The furcocercus cercariae of Neodiplostomum seoulense (Digenea: Neodiplostomidae) penetrate the skins of tadpoles and shed their tails. The speculated mechanism of this tail loss was physical efforts required to produce a vigorous zigzag motion during skin penetration; no other mechanism has been proposed. We examined the relationship between the host serum and cercarial tail loss. Cercariae of N. seoulense were collected from experimentally infected Segmentina hemisphaerula, and lots of 300 cercariae were cultured in medium 199 contained several types of sera. Cercarial tail degradation was induced in all media, but all the cercariae cultured except those cultured in media containing fetal bovine serum (FBS) died within 48 hr. After 72 hr cultivation in media containing FBS, cercarial tail degradation was induced in 67.0%; in continuous cultivation 13.3% of larvae survived for 7 days. Tail degradation did not occur in the absence of serum and when serum was heat inactivated at 56 degrees C for 30 min. The addition of 20 mM ethylenediaminetetraacetic acid (EDTA) blocked cercarial tail degradation completely. Moreover, the addition of 20 mM MgCl2 restored tail degradation blocked by EDTA. These results suggest that the alternative complement pathway is related with the N. seoulense cercarial tail degradation induced by serum.
Trematoda/*physiology ; Tail/*physiology ; Larva/parasitology ; Complement System Proteins/immunology/*physiology ; Anura/parasitology ; Animals

The CatSper channel is known as one of the most important Ca²⁺ channels on the cell membrane of mammalian sperm and plays a key role in the motility, hyperactivation and fertilization function of sperm. The CatSper protein, expressed exclusively in the principal piece of the sperm tail, is composed of CatSper1-4 and 5 auxiliary unitsβ,γ,δ and ε, and has an essential part in the functional and structural domains of Ca²⁺as well as in the spatiotemporal regulation of the P-Tyr protein, sperm hyperactivation, efficient sperm migration in the oviduct, egg penetration, and normal fertility. Recent studies show that functional deficiency of CatSper seriously affects sperm function,and the loss of any one of its 9 subunits may lead to male reproductive dysfunction. This paper outlines recent advances in the studies of the CatSperprotein, focusing on its expression, location, structure, and regulation,as well as itsinfluence on sperm hyperactivation and male reproduction.
Animals ; Calcium Channels ; chemistry ; physiology ; Humans ; Infertility, Male ; etiology ; Male ; Sperm Motility ; physiology ; Sperm Tail ; metabolism ; Sperm-Ovum Interactions ; physiology ; Spermatozoa ; physiology

Oligoasthenozoospermia, teratozoospermia or low sperm motility is the main cause of male infertility. Low sperm motility can be induced by abnormalities of the sperm tail structure and sperm function. The outer dense fiber protein 2 (ODF2) is a protein fiber maintaining cytoskeleton, as a major component of the mammalian sperm tail and centrosome, and its abnormality is closely related to asthenospermia. Recent studies indicate that ODF2 includes many proteins of the same name and homologous splices located in the sperm centrosomes and spindles of cleaved-embryos, necessary for animal ciliogenesis and associated with sperm capacitation. The features of ODF2 indicate that it is not a single-structural protein. This paper reviews the known functions of ODF2, paving a ground for further studies of the relationship between the ODF2 protein and fertilization.
Animals ; Asthenozoospermia ; complications ; Azoospermia ; complications ; Centrosome ; chemistry ; Cytoskeleton ; chemistry ; Heat-Shock Proteins ; physiology ; Humans ; Infertility, Male ; etiology ; Male ; Sperm Motility ; physiology ; Sperm Tail ; Spermatozoa ; physiology

OBJECTIVETo investigate the feasibility and clinical application value of selecting viable spermatozoa by noncontact diode laser.

METHODSWe obtained immotile spermatozoa from 2 infertile men with obstructive azoospermia or severe asthenospermia and selected viable spermatozoa using a single laser shot at the sperm tail. Those that responded to the laser shot by a curling reaction of the tail were regarded as presumably viable and used for intracytoplasmic sperm injection (ICSI).

RESULTSThe mean fertilization rate was 88.89% after ICSI with the laser-selected viable spermatozoa. Both of the embryo transfers resulted in a single pregnancy.

CONCLUSIONNoncontact diode laser is a useful alternative for the assessment of sperm viability, which may help to achieve successful pregnancy.

