Biology Reference
In-Depth Information
Table 13.1: Molecular Methods that Can be Used to Evaluate Insects in Ecological Studies.
Technique
Level of discrimination
Selected references
Advantages ( + ) and disadvantages (-)
Type of data obtained
(gene frequencies or
base-pair changes)
l
AFLP-PCR
Detect differences
in individuals and
populations
+ More reliable than RAPD-PCR,
more user-friendly than RFLPs and
microsatellites, samples large amounts
of genome, sequence information not
needed
Mueller and
Wolfenbarger
1999, see
Chapter 8
May require relatively large amounts of
clean DNA, requires multiple operations
Allele-specific
PCR
Detect single nucleotide
differences in
individuals and
populations
+ Small amounts of DNA required,
relatively rapid and inexpensive, results
can be visualized by staining with
ethidium bromide/other labels
See Chapter 8,
Arnheim et al.
1990, Innis et al.
1990, Erlich 1989
l
Gene frequency and
base pair changes
DNA sequence information needed for
primers, or consensus primers, each
reaction provides information for only
one locus
Long PCR variant
l
Same as above
+ Detects microbial DNA mixed with
insect or plant DNA, is 6-8 orders
of magnitude more sensitive than
standard PCR
Jeyaprakash and
Hoy 2000, Hoy
et al. 2001
More expensive because it uses two
polymerases, including one that
corrects errors, care must be taken
to avoid contamination because of
increased sensitivity
Double-strand
conformation
polymorphism
(DSCP)
l
Detect changes
in mobility of
double-stranded
DNA molecules on
polyacrylamide gels
+ Can use PCR products for analysis,
rapid and inexpensive, can identify
new haplotypes for additional analysis
Hagerman 1990,
Saad et al. 1994,
Atkinson and
Adams 1997
Some mutations don't produce
changes in mobility, thus won't work
with all PCR products, sequence
differences can't be estimated,
sequencing may be required
Microsatellites
Detect differences
in individuals and
populations in
tandemly repeated
units in nuclear DNA
+ High levels of variation present in
most insects
Bruford et al. 1992,
Kirby 1990, Zane
et al. 2002
Comigrating bands may not be
identical alleles at a locus, relatively
large amounts of clean, high-molecular
weight DNA required, labeled probes
required, relatively expensive and labor
intensive, time and effort are required
to identify repeated units
RAPD-PCR
Differences in single
nucleotides in nuclear
DNA
+ Useful for species with limited genetic
information, efficient, relatively
inexpensive, requires little DNA
Hadrys et al. 1992,
Haymer 1994
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