The importance of fluorescence light microscopy for understanding cellular and sub-cellular structures and functions is undeniable. However, the resolution is limited by light diffraction (~200-250 nm laterally, ~500-700 nm axially). Meanwhile, super-resolution microscopy, such as structured illumination microscopy (SIM), is being applied more and more to overcome this restriction. Instead, super-resolution by stimulated emission depletion (STED) microscopy achieving a resolution of ~50 nm laterally and ~130 nm axially has not yet frequently been applied in plant cell research due to the required specific sample preparation and stable dye staining. Single-molecule localization microscopy (SMLM) including photoactivated localization microscopy (PALM) has not yet been widely used, although this nanoscopic technique allows even the detection of single molecules. In this study, we compared protein imaging within metaphase chromosomes of barley via conventional wide-field and confocal microscopy, and the sub-diffraction methods SIM, STED, and SMLM. The chromosomes were labeled by DAPI (4',6-diamidino-2-phenylindol), a DNA-specific dye, and with antibodies against topoisomerase IIα (Topo II), a protein important for correct chromatin condensation. Compared to the diffraction-limited methods, the combination of the three different super-resolution imaging techniques delivered tremendous additional insights into the plant chromosome architecture through the achieved increased resolution.
- MeSH
- chromozomy rostlin chemie genetika metabolismus MeSH
- DNA-topoisomerasy typu II metabolismus MeSH
- fluorescenční barviva chemie MeSH
- fluorescenční mikroskopie metody MeSH
- indoly chemie MeSH
- ječmen (rod) cytologie genetika MeSH
- konfokální mikroskopie metody MeSH
- metafáze genetika MeSH
- reprodukovatelnost výsledků MeSH
- zobrazení jednotlivé molekuly metody MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
In mammals, leptin and tumor-necrosis factor (TNF) are prominent interacting adipokines mediating appetite control and insulin sensitivity. While TNF pleiotropically functions in immune defense and cell survival, leptin is largely confined to signaling energy stores in adipocytes. Knowledge about the function of avian leptin and TNF is limited and they are absent or lowly expressed in adipose, respectively. Employing radiation-hybrid mapping and FISH-TSA, we mapped TNF and its syntenic genes to chicken chromosome 16 within the major histocompatibility complex (MHC) region. This mapping position suggests that avian TNF has a role in regulating immune response. To test its possible interaction with leptin within the immune system and beyond, we compared the transcription patterns of TNF, leptin and their cognate receptors obtained by meta-analysis of GenBank RNA-seq data. While expression of leptin and its receptor (LEPR) were detected in the brain and digestive tract, TNF and its receptor mRNAs were primarily found in viral-infected and LPS-treated leukocytes. We confirmed leptin expression in the duodenum by immunohistochemistry staining. Altogether, we suggest that whereas leptin and TNF interact as adipokines in mammals, in birds, they have distinct roles. Thus, the interaction between leptin and TNF may be unique to mammals.
- MeSH
- buněčné linie MeSH
- duodenum metabolismus MeSH
- kur domácí genetika metabolismus MeSH
- leptin genetika metabolismus MeSH
- leptinové receptory metabolismus MeSH
- mapování chromozomů * MeSH
- mapování pomocí radiačních hybridů MeSH
- messenger RNA genetika metabolismus MeSH
- metafáze genetika MeSH
- receptory TNF genetika metabolismus MeSH
- regulace genové exprese * MeSH
- savci genetika MeSH
- signální transdukce * MeSH
- syntenie genetika MeSH
- TNF-alfa genetika metabolismus MeSH
- trávení * MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The human bed bug Cimex lectularius is one of the most prevalent human ectoparasites in temperate climate zones. The cytogenetic features of this resilient pest include holokinetic chromosomes, special chromosome behavior in meiosis, and numerical variation of chromosomes, where the diploid number ranges from 26 + X1 X2 Y to 26 + X1-20 Y. It is desirable to assess the nuclear DNA content of various cytotypes for a further detailed study of the C. lectularius genome. Detailed knowledge of the DNA content of this parasite could also clarify the origin of additional chromosomes. The average nuclear genome size C. lectularius with 2n = 26 + X1 X2 Y is 2C = 1.94 pg for males and 1.95 pg for females. There is a significant correlation between genome size and the number of chromosomes, but in some specimens with additional chromosomes, nuclear genome size decreases or remains average. Several species used as the internal reference standard were tested for further investigations of genome size in C. lectularius, and the plant Solanum pseudocaspicum turned out to be the most suitable. © 2019 International Society for Advancement of Cytometry.
