scholarly journals Resistance to meiotic drive at the MD locus in an Indian wild population of Aedes aegypti

1977 ◽  
Vol 29 (2) ◽  
pp. 123-132 ◽  
Author(s):  
S. G. Suguna ◽  
R. J. Wood ◽  
C. F. Curtis ◽  
A. Whitelaw ◽  
S. J. Kazmi
Keyword(s):  
Sex Ratio ◽  
Aedes Aegypti ◽  
Genetic Control ◽  
Wild Population ◽  
Sex Ratios ◽  
Meiotic Drive ◽  
In The Wild ◽  
Ratio Distortion ◽  
Sex Ratio Distortion ◽  
Different Parts

SUMMARYFemales from an Indian wild population of Aedes aegypti were crossed to males carrying the sex ratio distorter factor MD which shows meiotic drive. Progenies from F1 males were tested for sex ratio distortion, i.e. the chromosomes from the wild females were screened for their resistance to the action of MD. The distribution of sex ratio in the progenies of different F1 males indicated a polymorphism in the wild population for resistant and sensitive variants of the X chromosome. Seven discrete categories of X appear to exist, associated with sex ratios ranging from 50% ♀ to less than 1·25% ♀. The overall level of resistance varied slightly but significantly in different parts of a town. The results are discussed in relation to the use of sex ratio distortion for genetic control of mosquitoes.

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.

Variation in Y chromosome meiotic drive in Aedes aegypti (Diptera: Culicidae): a potential genetic approach to mosquito control

1997 ◽  
Vol 87 (6) ◽  
pp. 617-623 ◽  
Author(s):  
K. O. Owusu-Daaku ◽  
R. J. Wood ◽  
R. D. Butler
Keyword(s):  
Sex Ratio ◽  
Aedes Aegypti ◽  
Y Chromosome ◽  
Reciprocal Cross ◽  
Mosquito Control ◽  
Meiotic Drive ◽  
Genetic Approach ◽  
Single Form ◽  
Ratio Distortion ◽  
Sex Ratio Distortion

AbstractReciprocal crosses between strains of Aedes aegypti (Linnaeus) from different geographical areas have revealed an unexpectedly complex pattern of holandrically inherited male biased sex ratios in F2. The variation has been interpreted in terms of a web of X–Y interactions in Fl, in which the Y chromosome may or may not show meiotic drive against the X chromosome with which it is paired. The pattern of inheritance is not in agreement with a single form of Y chromosome, driving with different degrees of intensity against Xs of different sensitivity, but indicates different forms of driving Y chromosome. A rule has emerged that if Fl males from any cross give rise to a male distorted sex ratio in their progeny (F2), the males from the reciprocal cross give rise to a normal sex ratio. All eleven newly colonized strains from Ghana showed Y meiotic drive against the Xs of five strains, one of American and four of Australian origin, although one of the eleven showed a greater degree of drive than the other ten against the same sensitive strains. The variation observed is discussed in relation to previous studies on meiotic drive by the MD haplotype, and to the possible exploitation of sex ratio distortion in controlling this potentially dangerous insect.

scholarly journals Sex Ratios in a Warming World: Thermal Effects on Sex-Biased Survival, Sex Determination, and Sex Reversal

2021 ◽  
Vol 112 (2) ◽  
pp. 155-164
Author(s):  
Suzanne Edmands
Keyword(s):  
High Temperature ◽  
Sex Ratio ◽  
Sex Determination ◽  
Heat Tolerance ◽  
Sex Ratios ◽  
Sex Reversal ◽  
Survival Sex ◽  
Ratio Distortion ◽  
Warming World ◽  
Sex Ratio Distortion

Abstract Rising global temperatures threaten to disrupt population sex ratios, which can in turn cause mate shortages, reduce population growth and adaptive potential, and increase extinction risk, particularly when ratios are male biased. Sex ratio distortion can then have cascading effects across other species and even ecosystems. Our understanding of the problem is limited by how often studies measure temperature effects in both sexes. To address this, the current review surveyed 194 published studies of heat tolerance, finding that the majority did not even mention the sex of the individuals used, with <10% reporting results for males and females separately. Although the data are incomplete, this review assessed phylogenetic patterns of thermally induced sex ratio bias for 3 different mechanisms: sex-biased heat tolerance, temperature-dependent sex determination (TSD), and temperature-induced sex reversal. For sex-biased heat tolerance, documented examples span a large taxonomic range including arthropods, chordates, protists, and plants. Here, superior heat tolerance is more common in females than males, but the direction of tolerance appears to be phylogenetically fluid, perhaps due to the large number of contributing factors. For TSD, well-documented examples are limited to reptiles, where high temperature usually favors females, and fishes, where high temperature consistently favors males. For temperature-induced sex reversal, unambiguous cases are again limited to vertebrates, and high temperature usually favors males in fishes and amphibians, with mixed effects in reptiles. There is urgent need for further work on the full taxonomic extent of temperature-induced sex ratio distortion, including joint effects of the multiple contributing mechanisms.

