An adaptive chromosomal polymorphism affecting size-related traits, and longevity selection in a natural population ofDrosophila buzzatii

Genetica ◽  
1995 ◽  
Vol 96 (3) ◽  
pp. 285-291 ◽  
Author(s):  
Fabian M. Norry ◽  
Juan C. Vilardi ◽  
Juan J. Fanara ◽  
Esteban Hasson ◽  
Constantina Rodriguez
Genetics ◽  
1978 ◽  
Vol 90 (4) ◽  
pp. 783-800
Author(s):  
Hui Fang Yu ◽  
Eliot B Spiess

ABSTRACT In a natural population of Drosophila persimilis (McDonald Ranch, Napa Valley, California), KL and MD chromosomal arrangement frequencies undergo a seasonal cycle, with MD common in spring and KL common in summer. Samples collected from spring and summer provided isofemale strains established as homozygous KL and MD pairs (kinlines) with each pair derived from a single heterokaryotype wild progenitor. Haploid doses of chromosomes 2 and 4 were controlled by marker-cross derivations of kinlines. Percentage onset of female receptivity was measured from cultures at 25° and at 15°, using ten kinlines from spring and nine from summer collections, with fast-mating hybrid males as standard testers. Mating tests consisted of 20 tester males x 20 females of specific age, karyotype, and kinline observed for 30 min. At 25° females became receptive at 48 hr after eclosion: parental line (KLi/KLi and MDi/MDi) females were approximately equal at 55 to 60% receptive, while among hybrids, MDi/MDj homokaryotype females were significantly less receptive (68%) than all other outbred combinations (73 to 77%). At 15°, females became receptive at four days of age, with increases on the fifth and sixth days: both parental line and outbred MD/MD females were significantly more receptive (28% at four days and 62% at six days) than all heterokaryotype females (20 to 26% at four days and 55 to 59% at six days), which in turn were more receptive than KL/KL parental and outbred females (10% at four days and 40% at six days). Heterosis was expressed at 25°, but not at 15°. Thus, dominance for female receptivity was temperature dependent. Females polymorphic for these third chromosomal karyotypes possess differential temperature sensitivity for onset of receptivity and are likely to contribute in a significant way to the observed seasonal frequency cycle in the natural population from which they have been derived.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Maciej Ligaszewski ◽  
Przemysław Pol

AbstractThe aim of this study was to compare the quality of clutches and reproduction results of two groups of Roman snails (Helix pomatia) from the same local population, laying eggs simultaneously in semi-natural farm conditions and in a natural habitat. The study material were Roman snails aged 2 or more years which had entered the third phenological season of their life and thus the first season of sexual maturity. Observations were conducted at an earthen enclosure in a greenhouse belonging to the experimental farm for edible snails at the National Research Institute of Animal Reproduction in Balice near Kraków (Poland) as well as at a site where a local population naturally occurs in the uncultivated park surrounding the Radziwiłł Palace. In the June-July season, differences among such parameters as weight of clutch, number of eggs in clutch, mean egg weight, and hatchling percentage when compared to the total number of eggs in the clutch were compared. It was determined that clutches of eggs from the natural population laid in the greenhouse were of lesser weight (P<0.01), contained fewer eggs (P<0.05), and the mean weight of individual eggs was less (P<0.05) than in clutches laid simultaneously in a natural habitat. Both in the greenhouse and the natural habitat, in the first phase of laying eggs (June) the weight of the clutch and number of eggs its contained were greater than in the second phase (July). However, only for snails laying eggs in the greenhouse were these differences statistically significant (P<0.05) and highly significant (P<0.01), respectively. Statistically significant differences were not observed in hatchling percentage between eggs laid in the greenhouse and the natural habitat. The lower number of eggs laid in the farmed conditions of the greenhouse was successfully compensated for by the absence of mass destruction by rodents which occurred in the natural habitat.


2012 ◽  
Vol 37 (11) ◽  
pp. 1967-1974 ◽  
Author(s):  
Li HUANG ◽  
Xin-Yan ZHAO ◽  
Wen-Hua ZHANG ◽  
Zhi-Ming FAN ◽  
Xiao-Ping REN ◽  
...  

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