TY - JOUR
T1 - Evolutionary regulation of the blind subterranean mole rat, Spalax, revealed by genome-wide gene expression
AU - Brodsky, L. I.
AU - Jacob-Hirsch, J.
AU - Avivi, A.
AU - Trakhtenbrot, L.
AU - Zeligson, S.
AU - Amariglio, N.
AU - Paz, A.
AU - Korol, A. B.
AU - Band, M.
AU - Rechavi, G.
AU - Nevo, E.
PY - 2005/11/22
Y1 - 2005/11/22
N2 - We applied genome-wide gene expression analysis to the evolutionary processes of adaptive speciation of the Israeli blind subterranean mole rats of the Spalax ehrenbergi superspecies. The four Israeli allospecies climatically and adaptively radiated into the cooler, mesic northern domain (N) and warmer, xeric southern domain (S). The kidney and brain mRNAs of two N and two S animals were examined through cross-species hybridizations with two types of Affymetrix arrays (mouse and rat) and muscle mRNA of six N and six S animals with spotted cDNA mouse arrays. The initial microarray analysis was hypothesis-free, i.e., conducted without reference to the origin of animals. Principal component analysis revealed that 20-30% of the expression signal variability could be explained by the differentiation of N-S species. Similar N-S effects were obtained for all tissues and types of arrays: two Affymetrix microarrays using probe oligomer signals and the spotted array. Likewise, ANOVA and t test statistics demonstrated significant N-S ecogeographic divergence and region-tissue specificity in gene expression. Analysis of differential gene expression between species corroborates previous results deduced by allozymes and DNA molecular polymorphisms. Functional categories show significant N-S ecologic putative adaptive divergent upregulation of genes highlighting a higher metabolism in N, and potential adaptive brain activity and kidney urine cycle pathways in S. The present results confirm ecologic-genomic separation of blind mole rats into N and S. Gene expression regulation appears to be central to the evolution of blind mole rats.
AB - We applied genome-wide gene expression analysis to the evolutionary processes of adaptive speciation of the Israeli blind subterranean mole rats of the Spalax ehrenbergi superspecies. The four Israeli allospecies climatically and adaptively radiated into the cooler, mesic northern domain (N) and warmer, xeric southern domain (S). The kidney and brain mRNAs of two N and two S animals were examined through cross-species hybridizations with two types of Affymetrix arrays (mouse and rat) and muscle mRNA of six N and six S animals with spotted cDNA mouse arrays. The initial microarray analysis was hypothesis-free, i.e., conducted without reference to the origin of animals. Principal component analysis revealed that 20-30% of the expression signal variability could be explained by the differentiation of N-S species. Similar N-S effects were obtained for all tissues and types of arrays: two Affymetrix microarrays using probe oligomer signals and the spotted array. Likewise, ANOVA and t test statistics demonstrated significant N-S ecogeographic divergence and region-tissue specificity in gene expression. Analysis of differential gene expression between species corroborates previous results deduced by allozymes and DNA molecular polymorphisms. Functional categories show significant N-S ecologic putative adaptive divergent upregulation of genes highlighting a higher metabolism in N, and potential adaptive brain activity and kidney urine cycle pathways in S. The present results confirm ecologic-genomic separation of blind mole rats into N and S. Gene expression regulation appears to be central to the evolution of blind mole rats.
KW - Adaptive speciation
KW - Cross-species hybridization
KW - Ecological stress
KW - Genome-wide expression
KW - Microarray
UR - http://www.scopus.com/inward/record.url?scp=28044456943&partnerID=8YFLogxK
U2 - 10.1073/pnas.0505043102
DO - 10.1073/pnas.0505043102
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AN - SCOPUS:28044456943
SN - 0027-8424
VL - 102
SP - 17047
EP - 17052
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 47
ER -