scholarly journals Opposing effects of mortality factors on progeny operational sex ratio may thwart adaptive manipulation of primary sex ratio

2017 ◽  
Vol 7 (13) ◽  
pp. 4973-4981 ◽  
Author(s):  
Gaétan Moreau ◽  
Eldon S. Eveleigh ◽  
Christopher J. Lucarotti ◽  
Benoit Morin ◽  
Dan T. Quiring
Keyword(s):  
Sex Ratio ◽  
Operational Sex Ratio ◽  
Mortality Factors ◽  
Primary Sex Ratio ◽  
Opposing Effects

scholarly journals Sex Chromosome Meiotic Drive in Stalk-Eyed Flies

Genetics ◽  
1997 ◽  
Vol 147 (3) ◽  
pp. 1169-1180 ◽  
Author(s):  
Daven C Presgraves ◽  
Emily Severance ◽  
Gerald S Willrinson
Keyword(s):  
Sex Ratio ◽  
Sex Chromosome ◽  
Sex Ratios ◽  
Natural Populations ◽  
Meiotic Drive ◽  
Operational Sex Ratio ◽  
Genetic Modifiers ◽  
Ratio Distortion ◽  
The Impact ◽  
Sex Ratio Distortion

Meiotically driven sex chromosomes can quickly spread to fixation and cause population extinction unless balanced by selection or suppressed by genetic modifiers. We report results of genetic analyses that demonstrate that extreme female-biased sex ratios in two sister species of stalk-eyed flies, Cyrtodiopsis dalmanni and C. whitei, are due to a meiotic drive element on the X chromosome (Xd). Relatively high frequencies of Xd in C. dalmanni and C. whitei (13–17% and 29%, respectively) cause female-biased sex ratios in natural populations of both species. Sex ratio distortion is associated with spermatid degeneration in male carriers of Xd. Variation in sex ratios is caused by Y-linked and autosomal factors that decrease the intensity of meiotic drive. Y-linked polymorphism for resistance to drive exists in C. dalmanni in which a resistant Y chromosome reduces the intensity and reverses the direction of meiotic drive. When paired with Xd, modifying Y chromosomes (Ym) cause the transmission of predominantly Y-bearing sperm, and on average, production of 63% male progeny. The absence of sex ratio distortion in closely related monomorphic outgroup species suggests that this meiotic drive system may predate the origin of C. whitei and C. dalmanni. We discuss factors likely to be involved in the persistence of these sex-linked polymorphisms and consider the impact of Xd on the operational sex ratio and the intensity of sexual selection in these extremely sexually dimorphic flies.

The Life-History of Badumna-Candida (Araneae, Amaurobioidea)

1993 ◽  
Vol 41 (5) ◽  
pp. 441 ◽  
Author(s):  
MF Downes
Keyword(s):  
Sex Ratio ◽  
Egg Production ◽  
Production Cycle ◽  
Social Spider ◽  
Social Spiders ◽  
Primary Sex Ratio ◽  
The Social ◽  
The Status ◽  
History Of ◽  
Changes Over Time

A two-year study of the social spider Badumna candida at Townsville, Queensland, provided information on colony size and changes over time, maturation synchrony, temperature effects on development, sex ratio, dispersal, colony foundation, fecundity and oviposition. Key findings were that B. candida outbred, had an iteroparous egg-production cycle between March and October, had an even primary sex ratio and achieved maturation synchrony by retarding the development of males, which matured faster than females at constant temperature. There was no overlap of generations, the cohort of young from a nest founded by a solitary female in summer dispersing the following summer as subadults (females) or subadults and adults (males). These findings confirm the status of B. candida as a periodic-social spider (an annual outbreeder), in contrast to the few known permanent-social spider species whose generations overlap. Cannibalism, normally rare in social spiders, rose to 48% when spiders were reared at a high temperature. This may be evidence that volatile recognition pheromones suppress predatory instincts in social spiders.

scholarly journals Primary sex ratio adjustment to experimentally reduced male UV attractiveness in blue tits

2006 ◽  
Vol 17 (4) ◽  
pp. 539-546 ◽  
Author(s):  
Peter Korsten ◽  
C. (Kate) M. Lessells ◽  
A. Christa Mateman ◽  
Marco van der Velde ◽  
Jan Komdeur
Keyword(s):  
Sex Ratio ◽  
Primary Sex Ratio ◽  
Sex Ratio Adjustment ◽  
Blue Tits

scholarly journals Deer Indirectly Alter the Reproductive Strategy and Operational Sex Ratio of an Unpalatable Forest Perennial

2020 ◽  
Vol 195 (1) ◽  
pp. 56-69
Author(s):  
Lalasia Bialic-Murphy ◽  
Christopher D. Heckel ◽  
Robert M. McElderry ◽  
Susan Kalisz
Keyword(s):  
Sex Ratio ◽  
Reproductive Strategy ◽  
Operational Sex Ratio
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