Platypus chain reaction: directional and ordered meiotic pairing of the multiple sex chromosome chain in Ornithorhynchus anatinus.
Reprod Fertil Dev
; 21(8): 976-84, 2009.
Article
en En
| MEDLINE
| ID: mdl-19874721
ABSTRACT
Monotremes are phylogenetically and phenotypically unique animals with an unusually complex sex chromosome system that is composed of ten chromosomes in platypus and nine in echidna. These chromosomes are alternately linked (X1Y1, X2Y2, ...) at meiosis via pseudoautosomal regions and segregate to form spermatozoa containing either X or Y chromosomes. The physical and epigenetic mechanisms involved in pairing and assembly of the complex sex chromosome chain in early meiotic prophase I are completely unknown. We have analysed the pairing dynamics of specific sex chromosome pseudoautosomal regions in platypus spermatocytes during prophase of meiosis I. Our data show a highly coordinated pairing process that begins at the terminal Y5 chromosome and completes with the union of sex chromosomes X1Y1. The consistency of this ordered assembly of the chain is remarkable and raises questions about the mechanisms and factors that regulate the differential pairing of sex chromosomes and how this relates to potential meiotic silencing mechanisms and alternate segregation.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Ornitorrinco
/
Cromosomas Sexuales
/
Emparejamiento Cromosómico
/
Meiosis
Tipo de estudio:
Prognostic_studies
Límite:
Animals
Idioma:
En
Revista:
Reprod Fertil Dev
Asunto de la revista:
MEDICINA REPRODUTIVA
Año:
2009
Tipo del documento:
Article
País de afiliación:
Australia