Maintenance of fertility in the face of meiotic drive

AbstractSelfish genetic elements that gain a transmission advantage through the destruction of sperm have grave implications for drive male fertility. In the X-linked SR meiotic drive system of a stalk-eyed fly, we found that drive males have greatly enlarged testes and maintain high fertility despite the destruction of half their sperm, even when challenged with fertilising large numbers of females. Conversely, we observed reduced allocation of resources to the accessory glands that probably explains the lower mating frequency of SR males. Body size and eyespan were also reduced, which are likely to impair viability and pre-copulatory success. We discuss the potential evolutionary causes of these differences between drive and standard males.

Download Full-text

Aplikasi Kuartu Berbasis Android Sebagai Media Pertukaran Informasi Kartu Nama

Jurnal ULTIMATICS ◽

10.31937/ti.v9i1.560 ◽

2017 ◽

Vol 9 (1) ◽

pp. 25-32

Author(s):

Nandi Syukri ◽

Eko Budi Setiawan

Keyword(s):

Mobile Devices ◽

Information Exchange ◽

Smart Phone ◽

Black Box ◽

Qr Code ◽

Business Card ◽

Large Numbers ◽

The World ◽

The Face ◽

Index Terms

Business Card is the most efficient, effective and appropriate tool for every business men no matter they are owners, employees, more over marketers to provide information about their businesses. Unfortunately, it is very difficult to bring and manage business card in large numbers also to remember the face of the business card owner. A Business Card application need to be built to solve all those issues mentioned above. The Application or software must be run in media which can be accessed anywhere and anytime such as smart phone. Kuartu is as business card application run in mobile devices. Kuartu is developed using object base modeling for mobile sub system. The platform of the mobile sub system is android, as it is the most widely used platform in the world. The Kuartu application utilizing NFC and QR Code technology to support the business card information exchange and the Chatting feature for communication. Based on the experiment and test using black box methodology, it can be concluded that Kuartu application makes business card owner to communicate each other easily, business card always carried, easy to manage the cards and information of the business card owner can be easily obtained. Index Terms— Business Card, Android, Kuartu, NFC, QrCode, Chatting.

Download Full-text

Red queen's race: rapid evolutionary dynamics of an expanding family of meiotic drive factors and their hpRNA suppressors

10.1101/2021.08.05.454923 ◽

2021 ◽

Author(s):

Jeffrey Vedanayagam ◽

Ching-Jung Lin ◽

Eric C. Lai

Keyword(s):

Evolutionary Dynamics ◽

Sex Chromosome ◽

De Novo ◽

Independent Set ◽

Meiotic Drive ◽

Sperm Chromatin ◽

Arms Races ◽

X Chromosomes ◽

Selfish Genetic Elements ◽

Satellite Repeats

Meiotic drivers are a class of selfish genetic elements that are widespread across eukaryotes. Their activities are often detrimental to organismal fitness and thus trigger drive suppression to ensure fair segregation during meiosis. Accordingly, their existence is frequently hidden in genomes, and their molecular functions are little known. Here, we trace evolutionary steps that generated the Dox meiotic drive system in Drosophila simulans (Dsim), which distorts male:female balance (sex-ratio) by depleting male progeny. We show that Dox emerged via stepwise mobilization and acquisition of portions of multiple D. melanogaster genes, including the sperm chromatin packaging gene protamine. Moreover, we reveal novel Dox homologs in Dsim and massive, recent, amplification of Dox superfamily genes specifically on X chromosomes of its closest sister species D. mauritiana (Dmau) and D. sechellia (Dsech). The emergence of Dox superfamily genes is tightly associated with 1.688 family satellite repeats that flank de novo genomic copies. In concert, we find coordinated emergence and diversification of autosomal hairpin RNA/siRNAs loci that target subsets of Dox superfamily genes across simulans clade species. Finally, an independent set of protamine amplifications the Y chromosome of D. melanogaster indicates that protamine genes are frequent and recurrent players in sex chromosome dynamics. Overall, we reveal fierce genetic arms races between meiotic drive factors and siRNA suppressors associated with recent speciation.

