A previous posting (Forsdyke, 1993. Molbio.evol 107, 1623est) reads:
I am looking for recent work on dosage compensation in birds, butterflies,
snakes and other species with Z/W chromosome systems. The best references I
have are Johnson and Turner (1979) Heredity 43, 71-77 and
Baverstock et al., (1982) Nature 296, 763-766.
I will be checking the Science Citation Index to see who is citing these
papers now but there may be some papers I miss. Can anyone help?
I have had a few replies,which indicate that there is very little work going
on at present on this problem in birds and butterflies. The references I cite
report only enzyme ACTIVITIES and NOT protein QUANTITIES. Sometimes, even in
dosage compensated species, sex-chromosome-linked enzyme activities can differ
quite markedly between the two sexes (Steel and Midgeon, 1973. Biochem. Genet.
9, 163-170). So the issue of whether sex-chromosome dosage compensation exists
in birds and butterflies is still up in the air.