Yakiv Ivanovych Ratushnyak

Revision as of 11:20, 13 May 2009

M.Sc., Ph.D

Date & Place of birth

April 5, 1961; Studena, Vinnytsya distr., Ukraine

Contacts

Education & Degrees

Positions Held

Teaching experience

Grants

Summary of Research Activities

As a MSc student, I worked on protoplast culture and plant regeneration of Lycium barbarum (woody bush).

My PhD thesis was devoted to obtaining and analysing transgenomic plants of: L. esculentum with L. peruvianum var. dentatum, L. pennellii, L. hirsutum var. glabratum, Solanum rickii and Lycium barbarum. The results obtained and perspective of future investigations of fertile asymmetric somatic hybrids L. esculentum + L. peruvianum var. dentatum were announced in Rice Biotechnology Quarterly (Gamma Fusion of Tomato Protoplasts, 1991, V 8, p 38-39).

My postdoctoral work started with studies of tomato cybrid plants with chloroplasts of L. peruvianum var. dentatum and reconstructed mitochondria with phenotypic traits of nucleo-cytoplasmic incompatibility.

Then cybrid plants of L. peruvianum var. dentatum were obtained containing tomato chloroplasts and L. peruvianum var. dentatum mitochondria that along with cybrid tomato/peruvianum could serve as an excellent model for studies of nuclear-cytoplasmic and chloroplast-mitochondrial interactions.

Also, by restriction analysis of chloroplast DNA for asymmetric somatic hybrids between L. esculentum and L. peruvianum var. dentatum the presence of the new nonparental patterns was shown. Blot-hybridization of chloroplast DNA with Nicotiana tabacum chloroplast DNA fragments revealed rearrangements which might be interpreted as recombination of chloroplast DNA.

At the same time, for fertile asymmetric somatic hybrids L. esculentum + L. peruvianum var. dentatum a considerable genetic variability was shown. Morphological, cytogenetic, isozyme, ribosomal DNA and random amplified polymorphism DNA analyses of F1 and F2 progenies obtained after self-pollination of somatic hybrids revealed new nonparental patterns of DNA and enzymes, chromosome elimination and variation of leaf morphology.

Also, in collaboration with Prof. C.M.Rick (Tomato Stock Center, Davis, USA) we studied protoplast culture of other species of Petota section S. ochrantum, S. juglandifolium, as well as possibilities of their somatic hybridization with tomato.

Then I worked on genetic transformation of Arabidopsis by leaf-disk and root co-cultivation with Agrobacterium in a project named “Identification, isolation and analysis of stress-induced plants genes in Arabidopsis thaliana by T-DNA tagging and gene fusion” funded by the INTAS.

Also, I worked on obtaining haploid plants from Petunia cultivars and Nicotiana species (using anther and pollen culture). These are used in activation tagging experiments aimed to achieve genetic transformation by co-cultivation of haploid protoplasts with Agrobacterium. Co-cultivation allowed the selection some PEG- and salt-resistant clones of N. tabacum. These clones might become useful material to isolate salt- and PEG-resistant plants, and to identify genes responsible for salt- and PEG-resistant. I also study possibilities of the use of diploid protoplasts of Arabidopsis thaliana in these experiments. The title of the project is “Activation tagging Arabidopsis thaliana and Petunia hybrida” and it is funded by the Royal Society and NATO.

At present, I am studying possibilities for successful integration of foreing sequences into plastome of some Solanaceae species via PEG-mediated protoplast transformation.