ul. Lwowska 1, 87-100 Toruń
tel.: +48 56 611-25-05
fax: +48 56 611-47-72
e-mail: dwbios@umk.pl

Dariusz Jan Smolinski prof. NCU

Head of Department of Cellular & Molecular Biology

tel. +48 56 611-44-54

Research interests. Team conducts the research on nucleus?s functional domains (nuclear bodies) connected with mRNA and snRNA metabolism. Our research interests are mainly concerned with evolutionary conserved domains of the nucleus – the Cajal bodies (CBs). Our team study the regulation of expression during gametogenesis in plants. We would like to focus on nuclear retention of mRNA and on the newly-discovered role of post-transcriptional splicing and its role in the regulation of gene expression during the development and differentiation of cells. Understanding this mechanism will contribute significantly to the understanding of the processes involved in the maturation of germ cells in plants as well as post-transcriptional regulation of mRNA expression in eukaryotic cells.

Research subjects:

Cellular cycle of snRNPs. One of the issues our team is examinig is the connection between the appearance of cytoplasmatic bodies containing the snRNP components CsBs and the formation of new CBs. We believe that this research will provides new insights into the spatial regulation of crucial steps of small nuclear ribonucleoprotein assembly and maturation within a cell (hypothetical model- video1).

A new role of CBs in pre-mRNA metabolism. The essence of the problem is the new role of the Cajal bodies, associated with the accumulation of mRNA transcripts in CBs. This is related to a more general problem of nuclear retention of mRNA ( video2 & video3 ). The results of this study will give a vast body on data on the involvement of the CBs in the regulation of mRNA expression in eukaryotic cells.

Participation of Sm proteins in post-transcriptional regulation of gene expression in the cytoplasm. Sm proteins play a fundamental role in pre-mRNA splicing as being core component of snRNPs. To date, however, the literature lacks information concerning interaction between mRNA and Sm proteins in processes other than splicing in plants. Our research revealed cyclic occurence of large, spherical cytoplasmic bodies enriched in Sm proteins and mRNAs in larch microsporocytes. The aim of our work is to investigate the cytoplasmic interaction of Sm proteins with polyadenylated mRNAs.

Chromatin-based regulation of gene expression during meiotic prophase I. The occurrence of a diplotene diffusion stage has been observed in many plant species. Interestingly, they have also been observed during spermiogenesis and oogenesis in animals. In the European larch the diplotene stage lasts approximately 5 months and it is possible to divide it into several substages and to observe each of them in details. Larch microsporocytes display changes in chromatin morphology during this stage, alternating between 4 short stages of chromatin condensation (contraction) and 5 longer diffusion (relaxation) stages. Our research reveal a correlation between the chromatin decondensation and transcriptional activity. Similar meiotic process were observed during oogenesis in animals. This indicates the existence of an evolutionarily conserved mechanism of chromatin-based regulation of gene expression during meiotic prophase I.

These studies are not only basic research but also practical. Our research are also carried out in the Centre for Modern Interdisciplinary Technologies Nicolaus Copernicus University in Torun (ICNT) as a Bio-Imaging Lab. Understanding the mechanisms involved in normal development of gametes that enable proper fertilization can afford to obtain high quality seeds of such economically important plants as European larch.