InBoveri introduced the term of CT based on a study performed on blastomere nuclei of the horse roundworm Parascaris equorum eggs [ 20 ]. In Eckstein,F. All these changes in the composition of the sex chromatin are accompanied by its compaction and re-localization at the periphery of the spermatocyte nucleus in a structure called the sex body [ 23 ].
Additional file 7. Sep 22, B3 also known as H2A. Alterations of CTs organization in spermatogenesis and infertility In view of all the data presented, there is no doubt that the nuclear topology in spermatogenic cells and spermatozoa shows a non-random chromosome organizational pattern.
An abundance of X-linked genes expressed in spermatogonia. Quantitative studies on the arrangement of human metaphase chromosomes. Dynamics of 5-hydroxymethylcytosine during mouse spermatogenesis. Whether or not XY chromosomes remain to some extent silent after meiosis is still controversial see below.
In this context, it is not daring to envisage that this specific arrangement is essential for regulating accurate gene expression to allow the proper progression of spermatogenesis and early embryo development.
To explain the chromosome size-dependent distribution of human chromosomes, there exist two biophysical models that act in a complementary way: the mitotic preset model and the volume-exclusion model [ 35 ]. Distinct feature between the X and Y chromosomes H3K27 residue can either be acetylated or methylated, and both modifications are enriched at the TSS.
The multicopy gene Sly represses the sex chromosomes in the male mouse germline after meiosis. During meiosis, the X and Y chromosomes are transcriptionally silenced. Soh et al. The authors hypothesized that the X chromosome regions covered by these marks could be particularly accessible to antibodies.