Hydroxyurea-resistant Aedes albopictus mosquito cells were selected by incr
emental exposure of unmutagenized cells to hydroxyurea concentrations rangi
ng from 0.1 to 8 mM, Clonal populations that had become 40-fold more resist
ant to hydroxyurea than wild-type cells varied in morphology, and their gro
wth rate decreased to a similar to 45 h doubling time, relative to an 18 h
doubling time in unselected cells. At this level of resistance, the cells r
emained diploid, with a modal chromosome number of 6, When labelled with S-
35[methionine/cysteine], clone HU1062, which grew in the presence of 8 mM h
ydroxyurea, overproduced a labeled protein with the approximate size of the
45,000 dalton M2 subunit of ribonucleotide reductase, Consistent with this
observation, ribonucleotide reductase activity in HU-1062 cells was approx
imately 10-fold higher than in wild-type control cells. This is the first e
xample of an hydroxyurea-resistant insect cell line. (C) 1997 Wiley-Liss, I
nc.