[Starch metabolism in potato tubers]. / Metabolizm skrobi w bulwach ziemniaka.

Sucrose is a substrate for starch biosynthesis, unloaded symplastically into the developing potato tubers. Sucrose is converted to glucose-6-phosphate in the cytosol and exported into the amyloplasts. Starch may be degraded either hydrolytically or phosphorolytically. Glucose and maltose are products of hydrolytic starch breakdown in the sprouting tubers. Glucose phosphates are products of the phosphorolytic activity, metabolized to glucose and fructose in cold-stored tubers. Development of molecular tools for assaying potato gene function provide opportunities to receive genetic progress in the sugar-starch potato breeding.

The structure of the synaptonemal complexes in meiocytes of European domestic goose (Anser anser).

The synaptonemal complex (SC) is a protein structure which binds two homologues during prophase of the first meiotic division and assures the correct course of genetic recombination. The demonstration and identification of SCs in European domestic goose Anser anser was the aim of the current research. Standard techniques of SC identification do not allow for an analysis of their molecular structure. In meiotic cells of one-day-old nestlings and 17-week-old geese the haploid number of bivalents, darkly stained kinetochores and subtelomeric regions may be evidence for the presence of SCs. Experimental chromosome staining with the DAPI fluorochrome permitted the observation of the characteristic ladder-like structure of SCs and the course of synapsis formation within homologues from early leptotene to their degradation in late pachytene. The detailed molecular structure of synaptonemal complexes can be analysed with an electron or scanning microscope only. Because the bivalent is a direct result of the complex's presence, in the literature the presence of bivalents is equivalent to the term "synaptonemal complex". However, the bivalent and the SC are two different structures.