Chromosome counts Dotaz Zobrazit nápovědu
Východisko. Mikrodelécie dlhého ramienka chromozómu Y patria k významným príčinám neobštrukčnej azoospermie a oligospermie. Cieľom tejto práce bolo zaviesť spoľahlivú molekulárne-genetickú metódu diagnostiky mikrodelécií chromozómu Y a zistiť zastúpenie jednotlivých typov mikrodelécií chromozómu Y u českých mužov so závažnými poruchami reprodukcie. Metódy a výsledky. Mikrodelécie chromozómu Y boli vyšetrované u 198 českých mužov s ťažkou poruchou reprodukcie so zníženým počtom spermií. Mikrodelécie chromozómu Y boli nájdené u 8/198 (4,0 %) vyšetrených mužov. Delécia v AZFc oblasti bola zistená v 62,5 % (5/8), kombinácia AZFc a AZFb delécie v 37,5 % (3/8) prípadov. Izolovaná delécia AZFb a ani delécia AZFa nebola nájdená. Závery. Určili sme zastúpenie jednotlivých typov mikrodelécií Y chromozómu u českých mužov s ťažkými poruchami reprodukcie. Bola zavedená štandardná molekulárne genetická diagnostika mikrodelécií chromozómu Y do rutinnej praxe.
Background. The Y chromosome microdeletions belong to the frequent genetical causes of male infertility. The aim of our studywas to introduce reliablemolecular genetic diagnosis of Ychromosomal microdeletions and to determine the prevalence of Y chromosomal microdeletions in Czech males with serious reproductive disorders. Methods and Results. The Ychromosomemicrodeletions were screened in 198Czech menwith serious reproductive disorders with decreased sperm count. The Y chromosome microdeletions were disclosed in 8/198 (4.0 %) examined males. The AZFc deletion type was revealed in 62,5 % (5/8) and the combined AZFc+b microdeletion in 37,5 % (3/8) of cases. Neither isolated AZFb nor AZFa microdeletion were found in any subject of the investigated group. Conclusions. Incidence of individual types of Y chromosomal microdeletions in Czech males with serious reproductive disorders was assessed. The standardisedmolecular genetic diagnosis ofYchromosomalmicrodeletions was introduced into the practice.
- MeSH
- asistovaná reprodukce MeSH
- chromozom Y genetika MeSH
- chromozomální delece MeSH
- dospělí MeSH
- finanční podpora výzkumu jako téma MeSH
- genetické markery MeSH
- lidé MeSH
- mužská infertilita diagnóza etiologie MeSH
- polymerázová řetězová reakce MeSH
- spermatogeneze MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- přehledy MeSH
- srovnávací studie MeSH
The species-rich and widespread genus Taraxacum F. H. Wiggers, 1780 (Asteraceae subfamily Cichorioideae) is one of the most taxonomically complex plant genera in the world, mainly due to its combination of different sexual and asexual reproduction strategies. Polyploidy is usually confined to apomictic microspecies, varying from 3x to 6x (rarely 10x). In this study, we focused on Taraxacum sect. Taraxacum (= T.sect.Ruderalia; T.officinale group), i.e., the largest group within the genus. We counted chromosome numbers and measured the DNA content for species sampled in Central Europe, mainly in Czechia. The chromosome number of the 28 species (T.aberrans Hagendijk, Soest & Zevenbergen, 1974, T.atroviride Štěpánek & Trávníček, 2008, T.atrox Kirschner & Štěpánek, 1997, T.baeckiiforme Sahlin, 1971, T.chrysophaenum Railonsala, 1957, T.coartatum G.E. Haglund, 1942, T.corynodes G.E. Haglund, 1943, T.crassum H. Øllgaard & Trávníček, 2003, T.deltoidifrons H. Øllgaard, 2003, T.diastematicum Marklund, 1940, T.gesticulans H. Øllgaard, 1978, T.glossodon Sonck & H. Øllgaard, 1999, T.guttigestans H. Øllgaard in Kirschner & Štěpánek, 1992, T.huelphersianum G.E. Haglund, 1935, T.ingens Palmgren, 1910, T.jugiferum H. Øllgaard, 2003, T.laticordatum Marklund, 1938, T.lojoense H. Lindberg, 1944 (= T.debrayi Hagendijk, Soest & Zevenbergen, 1972, T.lippertianum Sahlin, 1979), T.lucidifrons Trávníček, ineditus, T.obtusifrons Marklund, 1938, T.ochrochlorum G.E. Haglund, 1942, T.ohlsenii G.E. Haglund, 1936, T.perdubium Trávníček, ineditus, T.praestabile Railonsala, 1962, T.sepulcrilobum Trávníček, ineditus, T.sertatum Kirschner, H. Øllgaard & Štěpánek, 1997, T.subhuelphersianum M.P. Christiansen, 1971, T.valens Marklund, 1938) is 2n = 3x = 24. The DNA content ranged from 2C = 2.60 pg (T.atrox) to 2C = 2.86 pg (T.perdubium), with an average value of 2C = 2.72 pg. Chromosome numbers are reported for the first time for 26 species (all but T.diastematicum and T.obtusifrons), and genome size estimates for 26 species are now published for the first time.
