Histone H3 lysine 9 acetylation pattern suggests that X and B chromosomes are silenced during entire male meiosis in a grasshopper.
Cytogenet Genome Res
; 119(1-2): 135-42, 2007.
Article
en En
| MEDLINE
| ID: mdl-18160793
ABSTRACT
The facultative heterochromatic X chromosome in leptotene spermatocytes of the grasshopper Eyprepocnemis plorans showed marked hypoacetylation for lysine 9 in the H3 histone (H3-K9) with no sign of histone H2AX phosphorylation. Since H3-K9 hypoacetylation precedes the meiotic appearance of phosphorylated H2AX (gamma-H2AX), which marks the beginning of recombinational DNA double-strand breaks (DSBs), it seems that meiotic sex-chromosome inactivation (MSCI) in this grasshopper occurs prior to the beginning of recombination and hence synapsis (which in this species begins later than recombination). In addition, all constitutively heterochromatic chromosome regions harbouring a 180-bp tandem-repeat DNA and rDNA (B chromosomes and pericentromeric regions of A chromosomes) were H3-K9 hypoacetylated at early leptotene even though they will synapse at subsequent stages. This also suggests that meiotic silencing in this grasshopper might be independent of synapsis. The H3-K9 hypoacetylated state of facultative and constitutive heterochromatin persisted during subsequent meiotic stages and was even apparent in round spermatids. Finally, the fact that B chromosomes are differentially hypoacetylated in testis and embryo interphase cells suggests that they might be silenced early in development and remain this way for most (or all) life-cycle stages.
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Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Histonas
/
Cromosomas
/
Silenciador del Gen
/
Saltamontes
/
Lisina
/
Meiosis
Límite:
Animals
Idioma:
En
Revista:
Cytogenet Genome Res
Asunto de la revista:
GENETICA
Año:
2007
Tipo del documento:
Article
País de afiliación:
España