Transcript warm brain and eyes in tunas and sharks

Termogênese nos seres vivos
UCP em peixes
Roberto Andrade Jr
Rio de Janeiro, 09 de novembro de 2009
http://evolution.berkeley.edu/evosite
WARM BRAIN AND EYES IN TUNAS AND SHARKS
bluefin tuna
(Thunnus thynnus)
Linthicum & Carey (1972) Comp Biochem Physiol A 43(2)
WARM BRAIN AND EYES IN TUNAS AND SHARKS
porbeagle shark
(Lamna nasus)
Block & Carey (1985) J Comp Physiol B. 156(2)
The warm tissues temperatures in the heads of these fish are associated with the presence of
an eye muscle that is modified for heat production.
Block (1986) J Cell Biol. 107(3)
Calcium uptake in membrane vesicles prepared
from the sarcoplasmic reticulum of billfish
ENDOTHERMIC TELEOSTS
Bernal et al. (2001) Comp Biochem Physiol A 129
ENDOTHERMIC TELEOSTS
Relationship between the body temperature and surface water temperature in lamnid sharks.
Bernal et al. (2001) Comp Biochem Physiol A 129
nonshivering thermogenesis
The uncoupling proteins (UCPs) are transporters, present in the mitochondrial inner
membrane, that mediate a regulated discharge of the proton gradient that is generated by the
respiratory chain
This energy-dissipatory mechanism can serve functions such as thermogenesis,
maintenance of the redox balance, or reduction in the production of ROS
Ledesma et al. (2002) Genome Biology 3(12)
Uncoupling protein (UCP1) is a demonstrated uncoupler of oxidative phosphorylation
UCP1 expression is restricted to mammalian brown adipose tissue
UCP1 homologues, uncoupling proteins 2, 3 and others, have been considered candidates for
the catalysis of this basal level of uncoupling of oxidative phosphorylation that characterises
all mitochondria
carp
(Cyprinus carpio)
UCP cDNAs in expressed sequence tag (EST)
libraries
zebrafish
(Danio rerio)
Carp and zebrafish UCP2
predicted amino acid
sequences aligned with
mammalian UCP2s
82% sequence similarity to
the mammalian UCP2s
Multiple sequence alignment
of carp and zebrafish UCP2
translations with human
UCP1, UCP2 and UCP3
70% identity with UCP3s
59% identity with UCP1s
By comparison, the amino acid sequence of the fish UCP2s are approximately as similar to
human UCP1 (59%) as are human UCP2 (59%) and UCP3 (58%), which is perhaps
remarkable given the great evolutionary distance of fish from mammals
The expression of UCP2 in cells of an ectotherm strongly supports the idea that this protein
has a function not related to thermogenesis
UCP1 mechanism of nonshivering thermogenesis is considered as a monophyletic trait of
endothermic placental mammals that emerged about 140 million years ago
UCP2 and UCP3 are probably not thermogenic proteins but convey mild uncoupling, which
may serve to reduce the rate of mitochondrial ROS production
Genomic identification of UCP1, UCP2, and UCP3 in teleost fish
mammalian Ucp1 gene region is also found in the genomes of the zebrafish and pufferfish
Genomic identification of UCP1, UCP2, and UCP3 in teleost fish
homologous genes neighboring the Ucp2–Ucp3 cluster were also conserved in both
mammalian and fish genomes, forming a region of conserved synteny
Phylogenetic neighbor joining
tree of the UCP core family
Tissue-specific expression of UCP1, UCP2, and UCP3 in the common carp (C. carpio)
Regulation of gene expression in response to cold acclimation and fasting
Phylogenetic inference and comparative genomics
We conducted a comprehensive search for Ucp genes by blasting zebrafish (Danio
rerio) and pufferfish (Fugo rubripes) genomes with full-length coding sequences of
mammalian UCPs (Ensembl Genome Browser, http://www.ensembl.org).
To verify the membership of identified candidates to the core UCP family, the predicted
protein sequences of putative fish UCPs were aligned [ClustalX, ftp://ftp-igbmc.ustrasbg.fr/pub/ClustalX] together with all known UCP protein sequences available in
public databases and subjected to phylogenetic inference using the Neighbour joining
method (Felsenstein J. PHYLIP Phylogeny Inference Package version 3.6. Distributed
by
the
author.
Seattle,
WA:
Univ.
of
Washington,
2004.
http://evolution.genetics.washington.edu/phylip.html).
Bootstrapping involved 1,000 replicates, and the consensus tree was illustrated using
TreeView (http://taxonomy.zoology.gla.ac.uk/rod/treeview.html).
Physical gene maps of verified Ucp loci were scaled based on assemblies of the
Ensembl Genome Browser (http://www.ensembl.org). Genes located up- and
downstream of Ucp genes in these loci were blasted against mammalian genomes for
the highest score.