Maternally Inherited Sex Ratio in the Parasitoid Wasp Nasonia vitripennis

ABSTRACT We detected genetic variation for the sex ratio in the parasitoid wasp Nasonia vitripennis by analysis of inbred lines and with an artificial selection experiment. Sex ratios differed significantly among five independently isolated lines. Furthermore, sex ratio in broods produced by single females in single hosts shifted from 80-90% female to 50-55% female in 13 to 15 generations in each of two replicate selection lines. The final sex ratios of both selection lines were significantly lower than any of the inbred line sex ratios. Backcrosses revealed that the selection response was due to nuclear genes acting through the female parent. In light of known facultative sex ratio behavior and major genes affecting sex ratio in Nasonia, our results suggest that population and individual sex ratios in this species are molded by processes at both genetic and behavioral levels.

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Effects on microhymenopteran progeny of different host exposure periods (Chrysomya megacephala, Calliphoridae) to the parasitoid wasp Nasonia vitripennis (Hymenoptera: Pteromalidae)

Brazilian Archives of Biology and Technology ◽

10.1590/s1516-89132010000100010 ◽

2010 ◽

Vol 53 (1) ◽

pp. 77-85 ◽

Cited By ~ 1

Author(s):

Renata da Silva Mello ◽

Gonzalo Efrain Moya Borja ◽

Valéria Magalhães Aguiar Coelho

Keyword(s):

Sex Ratio ◽

Exposure Time ◽

Development Time ◽

Parasitoid Wasp ◽

Glass Tube ◽

Nasonia Vitripennis ◽

Significance Level ◽

Chrysomya Megacephala ◽

Immature Development ◽

The Mean

To test the assumption that exposure of the host to parasitoid for long periods could provoke superparasitism, the aim of this work was to test the consequences on the immature development time, productivity of parasitoids per pupa, sex ratio and rate of parasitism of Nasonia vitripennis bred in Chrysomya megacephala pupae. Each individual pupa was placed in a glass tube with one parasitoid female for 24, 48, 72 and 96 h period of exposure, under controlled laboratory conditions. Twenty replicates of each period were performed. ANOVA with a 5% significance level was applied. The 72 h exposure caused the immature development time to increase. The mean parasitoids emergence per pupa did not vary significantly with the time of exposure. There were a significantly higher number of females than males and a trend in sex ratio deviation towards the females in all of the treatments. An increase in the number of unviable pupae rates were observed with increased exposure time.

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Effects of constrained females on offspring sex ratios of Nasonia vitripennis in relation to local mate competition theory

Canadian Journal of Zoology ◽

10.1139/z05-006 ◽

2004 ◽

Vol 82 (12) ◽

pp. 1969-1974 ◽

Cited By ~ 8

Author(s):

B H King ◽

J A D'Souza

Keyword(s):

Sex Ratio ◽

Empirical Studies ◽

Virgin Female ◽

Parasitoid Wasp ◽

Local Mate Competition ◽

Mate Competition ◽

Nasonia Vitripennis ◽

Competition Theory ◽

Local Mate ◽

Mated Female

Empirical studies of how constrained females affect sex ratio are few. Constrained females are those that can produce only sons (e.g., in haplodiploid species, females that have not mated or older females that have used up their sperm). In the parasitoid wasp Nasonia vitripennis (Walker, 1836), failure to mate soon after emergence increased the probability of a female being constrained and thus affected sex ratio directly. Local mate competition theory shows that whether a female is constrained can also affect sex ratio indirectly by affecting what sex ratio other females produce. However, this was not the case in N. vitripennis. A female's sex ratio was not significantly different when she was with another young mated female versus a virgin female or an old mated female depleted of sperm. These results suggest that N. vitripennis females may be unable to recognize whether another female is constrained. The increased proportion of sons in response to other females relative to when alone did not persist the day after exposure.

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Genomics of sex allocation in the parasitoid wasp Nasonia vitripennis

10.1101/2020.03.18.997619 ◽

2020 ◽

Author(s):

Bart A. Pannebakker ◽

Nicola Cook ◽

Joost van den Heuvel ◽

Louis van de Zande ◽

David M. Shuker

Keyword(s):

Genetic Variation ◽

Sex Ratio ◽

Sex Allocation ◽

Genetic Basis ◽

Genome Wide Association Study ◽

Parasitoid Wasp ◽

Nasonia Vitripennis ◽

Ratio Variation ◽

Genome Wide ◽

A Genome

AbstractBackgroundWhilst adaptive facultative sex allocation has been widely studied at the phenotypic level across a broad range of organisms, we still know remarkably little about its genetic architecture. Here, we explore the genome-wide basis of sex ratio variation in the parasitoid wasp Nasonia vitripennis, perhaps the best studied organism in terms of sex allocation, and well known for its response to local mate competition (LMC).ResultsWe performed a genome-wide association study (GWAS) for single foundress sex ratios using iso-female lines derived from the recently developed outbred N. vitripennis laboratory strain HVRx. The iso-female lines capture a sample of the genetic variation in HVRx and we present them as the first iteration of the Nasonia vitripennis Genome Reference Panel (NVGRP 1.0). This panel provides an assessment of the standing genetic variation for sex ratio in the study population. Using the NVGRP, we discovered a cluster of 18 linked SNPs, encompassing 9 annotated loci associated with sex ratio variation. Furthermore, we found evidence that sex ratio has a shared genetic basis with clutch size on three different chromosomes.ConclusionsOur approach provides a thorough description of the quantitative genetic basis of sex ratio variation in Nasonia at the genome level and reveals a number of inter-related candidate loci underlying sex allocation regulation.