- MeSH
- barvení a značení MeSH
- buněčné jádro chemie genetika MeSH
- cytogenetika MeSH
- délka genomu * MeSH
- indoly MeSH
- meióza genetika MeSH
- metafáze genetika MeSH
- mitóza genetika MeSH
- pohlavní chromozomy * MeSH
- propidium MeSH
- průtoková cytometrie MeSH
- štěnice genetika MeSH
- zastoupení bazí MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
PROPOSE: The presence of metaphase II (MII) spindle together with the polar body (PB) indicates completion of oocyte maturation. This study was designed to explore if spindle imaging can be used to optimize timing of intracytoplasmic sperm injection (ICSI). METHODS: The study involved 916 oocytes from 234 conventionally stimulated ICSI cycles with an unexpectedly poor ovarian response. All PB-displaying oocytes were subjected to polarized light microscopy (PLM) prior to ICSI. When MII spindle was absent in the majority of oocytes, ICSI was postponed and performed after additional spindle imaging. Fertilization, embryo development, and clinical outcome were evaluated with respect to the observed spindle pattern. RESULTS: The visible spindle was absent in 32.64% of PB-displaying oocytes. The late-maturing oocytes extruding PB in vitro were less likely to exhibit a spindle signal than in vivo matured MII oocytes (38.86% vs. 89.84%). When fertilization was postponed, 59.39% of initially spindle-negative oocytes developed detectable MII spindle. Spindled eggs had significantly higher developmental potential, and the presence of the spindle has been identified as an independent measure for predicting the formation of the blastocyst. Embryos derived from spindle-positive oocytes also showed a higher chance to implant and develop to term. Notably, 11 children were conceived by finely timed fertilization of late-maturing oocytes which are normally discarded. CONCLUSIONS: The study confirms the prognostic value of spindle imaging and demonstrates that immature oocytes can be clinically utilized and give rise to live births when the timing of ICSI is adjusted to their developmental stage.
- MeSH
- embryonální vývoj genetika MeSH
- fertilizace in vitro * MeSH
- intracytoplazmatické injekce spermie * MeSH
- lidé MeSH
- metafáze genetika MeSH
- oocyty růst a vývoj ultrastruktura MeSH
- oogeneze genetika MeSH
- polarizační mikroskopie MeSH
- těhotenství MeSH
- Check Tag
- lidé MeSH
- těhotenství MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
Because low levels of DNA double strand breaks (DSBs) appear not to activate the ATM-mediated prophase I checkpoint in full-grown oocytes, there may exist mechanisms to protect chromosome integrity during meiotic maturation. Using live imaging we demonstrate that low levels of DSBs induced by the radiomimetic drug Neocarzinostatin (NCS) increase the incidence of chromosome fragments and lagging chromosomes but do not lead to APC/C activation and anaphase onset delay. The number of DSBs, represented by γH2AX foci, significantly decreases between prophase I and metaphase II in both control and NCS-treated oocytes. Transient treatment with NCS increases >2-fold the number of DSBs in prophase I oocytes, but less than 30% of these oocytes enter anaphase with segregation errors. MRE11, but not ATM, is essential to detect DSBs in prophase I and is involved in H2AX phosphorylation during metaphase I. Inhibiting MRE11 by mirin during meiotic maturation results in anaphase bridges and also increases the number of γH2AX foci in metaphase II. Compromised DNA integrity in mirin-treated oocytes indicates a role for MRE11 in chromosome integrity during meiotic maturation.
