Male germ cells experience a drastic chromatin remodeling through the nucleo-histone to nucleo-protamine (NH-NP) transition necessary for proper sperm functionality. Post-translational modifications (PTMs) of H4 Lys5, such as acetylation (H4K5ac), play a crucial role in epigenetic control of nucleosome disassembly facilitating protamine incorporation into paternal DNA. It has been shown that butyrylation on the same residue (H4K5bu) participates in temporal regulation of NH-NP transition in mice, delaying the bromodomain testis specific protein (BRDT)-dependent nucleosome disassembly and potentially marking retained nucleosomes. However, no information was available so far on this modification in human sperm. Here, we report a dual behavior of H4K5bu and H4K5ac in human normal spermatogenesis, suggesting a specific role of H4K5bu during spermatid elongation, coexisting with H4K5ac although with different starting points. This pattern is stable under different testicular pathologies, suggesting a highly conserved function of these modifications. Despite a drastic decrease of both PTMs in condensed spermatids, they are retained in ejaculated sperm, with 30% of non-colocalizing nucleosome clusters, which could reflect differential paternal genome retention. Whereas no apparent effect of these PTMs was observed associated with sperm quality, their presence in mature sperm could entail a potential role in the zygote.
- MeSH
- acetylace MeSH
- chromatin * metabolismus MeSH
- histony metabolismus MeSH
- lidé MeSH
- myši MeSH
- nukleozomy * metabolismus MeSH
- posttranslační úpravy proteinů MeSH
- protaminy metabolismus MeSH
- restrukturace chromatinu MeSH
- sperma metabolismus MeSH
- spermatidy metabolismus MeSH
- spermatogeneze fyziologie MeSH
- spermie metabolismus MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Testis development and ultrastructure of spermatogenic cells and spermatozoa of burbot Lota lota, a commercially important cold freshwater fish, were studied by light and transmission electron microscopy. Spermatogonia, spermatocytes, spermatids, and spermatozoa are distributed along the seminiferous tubules. Electron-dense bodies appear in germ cells from primary spermatogonia to secondary spermatocytes. We identified three distinct stages of spermatid cell differentiation based on chromatin condensation, development of the flagellum, formation of a nuclear fossa, and elimination of excess cytoplasm. Spermatozoa were anacrosomal and characterized by location of the centrioles outside the nuclear fossa and incomplete perpendicular arrangement of the centrioles. The sperm flagellum displayed an axoneme with nine doublets of peripheral microtubules and two central microtubules. These results provide valuable information for burbot taxonomy and may clarify the process of spermatogenesis for this species.
- MeSH
- kultivované buňky MeSH
- ryby metabolismus MeSH
- Sertoliho buňky ultrastruktura MeSH
- spermatidy ultrastruktura MeSH
- spermatogeneze * MeSH
- spermatogonie ultrastruktura MeSH
- spermie ultrastruktura MeSH
- testis cytologie ultrastruktura MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Spermiogenesis in progenetic and adult stages of Archigetes sieboldi Leuckart, 1878, a tapeworm parasitic in oligochaetes and fish respectively, has been examined using transmission electron microscopy and cytochemical staining for glycogen. General pattern of spermiogenesis is essentially like that of other caryophyllideans, i.e., apical dense material in the zone of differentiation in the early stages of spermiogenesis, rotation of free flagellum and a flagellar bud, and proximo-distal fusion. Interestingly, rotation of a free flagellum and flagellar bud to the median cytoplasmic process (MCP) has been observed unconventionally at > 90° only in progenetic stages. Typical striated roots associated with the centrioles occur rarely in A. sieboldi, and only in form of faint structures in advanced stages of spermiogenesis. In contrast to most caryophyllideans studied to date, penetration of the nucleus into the spermatid body has started before the fusion of the free flagellum with the MCP. This feature has been reported rarely but exclusively in the family Caryophyllaeidae. The unipartite mature spermatozoon of A. sieboldi is composed of one axoneme of the 9 + '1' trepaxonematan pattern with its centriole, parallel nucleus, and parallel cortical microtubules which are situated in a moderately electron-dense cytoplasm with glycogen particles. An unusual arrangement of cortical microtubules in the two parallel rows in region I of the spermatozoon is described here for the first time in the Caryophyllidea. Ultrastructural data on spermiogenesis and the spermatozoon in A. sieboldi from tubuficids and carp are compared and discussed with those in other caryophyllideans and/or Neodermata.