Download Full-text

Sharing the Risk

10.1093/oso/9780198869023.003.0016 ◽

2021 ◽

pp. 281-298

Author(s):

Andrew C. A. Elliott

Keyword(s):

Climate Change ◽

Law Of Large Numbers ◽

Insurance Market ◽

Insurance Companies ◽

Marine Insurance ◽

Fire Insurance ◽

Large Numbers ◽

Mutual Insurance ◽

The Face ◽

Friendly Societies

Insurance makes use of the law of large numbers to mitigate the effects of risks on individuals by allowing them to be shared collectively. Early insurance arrangements arose as friendly societies and mutual insurance companies. Marine insurance has a long history and remains a major insurance market. Fire insurance provides compensation in the face of a capricious and frightening risk, but also invites fraudulent claims. Increasing amounts of information provide challenges for insurance underwriting: can there be too much information? The principle of insurance is that of averaging out of independent risks, but when risks are not independent, as may be the case when it comes to climate change, is there still any role for insurance?

Download Full-text

Migrant Religious Groups

10.1093/oso/9780192897404.003.0007 ◽

2021 ◽

pp. 137-159

Author(s):

W. M. Jacob

Keyword(s):

World City ◽

Spiritual Needs ◽

Civic Life ◽

Eastern European ◽

Religious Groups ◽

Large Numbers ◽

The Face ◽

Roman Catholics ◽

Migrant Groups ◽

Poor Communities

As a world city, Victorian London was a magnet for migrants, including Italians, Germans, French, and Greeks. The two most numerous migrant groups were Eastern European Jews and Irish Roman Catholics, whose arrival challenged and changed their small host communities. Both host communities had to respond to the material and spiritual needs of relatively large numbers of poor migrants whose numbers in limited localities and unknown languages and customs aroused a degree of hostility and fear that they would disadvantage existing poor communities in those districts. The leaders of both communities adopted somewhat similar strategies to prevent ‘leakage’ of members from their respective faith groups in the face of militant Protestant mission activity, and to enculturate them as British citizens, playing a part in civic life, while not compromising the distinctiveness of their faith and its practice.

Download Full-text

Meiotic drive mechanisms: lessons from Drosophila

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2019.1430 ◽

2019 ◽

Vol 286 (1913) ◽

pp. 20191430 ◽

Cited By ~ 8

Author(s):

Cécile Courret ◽

Ching-Ho Chang ◽

Kevin H.-C. Wei ◽

Catherine Montchamp-Moreau ◽

Amanda M. Larracuente

Keyword(s):

Small Rna ◽

Molecular Mechanisms ◽

Meiotic Drive ◽

Gene Duplications ◽

Arms Races ◽

Transport Pathways ◽

Selfish Genetic Elements ◽

Genetic Origins ◽

Drive Systems ◽

Rna Pathways

Meiotic drivers are selfish genetic elements that bias their transmission into gametes, often to the detriment of the rest of the genome. The resulting intragenomic conflicts triggered by meiotic drive create evolutionary arms races and shape genome evolution. The phenomenon of meiotic drive is widespread across taxa but is particularly prominent in the Drosophila genus. Recent studies in Drosophila have provided insights into the genetic origins of drivers and their molecular mechanisms. Here, we review the current literature on mechanisms of drive with an emphasis on sperm killers in Drosophila species. In these systems, meiotic drivers often evolve from gene duplications and targets are generally linked to heterochromatin. While dense in repetitive elements and difficult to study using traditional genetic and genomic approaches, recent work in Drosophila has made progress on the heterochromatic compartment of the genome. Although we still understand little about precise drive mechanisms, studies of male drive systems are converging on common themes such as heterochromatin regulation, small RNA pathways, and nuclear transport pathways. Meiotic drive systems are therefore promising models for discovering fundamental features of gametogenesis.

