Evidence from neuronal heterokaryons for a trans-acting factor suppressing Thy-1 expression during neuronal development.
The expression of Thy-1 on developing sensory neurons cultured in vitro is strictly regulated and follows a temporal course identical to that observed in situ. We have investigated the role of trans-acting factors in this innate regulation by constructing heterokaryons between mature Thy-1.1+ expressing neurons and immature Thy-1.2- neurons. It has been observed by immunofluorescence that within 16 hr of fusion, Thy-1.1 expression is suppressed in such heterokaryons. However, this suppression is reversible, and after 3-4 days in vitro, at the time at which Thy-1.2 is normally expression, there is re-expression of the Thy-1.1 molecule producing Thy-1.1+/Thy-1.2+ co-expressing heterokaryons. As nuclear fusion does not occur, it appears that a developmentally regulated diffusible suppressor molecule is responsible for these observations.
Saleh
M
M
Walter and Eliza Hall Institute of Medical Research, Royal Melbourne Hospital, Victoria, Australia.
Bartlett
P F
PF
D000818:Animals; D000911:Antibodies, Monoclonal; D000954:Antigens, Surface / Q000235:genetics / Q000378:metabolism*; D002467:Cell Nucleus; D002478:Cells, Cultured; D005727:Ganglia, Spinal / Q000166:cytology / Q000254:growth & development / Q000378:metabolism*; D005786:Gene Expression Regulation; D006822:Hybrid Cells / Q000378:metabolism*; D007150:Immunohistochemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D009475:Neurons, Afferent / Q000166:cytology / Q000378:metabolism* / Q000502:physiology; D013489:Suppression, Genetic; D018800:Thy-1 Antigens
D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D018800:Thy-1 Antigens