- MeSH
- ATM protein genetika MeSH
- DNA vazebné proteiny genetika MeSH
- dvouřetězcové zlomy DNA účinky léků MeSH
- enzymy opravy DNA genetika MeSH
- histony genetika MeSH
- meióza genetika MeSH
- metafáze genetika MeSH
- myši MeSH
- oocyty růst a vývoj metabolismus MeSH
- poškození DNA účinky léků genetika MeSH
- zinostatin aplikace a dávkování MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
In most eukaryotes, centromere is determined by the presence of the centromere-specific histone variant CenH3. Two types of chromosome morphology are generally recognized with respect to centromere organization. Monocentric chromosomes possess a single CenH3-containing domain in primary constriction, whereas holocentric chromosomes lack the primary constriction and display dispersed distribution of CenH3. Recently, metapolycentric chromosomes have been reported in Pisum sativum, representing an intermediate type of centromere organization characterized by multiple CenH3-containing domains distributed across large parts of chromosomes that still form a single constriction. In this work, we show that this type of centromere is also found in other Pisum and closely related Lathyrus species, whereas Vicia and Lens genera, which belong to the same legume tribe Fabeae, possess only monocentric chromosomes. We observed extensive variability in the size of primary constriction and the arrangement of CenH3 domains both between and within individual Pisum and Lathyrus species, with no obvious correlation to genome or chromosome size. Search for CenH3 gene sequences revealed two paralogous variants, CenH3-1 and CenH3-2, which originated from a duplication event in the common ancestor of Fabeae species. The CenH3-1 gene was subsequently lost or silenced in the lineage leading to Vicia and Lens, whereas both genes are retained in Pisum and Lathyrus. Both of these genes appear to have evolved under purifying selection and produce functional CenH3 proteins which are fully colocalized. The findings described here provide the first evidence for a highly dynamic centromere structure within a group of closely related species, challenging previous concepts of centromere evolution.
- MeSH
- centromera genetika MeSH
- chromatin metabolismus MeSH
- chromozomy rostlin genetika MeSH
- duplikace genu * MeSH
- Fabaceae cytologie genetika MeSH
- fylogeneze MeSH
- genetická variace MeSH
- metafáze genetika MeSH
- molekulární evoluce MeSH
- molekulární sekvence - údaje MeSH
- rostlinné geny * MeSH
- rostlinné proteiny chemie MeSH
- sekvence aminokyselin MeSH
- sekvence nukleotidů MeSH
- selekce (genetika) MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Gekkotan lizards are a highly specious (∼1600 described species) clade of squamate lizards with nearly cosmopolitan distribution in warmer areas. The clade is primarily nocturnal and forms an ecologically dominant part of the world nocturnal herpetofauna. However, molecular cytogenetic methods to study the evolution of karyotypes have not been widely applied in geckos. Our aim here was to uncover the extent of chromosomal rearrangements across the whole group Gekkota and to search for putative synapomorphies supporting the newly proposed phylogenetic relationships within this clade. We applied cross-species chromosome painting with the recently derived whole-chromosomal probes from the gekkonid species Gekko japonicus to members of the major gekkotan lineages. We included members of the families Diplodactylidae, Carphodactylidae, Pygopodidae, Eublepharidae, Phyllodactylidae and Gekkonidae. Our study demonstrates relatively high chromosome conservatism across the ancient group of gekkotan lizards. We documented that many changes in chromosomal shape across geckos can be attributed to intrachromosomal rearrangements. The documented rearrangements are not totally in agreement with the recently newly erected family Phyllodactylidae. The results also pointed to homoplasy, particularly in the reuse of chromosome breakpoints, in the evolution of gecko karyotypes.