scholarly journals SEX RATIO DISTORTION CAUSED BY MEIOTIC DRIVE IN A MOSQUITO, Culex pipiens L

Genetics ◽  
1978 ◽  
Vol 88 (3) ◽  
pp. 427-446
Author(s):  
Theresa Luine Sweeny ◽  
A Ralph Barr
Keyword(s):  
Sex Ratio ◽  
Chromosome Pair ◽  
Culex Pipiens ◽  
Recessive Gene ◽  
Meiotic Drive ◽  
Female Offspring ◽  
Large Excess ◽  
Daughter Cells ◽  
Ratio Distortion ◽  
Sex Ratio Distortion

ABSTRACT A genetic factor, distorter (d), has been discovered that upsets the normal sex ratio of 1:1 and results in a large excess of males in Culex pipiens. The effect can be explained by a sex-linked, recessive gene. Males homozygous for the gene (Md/md) produce few female offspring; the effect is not due to postzygotic mortality. During the first meiotic division in spermatogenesis, the shortest chromosome pair, which, according to Jost and Laven (1971), is associated with sex determination, can be seen to be abnormal. In a high proportion of spermatocysts, one of the dyads of the shortest bivalent fragments, and the pieces are distributed irregularly to the daughter cells. It is believed that the female-determining chromosomes fragment. This would give rise to an excess of male-determining sperm. The possible usefulness of this factor for control or for experimental purposes is discussed.

Sex-Ratio Distortion Caused by Meiotic Drive in Mosquitoes

1991 ◽  
Vol 137 (3) ◽  
pp. 379-391 ◽  
Author(s):  
Roger J. Wood ◽  
Martha E. Newton
Keyword(s):  
Sex Ratio ◽  
Meiotic Drive ◽  
Ratio Distortion ◽  
Sex Ratio Distortion

scholarly journals Sex-ratio distortion in Drosophila simulans: co-occurence of a meiotic drive and a suppressor of drive

1995 ◽  
Vol 8 (3) ◽  
pp. 283-300 ◽  
Author(s):  
Herve Mercot ◽  
Anne Atlan ◽  
Micheline Jacques ◽  
Catherine Montchamp-Moreau
Keyword(s):  
Sex Ratio ◽  
Meiotic Drive ◽  
Drosophila Simulans ◽  
Ratio Distortion ◽  
Sex Ratio Distortion

Nutritional stress causes male-biased sex ratios in eastern spruce budworm (Lepidoptera: Tortricidae)

2014 ◽  
Vol 146 (2) ◽  
pp. 219-223 ◽  
Author(s):  
Roberto Quezada-García ◽  
Deepa Pureswaran ◽  
Éric Bauce
Keyword(s):  
Sex Ratio ◽  
Sex Ratios ◽  
Spruce Budworm ◽  
Nutritional Stress ◽  
Larval Survival ◽  
Normal Diet ◽  
Lower Percentage ◽  
Differential Mortality ◽  
Ratio Distortion ◽  
Sex Ratio Distortion

AbstractNutritional variability in resources may cause differential mortality between sexes resulting in biased sex ratios. If males and females differ in fitness, then mortality of the more sensitive sex can cause a bias in sex ratios, and can stimulate dispersion of males. We reared three generations of spruce budworm (Choristoneura fumiferana (Clemens); Lepidoptera: Tortricidae) on two artificial diets: a “normal” diet that provided all nutritional requirements for development and a “stress” diet (deficient in sugars and slightly higher in nitrogen), that simulated deterioration of food quality during outbreak conditions and had a detrimental impact on larval survival, development and growth. We tested the effects of continued nutritional stress on the sex ratio of pupae and adults. We found biased sex ratios in favour of males related to diet. Low quality food resulted in fewer females. This distortion was observed from the second generation onward, with a lower percentage of females reaching the pupal and adult stage. These results provide evidence that nutritional variation causes differential mortality between sexes, suggesting that females are more sensitive to nutritional stress. This is the first study that demonstrates sex ratio distortion due to nutritional selection pressure in spruce budworm. Our results indicate the importance of studying sex ratio distortion of spruce budworm in outbreak conditions.

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