Cell Culture and Karyotype of Sakhalin Sturgeon Acipenser mikadoi

Vishnyakova KS, Mugue NS, Zelenina DA, Mikodina EV, Kovaleva OA, Madan GV, Yegorov YE

Cell culture of a rare threatened species of Sakhalin sturgeon Acipenser mikadoi, was obtained from a fragment of pectoral fin and neighboring tissues. At the beginning the Culture consisted of cells of different types including typical fibroblasts as well its cells of epithelial origin, myofibroblasts, etc. After approximately five passages, the culture contained mainly cells of fibroblast morphology. In the normal Culturing conditions, these cells grew for more than one year with constant rate and passed approximately 80 population doublings. In the absence of serum, the cells passed into the state of proliferative quiescence (Go- state). After it long culturing without media replacement the cells fused and formed myofibers about 1 cm long. These myofibers exhibited an ability to branch out and with time acquired cross striation. After cultivation for approximately 40 days, myofibers degenerated, lost their morphological features, detached from the substrate, and died. Induction of adipogenic differentiation led to the proliferation arrest and appearance of lypophilic inclusions in some cells. The quantity of these inclusions was restricted; cells with inclusions considerably varied by morphology and did not resemble adipocytes. Induction of osteogenic differentiation led to the emergence of cells producing mineralized extracellular matrix and formation of bone nodules. Chromosome analysis revealed a set of chromosomes typical for several sturgeon species. The variability of the chromosome numbers was very high (mean 247 +/- 33, mode 248). Using AT- and GC-specific fluorescent ligands it was found that telomeric and centromeric regions of all chromosomes are enriched by GC-sequences. Distribution of AT- and GC-rich sequences among chromosomes was heterogeneous. Long chromosomes were preferentially stained by an AT-specific DAPI whereas small chromosomes had brighter fluorescence after 7-aminoactinomycin D treatment. Several small chromosomes fluoresced extremely bright after that. Our work is a first attempt. of the Sakhalin sturgeon cell Culturing and karyotype analysis.