Chironomus thummi

CD spectra have also been used to establish the presence of El-dependent conformational isomers in ferrihemoglobin of Chironomus thummi, which had been postulated earlier from EPR data (154), and also of conformational isomers of horse ferrihemoglobin (155). Correlations between ellipticity changes and the Bohr effect (154, 156) and between the optical activity of heme transitions in hemoglobin derivatives and their absorption and magnetic properties have been suggested (157) [see also (155, 152]). 

In contrast to the high a-helix contents of sperm whale myoglobin or horse hemoglobin, a respiratory hemoprotein from Chironomus thummi had about one third less a-helix content as estimated from its rotation at 233 nm (153) lamprey hemoglobin also indicated less a-helix content (179, 144). 

Fig. 4.23. b) Representatives of smaller water animals. Others 7 — Plumatella repens (5 mm), 8 — Larva of Chironomus thummi (10-12 mm), 9 — Phryganea grandis (caddis-ily) imago, larva without and with receptacle, and different receptacles (15-20 mm), 10 — water-spider Argyroneta aquatica (10-20 mm) with its air bell, 11 — shell of Lym-... 

Wobus U. (1975). Molecular characterization of an insect genome Chironomus thummi. Fur. J. Biochem. 59 287-93. 

Histone acetylation has been observed in the salivary chromosomes of Chironomus thummi when RNA synthesis is active. Although acetylation can be demonstrated by radioautographic methods, there seems to be no way to measure its extent exactly. It is not known whether histone acetylation and RNA synthesis are related and, for example, if histone synthesis is a necessary prerequisite for the synthesis of RNA [73]. 

Fig. 10. Incorporation of H -uridine in RNA of chromosome 1 of the salivary gland in Chironomus thummi with the induced heterozygous puffs. Top, the squash preparation, aceto-acid carmine staining. Bottom, the autography of the heterozygous puffs in the Ie2, Ifl, and If4 regions. Only two puffs (Ifl and If4) are heterozygous on the squash preparation. (After Serfling et al., 1969)...

Fig. 12. Changing of activity of the main puffs in salivary glands chromosomes during Chironomus thummi development.

Furthermore, no differences were found in the electrophoretic spectra of salivary gland proteins in two strains of Chironomus thummi with either two or three Balbiani s rings. In the strain with an additional ring of Balbiani, intensive RNA synthesis was observed (Wobus et al., 1971). 

Laufer, H., Nakase, Y., and Vanderberg, J. (1964). Developmental studies of the dipteran salivary gland. I. The effects of actinomycin D on larval development, enzyme activity, and chromosomal differentiation in Chironomus thummi. Develop, Biol. 9, 367-384. 

---