Model of chromosome associations in Mus domesticus spermatocytes
Biol. Res
; 43(3): 275-285, 2010. ilus, graf, tab
Article
en En
| LILACS
| ID: lil-571988
Biblioteca responsable:
CL1.1
ABSTRACT
Understanding the spatial organization of the chromosomes in meiotic nuclei is crucial to our knowledge of the genome's functional regulation, stability and evolution. This study examined the nuclear architecture of Mus domesticus 2n=40 pachytene spermatocytes, analyzing the associations among autosomal bivalents via their Centromere Telomere Complexes (CTC). The study developed a nuclear model in which each CTC was represented as a 3D computer object. The probability of a given combination of associations among CTC was estimated by simulating a random distribution of 19 indistinguishable CTC over n indistinguishable "cells" on the nuclear envelope. The estimated association frequencies resulting from this numerical approach were similar to those obtained by quantifying actual associations in pachytene spermatocyte spreads. The nuclear localization and associations of CTC through the meiotic prophase in well-preserved nuclei were also analyzed. We concluded that throughout the meiotic prophase 1) the CTC of autosomal bivalents are not randomly distributed in the nuclear space; 2) the CTC associate amongst themselves, probably at random, over a small surface of the nuclear envelope, at the beginning of the meiotic prophase; 3) the initial aggregation of centromere regions occurring in lepto-zygotene likely resolves into several smaller aggregates according to patterns of preferential partitioning; 4) these smaller aggregates spread over the inner face of the nuclear envelope, remaining stable until advanced stages of the meiotic prophase or even until the first meiotic division.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
LILACS
Asunto principal:
Espermatocitos
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Núcleo Celular
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Cromosomas de los Mamíferos
Tipo de estudio:
Risk_factors_studies
Límite:
Animals
Idioma:
En
Revista:
Biol Res
/
Biol. Res
/
Biol. Res. (Online)
/
Biological Research
Asunto de la revista:
BIOLOGIA
Año:
2010
Tipo del documento:
Article
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Project document