Publications by authors named "Irina S Stepanova"
Article Synopsis
- The study analyzed DNA hydroxymethylation and methylation in human testicular cells and sperm from azoospermic patients and sperm donors, finding that while methylation was consistent throughout spermatogenesis, hydroxymethylation varied and was mostly low in sperm samples.
- High levels of hydroxymethylcytosine were primarily found in a small population of sperm cells, indicating that variations in hydroxymethylation patterns are likely not genetically programmed but may indicate abnormalities.
- Increased levels of hydroxymethylated sperm correlated negatively with markers of good semen quality and positively with sperm DNA fragmentation, suggesting that hydroxymethylation could serve as a new indicator for assessing sperm quality in infertile couples.
Background: The oocyte chromosomes of the red flour beetle, , are gathered into a knot, forming a karyosphere at the diplotene stage of meiotic prophase. Chromatin rearrangement, which is a characteristic feature of oocyte maturation, is well documented. The karyosphere is surrounded by a complex extrachromosomal structure termed the karyosphere capsule.
View Article and Find Full Text PDFThe first ultrastructural and immunomorphological characteristics of the karyosphere (karyosome) and extrachromosomal nuclear bodies in the red flour beetle, Tribolium castaneum, are presented. The karyosphere forms early in the diplotene stage of meiotic prophase by the gathering of all oocyte chromosomes in a limited nuclear volume. Using the BrUTP assay, T.
View Article and Find Full Text PDFThe organization and molecular composition of complicated Cajal bodies (CBs) and interchromatin granule clusters (IGCs) in oocytes of the house cricket, Acheta domesticus, were studied using immunofluorescent/confocal and Immunogold labeling/electron microscopy. In A. domesticus oocytes, the CB consists of the fibrillar matrix and a central cavity containing a predominantly granular body with insertions of tightly packed fibrillar material.
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