Biology Reference
In-Depth Information
Tail (7)
Body skin (2)
Face (1)
Brain (4)
Hind limb (3)
Intestine (3)
Whole body (4)
Species
Endocrine disruptors
Xenopus laevis
(16)
Xenopus tropicalis
(1)
Rana catesbiana
(1)
Rana pirica
(2)
Bufo marinus
(1)
Bisphenol A (1)
Atrazine (2)
Polychlory biphenols (1)
Acetochlor (1)
Figure 12.2 Summary diagram of tadpole microarray studies. A total of 21 studies have
been carried out on tadpoles using the five species and seven body regions indicated.
The numbers in parentheses indicate the number of studies using the associated body
region, species, or endocrine disrupting chemical.
metamorphosis was composed of 420 cDNAs, chosen from available
sequences in GenBank in 2001 whose products were believed to be impor-
tant in frog embryogenesis and metamorphosis (
Crump, Werry, Veldhoen,
Van Aggelen, & Helbing, 2002
). With advances in microarray technology,
genome-wide analysis of gene expression for more than 20,000 genes during
metamorphosis became possible (
Das et al., 2006
).
The use of microarray technology in studies of frog metamorphosis is the
subject of this review (see
Fig. 12.2
and
Table 12.1
for summaries of these
studies). Two main goals have motivatedmicroarray analysis in frogmetamor-
phosis, namely, developmental genetic analysis of the TH gene regulation cas-
cade and biomarker discovery and mechanism of action for endocrine
disruption studies. In the first case, researchers want to identify all gene expres-
sion changes associated with a particular developmental stage or experimental
treatment as a means toward understanding underlying pathways and mech-
anisms of tissue-specific TH-dependent metamorphosis. We discuss progress
made using microarrays to understand developmental programs of tail, brain,
hind limb, intestine, and skin. In the second case, researchers wish to identify a
gene or genes robustly associated with TH signaling to serve as a reliable gauge
of TH endocrine disruption. Also, several studies have used microarrays to
examine the mechanism of action of TH disrupting chemicals, including
bisphenol A, atrazine, polychlorinated biphenols, and acetochlor. Additional
