SCP3 is a meiosis-specific structural protein appearing at axial elements and lateral of the synaptonemal complex. We have analysed behaviour cohesin subunit Rad21 in mouse spermatocytes by means squashing technique. Our results demonstrate that both proteins colocalize are partially released from chromosome arms during late prophase I stages, although they persist interchromatid domain metaphase bivalents. Thus, cannot be considered `mitotic'-specific variant, but coexists with Rec8. During...

Meiosis is a complex type of cell division that involves homologous chromosome pairing, synapsis, recombination, and segregation. When any these processes altered, cellular checkpoints arrest meiosis progression induce elimination. Meiotic impairment particularly frequent in organisms bearing chromosomal translocations. translocations appear heterozygosis, the chromosomes involved may not correctly complete and/or segregation, thus promoting activation lead to death meiocytes. In mammals...

Homologous recombination (HR) is the principal mechanism of DNA repair acting during meiosis and fundamental for segregation chromosomes increase genetic diversity. Nevertheless, non-homologous end joining (NHEJ) mechanisms can also act meiosis, mainly in response to exogenously-induced damage late stages first meiotic prophase. In order better understand relationship between these two pathways, we studied male mouse after gamma radiation. We clearly discerned types responses immediately...

In most eutherian mammals, sex chromosomes synapse and recombine during male meiosis in a small region called pseudoautosomal region. However some species do not synapse, how these manage to ensure their proper segregation is under discussion. Here we present study of the meiotic structure behavior one species, Mongolian gerbil (Meriones unguiculatus). We have analyzed location synaptonemal complex (SC) proteins SYCP1 SYCP3, as well three involved process recombination (RAD51, MLH1, γ-H2AX)....

Type 2 diabetes mellitus and obesity are the most frequent endocrine-metabolic diseases in world their pathogenic basis characterized by insulin resistance secretion defects that can be demonstrated through several alterations carbohydrates, lipids, protein metabolism. The peroxisome proliferator-activated receptors have been identified as key regulators of glucose lipid metabolism, because they act transcription factors stimulate synthesis a wide variety processes (energetic proliferation,...

Unlike eutherian males, pairing of the sex chromosomes in marsupial males during first meiotic prophase is not mediated by a synaptonemal complex. Instead, specific structure, dense plate, develops pachytene between chromosomes. We have investigated development and structural nature this asynaptic association species Thylamys elegans means immunolabelling electron microscopy techniques. Our results show that behaviour male complex, involving modifications their structure and/or composition....

INCENP and aurora-B kinase are two chromosomal passenger proteins that thought to play key roles in coordinating chromosome segregation with cytokinesis somatic cells. Here we have analyzed their subcellular distribution, of phosphorylated histone H3, the timing relative appearance mouse spermatocytes during both meiotic divisions. Our results show mitotic spermatogonial cells, same pattern distribution as they do cultured labels synaptonemal complex central element from zygotene up late...

The assembly of the mitotic centromere has been extensively studied in recent years, revealing sequence and regulation protein loading to this chromosome domain. However, few studies have analyzed during mammalian meiosis. This study specifically targets approach on mouse spermatocytes. We found that prophase I, proteins chromosomal passenger complex Borealin, INCENP, Aurora-B load sequentially inner before Shugoshin 2 MCAK. last be assembled are outer kinetochore BubR1 CENP-E. All these not...

Marsupial sex chromosomes break the rule that recombination during first meiotic prophase is necessary to ensure reductional segregation division. It widely accepted in marsupials X and Y do not share homologous regions, male synaptonemal complex absent between them. Although these recombine, they segregate reductionally anaphase I. We have investigated nature of chromosome association spermatocytes marsupial Thylamys elegans, order discern mechanisms involved ensuring their proper...

The temporal and functional relationships between DNA events of meiotic recombination synaptonemal complex formation are a matter discussion within the field. To analyse this subject in grasshoppers, organisms that have been considered as models for studies many years, we studied localization phosphorylated histone H2AX (γ‐H2AX), which marks sites double‐strand breaks (DSBs), combination with cohesin SMC3 recombinase Rad51. We show loss γ‐H2AX staining is spatially temporally linked to...

Abstract Marsupials present a series of genetic and chromosomal features that are highly conserved in very distant species. One these is the absence homologous region between X Y chromosomes. According to this differentiation, sex chromosomes do not synapse during first meiotic prophase males, special structure, dense plate, maintains chromosome association. In report we results on process pairing obtained from three different species, Thylamys elegans, Dromiciops gliroides, Rhyncholestes...

Chromosome shaping and individualization are necessary requisites to warrant the correct segregation of genomes in either mitotic or meiotic cell divisions. These processes mainly prompted vertebrates by three multiprotein complexes termed cohesin condensin I II. In present study we have analyzed immunostaining appearance subcellular distribution mouse chromosomes. Our results demonstrate that mitotically meiotically dividing cells, is loaded onto chromosomes prometaphase. Condensin...

Sex chromosomes of eutherian mammals are highly different in size and gene content, share only a small region homology (pseudoautosomal region, PAR). They thought to have evolved through an addition-attrition cycle involving the addition autosomal segments sex their subsequent differentiation. The events that drive this process difficult investigate because almost all at very advanced stage Here, we taken advantage recent translocation autosome both African pygmy mouse Mus minutoides, which...

The relationship between meiotic recombination events and different patterns of pairing synapsis has been analysed in prophase I spermatocytes the grasshopper Stethophyma grossum, which exhibit very unusual characteristics, namely (1) three shortest bivalents achieve full do not show chiasma localisation; (2) remaining eight restricted proximal localisation, (3) X chromosome remains unsynapsed. We have studied by means immunofluorescence localisation phosphorylated histone H2AX (gamma-H2AX),...

Mitotic Centromere-Associated Kinesin (MCAK) is a member of the kinesin-13 subfamily kinesin-related proteins. In mitosis, this microtubule-depolymerising kinesin seems to be implicated in chromosome segregation and correction improper kinetochore-microtubule interactions, its activity regulated by Aurora-B kinase. However, there are no published data on behaviour function during mammalian meiosis. We have analysed immunofluorescence squashed mouse spermatocytes, distribution possible MCAK,...

The cohesin complexes play a key role in chromosome segregation during both mitosis and meiosis. They establish sister chromatid cohesion between duplicating DNA molecules S-phase, but they also have an important postreplicative double-strand break repair mitosis, as well recombination homologous chromosomes An additional function meiosis is related to the kinetochore cohesion, so can be pulled by microtubules same pole at anaphase I. Data about dynamics of subunits are scarce; therefore, it...

We have analysed the chromosome organisation and location temporal appearance of different proteins in X B chromosomes grasshopper Eyprepocnemis plorans throughout first meiotic prophase. used adult males that carry a collected natural Spanish populations. The scaffold has been by means silver stained chromatid cores. In addition, we detected immunolabelling presence phosphoepitopes, ensemble cohesin axes, histone gamma-H2AX, recombinase Rad51. Our observations demonstrate share similarities...

Meiosis involves a series of specific chromosome events, namely homologous synapsis, recombination, and segregation. Disruption either recombination or synapsis in mammals results the interruption meiosis progression during first meiotic prophase. This is usually accompanied by defective transcriptional inactivation X Y chromosomes, which triggers breakdown many mutant models. However, epigenetic changes regulation are also expected to affect autosomes. In this work, we studied dynamics...