V-myb oncogene and c-myb proto-oncogene expression in avian cells: morphological changes of the cells and topographic localization of myb proteins.
Morphological changes of avian cells expressing the v-myb oncogene or c-myb proto-oncogene were studied by means of electron microscopy. Expression of both genes lead to distinct morphological changes of these cells. The nucleus of LSCC-BM2 cells espressing v-myb gene was of normal size but usually of irregular shape. It contained large unravelled nucleoli with typical interstices in some cells. Small nucleolar structures were also localized in the periphery of nuclear membrane. Nuclear envelope revealed reduced perinuclear space between two membranes. LSCC-BK3 cells expressing the c-myb gene were characterized by distinctly enlarged nucleus, in most cases of irregular shape. It contained only one nucleolus markedly enlarged, often unravelled, with apparent interstitial area. Nucleoli with nucleolonemas were observed in some cells. Nuclear envelope formed by two obscure membranes showed reduced perinuclear space. Topographic localization of v-Myb and c-Myb protein products was not basically different, both being detected in the nucleus of avian cells. v-Myb and c-Myb markers were distributed mostly in clusters, usually associated with interchromatin granules, but some marker was associated also with the nuclear membrane. Both Myb products were never detected in nucleolar structures of avian cells. Morphological changes of avian cells expressing myb genes and topographic localization of Myb proteins in these cells were different from those found in the insect cells expressing myb genes. The observed differences are discussed.
Korb
J
J
Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Praha, Czech Republic.
Stokrová
J
J
Karafiát
V
V
Dvoráková
M
M
Cermáková
V
V
D000818:Animals; D001717:Birds; D002460:Cell Line; D015870:Gene Expression; D020626:Oncogene Proteins v-myb; D011518:Proto-Oncogene Proteins / Q000235:genetics* / Q000378:metabolism; D020598:Proto-Oncogene Proteins c-myb; D011817:Rabbits; D015682:Retroviridae Proteins, Oncogenic / Q000235:genetics* / Q000378:metabolism; D015534:Trans-Activators / Q000235:genetics* / Q000378:metabolism
D020626:Oncogene Proteins v-myb; D011518:Proto-Oncogene Proteins; D020598:Proto-Oncogene Proteins c-myb; D015682:Retroviridae Proteins, Oncogenic; D015534:Trans-Activators