Nucleic Acids Research, 1981, Vol. 9, No. 24 7013-7032
© 1981
MOLECULAR BIOLOGY |
Sequence complexity and diversity of polyadenylated RNA molecules of human normal resting, PHA-stimulated and leukemic lymphocytes
Centre for Experimental Haematology, Institutes of Clinical Medicine and Biochemistry, University of Modena 41100 Modena, Italy
*To whom correspondence should be addressed
Received September 15, 1981. The abundance and complexity of total poly(A)+RNA of human normal unstimulated lymphocytes,PHA-stimulated and leukemic lymphocytes were examined using the cDNA-poly(A)+ RNA hybridization technique. It was found that in both PHA-stimulated and leukemic lymphocytes the complexity of total poly(A)+RNA is strongly reduced in respect to normal unstimulated lymphocytes. The difference is due to a small portion,by weight,of high complexity sequences,suggesting the involvement of nuclear,not necessarily transcriptional,events. Moreover the heterologous hybridizations show that:1)in PHA-stimulated lymphocytes there is a set of highly abundant sequences which are represented in normal and leukemic lymphocytes at a very reduced rate;2)the sequences abundant in normal unstimulated lymphocytes are less represented in leukemic lymphocytes;the converse also is true,but at a lower extent. On the basis of available data,it is suggested that the observed changes in the abundance pattern of PHA-stimulated lymphocytes may be related mainly to a difference in the half-life of the mRNAs,while those of leukemic lymphocytes require some transcriptional or post-transcriptional nuclear event.