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Powstawanie, rodzaje i rola zmienności w ewolucji

100%

Jerzmanowski A.

Kosmos

2009

tom 58

nr 3-4

329-334

Genetic variation among individuals within a population concerns both quantitative and discrete traits and manifests at a variety of organizational levels, from whole organisms down to chemical constituents of cells. The results of DNA sequencing revealed even more variation than was detected by earlier comparisons of proteins by gel electrophoresis. The observation of unexpectedly high levels of genetic variation in both coding and the non-coding regions of DNA led to development of the neutral theory which holds that most variation at the molecular level does not affect fitness and can be accounted for by stochastic processes. A relatively constant rate of molecular evolution - the molecular clock - provided it is properly calibrated, became a useful method of estimating the time of events in evolutionary history. While mutations are the ultimate source of genetic variation, the major source of differences among sexually reproducing individuals in populations results from meiotic crossing over, recombination of chromosomes and random fertilization. Since recently, high throughput sequencing methods provide new insights into the evolution of genomes revealing major contributions from gene and whole genome duplications, large deletions and horizontal transfer of genes. The uncovering of the mechanisms responsible for epigenetic phenomena in plants and animals and the observations of transgenerational epigenetic inheritance (i.e. inheritance not dependent on changes in the sequence of DNA) opens the way to study the importance of multigenerational epigenetics for evolution and adaptation.

Biologia w erze pogenomowej

100%

Jerzmanowski A.

tom 51

nr 1

1-4

Summary The current postgenomic phase in biology is characterized by the occurrence of numerous novel research areas. Within the next twenty years or so, some of them will probably develop into well defined sub-disciplines, the other will disappear or transform into something completely new. Of the emerging directions, three seem particularly promising. They are: comparative genomics, deep analysis of the genomes and a search for the new ways of describing organisms. The recent exemplary achievments obtained by researchers pursuing these directions were the elucidation of the role of segmental DNA duplications in the evolution of mammals, the discovery of the regulatory functions and the widespread occurrence in the genomes of the tiny RNA molecules, the microRNA, and the finding that such processes as karyokinesis or nuclear-cytoplasmic transport are controlled by the fields of interactions resulting form gradients of regulatory molecules.

Some unusual features of Physarum polycephalum chromatin are due to the presence of slime

51%

Staroń K. , Jerzmanowski A. , Fronk J. , Toczko K.

Acta Biochimica Polonica

1980

tom 27

nr 3-4

413-420

Od cząsteczek do organizmów.

44%

Jerzmanowski A.

tom 49

nr 3

399-402

Transcriptionally active chromatin can be selectively released by DNase I from Physarum polycephalum genome

38%

Fronk J. , Jerzmanowski A. , Wiśniewski J. , Czupryn M. , Toczko K. , Wilhelm M. L. , Wilhelm F. X.

Acta Biochimica Polonica

1988

tom 35

nr 3

191-198

Binding of SPXK- and APXK- peptide motifs to AT-rich DNA. Experimental and theoretical studies

38%

Brzeski J. , Grycuk T. , Lipkowski A. W. , Rudnicki W. , Lesyng B. , Jerzmanowski A.

Acta Biochimica Polonica

1998

tom 45

nr 1

221-231

Histon H1 in modulation of chromatin transcriptional activity

38%

Jerzmanowski A. , David Cole R.

Acta Biochimica Polonica

1993

tom 40

nr 1

17-22