Embryo Transfer ; Female ; Fertilization ; Humans ; Infertility, Male ; therapy ; Male ; Pregnancy ; Pregnancy Outcome ; Sperm Injections, Intracytoplasmic ; Sperm Motility ; Sperm Tail ; physiology

The ultrastructural abnormalities of human sperm flagella can cause sperm movement disorders. Dysplasia of the fibrous sheath (DFS) is an autosomal recessive genetic disease. The affected sperm in 95-100% of the patients display short, thick and irregular tails. Transmission electron microscopy can be used to confirm the diagnosis, which reveals gross abnormal flagella, with hypertrophy and hyperplasia of the fibrous sheath, without orderly disposition in longitudinal columns and transversal ribs. The axoneme shows variable distortion or almost complete obliteration. Microtubular doublets may exhibit partial or total lack of dynein arms. The genetic etiology of DFS is not yet clear. DFS does not affect the rates of fertilization and clinical pregnancy in ICSI, but due attention should be paid to the genetic risks in the offspring of the patient.
Humans ; Hyperplasia ; complications ; pathology ; Hypertrophy ; complications ; pathology ; Infertility, Male ; Male ; Microscopy, Electron ; Sperm Motility ; physiology ; Sperm Tail ; pathology ; ultrastructure ; Spermatozoa

In human reproduction, fertilization is the first step for successful pregnancy. From the perspective of sperm physiology, the progressive motility and capacitation, including hyperactivation and acrosome reaction, are the most important factors in the fertilization of oocytes. Numerous studies have demonstrated the roles of calcium ions, cyclic nucleotides, and bicarbonate in the acquisition of progressive motility and capacitation. Among these factors, calcium ion plays the most important role. Sperm possess several calcium channels, including voltage-gated calcium channel, cyclic nucleotide-gated calcium channel, transient receptor potential channel, and channels of the CatSper family The CatSper family is a newly-identified group of four sperm-specific cation channels. CatSper1 and CatSper2 proteins localize on the sperm tail and play a critical role in sperm motility and fertilization. In contrast, CatSper3 and CatSper4 proteinsare expressed only in the acrosomal region of sperm head, which implies that they may have a role in the acrosome reaction. Taken together, the CatSper family is the most important group of calcium channels for regulating sperm physiology and appear to be an attractive target for non-hormonal male contraceptives.
Acrosome Reaction ; Calcium ; Calcium Channels ; Contraceptive Agents, Male ; Fertilization ; Humans ; Ions ; Nucleotides, Cyclic ; Oocytes ; Physiology ; Pregnancy ; Reproduction ; Sperm Head ; Sperm Motility ; Sperm Tail ; Spermatozoa

Multiple morphological abnormalities of the sperm flagella (MMAF) is a specific type of asthenoteratozoospermia, presenting with multiple morphological anomalies in spermatozoa, such as absent, bent, coiled, short, or irregular caliber flagella. Previous genetic studies revealed pathogenic mutations in genes encoding cilia and flagella-associated proteins (CFAPs; e.g., CFAP43, CFAP44, CFAP65, CFAP69, CFAP70, and CFAP251) responsible for the MMAF phenotype in infertile men from different ethnic groups. However, none of them have been identified in infertile Pakistani males with MMAF. In the current study, two Pakistani families with MMAF patients were recruited. Whole-exome sequencing (WES) of patients and their parents was performed. WES analysis reflected novel biallelic loss-of-function mutations in CFAP43 in both families (Family 1: ENST00000357060.3, p.Arg300Lysfs*22 and p.Thr526Serfs*43 in a compound heterozygous state; Family 2: ENST00000357060.3, p.Thr526Serfs*43 in a homozygous state). Sanger sequencing further confirmed that these mutations were segregated recessively in the families with the MMAF phenotype. Semiquantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) was carried out to detect the effect of the mutation on mRNA of the affected gene. Previous research demonstrated that biallelic loss-of-function mutations in CFAP43 accounted for the majority of all CFAP43-mutant MMAF patients. To the best of our knowledge, this is the first study to report CFAP43 biallelic loss-of-function mutations in a Pakistani population with the MMAF phenotype. This study will help researchers and clinicians to understand the genetic etiology of MMAF better.
Adolescent ; Adult ; Humans ; Infertility, Male/epidemiology* ; Loss of Function Mutation/genetics* ; Male ; Microtubule Proteins/genetics* ; Middle Aged ; Pakistan/epidemiology* ; Sperm Tail/physiology*