- MeSH
- chromozomy * MeSH
- fylogeneze MeSH
- hybridizace in situ fluorescenční MeSH
- ještěři klasifikace genetika MeSH
- karyotyp MeSH
- malování chromozomů MeSH
- metafáze genetika MeSH
- molekulární evoluce MeSH
- rekombinace genetická * MeSH
- translokace genetická * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The captive bred animal populations showing centric fusion polymorphism can serve as a model for analysis of the impact of the rearrangement on meiosis and reproduction. The synapsis of homologous chromosomes and the frequency and distribution of meiotic recombination events were studied in pachytene spermatocytes of captive bred male impalas (Aepyceros melampus) polymorphic for der(14;20) by immunofluorescent analysis and fluorescence in situ hybridization. The chromosomes 14 and 20 involved in the centric fusion were significantly shorter due to the loss of sat I repeats indicating ancient origin of the rearrangement. The fused chromosome and the normal acrocentric chromosomes 14 and 20 formed trivalent in pachynema which showed either protruding proximal ends of the acrocentric chromosomes or single axis with synaptic adjustment in the pericentromeric region. There was no significant difference in the number of recombination events per cell between the group of translocation heterozygotes and the animals with normal karyotype. A significant reduction in the number of recombination events was observed in the trivalent chromosomes compared to the normal chromosomes 14 and 20. The level of the recombination reduction was related to the trivalent configuration. The centric fusion der(14;20) was not apparently demonstrated by any spermatogenic defects or reproductive impairment in heterozygous impalas. However, the high incidence of the chromosomal polymorphism within the captive bred population shows the importance of cytogenetic examinations in captive breeding and wildlife conservation programs, especially in the case of reintroduction of the endangered species.
- MeSH
- hybridizace in situ fluorescenční MeSH
- jaderné proteiny genetika MeSH
- lymfocyty metabolismus MeSH
- meióza genetika MeSH
- metafáze genetika MeSH
- modely u zvířat MeSH
- pachytenní stadium MeSH
- přežvýkavci genetika MeSH
- rekombinace genetická genetika MeSH
- rozmnožování genetika MeSH
- savčí chromozomy genetika MeSH
- spermatocyty cytologie metabolismus MeSH
- synaptonemální komplex genetika MeSH
- translokace genetická * MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Sex chromosomes are an ideal system to study processes connected with suppressed recombination. We found evidence of microsatellite expansion, on the relatively young Y chromosome of the dioecious plant sorrel (Rumex acetosa, XY1Y2 system), but no such expansion on the more ancient Y chromosomes of liverwort (Marchantia polymorpha) and human. The most expanding motifs were AC and AAC, which also showed periodicity of array length, indicating the importance of beginnings and ends of arrays. Our data indicate that abundance of microsatellites in genomes depends on the inherent expansion potential of specific motifs, which could be related to their stability and ability to adopt unusual DNA conformations. We also found that the abundance of microsatellites is higher in the neighborhood of transposable elements (TEs) suggesting that microsatellites are probably targets for TE insertions. This evidence suggests that microsatellite expansion is an early event shaping the Y chromosome where this process is not opposed by recombination, while accumulation of TEs and chromosome shrinkage predominate later.
- MeSH
- A-DNA genetika MeSH
- chromozomy rostlin genetika MeSH
- duplikace genu MeSH
- hybridizace in situ fluorescenční MeSH
- lidé MeSH
- lidský chromozom Y genetika MeSH
- Marchantia genetika MeSH
- metafáze genetika MeSH
- mikrosatelitní repetice genetika MeSH
- modely genetické MeSH
- molekulární evoluce * MeSH
- periodicita MeSH
- Rumex genetika MeSH
- sekvence nukleotidů MeSH
- sekvenční analýza DNA MeSH
- transpozibilní elementy DNA genetika MeSH
- Z-DNA genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Genome analysis in many plant species is hampered by large genome size and by sequence redundancy due to the presence of repetitive DNA and polyploidy. One solution is to reduce the sample complexity by dissecting the genomes to single chromosomes. This can be realized by flow cytometric sorting, which enables purification of chromosomes in large numbers. Coupling the chromosome sorting technology with next generation sequencing provides a targeted and cost effective way to tackle complex genomes. The methods outlined in this article describe a procedure for preparation of chromosomal DNA suitable for next-generation sequencing.
- MeSH
- chromozomy rostlin ultrastruktura MeSH
- délka genomu MeSH
- fluorescenční mikroskopie MeSH
- genom rostlinný * MeSH
- hybridizace in situ fluorescenční MeSH
- ječmen (rod) cytologie genetika MeSH
- klíčení genetika MeSH
- metafáze genetika MeSH
- polyploidie MeSH
- průtoková cytometrie metody MeSH
- pšenice cytologie genetika MeSH
- sekvenční analýza DNA MeSH
- semena rostlinná genetika MeSH
- umělé bakteriální chromozomy MeSH
- vysoce účinné nukleotidové sekvenování MeSH
- žito cytologie genetika MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH