Viçosa, Brazil
Universidade Federal de Viçosa
Chromomere map of meiotic maize chromosome
--Caixeta, ET, Carvalho, CR
Computational and cytogenetic methods were
used with the objective of mapping with high resolution, the longitudinal
differentiation of maize chromosomes. Tassels of the line L-869 were collected
and fixed in a methanol:acetic acid solution (3:1). Pollen mother cells
were macerated with an enzymatic solution, prepared cytogenetically by
the air-drying technique and later stained with a Giemsa solution. Meiotic
figures were photomicrographed and digitized by means of a scanner or captured
directly by a CCD video camera from microscope to a computer. The technique
used allowed a visualization of well defined chromosomes that were spread
out in the same focus level on the slide. The morphologic preservation
of the bivalents and the almost absence of background or artifact resulted
in high quality cytogenetic preparations. Digitized image analysis made
the graphic plot of relative density of the chromosomes in 256 tones of
gray scale possible. The profile of the gray value standards analyzed from
these graphs revealed absolute and relative measures of the chromosomes.
The longitudinal differentiations recognized by the centromere, knob, chromomeric
and interchromomeric regions were precisely mapped throughout the meiotic
chromosomes.
Figure
1. Maize pachytene chromosome number 7 and diagram showing chromomeres
map. C = centromere, K=Knob.
Please Note: Notes submitted to the Maize Genetics Cooperation Newsletter may be cited only with consent of the authors.
Return to the MNL 75 On-Line Index
Return to the Maize Newsletter Index
Return to the MaizeGDB Homepage
