Sex-ratio distorters and other selfish genetic elements: implications for biological control.

2009 ◽  
pp. 235-252 ◽  
Author(s):  
R. Stouthamer
Keyword(s):  
Biological Control ◽  
Sex Ratio ◽  
Genetic Elements ◽  
Selfish Genetic Elements

scholarly journals Transposable element control disrupted by meiotic drive in a stalk-eyed fly genome

2020 ◽  
Author(s):  
Josephine A Reinhardt ◽  
Richard H. Baker ◽  
Aleksey V. Zimin ◽  
Chloe Ladias ◽  
Kimberly A Paczolt ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Transposable Element ◽  
X Chromosome ◽  
Meiotic Drive ◽  
Genetic Elements ◽  
Selfish Genetic Elements ◽  
Genome Defense ◽  
Genomic Divergence ◽  
Pirna Pathway ◽  
Female Carriers

AbstractSome stalk-eyed flies in the genus Teleopsis carry selfish genetic elements that induce sex ratio (SR) meiotic drive and impact the fitness of male and female carriers. Here, we produce a chromosome-level genome assembly of the stalk-eyed fly, T. dalmanni, to elucidate the pattern of genomic divergence associated with the presence of drive elements. We find evidence for multiple nested inversions along the sex ratio haplotype and widespread differentiation and divergence between the inversion types along the entire X chromosome. In addition, the genome contains tens of thousands of transposable element (TE) insertions and hundreds of transcriptionally active TE families that have produced new insertions. Moreover, we find that many TE families are expressed at a significantly higher level in SR male testis, suggesting a molecular connection between these two types of selfish genetic elements in this species. We identify T. dalmanni orthologs of genes involved in genome defense via the piRNA pathway, including core members maelstrom, piwi and Argonaute3, that are diverging in sequence, expression or copy number between the SR and standard (ST) chromosomes, and likely influence TE regulation in flies carrying a sex ratio X chromosome.

scholarly journals Biology and parasitic potential of Doryctobracon areolatuson Anastrepha fraterculus larvae

2011 ◽  
Vol 46 (6) ◽  
pp. 669-671 ◽  
Author(s):  
Adrise Medeiros Nunes ◽  
Dori Edson Nava ◽  
Fernanda Appel Müller ◽  
Rafael da Silva Gonçalves ◽  
Mauro Silveira Garcia
Keyword(s):  
Biological Control ◽  
Sex Ratio ◽  
Adult Emergence ◽  
Parasitism Rate ◽  
Anastrepha Fraterculus ◽  
The Mean ◽  
Parasitoid Development

The objective of this work was to study the biology and parasitic potential of Doryctobracon areolatus on larvae of Anastrepha fraterculus. The egg-adult period, the sex ratio, the longevity, the pupal viability, and the parasitism rate of D. areolatus were determined in laboratory, using A. fraterculus as host. The parasitoid development from oviposition to adult emergence required 25.00±1.70 days, the sex ratio was 0.62±0.09, and the mean longevity was 16.36±3.62 days for males and 10.24±1.71 days for females. The mean parasitism rate was 53.50±8.93%, varying from 41.60 to 68.60%, which shows the potential of this parasitoid for biological control of A. fraterculus.

scholarly journals Reproduction of Ooencyrtus submetallicus (Hymenoptera: Encyrtidae) and Trissolcus sp. aff. urichi (Hymenoptera: Scelionidae) in Eggs of Nezara viridula (Hemiptera: Pentatomidae) of Different Ages

2021 ◽  
Vol 13 (10) ◽  
pp. 96
Author(s):  
Eduardo Carvalho Faca ◽  
Fabrício Fagundes Pereira ◽  
Winnie Cezario Fernandes ◽  
Ivana Fernandes da Silva ◽  
Valmir Antônio Costa ◽  
...  
Keyword(s):  
Biological Control ◽  
Life Cycle ◽  
Sex Ratio ◽  
Cycle Length ◽  
Nezara Viridula ◽  
Control Programs ◽  
Breeding Methodology ◽  
Different Ages ◽  
Laboratory Bioassays