- Publikační typ
- časopisecké články MeSH
Sperm chromatin compaction in the sperm head is achieved when histones are replaced by protamines during spermatogenesis. Haploinsufficiency of the protamine 1 (PRM1) or PRM2 gene causes infertility in mice. However, the published data remain inconclusive about a role of PRM1/2 variants in male infertility and their association with semen parameters. By full sequence analysis, we assessed the frequency of sequence variations in PRM1 and PRM2 in three groups of Caucasian patients with idiopathic teratozoospermia and normal (n = 88) or reduced sperm concentration (n = 83) and in men with a high percentage of normal sperm morphology and normal concentrations (n = 77). Two rare (c.54G>A and c.102G>T) and one common SNP (c.230A>C) were identified in PRM1. In PRM2, some rare heterozygous mutations and the two common intronic SNPs 298G>C and 373C>A were detected. None of the PRM1/2 variants was associated with teratozoospermia or individually with other semen parameters. However, significant linkage disequilibrium was detected between the common SNPs of PRM1 and PRM2 which formed haplotypes. Analysis of the pooled group (n = 248) revealed that homozygous carriers of the common haplotype ACC had a twofold higher sperm concentration and count than men lacking this haplotype, with sperm counts of heterozygotes for ACC being midway between the homozygotes. This markedly decreased sperm output might either be caused by spermatozoa lacking the ACC haplotype not being viable, or subject to negative selection. In addition, a significant deviation from Hardy-Weinberg-Equilibrium of these SNPs might indicate natural selection in favour of the ACC allele which leads to higher sperm output and therefore better fertility. In conclusion, for the first time we describe an association of a common haplotype formed by PRM1 and PRM2 with sperm output in a large group of men.
- MeSH
- chromatin metabolismus MeSH
- dospělí MeSH
- fertilita genetika MeSH
- geny MeSH
- haplotypy MeSH
- heterozygot MeSH
- histony genetika MeSH
- jednonukleotidový polymorfismus genetika MeSH
- lidé středního věku MeSH
- lidé MeSH
- mutace MeSH
- mužská infertilita genetika MeSH
- protaminy * genetika MeSH
- spermatogeneze genetika MeSH
- spermie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- práce podpořená grantem MeSH
Counting chromosomes is the first step towards a better understanding of the karyotype evolution and the role of chromosome evolution in species diversification within Carex; however, the chromosome count is not known yet for numerous sedges. In this paper chromosome counts were performed for 23 Carex taxa from Armenia, Austria, the Czech Republic, and Poland. Chromosome numbers were determined for the first time in three species (Carex cilicica, 2n = 54; C. phyllostachys, 2n = 56; C. randalpina, 2n = 78), two subspecies (C. muricata subsp. ashokae, 2n = 58; C. nigra subsp. transcaucasica, 2n = 84) and two hybrids (C. ×decolorans, 2n = 74; C. ×walasii, 2n = 108). Among the taxa whose number of chromosomes had been known before, the largest difference was found in C. hartmaniorum (here 2n = 52) and C. aterrima subsp. medwedewii (here 2n = 52). A difference in the chromosome count was demonstrated for C. cilicica (2n = 54) versus the species of the section Aulocystis (2n = 30 to 40) and for C. tomentosa (2n = 48) versus the species of the section Acrocystis (2n = 18 to 38). The results of this study indicate that the position of C. cilicica in Aulocystis section may raise doubts. Attention was paid to the relationship between C. phyllostachys and taxa of the subgenus Carex section Gynobasidae.
- MeSH
- Carex (rostlina) klasifikace genetika MeSH
- chromozomy rostlin genetika MeSH
- fylogeneze * MeSH
- genetická variace * MeSH
- molekulární evoluce * MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Arménie MeSH
- Česká republika MeSH
- Polsko MeSH
- Rakousko MeSH
OBJECTIVES: In about 50% of male infertility the underlying pathogenesis remains unknown. A recent Japanese study provided evidence that the rs6836703: G>A single-nucleotide polymorphism (SNP) from the ADP-ribosyltransferase 3 (ART3) gene is significantly associated with non-obstructive azoospermia. However, the functional significance of this association is unknown and replication studies in unrelated populations are thus necessary. DESIGN: In this study, 257 fertile Czech controls of proven paternity and 98 sub-/infertile patients selected according to stringent exclusion / inclusion criteria were genotyped by High Resolution Melting (HRM) of small amplicons. SETTING: This study was performed at University Hospital Motol - Laboratory of reproductive genetics using routinely analyzed cases. RESULTS: Significant differences in allele distribution between fertile and sub-/infertile men were found (OR=1.78, 95% CI: 1.17-2.70; p=0.007). Following sub-stratification of cases according to their sperm counts we found that observed differences in allele distributions were increased in oligozoospermic men with sperm counts of <15 million sperm/mL (OR=1.98, 95% CI: 1.28-3.07; p=0.002). This difference was also reflected in genotype distributions between fertile and sub-/infertile men (p=0.008), and fertile versus oligozoospermic men (p=0.004). CONCLUSIONS: Our study serves as a first replication of the original Japanese report and opens new avenues of research. Compared to the Japanese patient cohort, we provided evidence that the analyzed ART3 variant is associated with quantitative impairment of spermatogenesis.