- MeSH
- axonema ultrastruktura MeSH
- barvení a značení MeSH
- buněčné jádro fyziologie MeSH
- Cestoda ultrastruktura MeSH
- cestodózy veterinární MeSH
- flagella fyziologie MeSH
- glykogen analýza MeSH
- kapři parazitologie MeSH
- nemoci ryb parazitologie MeSH
- spermatidy cytologie ultrastruktura MeSH
- spermatogeneze fyziologie MeSH
- transmisní elektronová mikroskopie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Calcium plays a variety of vital regulatory functions in many physiological and biochemical events in the cell. The aim of this study was to describe the ultrastructural distribution of calcium during different developmental stages of spermatogenesis in a model organism, the zebrafish (Danio rerio), using a combined oxalate-pyroantimonate technique. Samples were treated by potassium oxalate and potassium pyroantimonate during two fixation stages and examined using transmission electron microscopy to detect electron dense intracellular calcium. The subcellular distribution of intracellular calcium was characterized in spermatogonium, spermatocyte, spermatid, and spermatozoon stages. The area which is covered by intracellular calcium in different stages was quantified and compared using software. Isolated calcium deposits were mainly detectable in the cytoplasm and the nucleus of the spermatogonium and spermatocyte. In the spermatid, calcium was partially localized in the cytoplasm as isolated deposits. However, most calcium was transformed from isolated deposits into an unbound pool (free calcium) within the nucleus of the spermatid and the spermatozoon. Interestingly, in the spermatozoon, calcium was mainly localized in a form of an unbound pool which was detectable as an electron-dense mass within the nucleus. Also, sporadic calcium deposits were scattered in the midpiece and flagellum. The proportional area which was covered by intracellular calcium increased significantly from early to late stages of spermatogenesis. The extent of the area which was covered by intracellular calcium in the spermatozoon was the highest compared to earlier stages. Calcium deposits were also observed in the somatic cells (Sertoli, myoid, Leydig) of zebrafish testis. The notable changes in the distribution of intracellular calcium of germ cells during different developmental stages of zebrafish spermatogenesis suggest its different homeostasis and physiological functions during the process of male gamete development.
- MeSH
- buněčné jádro ultrastruktura MeSH
- dánio pruhované metabolismus MeSH
- spermatidy cytologie ultrastruktura MeSH
- spermatogeneze * MeSH
- subcelulární frakce metabolismus ultrastruktura MeSH
- testis cytologie ultrastruktura MeSH
- vápník metabolismus MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Calcium regulates many intracellular events such as growth and differentiation during different stages of gamete development. The aim of this study was to localize and quantify the intracellular distribution of calcium during different developmental stages of spermatogenesis in sterlet, Acipenser ruthenus, using a combined oxalate-pyroantimonate technique. The distribution of calcium was described in spermatogonium, spermatocyte, spermatid, and spermatozoon stages. In the spermatogonium and spermatocyte, calcium deposits were mainly localized in the nucleus and cytoplasm. The spermatid had calcium in the nucleus, developing acrosomal vesicle, and cytoplasm. Intracellular calcium transformed from scattered deposits in spermatogonia and spermatocyte stages into an unbound form in spermatid and the spermatozoon. The proportion of area covered by calcium increased significantly (p<0.05) from early to late stages of spermatogenesis. The largest proportion of area covered by calcium was observed in the nucleus of the spermatozoon. In conclusion, although most of the intracellular calcium is deposited in limited areas of the spermatogonium and spermatocyte, it is present an unbound form in the larger area of spermatids and spermatozoa which probably reflects changes in its physiological function and homeostasis during the process of male gamete production in spermatogenesis.
- MeSH
- ryby anatomie a histologie metabolismus fyziologie MeSH
- spermatidy ultrastruktura MeSH
- spermatogeneze fyziologie MeSH
- spermatogonie ultrastruktura MeSH
- spermie ultrastruktura MeSH
- vápník metabolismus MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The hypodactylous (hd) locus impairs limb development and spermatogenesis, leading to male infertility in rats. We show that the hd mutation is caused by an insertion of an endogenous retrovirus into intron 10 of the Cntrob gene. The retroviral insertion in hd mutant rats disrupts the normal splicing of Cntrob transcripts and results in the expression of a truncated protein. During the final phase of spermiogenesis, centrobin localizes to the manchette, centrosome, and the marginal ring of the spermatid acroplaxome, where it interacts with keratin 5-containing intermediate filaments. Mutant spermatids show a defective acroplaxome marginal ring and separation of the centrosome from its normal attachment site of the nucleus. This separation correlates with a disruption of head-tail coupling apparatus, leading to spermatid decapitation during the final step of spermiogenesis and the absence of sperm in the epididymis. Cntrob may represent a novel candidate gene for presently unexplained hereditary forms of teratozoospermia and the "easily decapitated sperm syndrome" in humans.
