Chromosome examinations and morphometric measurements
Mitotic and meiotic metaphases were examined under a microscope (Olympus BX40)
with an oil immersion lens at 1000 magnification. The chromosomes at the metaphase
were photographed with a digital camera (Olympus C-35AD-4) onto Fuji colour films
(ISO400/27j). Nine of the best mitotic metaphases were karyotyped. The morphometric
measurements of chromosome pictures were conducted with photographic software
Photoshop 6.0 (Adobe Systems). Each chromosome was tagged with a reference
number, and then the chromosome was divided into four arms at the centromere. The
length of each arm was measured. The data were transferred to the Excel 2000
(Microsoft) for analysis.