (QOL), operative duration, blood loss volume, catheterization period, duration of hospitalization, perioperative complications and the weight of enucleated tissue were evaluated. IPSS and QOL were recorded during the follow-up. RESULTS: No patient had significant blood loss or signs of transurethral resection syndrome. The mean patient age was 67.3 ± 8.1 years. Mean preoperative prostate weight was 49 ± 24 g (range: 19 - 91) and mean resected tissue weight 36 ± 16 g (range: 10 - 50). Serious complications were not observed. Operative duration was 116 ± 31 minutes, mean catheter time 4.9 ± 1.8 days and the duration of hospitalization was 16.6 ± 5.5 days. Transurethral vapor enucleation and resection of prostate induced significant, pronounced, immediate and lasting improvement in IPSS (15.6 ± 6.8 vs 6.7 ± 2.4, P < 0.01) and QOL (3.4 ± 1.4 vs 1.6 ± 0.6, P < 0.01). CONCLUSION: Transurethral vapor enucleation and resection of prostate with Olympus TURis plasma button electrode is a safe, effective and thorough surgical method in the treatment of benign prostatic hyperplasia.

An unusual case of retrovesical ectopic prostate tissue accompanied by primary prostate cancer.

We report an unusual case of retrovesical ectopic prostate tissue in a 73-year-old man with primary prostate cancer. The man's prostate-specific antigen was 24.66 ng/ml.Transabdominal ultrasonography, pelvic computed tomography,and pelvic magnetic resonance imaging demonstrated a heterogeneous 8.5 × 8.0 × 7.0 cm mass in contact with the posterior wall of the urinary bladder. The patient underwent a retropubic radical prostatectomy and resection of tumor. Pathological examination of prostate revealed a prostatic adenocarcinoma, Gleason score of 4 + 5 = 9, and the retrovesical tumor was confirmed to be a benign prostate tissue.

Expression and function analysis of metallothionein in the testis of stone crab Charybdis japonica exposed to cadmium.

Metallothionein (MT) participates in metallic homeostasis and detoxification in living animals. Previous studies have focused mainly on the functions of MT in vertebrates, but the functions of MT during spermiogenesis in invertebrates remain unclear. In order to investigate the functions of MT during spermiogenesis in the Japanese stone crab (Charybdis japonica), we identified the C. japonica MT complete cDNA sequence from the total RNA of the testis using RT-PCR and RACE. The 587 bp MT cDNA contains: an 80 bp 5' untranslated region, a 333 bp 3' untranslated region, and a 174 bp open reading frame. MT has 57 amino acids including 19 cysteines. The protein alignment between MT sequences of C. japonica and other crabs shows a high similarity and a strong identity in cysteine residues vital for the metal-binding affinity of MT. After the cadmium (Cd) exposure, the testis displays both abnormal morphology and MT mRNA expression both of which indicate a sensitive response of testis MT to Cd. Therefore, we suggest that MT is an excellent biomarker candidate for evaluating Cd pollution.

Hand-assisted-drawing-needle running suture with a curved needle: an effective technique to create a W-ileal neobladder.

BACKGROUND: An important milestone in the area of urinary diversion was the advent of a series of orthotopic bladder substitution (OBS). However, reconstruction of OBS by the traditional hand suture method (THSM) is a time-consuming process. Stapling techniques are considered to be inferior to hand-sewn methods. We report our experience and functional results in patients with W-ileal neobladder by a hand-assisted-drawing-needle running suture (HADNRS). METHODS: Between April 1993 and December 2011, 347 patients (338 men and 9 women) aged 28 - 77 years (median age: 59 years) underwent radical cystectomy, followed by the creation of a modified W-ileal neobladder by HADNRS with a curved needle. A total of 347 (20 patients in 2003) were evaluated by urodynamic tests. RESULTS: The operative time ranged from 110 to 310 minutes (mean 148 minutes), and the mean time of reconstruction by HADNRS, excluding ureterointestinal and ileouretral anastomosis, was (20.2 ± 4.3) minutes. Histopathological analysis of removed specimens showed that 317 patients had transitional cell bladder carcinoma. Of these 317 patients, 19 also had squamous carcinoma and 13 had adenocarcinoma. Glandularis and prostate cancer occurred in 16 and 14 patients, respectively. Three patients (0.8%) had neobladder abdominal fistula. No other early complications or injury to the surgeon's hands occurred due to HADNRS. Of the 20 cases with urodynamic examinations in 2003, two suffered from daytime incontinence and six had nocturnal incontinence. The maximum capacity of the neobladder was (492.9 ± 177.8) ml, and the maximum pressure within the reservoir at the end of filling was (32.1 ± 8.6) cmH2O. CONCLUSION: Reconstruction of W-ileal neobladder by HADNRS is effective and economical.

