Differential evolutionary rates of neuronal transcriptome in Aplysia kurodai and Aplysia californica as a tool for gene mining.
The marine mollusk Aplysia is a fascinating model organism for studying molecular mechanisms underlying learning and memory. However, evolutionary studies about Aplysia have been limited by the lack of its genomic information. Recently, large-scale expressed sequence tag (EST) databases have been acquired by sequencing cDNA libraries from A. californica and A. kurodai. The closeness between the two species allowed us to investigate rapidly evolving genes by comparing their orthologs. Using this method, we found that a subset of signal transduction genes in neurons showed rates of protein evolution higher than those of housekeeping genes. Moreover, we were also able to find several candidate genes that may be involved in learning and memory or synaptic plasticity among genes showing relatively higher K(a)/K(s) ratios. We also investigated the relationship between evolutionary rates and tissue distribution of Aplysia genes. They propose that the estimation of evolutionary rates cannot be a good marker to assess neuronal expression; however, it still can be an efficient way to narrow down the pool of candidate genes involved in neuronal functions for the further studies.
Choi
Sun-Lim
SL
National Creative Research Initiative Center for Memory and Institute of Molecular Biology and Genetics, Department of Biological Sciences, College of Natural Sciences, Seoul National University, Bldg 504, Rm 202, 599 Gwanangno, Gwanak-gu, Seoul 151-747, Korea.
Lee
Yong-Seok
YS
Rim
Young-Soo
YS
Kim
Tae-Hyung
TH
Moroz
Leonid L
LL
Kandel
Eric R
ER
Bhak
Jong
J
Kaang
Bong-Kiun
BK
D000818:Animals; D001048:Aplysia / Q000166:cytology / Q000235:genetics*; D057225:Data Mining / Q000379:methods*; D019143:Evolution, Molecular; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000235:genetics*; D015723:Gene Library; D053263:Gene Regulatory Networks / Q000235:genetics; D023421:Models, Animal; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D040901:Proteomics / Q000379:methods; D015398:Signal Transduction / Q000235:genetics; D013045:Species Specificity; D013997:Time Factors
D009419:Nerve Tissue Proteins