INVESTIGADORES
MASUELLI Ricardo Williams
artículos
Título:
Centromeric Localization and Adaptive Evolution of an Arabidopsis Histone H3 Variant
Autor/es:
RICARDO WILLIAMS MASUELLI, RICARDO MASUELLI
Revista:
PLANT CELL
Editorial:
The Plant Cell
Referencias:
Año: 2002 vol. 14 p. 1053 - 1066
ISSN:
1040-4651
Resumen:
Centromeric H3-like histones, which replace histone H3 in the centromeric chromatin of animals and fungi, have not
been reported in plants. We identified a histone H3 variant from
Arabidopsis thaliana
that encodes a centromere-identifying
protein designated HTR12. By immunological detection, HTR12 localized at centromeres in both mitotic and
meiotic cells. HTR12 signal revealed tissue- and stage-specific differences in centromere morphology, including a distended
bead-like structure in interphase root tip cells. The anti-HTR12 antibody also detected spherical organelles in
meiotic cells. Although the antibody does not label centromeres in the closely related species
Arabidopsis arenosa
,
HTR12 signal was found on all centromeres in allopolyploids of these two species. Comparison of the
HTR12
genes of
A. thaliana
and
A. arenosa
revealed striking adaptive evolution in the N-terminal tail of the protein, similar to the pattern
seen in its counterpart in
Drosophila
. This finding suggests that the same evolutionary forces shape centromeric chromatin
in both animals and plants.