INVESTIGADORES
CONFALONIERI Viviana Andrea
artículos
Título:
Evolutionary relationships in the genus Zea: analysis of repetitive sequences used as cytological FISH markers.
Autor/es:
POGGIO, L.; CONFALONIERI, V.; COMAS, C.; GONZALEZ, G.; NARANJO, C.
Revista:
GENETICS AND MOLECULAR BIOLOGY
Editorial:
SOC BRASIL GENETICA
Referencias:
Lugar: San Pablo; Año: 2000 vol. 23 p. 1021 - 1027
ISSN:
1415-4757
Resumen:
The present study is a revision of our work on evolutionary cytogenetics
of the genus Zea, including several new experiments which
give a deeper insight into the nature of the DNA sequences involved
in telomeric regions of Zea luxurians. These new experiments,
based on the Southern blotting technique and in situ hybridization,
have demonstrated the following: 1) in situ hybridization
(FISH) demonstrated the presence of the 180-bp repeat maizeknob-
repeat-sequence in DAPI-positive terminal heterochromatic
blocks of Z. luxurians (ZL-THB region); 2) Southern blot analysis
confirmed that the 180-bp repeat present in maize is also present
in Z. diploperennis, Z. luxurians and Tripsacum dactyloides,
but not in Z. perennis; 3) another sequence with targeted sites for
endonucleases, but without recognition sites for the 180-bp repeat,
may be interspersed with the 180-bp repeat in a tandem
array sited in the ZL-THB region; 4) in situ hybridization (GISH)
of probes and blocking-probes with chromosomes of Z. luxurians
(using Z. luxurians as a probe and Z. diploperennis or Z. perennis
as a blocking-probe) gave strong fluorescence in both cases. Since
Z. diploperennis possesses the 180-bp repeat, fluorescence on
Z. luxurians chromosomes was not expected. These results can
be explained if the ZL-THB regions are composed not only of
180-bp repeats interspersed with other sequences, but also of other
tandem arrays unique to Z. luxurians, which, according to our