The apoptotic function analysis of p53, Apaf1, Caspase3 and Caspase7 during the spermatogenesis of the Chinese fire-bellied newt Cynops orientalis.

BACKGROUND: Spontaneous and stress-induced germ cell apoptosis during spermatogenesis of multicellular organisms have been investigated broadly in mammals. Spermatogenetic process in urodele amphibians was essentially like that in mammals in spite of morphological differences; however, the mechanism of germ cell apoptosis in urodele amphibians remains unknown. The Chinese fire-belly newt, Cynops orientalis, was an excellent organism for studying germ cell apoptosis due to its sensitiveness to temperature, strong endurance of starvation, and sensitive skin to heavy metal exposure. METHODOLOGY/PRINCIPAL FINDINGS: TUNEL result showed that spontaneous germ cell apoptosis took place in normal newt, and severe stress-induced apoptosis occurred to spermatids and sperm in response to heat shock (40°C 2 h), cold exposure (4°C 12 h), cadmium exposure (Cd 36 h), and starvation stress. Quantitative reverse transcription polymerase chain reactions (qRT-PCR) showed that gene expression of Caspase3 or Caspase7 was obviously elevated after stress treatment. Apaf1 was not altered at its gene expression level, and p53 was significantly decreased after various stress treatment. Caspase assay demonstrated that Caspase-3, -8, -9 enzyme activities in newt testis were significantly elevated after heat shock (40°C 2 h), cold exposure (4°C 12 h), and cadmium exposure (Cd 36 h), while Caspase3 and Caspase8 activities were increased with Caspase9 significantly decreased after starvation treatment. CONCLUSIONS/SIGNIFICANCE: Severe germ cell apoptosis triggered by heat shock, cold exposure, and cadmium exposure was Caspase3 dependent, which probably involved both extrinsic and intrinsic pathways. Apaf1 may be involved in this process without elevating its gene expression. But starvation-induced germ cell apoptosis was likely mainly through extrinsic pathway. p53 was probably not responsible for stress-induced germ cell apoptosis in newt testis. The intriguing high occurrence of spermatid and sperm apoptosis probably resulted from the sperm morphology and unique reproduction policy of Chinese fire-belly newt, Cynops orientalis.

Molecular characterization of a KIF3A-like kinesin gene in the testis of the Chinese fire-bellied newt Cynops orientalis.

KIF3A, the subunit within the kinesin-2 superfamily, is a typically N-terminal motor protein, which is involved in membranous organelle and intraflagellar transport. During spermatogenesis, KIF3A plays a critical role in the formation of flagella and cilia. KIF3A is also related to the left-right asymmetry, the signal pathway, DNA damage and tumorigenesis. We used RT-PCR and in situ hybridization to clone the kif3a gene, and we identified its function in the testis of the Chinese fire-bellied newt Cynops orientalis (termed as co-kif3a). The full-length sequence of co-kif3a was 2193 bp, containing a 56 bp 5'UTR, 2073 bp ORF encoding a protein of 691 amino acids and a 64 bp 3'UTR. The secondary structure analysis showed that co-KIF3A had three motor domains, representing the N-terminal motor domain (1-400 aa), α-helix domain (400-600 aa) and C-terminal tail domain (600-691 aa). The amino acid sequence of co-KIF3A shared an identity of 55.9%, 90.9%, 89.9%, 91.3% and 85.7% with its counterparts in Aedes aegypti, Mus musculus, Xenopus tropicalis, Homo sapiens and Danio rerio, respectively. The calculated molecular weight of the putative co-KIF3A was 79 kDa and its estimated isoelectric point was 6.8. RT-PCR result showed that co-kif3a was expressed in several examined tissues, with a high level in the testis and low levels in liver, muscle and ovum. Kif3a was weakly expressed in the heart and spleen, and barely detected in the intestine. In situ hybridization analysis demonstrated that in early spermatid co-kif3a was expressed around the nuclear membrane. When the tail began to emerge in the middle spermatid, mRNA transcript was abundantly concentrated in the flagellum. The mRNA signal was still very strong along all the flagellum in late spermatid. In mature spermatid, the message was weak. Therefore, co-KIF3A probably plays a functional role in the spermiogenesis of C. orientalis.