- MeSH
- ADP-ribosatransferasy * MeSH
- genotyp MeSH
- lidé MeSH
- mužská infertilita MeSH
- počet spermií * MeSH
- spermie MeSH
- studie případů a kontrol MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
BACKGROUND: One of the five basal actinopterygian lineages, the Chondrostei, including sturgeon, shovelnose, and paddlefish (Order Acipenseriformes) show extraordinary ploidy diversity associated with three rounds of lineage-specific whole-genome duplication, resulting in three levels of ploidy in sturgeon. Recently, incidence of spontaneous polyploidization has been reported among cultured sturgeon and it could have serious negative implications for the economics of sturgeon farming. We report the occurrence of seven spontaneous heptaploid (7n) Siberian sturgeon Acipenser baerii, which is a functional tetraploid species (4n) with ~245 chromosomes. Our aims were to assess ploidy level and chromosome number of the analysed specimens and to identify the possible mechanism that underlies the occurrence of spontaneous additional chromosome sets in their genome. RESULTS: Among 150 specimens resulting from the mating of a tetraploid (4n) A. baerii (~245 chromosomes) dam with a hexaploid (6n) A. baerii (~368 chromosomes) sire, 143 displayed a relative DNA content that corresponds to pentaploidy (5n) with an absolute DNA content of 8.98 ± 0.03 pg DNA per nucleus and nuclear area of 35.3 ± 4.3 μm(2) and seven specimens exhibited a relative DNA content that corresponds to heptaploidy (7n), with an absolute DNA content of 15.02 ± 0.04 pg DNA per nucleus and nuclear area of 48.4 ± 5.1 μm(2). Chromosome analyses confirmed a modal number of ~437 chromosomes in these heptaploid (7n) individuals. DNA genotyping of eight microsatellite loci followed by parental assignment confirmed spontaneous duplication of the maternal chromosome sets via retention of the second polar body in meiosis II as the mechanism for the formation of this unusual chromosome number and ploidy level in a functional tetraploid A. baerii. CONCLUSIONS: We report the second highest chromosome count among vertebrates in cultured sturgeon (~437) after the schizothoracine cyprinid Ptychobarbus dipogon with ~446 chromosomes. The finding also represents the highest documented chromosome count in Acipenseriformes, and the first report of a functional heptaploid (7n) genome composition in sturgeon. To our knowledge, this study provides the first clear evidence of a maternal origin for spontaneous polyploidization in cultured A. baerii. To date, all available data indicate that spontaneous polyploidization occurs frequently among cultured sturgeons.
- MeSH
- buněčné jádro genetika MeSH
- chromozomy genetika MeSH
- DNA analýza MeSH
- fertilita genetika MeSH
- genom * MeSH
- genotyp MeSH
- hybridizace genetická * MeSH
- meióza genetika MeSH
- mikrosatelitní repetice genetika MeSH
- ploidie * MeSH
- ryby genetika MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Biodosimetry is focused on effects of ionizing radiation at cellular and molecular levels of living organisms so that a qualified retrospective estimate of radiation load can be made. Two biodosimetry methods were evaluated in irradiated piglets: complete blood count analysis and quantification of chromosomal aberrations in lymphocytes using a micronucleus test. Animals were whole-body irradiated with gamma radiation at doses of 0-10 Gy. The analysis of complete blood count was performed at intervals ranging from 0 to 48 hours. Micronuclei were measured at 4 hours after irradiation. Changes in lymphocyte counts and increased levels of micronuclei reflected received dose of ionizing radiation.
- MeSH
- celotělové ozáření * MeSH
- chromozomální aberace účinky záření MeSH
- cytokiny metabolismus MeSH
- ionizující záření MeSH
- krevní obraz MeSH
- lymfocyty účinky záření MeSH
- mikrojaderné testy * MeSH
- neutrofily cytologie MeSH
- počet lymfocytů MeSH
- prasata MeSH
- radiometrie metody MeSH
- retrospektivní studie MeSH
- vztah dávky záření a odpovědi MeSH
- záření gama MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
