Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học Journal of Biology đề tài: Latitudinal clines for alcohol dehydrogenase allozymic variation and ethanol tolerance in Indian populations of Drosophila ananassae | Genet Sei Evol 1994 26 217-228 Elsevier INRA 217 Original article Latitudinal clines for alcohol dehydrogenase allozymic variation and ethanol tolerance in Indian populations of Drosophila ananassae R Parkash Shamina Maharshi Dayanand University Department of Biosciences Rohtak 124001 India Received 17 June 1993 accepted 18 November 1993 Summary - Eight Indian geographical populations of D ananassae collected along a 20 N latitudinal range revealed significant clinal variation at the Adh alcohol dehydrogenase locus and AdhF allelic frequency increased by about with 1 latitude. Latitudinal increase of ethanol tolerance was observed in adults. Survival studies with adults showed that in all cases ethanol was used as a resource at low concentrations while becoming a stress at higher concentrations. The resource stress concentration threshold increased from to 4 with latitude. Larval behaviour also exhibited an attraction avoidance threshold increasing from to ethanol with increasing latitude of origin. The parallel occurrence of latitudinal variation at the Adh locus and ethanol tolerance and utilisation in natural populations of D ananassae could be maintained by balancing the natural selection which varies spatially along the northsouth axis of the Indian sub-continent. Drosophila ananassae Adh polymorphism ethanol utilisation larval behaviour latitudinal cline Resume Clines de latitude pour la variation allozymique de la déshydrogénase alcoolique Adh et la tolerance à 1 éthanol dans des populations indiennes de Drosophila ananassae. Huit populations géographiques indiennes de D ananassae récoltées sur une étendue de 20 degrés de latitude nord ont révélé une variation clinale significative au locus Adh déshydrogénase alcoolique et une augmentation de la frequence de 1 allèle AdhF d environ 1 5 point de pourcentage par degré de latitude. Une augmentation de la tolerance à 1 éthanol avec la latitude de 1 8 à 3 7 a été observée chez les adultes.