- MeSH
- bičík spermie metabolismus MeSH
- blotting far-western MeSH
- centrozom metabolismus MeSH
- elektronová mikroskopie MeSH
- endogenní retroviry genetika MeSH
- epididymis metabolismus MeSH
- fluorescenční protilátková technika MeSH
- hlavička spermie metabolismus MeSH
- homeoboxové geny genetika MeSH
- homeodoménové proteiny metabolismus MeSH
- introny genetika MeSH
- keratin-5 genetika metabolismus MeSH
- krysa rodu rattus MeSH
- mutace genetika MeSH
- mužská infertilita genetika metabolismus MeSH
- polymerázová řetězová reakce s reverzní transkripcí MeSH
- proteiny buněčného cyklu fyziologie MeSH
- spermatidy metabolismus MeSH
- spermatogeneze genetika MeSH
- transport proteinů genetika MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- práce podpořená grantem MeSH
- MeSH
- dospělí MeSH
- fertilizace in vitro metody MeSH
- kolagenasy MeSH
- kryoprezervace metody MeSH
- kultivované buňky metody MeSH
- lidé MeSH
- odběr biologického vzorku metody MeSH
- spermatidy MeSH
- spermie MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- přehledy MeSH
Cíl studie: Transfer kvalitního embrya v programu asistované reprodukce v případě azoospermies dg. Sertolli cells only syndrome (SCO sy) + maturation arrest (MA), kde v testes byl zaznamenánvýskyt převážně Sertoliho buněk s nepatrným množstvím zárodečných buněk, které prokazovalyzástavu zrání (MA) ve stadiu kulatých spermatid. Histologickým hodnocením byla stanovenahypospermatogeneze gr. 3 (minimum jedna spermatida/vzorek).Typ studie: Kazuistika.Název a sídlo pracoviště: Laboratoř IVF, Iscare IVF, a. s., Oddělení biologie a biochemické fertilizace,Ústav molekulární genetiky AV ČR, Praha.Předmět a metodika studie: K úspěšnému řešení uvedeného typu azoospermie je možné použítimunologické, histologické a kultivační metody. Monoklonální protilátky proti akrosomálnímproteinům lidských spermií umožní pomocí immunofl uorescenčního testu zviditelnit prekurzoryspermií v ejakulátu a odhad spermatogeneze je upřesněn histologickou metodou. Po stanovenístupně spermatogeneze je použita kultivace buněčné suspenze in vitro, která umožní získat spermieči jejich prekurzory použitelné v metodě ISCI.Závěr: Využití uvedených metod a jejich vhodná kombinace zvýšila pravděpodobnost zisku kvalitníhoembrya v programu asistované reprodukce.
Objective: The transfer of good quality embryo in the program of assisted reproduction in thecase of azoospermia, dg. Sertolli cells only syndrome (SCO sy) + maturation arrest (MA). Testeswere assessed and found to have a high occurrence of Sertolli cells and very low occurrence ofgerminal cells, which were arrested at the round spermatid level. The histological evaluation washypospermatogenesis gr. 3 (minimum 1 spermatid/sample).Design: Case report.Setting: Laboratory IVF, Iscare, a. s., Department of Biology and Biochemistry of Fertilization,Institute of Molecular Genetics, Czech Academy of Sciences, Prague.Subject and Method: The successful integration of three methods provides a solution for this caseof azoospermia. Immunology and histology can more exactly diagnose the degree of azoospermia.Detection and visualisation of spermatids using monoclonal antibodies against sperm proteinspredicts the eventual occurrence of spermatogenesis, and histological evaluation confi rms theseimmunological fi ndings. Using the information of both methods it is possible to use special invitro cultivation of testicular cells and so obtain injectable spermatozoa, or precursors of sperm,for the ICSI method.Conclusion: The probability of acquisition of goood-quality embryo in the program of assistedreproduction is higher when these three methods are applied in combination.
- MeSH
- asistovaná reprodukce metody MeSH
- finanční podpora výzkumu jako téma MeSH
- lidé MeSH
- mužská infertilita diagnóza etiologie terapie MeSH
- Sertoliho buňky MeSH
- spermatidy MeSH
- spermatogeneze MeSH
- testis anatomie a histologie patologie MeSH
- zrání spermie MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- přehledy MeSH
- srovnávací studie MeSH