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The effect of exposure to conspecifics on restlessness in the parasitoid wasp Nasonia vitripennis (Hymenoptera: Pteromalidae)

The Canadian Entomologist ◽

10.4039/n06-109 ◽

2007 ◽

Vol 139 (5) ◽

pp. 678-684 ◽

Cited By ~ 3

Author(s):

B.H. King

Keyword(s):

Habitat Quality ◽

Parasitoid Wasp ◽

Poor Quality ◽

The Other ◽

Dispersal Ability ◽

Nasonia Vitripennis ◽

Adult Females ◽

Selection For ◽

The Difference ◽

Abundance And Distribution

AbstractWhen habitat quality is variable, there should be strong selection for the ability to detect and respond to the variation. Adult females of the parasitoid wasp Nasonia vitripennis (Walker) are known to increase their restlessness (the proportion of time in locomotion) both during and after exposure to a poor quality host. Doing so provides a mechanism for leaving a poor host and potentially finding a better host. This study examined whether restlessness also changes in response to competition as indicated by the presence of adult conspecifics. Both restlessness and the probability of dispersing across an inhospitable environment were greater when a female was with another female than when she was alone. However, restlessness did not remain elevated after the other female was removed. In contrast with females, restlessness of males did not increase either during or after exposure to other males, and the probability of dispersing across an inhospitable environment was unaffected by the presence of another male. The difference between females and males may be related to differences in dispersal ability and in the abundance and distribution of hosts versus mates.

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Extensive zygotic control of the anteroposterior axis in the wasp Nasonia vitripennis

Development ◽

10.1242/dev.126.4.701 ◽

1999 ◽

Vol 126 (4) ◽

pp. 701-710 ◽

Cited By ~ 3

Author(s):

M.A. Pultz ◽

J.N. Pitt ◽

N.M. Alto

Keyword(s):

Parasitoid Wasp ◽

Axis Formation ◽

Gene Products ◽

Nasonia Vitripennis ◽

Anteroposterior Patterning ◽

Lethal Mutations ◽

Gap Genes ◽

Maternal Gene ◽

Zygotic Control ◽

Zygotic Genome

Insect axis formation is best understood in Drosophila melanogaster, where rapid anteroposterior patterning of zygotic determinants is directed by maternal gene products. The earliest zygotic control is by gap genes, which determine regions of several contiguous segments and are largely conserved in insects. We have asked genetically whether early zygotic patterning genes control similar anteroposterior domains in the parasitoid wasp Nasonia vitripennis as in Drosophila. Nasonia is advantageous for identifying and studying recessive zygotic lethal mutations because unfertilized eggs develop as males while fertilized eggs develop as females. Here we describe recessive zygotic mutations identifying three Nasonia genes: head only mutant embryos have posterior defects, resembling loss of both maternal and zygotic Drosophila caudal function; headless mutant embryos have anterior and posterior gap defects, resembling loss of both maternal and zygotic Drosophila hunchback function; squiggy mutant embryos develop only four full trunk segments, a phenotype more severe than those caused by lack of Drosophila maternal or zygotic terminal gene functions. These results indicate greater dependence on the zygotic genome to control early patterning in Nasonia than in the fly.

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The comparative biology of second sex ratio evolution within a natural population of a parasitic wasp, Nasonia vitripennis.

Genetics ◽

10.1093/genetics/124.2.385 ◽

1990 ◽

Vol 124 (2) ◽

pp. 385-396 ◽

Cited By ~ 2

Author(s):

S H Orzack

Keyword(s):

Sex Ratio ◽

Parasitic Wasp ◽

Comparative Biology ◽

Significant Heterogeneity ◽

Regression Analyses ◽

Nasonia Vitripennis ◽

Second Sex ◽

Sex Ratio Adjustment ◽

Optimality Models ◽

Isofemale Strains

Abstract Correlation and regression analyses indicate that isofemale strains extracted from a population of the parasitic wasp, Nasonia vitripennis, differ in the fit of their second sex ratios (those produced in previously parasitized hosts) to the predictions of the theory of optimal facultative sex ratio adjustment. Under the theory's simple assumptions about population structure, there is significant heterogeneity of fitnesses among the isofemale strains. The reasons underlying these types of heterogeneity must be understood before we can make statements about the nature of sex ratio evolution in this species. These results suggest that comparative analyses are essential for testing the qualitative predictions of optimality models.

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