Download Full-text

Double trouble: combined action of meiotic drive and Wolbachia feminization in Eurema butterflies

Biology Letters ◽

10.1098/rsbl.2015.0095 ◽

2015 ◽

Vol 11 (5) ◽

pp. 20150095 ◽

Cited By ~ 27

Author(s):

Peter Kern ◽

James M. Cook ◽

Daisuke Kageyama ◽

Markus Riegler

Keyword(s):

Meiotic Drive ◽

Sex Bias ◽

Z Chromosome ◽

Female Development ◽

Pcr Assay ◽

Interphase Nuclei ◽

Diverse Range ◽

Selfish Genetic Elements ◽

Combined Action ◽

Quantitative Pcr Assay

Arthropod sex ratios can be manipulated by a diverse range of selfish genetic elements, including maternally inherited Wolbachia bacteria. Feminization by Wolbachia is rare but has been described for Eurema mandarina butterflies . In this species, some phenotypic and functional females, thought to be ZZ genetic males, are infected with a feminizing Wolbachia strain, w Fem. Meanwhile, heterogametic WZ females are not infected with w Fem. Here, we establish a quantitative PCR assay allowing reliable sexing in three Eurema species. Against expectation, all E. mandarina females, including w Fem females, had only one Z chromosome that was paternally inherited. Observation of somatic interphase nuclei confirmed that W chromatin was absent in w Fem females, but present in females without w Fem. We conclude that the sex bias in w Fem lines is due to meiotic drive (MD) that excludes the maternal Z and thus prevents formation of ZZ males. Furthermore, w Fem lines may have lost the W chromosome or harbour a dysfunctional version, yet rely on w Fem for female development; removal of w Fem results in all-male offspring. This is the first study that demonstrates an interaction between MD and Wolbachia feminization, and it highlights endosymbionts as potentially confounding factors in MD of sex chromosomes.

Download Full-text

Solidarity Not Charity

Social Text ◽

10.1215/01642472-7971139 ◽

2020 ◽

Vol 38 (1) ◽

pp. 131-151 ◽

Cited By ~ 8

Author(s):

Dean Spade

Keyword(s):

Climate Change ◽

Social Movements ◽

Social Relations ◽

Disaster Relief ◽

Mutual Aid ◽

Border Enforcement ◽

Large Numbers ◽

The Face ◽

Wealth Gap ◽

Prison Abolition

This article argues that, in the face of worsening conditions from climate change, enhanced border enforcement, a growing wealth gap, housing crises, and policing, social movements should focus on expanding mutual aid strategies. Mutual aid projects directly address survival needs, mobilize large numbers of people to participate in movements actively rather than solely participating online or through voting, and offer spaces to practice new social relations. The article looks at examples from efforts for migrant justice, police and prison abolition, disaster relief, and other contemporary struggles and discusses potential pitfalls of mutual aid strategies, such as supplementing and therefore stabilizing existing systems of maldistribution and adopting principles and practices from the charity frameworks that proliferate in capitalism.

Download Full-text

The dynamic relationship between polyandry and selfish genetic elements

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2012.0049 ◽

2013 ◽

Vol 368 (1613) ◽

pp. 20120049 ◽

Cited By ~ 42

Author(s):

Nina Wedell

Keyword(s):