The study of the interaction between parasitoid and host, especially the age of these organisms, is an important step towards the implementation of biological control programs. Therefore, we investigated the performance of Ooencyrtus submetallicus (Hymenoptera: Encyrtidae) and Trissolcus sp. aff. urichi (Hymenoptera: Scelionidae) parasitizing eggs of Nezara viridula (Hemiptera: Pentatomidae), considering different ages of the parasitoids and the host. We performed four laboratory bioassays: two using females of O. submetallicus and Trissolcus sp. aff. urichi at 24, 48, 72, 96, 120, or 144 hours of age exposed to parasitism in N. viridula eggs (24 h) and two trials with N. viridula eggs at 24, 48, 72, 96, 120, or 144 hours exposed to the parasitism of O. submetallicus and Trissolcus sp. aff. urichi (24 h). We evaluated the percentage of parasitism and emergence, life cycle length, progeny, sex ratio, and the longevity of the parasitoids. The parasitism of O. submetallicus in N. viridula eggs was influenced by the age of the parasitoid, 120 hours being the minimum to obtain better parasitism. From this age on, there is interference in the longevity of the progeny. Trisolcus sp. aff. urichi, at all ages, parasitized N. viridula eggs relatively well, but with almost no emergence of the parasitized eggs. Females of O. submetallicus parasitized and developed in eggs of N. viridula of all ages. Females of Trissolcus sp. aff. urichi parasitized their host, but there was barely any emergence. These pieces of information regarding the breeding methodology contribute to the implementation of new protocols for the multiplication of these parasitoids in the laboratory, and later, their release in the field.

scholarly journals Experimental manipulation of selfish genetic elements links genes to microbial community function

2020 ◽  
Vol 375 (1798) ◽  
pp. 20190681 ◽  
Author(s):  
Steven D. Quistad ◽  
Guilhem Doulcier ◽  
Paul B. Rainey
Keyword(s):  
Microbial Community ◽  
Experimental Manipulation ◽  
Dynamical Behaviour ◽  
Genetic Elements ◽  
Microbial Community Function ◽  
Comparative Metagenomics ◽  
Community Function ◽  
Selfish Genetic Elements ◽  
Biochemical Assays ◽  
Microbial Community Ecology

Microbial communities underpin the Earth's biological and geochemical processes, but their complexity hampers understanding. Motivated by the challenge of diversity and the need to forge ways of capturing dynamical behaviour connecting genes to function, biologically independent experimental communities comprising hundreds of microbial genera were established from garden compost and propagated on nitrogen-limited minimal medium with cellulose (paper) as sole carbon source. After 1 year of bi-weekly transfer, communities retained hundreds of genera. To connect genes to function, we used a simple experimental manipulation that involved the periodic collection of selfish genetic elements (SGEs) from separate communities, followed by pooling and redistribution across communities. The treatment was predicted to promote amplification and dissemination of SGEs and thus horizontal gene transfer. Confirmation came from comparative metagenomics, which showed the substantive movement of ecologically significant genes whose dynamic across space and time could be followed. Enrichment of genes implicated in nitrogen metabolism, and particularly ammonification, prompted biochemical assays that revealed a measurable impact on community function. Our simple experimental strategy offers a conceptually new approach for unravelling dynamical processes affecting microbial community function. This article is part of the theme issue ‘Conceptual challenges in microbial community ecology’.

Selfish Genetic Elements Promote Polyandry in a Fly

Science ◽  
2008 ◽  
Vol 322 (5905) ◽  
pp. 1241-1243 ◽  
Author(s):  
T. A. R. Price ◽  
D. J. Hodgson ◽  
Z. Lewis ◽  
G. D. D. Hurst ◽  
N. Wedell
Keyword(s):  
Genetic Elements ◽  
Selfish Genetic Elements

The biology of the ectoparasitoid wasp Eulophus pennicornis (Hymenoptera: Eulophidae) on host larvae of the tomato moth, Lacanobia oleracea (Lepidoptera: Noctuidae)

1995 ◽  
Vol 85 (4) ◽  
pp. 507-513 ◽  
Author(s):  
G.C. Marris ◽  
J.P. Edwards
Keyword(s):  
Biological Control ◽  
Sex Ratio ◽  
Artificial Diet ◽  
Limited Range ◽  
Pest Species ◽  
Biological Control Agents ◽  
Biased Sex Ratio ◽  
Horticultural Pest ◽  
Lepidoptera Noctuidae

AbstractThere is a need to identify potential biological control agents for use against noctuid pests in greenhouses. The gregarious ectoparasitoid Eulophus pennicornis (Nees) attacks a limited range of macrolepidopterous larvae, including those of some important horticultural pest species. Laboratory trials designed to investigate the biology of E. pennicornis on larvae of the tomato moth, Lacanobia oleracea Linnaeus, reveal that wasps preferentially parasitize penulitmate (fifth) or final (sixth) instar hosts. More than two-thirds of wasps lay viable eggs, and individual females oviposit on up to four hosts during their lifespan. Wasp fecundity is high, preadult development is rapid, and offspring show a markedly female-biased sex ratio. Parasitized fifth instar L.oleracea hosts do not grow as quickly as unparasitized larvae, and neither do they undergo normal ecdysis to the final larval stadium. Furthermore, the consumption of artificial diet by parasitized fifth instar hosts is greatly reduced in comparison to that of unparasitized larvae (overall feeding-reduction over a 12 day period was 64.7%). Our results suggest that E. pennicornis affects both the developmental and feeding physiology of host larvae, and that inoculative releases of this parasitoid could provide effective biological control for L. oleracea and other greenhouse pests.

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