遗传学6染色体的数量和结构的变化

G bands
➢ Like quinacrine, Giemsa creates a reproducible pattern of bands on each chromosome.
➢ However, the nature of the banding pattern depends on how the chromosomes were prepared prior to staining.
➢another procedure, called R banding, gives the reverse pattern—dark bands that correspond roughly to light G bands.
➢A third procedure, called C banding, stains the region around the centromere of each chromosome.
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➢ Metaphase human chromosomes stained with acridine orange (吖啶橙) to
show R banding.
➢ Metaphase chromosome of the Melipona rufiventris (卖 蜂), M. mondury and M.
with aceto-carmine.
molecules in DNA, or with aceto-carmine (乙 酸洋红), a deep red dye.
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➢ Chromosomes that have stained with quinacrine show a characteristic pattern of bands.
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Chapter Outline
➢Cytological Techniques ➢Polyploidy (多倍体) ➢Aneuploidy (非整倍体) ➢Rearrangements of Chromosome Structure
5
and Structure
➢ Until the late 1960s and
early 1970swere stained with
Feulgen’s reagent, a
purple dye that reacts
with the sugar
➢Chromosomes of the incense cedar (Calocedrus decurrens) 北美翠柏stained
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1. Analysis of Mitotic Chromosomes
➢ Preparation of cells for cytological analysis.
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seminigra fuscopilosa stained to show C banding.
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2. The Human Karyotype
➢Diploid human cells contain 46 chromosomes— 44 autosomes and two sex chromosomes, which are XX in females and XY in males.
➢ However, because
quinacrine is a
➢ Metaphase chromosomes
of the plant Allium
carinatum, stained with quinacrine (奎纳克林， 阿的平) to reveal Q band.
fluorescent compound, the band appear only when the chromosomes are exposed to ultraviolet light.
Chapter 6
Variation in Chromosome Number and Structure
生命科学技术学院 乔中东
1
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Chromosomes, Agriculture, and Civilization
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➢One procedure, called G banding, gives dark bands that correspond roughly to the bright bands obtained with quinacrine;
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Section 1
Cytological Techniques
➢Geneticists use stains to identify specific chromosomes and to analyze their structures.
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➢ The most popular of these uses Giemsa stain, a mixture of dyes named after its inventor, Gustav Giemsa.