Amputation of a segment of the tail produced long-lasting changes in nociception and morphine-induced antinociception. Plastic changes in nociceptive transmission may occur at the spinal cord as well as supraspinal structures after tail amputation. Acute hyperalgesia is detected at the remaining part of the tail as well as hindpaw. Morphine induced facilitation of the hot-plate (HP) response at a low dose and a greater dose of morphine is required to produce complete inhibition of the HP response. Since these effects happen at five weeks after the surgery, tail amputation may serve as a mouse model for studying long-term plastic changes in central nervous system after amputation.
Amputation ; adverse effects ; Animals ; Hyperalgesia ; drug therapy ; etiology ; physiopathology ; Male ; Mice ; Mice, Inbred C57BL ; Morphine ; pharmacology ; Narcotic Antagonists ; pharmacology ; Neurons ; drug effects ; metabolism ; physiology ; Nociceptors ; physiology ; Pain Threshold ; drug effects ; physiology ; Tail

AIMTo characterize mouse capping protein alpha3 (CPalpha3) during spermatogenesis and sperm maturation.

METHODSWe produced rat anti-CPalpha3 antiserum and examined the expression of CPalpha3 in various mouse tissues using Western blot analysis and the localization of CPalpha3 in testicular and epididymal sperm using immunohistochemical analyses. We also examined how the localization of CPalpha3 and beta-actin (ACTB) in sperm changed after the acrosomal reaction by performing immunohistochemical analyses using anti-CPalpha3 antiserum and anti-actin antibody.

RESULTSWestern blot analysis using specific antiserum revealed that CPalpha3 was expressed specifically in testes. Interestingly, the molecular weight of CPalpha3 changed during sperm maturation in the epididymis. Furthermore, the subcellular localization of CPalpha3 in sperm changed dynamically from the flagellum to the post-acrosomal region of the head during epididymal maturation. The distribution of ACTB was in the post-acrosomal region of the head and the flagellum. After inducing the acrosomal reaction, the CPalpha3 and ACTB localization was virtually identical to the localization before the acrosomal reaction.

CONCLUSIONCPalpha3 might play an important role in sperm morphogenesis and/or sperm function.

Acrosome Reaction ; physiology ; Actins ; metabolism ; Animals ; Blotting, Western ; CapZ Actin Capping Protein ; metabolism ; Cells, Cultured ; Epididymis ; cytology ; metabolism ; Male ; Mice ; Mice, Inbred C57BL ; Sperm Head ; metabolism ; Sperm Tail ; metabolism ; Spermatogenesis ; physiology ; Spermatozoa ; cytology ; metabolism ; Testis ; cytology ; metabolism

The present study aimed at evaluation of prophylactic efficacy and possible mechanisms of asiaticoside (AS) based standardized extract of Centella asiatica (L.) Urban leaves (INDCA) in animal models of migraine. The effects of oral and intranasal (i.n.) pretreatment of INDCA (acute and 7-days subacute) were evaluated against nitroglycerine (NTG, 10 mg·kg(-1), i.p.) and bradykinin (BK, 10 μg, intra-arterial) induced hyperalgesia in rats. Tail flick latencies (from 0 to 240 min) post-NTG treatment and the number of vocalizations post-BK treatment were recorded as a measure of hyperalgesia. Separate groups of rats for negative (Normal) and positive (sumatriptan, 42 mg·kg(-1), s.c.) controls were included. The interaction of INDCA with selective 5-HT1A, 5-HT1B, and 5-HT1D receptor antagonists (NAN-190, Isamoltane hemifumarate, and BRL-15572 respectively) against NTG-induced hyperalgesia was also evaluated. Acute and sub-acute pre-treatment of INDCA [10 and 30 mg·kg(-1) (oral) and 100 μg/rat (i.n.) showed significant anti-nociception activity, and reversal of the NTG-induced hyperalgesia and brain 5-HT concentration decline. Oral pre-treatment with INDCA (30 mg·kg(-1), 7 d) showed significant reduction in the number of vocalization. The anti-nociceptive effects of INDCA were blocked by 5-HT1A and 5-HT1B but not 5-HT1D receptor antagonists. In conclusion, INDCA demonstrated promising anti-nociceptive effects in animal models of migraine, probably through 5-HT1A/1B medicated action.
Administration, Intranasal ; Administration, Oral ; Animals ; Bradykinin ; Female ; Hyperalgesia ; chemically induced ; prevention & control ; Male ; Migraine Disorders ; chemically induced ; prevention & control ; Models, Animal ; Nitroglycerin ; Nociception ; drug effects ; Plant Leaves ; chemistry ; Pre-Exposure Prophylaxis ; Rats ; Rats, Wistar ; Reaction Time ; Receptors, Serotonin, 5-HT1 ; drug effects ; Serotonin 5-HT1 Receptor Antagonists ; metabolism ; Tail ; physiology ; Triterpenes ; administration & dosage ; pharmacology