tailieunhanh - báo cáo khoa học: "Environment-dependent heterosis in Drosophila melanogaster"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Environment-dependent heterosis in Drosophila melanogaster | Génét. Sét. Evol. 1987 19 1 37-48 Environment-dependent heterosis in Drosophila melanogaster A. DOMINGUEZ and J. ALBORNOZ Departamento de Genética Universidad de Oviedo 33071 Oviedo Spain Summary Heterosis for viability rate of development and fecundity were measured in optimal or stress environments development at high larval density for preadult traits and both crowded development and low temperature for egg laying using diallei crosses among 5 inbred lines of D. melanogaster from different geographic origins. Some cases of significant heterosis for viability and rate of development were found but the results did not permit any general conclusion to be drawn about the effect of environment for these traits. Every pair of lines displayed heterosis for fecundity both under optimal and crowded development conditions while only 2 pairs of lines showed significant heterosis for fecundity at low temperature. Contrary to what is usually found for most traits heterosis for fecundity was greater in the optimal environment. Hybrids were more affected by environmental stress than their inbred parents but the error variance within environment was lower for the hybrids. This suggests that the greater homeostasis of hybrids to minor changes in environment can not be extended to major changes in the environment in which different sets of genes may be implicated. Key words Drosophila melanogaster heterosis genotype X environment interaction. Resume Hétérosis dépendante du milieu chez Drosophila melanogaster A partir d un diallele entre 5 lignées de D. melanogaster de differentes origines géographi-ques on a mesuré rhétérosis sur la viabilité la vitesse de développement et la fecondite dans un milieu optimal OU de stress haute densité larvaire pour la viabilite et la Vitesse de développement et développement à haute densité larvaire et basse temperature pour la ponte d oeufs . On a trouvé queiques cas d heterosis sur la viabilité et la Vitesse de developpement mais les résúltats