Investigation of genetic variability in natural Drosophila populations

Abstract

The paper describes the origin and development of population genetics, its main disco veries achieved in experiments with Drosophila before 1948 breakage and summarized the results of two series of long-term studies on genetic variability in Drosophila car ried out by the authors. The conceptual contribution of two main centers or school leaded by N. Koltzov and S. Chetverikov in Moscow and Yu. Filipchenko in St.-Pelersburg is considered. The ideas and methodology of these schools were introduced into American and European genetics by Th. Dobzhansky and N. V. Timofeev-Ressovsky. A new approach to the description of the eukaryotic genome organizations is des cribed. The authors argued that main source of the origin of various hereditary changes in nature is the interaction of environment with the facultative genomic elements. Biological background and the origin of genetics. At the beginning of our century, biology in Russia was flourishing. It is noteworthy to men tion here that I. P. Pavlov in 1904 and I. I. Mechnikov in 1908 were No bel prize winners. Leading Russian biologists traditionally were interes ted in evolutionary problems [1]. In his comprehensive review Vucinich [110] correctly concludes that Russian scientists «alone represented the full spectrum of attitudes and critical stances toward the scientific, socio logical and general intellectual merits of the Darwinian theory of evolu tion». Even an idea as popular in modern cellular and evolutionary bio logy as symbiogenesis was conceptually developed firstly by Russian bo tanists but almost completely ignored in the West [74]. Russian evolutionary thought developed through dynamic discussion and often controversy. One group of evolutionists accepted and contribu ted widely to Darwinian theory. Among them were the eminent Russian zoologists-brothers Alexander and Vladimir Kovalevsky, Menzbir, A. N. Severtzov and his follower I. I. Schmalhausen, Dogel, Zavarzin, Shimkevitch, botanists Komarov, Sukachev, Taliev, Tsinger. At the same time there were the eminent critics of the main concepts of Darwinian theory. The most illustrious embryologist of the pre-Darwinian period, Karl von Baer (1792-1876), a distinguished member of the St. Petersburg Academy of Sciences was one such critic. We may al so include here the famous botanists: Korzhinsky who discovered, simul taneously with Hugo de Vries, mutations in plants, and also Famintsyn, Borodin. The great zoologist Lev Berg (the father of a famous populati on geneticist Raissa Berg) developed the impressive anti-Darwinian con ception of Nomogenesis. His book was translated into English and issued in the 1960s as a second edition with a preface by Th. Dobzhansky. Mo re recently Dobzhansky [20] characterised this book as «marshalling an abundance of evidence comparable to Darwin». With this intellectual background the appearance and flourishing of population and evolutionary genetics seem preadapted. Two main cen ters or ohools of general and population genetics were set up in Moscow and Petersburg (Leningrad). ...

Frequent transpositions of Drosophila melanogaster HeT-A transposable elements to receding chromosome ends.

“…The 1(2)gl gene is the most distal locus on the left arm of chromosome 2. Golubovski (Golubovsky and Sokolova, 1973;Golubovsky, 1978) found that 1-2% of second chromosomes in nature carried a heterozygous 1(2)lgl mutation. Cloning and molecular analysis of the locus (Mechler et al, 1985) revealed that the vast majority of 1(2)lgl mutations are associated with terminal chromosome deficiencies resulting in 3' truncations of the gene, which is transcribed from proximal to distal.…”