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P G Svetlov

Publications and source records attributed to P G Svetlov.

18 recordsLinked to original sources
PubMed1976

[Critical periods in the development of mutants in scute Drosophila melanogaster].

Thermosensitive periods of the development of germs of separate pairs of macrochaetae were studied in two lines of mutation of scute Drosophila melanogaster (y/sc4B and cs7). The experiments have revealed the following three features which had not been observed earlier in similar investigations in other mutants of drosophila: 1) change of thermosensitivity in mutants sc7 in different periods of ontogenesis; 2) different sensitivity in mutants of both lines in different critical periods of the same pair of macrochaetae; 3) discrete sensitivity of separate macrochaetae in mutants of both lines at different stages of oogenesis when there are no germs of these organs yet. The change of penetrability of the mutation of scute for scuttellar macrochaetae in mutants y/sc4B caused by the 90-minute-long heating of larvae on the 4th day of their life (critical period of development) is inherited in 15 observed generations of the maternal line. One may consider these periods of the increased thermosensitivity to be tje periods of stepwise determination of germs of separate pairs of macrochaetae.

Animals↗
PubMed1975

New data on the hereditary adaptive increase in thermostability in the forked mutant of Drosophila melanogaster under repeated thermal shock.

It was confirmed that forked mutants of D. melanogaster strain C(I)RM developing after a single intrauterine heating of oocytes in females at 39 degrees for 30 and 45 min exhibited changes in the average number of anomalous thoracic macrochaetae on females: heating for 30 min caused a decrease (normalization of the phenotype), while heating for 45 min caused an increase (intensification of mutation expression). It was established that these changes are inherited maternally, in the same manner as long-term Jollos modifications. Evaluation of the number of anomalous thoracic macrochaetae in parallel strains of flies after heating of the oocytes during the critical periods of macrochaeta development (seven days before egg laying), i.e., the stage of oocyte formation in the germarium. Heating of oocytes in F2t1 females "preliminarily heated in the F1 generation showed that the stability curve for the oocytes after "preliminary" heating during the critical developmental period exhibited an abrupt decrease rather than the anticipated rise, which can only be attributed to an adaptive increase in oocyte thermostability as a result of preliminary heating.

Adaptation, Biological↗
PubMed1975

Adaptive changes in degree of eye reduction in eyeless mutants of Drosophila melanogaster after thermal shock during the critical periods of faceted eye development.

Brief heating of the oocytes and larvae of eyeless mutants during the critical periods of faceted-eye development caused an increase in the thermal sensitivity of the eye rudiments, which led to an increase in the number of one-eyed individuals among the flies that hatched. These changes eye development were transmitted through a number of successive generations without exposure to additional thermal shock, by maternal inheritance. It was established that repeated heating of oocytes and larvae of eyeless mutants whose ancestors had been subjected to similar heating during the same stages of development caused a decrease rather than the expected increase in thermal sensitivity, i.e., there was an adaptive increase in the thermostability of the eye rudiments. Thus, the effect of reheating was the opposite of that of the original heating.

Animals↗