GENOMIC STUDIES IN
Krutovsky K. V.
Department of
Ecosystem Science & Management,
Synthesis
of evolutionary theory and genetics is one of the largest achievements of the
last century in biology. It integrated biological knowledge and developed a new
conceptual thinking at the population genetics level, when population is
considered as a main unit of evolution. Integration of molecular genetics and
bioinformatics can be considered as a new synthesis of the new century.
Integration of molecular population genetics and bioinformatics promotes a new
conceptual thinking at the population genomics level, when genetic processes in
population can be studied, taking into consideration entire complex
interactions between multiple genes and environmental factors. Population genomics is a novel,
fast-developing discipline, combining traditional population genetic approaches
with the genome-wide level of analysis. Thousands of genes with known function
and sometimes known genome-wide localization can be simultaneously studied in
many individuals. This opens new prospects for obtaining statistical estimates
for a great number of genes and segregating elements. Mating system, gene
exchange, reproductive population size, population disequilibrium, interaction
among populations, and many other traditional problems of population genetics
can be now studied using data on variation in many genes. Moreover, population
genome-wide analysis allows one to distinguish factors that affect individual
genes, alleles, or nucleotides (such as, for example, natural selection) from
factors affecting the entire genome (e.g., demography). A brief review of
traditional methods of studying genetic variation in forest tree species is
presented, and a new, integrated population genomics approach is introduced in
this presentation. The main stages of the latter are: (1) selection of genes,
which are tentatively involved in variation of adaptive traits, by means of a
detailed examination of the regulation and the expression of individual genes
and genotypes, with subsequent determination of their complete allelic
composition by direct nucleotide sequencing; (2) examination of the phenotypic
effects of individual alleles by, e.g., association mapping; and (3)
determining the frequencies of the selected alleles in natural population for
identification of the adaptive variation pattern in the heterogeneous
environment.
Through decoding the phenotypic
effects of individual alleles and identification of adaptive variation patterns
at the population level, population genomics in the future will serve as a very
helpful, efficient, and economical tool, essential for developing a correct
strategy for conserving, increasing and improving forests and other
commercially valuable plant and animal species.