Heat and cold-induced male sterility in Drosophila buzzatii: genetic variation among populations for the duration of sterility

Abstract

Here we studied three phenotypic traits in Drosophila buzzatii that are strongly effected by temperature, and are expected to be closely associated with fitness in nature. The traits measured were thermal threshold of male sterility, time for males to gain fertility when reared at a sterility-inducing temperature and transferred to 251C on eclosion and survival after development. The last two traits were measured under four temperature regimes, constant 121C, 251C, 311C, and fluctuating 251C (18 h) and 381C (6 h). We looked for genetic variation in these traits and relations among them in four lines of D. buzzatii originating from Argentina and Tenerife. The thermal threshold of heat-induced male sterility was found to lie within the range of 30.0-31.01C. When measuring the time for males to gain fertility, males reared at a nonstressful temperature (251C) were fertile 58-67 h after emergence with only minor differences among lines. When reared constant 311C, males were fertile 174-225 h after hatching. The Argentinean lines were significantly faster in recovering from sterility than were the lines from Tenerife. When reared in a fluctuating temperature regime, differences among lines increased, dividing the lines into three significantly different groups, with a sterility period of 135-215 h. When reared at 121C from the pupal stage, males were fertile after 106-130 h with significant difference in the variance but not in the mean duration of sterility. Significant differences in viability were found among development temperatures, but not among lines, and viability and the duration of sterility seem to be genetically independent.

Heat induced male sterility inDrosophila melanogaster: adaptive genetic variations among geographic populations and role of the Y chromosome

“…Interestingly, male sterility at high temperature is evident in all species investigated so far (Chakir et al, 2002;Vollmer et al, 2004;Araripe et al, 2004). The sterility threshold, however, varies among species, and most temperate species cannot be grown at 30°C.…”

“…After transfer to a mild, permissive temperature, males may eventually recover fertility. In several species, recovery time is proportional to the sterilizing temperature (Chakir et al, 2002;Vollmer et al, 2004;Araripe et al, 2004) and may take up to 10 days, which is equivalent to the duration of spermatogenesis (Lindsley and Tokuyasu, 1980). Possibly, therefore, heatinduced perturbations are expressed at the level of germ cells themselves.…”

Environments and evolution: interactions between stress, resource inadequacy and energetic efficiency

“…As already noted in Section I (2), this is not an easy task. Vollmer et al (2004) ascertained that the thermal threshold for heat-induced male sterility in D. buzzatii is in the narrow range of 30.0-31.0 xC, which is higher than that for D. melanogaster and D. simulans, and could contribute to the ability of D. buzzatii to inhabit more extreme habitats. The difficulty of transferring from the benign environments of the laboratory to the unpredictability of the field is clearly highlighted, as will be illustrated below.…”

The Expression Quantity Changes of Leptocybe invasa Fisher & LaSalle (Hymenoptera Eulophidae) hsp70 under High Temperature Stress

“…The survival rate was 96.67% after 1h of exposure within the range from 35 to 42 , so that 1h of exposure to high temperature could not significantly affect the survival rates of L. invasa adults. Organisms in the process of high temperature stress, their expression of heat shock protein will consume large amounts of matter and energy, which leads to the organism growth hindered, spawning decreased, offspring adaptability reduced [18][19][20] . Leptocybe invasa Fisher & LaSalle in the high temperature stress, if its' hsp70 over expression will effect the insects' biological characteristics and population develop, that is worth to deeply research.…”