Biological, cytomorphological and karyological heterogeneity of transformed cell lines derived from domestic pig (Sus scrofa L.) organs

Abstract

The main advantage of transformed cell lines as compared to primary ones is that they allow generation of the stable material suitable for long-term research and practical use. Therefore, development of new continuous cell cultures from various animal tissues is of great practical importance. Results of examination of transformed cell lines derived from organs of domestic pigs (Sus scrofa L.) for their biological, cytomorphological and karyological features are described in the paper. The said cell cultures are confirmed to be susceptible to various animal viruses. Also, a procedure for preparation of new diploid cell culture from porcine spleen (SSs – Splеen Sus scrofa) is described. Based on the obtained data analysis it was concluded that the epithelial cells derived from trypsinized porcine spleens could be successfully immortalized. All transformed cell lines of porcine origin have similar morphology with predominated epithelium-like forms. Some of them – SPEV, А4 С2 , RSK – tend to adopt a spherical shape in suspension. Such cell lines as PSGK-30 and PPES cell lines form partial multilayer or they are characterized by significant monolayer compaction with pseudosyncytium formation. Only pseudodiploid cell culture (SPEV cell culture) tends to grow in suspension, it also grows in rotating culture flasks. Karyological transformations in different cell cultures stabilized at certain level. Spontaneous increase in chromosome numbers in the main population of transformed cell lines towards triploidy resulted in stabilization of culture properties and increase in proliferation. PSGK-30 cell culture has the highest modal class – 64 chromosomes. Near-diploid cultures (А4 С2 , RSK) demonstrate stable growth properties and are similar to SPEV cell culture in adopting spherical cell forms in medium, monolayer character and cell morphology. PK-15 cell culture having a distinct karyotype under different cultivation conditions while retaining other culture properties is found to be the most adaptive. A new transformed diploid SSs cell culture is developed by long-term incubation, subcultivation (more than 80 passages) and selection at the FGBI “ARRIAH” laboratory; it can remain diploid or may spontaneously become heteroploid-immortalized during further passaging. The cell hyperploidy is very likely to enhance telomerase activity, which in turn stabilizes immortalization and results in proliferative activity increase The cell viability has been maintained so far by regular reseedings (split ratio – 1:2–1:3) performed 1–2 times a week.

Keywords

• transformed cell line
• continuous cell line
• hybridoma
• diploidy
• heteroploidy
• modal class of cells
• proliferative activity