Adaptive evolution on the level of speciation is thought to be the result of
some shifts in gene regulation system. For many years we study histone H1 - a
nonspecific repressor of gene activity. We have shown that in the insect orders
the rate of speciation correlates well with the variation in histone H1
molecule. Studying the allelic polymorphism of histone H1 subtypes in the garden
pea and some other legumes, we found out several cases of clinal variation
implying an action of natural selection. Finally, the comparison of pea isogenic
lines differing in alleles of the H1 genes showed weak but significant
differences in a number of quantitative traits, including the seed number.
On the population level the rate of adaptive evolution is determined
by the variation in fitness of individuals. This variation may be enchanced if
we introduce an artificial source of it into experimental system. We have chosen
the garden pea as a convenient genetic model and are constructing genetic
systems which would produce variation in the dose of histone H1 genes. We
decided to make small dispensable (genetically empty) chromosomes whose number
could vary. These chromosomes could serve as vectors carrying histone or other
important genes affecting numerous traits. The experimental population carrying
such chromosomes is expected to show a profound response to selection.
While working out a desirable genetic system, we conduct a lot of work
on genetics of garden pea, the linkage groups 1 and 5 being the main subjects of
our attention. We induce and map new mutations, and work intensively with
translocations and trisomics. Some balancer systems will be constructed on the
basis of some genetic systems we use.