Male Fertility ◽

Reproductive Tract ◽

Mating Behaviour ◽

Reproductive Traits ◽

Female Reproductive Tract ◽

Low Fertility ◽

Genetic Elements ◽

Selfish Genetic Elements ◽

Dynamic Relationship ◽

Male Carriers

Selfish genetic elements (SGEs) are ubiquitous in eukaryotes and bacteria, and make up a large part of the genome. They frequently target sperm to increase their transmission success, but these manipulations are often associated with reduced male fertility. Low fertility of SGE-carrying males is suggested to promote polyandry as a female strategy to bias paternity against male carriers. Support for this hypothesis is found in several taxa, where SGE-carrying males have reduced sperm competitive ability. In contrast, when SGEs give rise to reproductive incompatibilities between SGE-carrying males and females, polyandry is not necessarily favoured, irrespective of the detrimental impact on male fertility. This is due to the frequency-dependent nature of these incompatibilities, because they will decrease in the population as the frequency of SGEs increases. However, reduced fertility of SGE-carrying males can prevent the successful population invasion of SGEs. In addition, SGEs can directly influence male and female mating behaviour, mating rates and reproductive traits (e.g. female reproductive tract length and male sperm). This reveals a potent and dynamic interaction between SGEs and polyandry highlighting the potential to generate sexual selection and conflict, but also indicates that polyandry can promote harmony within the genome by undermining the spread of SGEs.

Download Full-text

Sperm should evolve to make female meiosis fair.

10.1101/005363 ◽

2014 ◽

Author(s):

Yaniv Brandvain ◽

Graham Coop

Keyword(s):

Population Genetic ◽

Animal Species ◽

Meiotic Drive ◽

Female Meiosis ◽

Genetic Theory ◽

Evolutionary Advantage ◽

The Face ◽

Perceived Danger ◽

Organismal Fitness

Genomic conflicts arise when an allele gains an evolutionary advantage at a cost to organismal fitness. Oogenesis is inherently susceptible to such conflicts because alleles compete for inclusion into the egg. Alleles that distort meiosis in their favor (i.e. meiotic drivers) often decrease organismal fitness, and therefore indirectly favor the evolution of mechanisms to suppress meiotic drive. In this light, many facets of oogenesis and gametogenesis have been interpreted as mechanisms of protection against genomic outlaws. That females of many animal species do not complete meiosis until after fertilization, appears to run counter to this interpretation, because this delay provides an opportunity for sperm-acting alleles to meddle with the outcome of female meiosis and help like alleles drive in heterozygous females. Contrary to this perceived danger, the population genetic theory presented herein suggests that, in fact, sperm nearly always evolve to increase the fairness of female meiosis in the face of genomic conflicts. These results are consistent with the apparent sperm dependence of the best characterized female meiotic drivers in animals. Rather than providing an opportunity for sperm collaboration in female meiotic drive, the 'fertilization requirement' indirectly protects females from meiotic drivers by providing sperm an opportunity to suppress drive.

Download Full-text

Fertility and Other Characteristics of F1 and Backcross1 Progeny from an Intersectional Blueberry Cross [(highbush cultivar × Vaccinium arboreum) × highbush cultivar]

HortScience ◽

10.21273/hortsci.48.2.146 ◽

2013 ◽

Vol 48 (2) ◽

pp. 146-149 ◽

Cited By ~ 3

Author(s):

Paul M. Lyrene

Keyword(s):

Fruit Quality ◽

Morphological Traits ◽

High Variability ◽

Highbush Blueberry ◽

High Fertility ◽

Berry Size ◽

Large Numbers ◽

Berry Quality ◽

Plant Characteristics

Fertility and morphological traits were studied in the F1 and BC1 generations of intersectional crosses between tetraploid highbush blueberry cultivars (Vaccinium section Cyanococcus) and colchicine-induced tetraploid V. arboreum (Vaccinium section Batodendron). The goal of the introgression project was to combine desirable plant characteristics from V. arboreum with the large fruit and high fruit quality of highbush cultivars. Highbush × V. arboreum crosses were hard to make, but large numbers of BC1 seedlings were easily obtained using the most fertile F1 plants as parents in backcrosses to highbush. Anther awns, a character from V. arboreum, were present in all F1 seedlings, but fruit sclerids, another V. arboreum trait, were absent in most seedlings. Berry size in the BC1 generation was twice as large as in the F1 generation and was twice as large in the F1 as in V. arboreum. The BC1 generation was extremely variable in vigor and berry quality. Although berries of most BC1 plants were smaller, darker, and less desirable in texture and flavor than highbush berries, the high fertility of BC1 plants and the high variability among plants indicate that useful clones could be selected or developed by further breeding.

Download Full-text