Selfish genes and sexual selection: the impact of genomic parasites on host reproduction

This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record.Selfish genetic elements (SGEs) such as replicating mobile elements, segregation distorters, and maternally inherited endosymbionts, bias their transmission success relative to the rest of the genome to increase in representation in subsequent generations. As such they generate conflict with the rest of the genome. Such intra-genomic conflict is also a hallmark of sexually antagonistic (SA) alleles, which are shared genes between the sexes but that have opposing fitness effects when expressed in males and females. However, while both SGEs and SA alleles are recognised as common and potent sources of genomic conflict, the realisation that SGEs can also generate sexually antagonistic selection and contribute to sexual conflict in addition to generate sexual selection is largely overlooked. Here I show that SGEs frequently generate sex-specific selection and outline how SGEs that are associated with compromised male fertility can shape female mating patterns, play a key role in the dynamics of sex determination systems, and likely be an important source of sexually antagonistic genetic variation. Given the prevalence of SGEs their contribution to sexual conflict is likely to be greatly overlooked.Royal Societ

THE RATE OF BINARY BLACK HOLE MERGERS INFERRED FROM ADVANCED LIGO OBSERVATIONS SURROUNDING GW150914

A transient gravitational-wave signal, GW150914, was identi fi ed in the twin Advanced LIGO detectors on 2015 September 2015 at 09:50:45 UTC. To asse ss the implications of this discovery, the detectors remained in operation with unchanged con fi gurations over a period of 39 days around the time of t he signal. At the detection statistic threshold corresponding to that observed for GW150914, our search of the 16 days of simultaneous two-detector observational data is estimated to have a false-alarm rate ( FAR ) of < ́ -- 4.9 10 yr 61 , yielding a p -value for GW150914 of < ́ - 210 7 . Parameter estimation follo w-up on this trigger identi fi es its source as a binary black hole ( BBH ) merger with component masses ( )( ) = - + - + mm M ,36,29 12 4 5 4 4 at redshift = - + z 0.09 0.04 0.03 ( median and 90% credible range ) . Here, we report on the constraints these observations place on the rate of BBH coalescences. Considering only GW150914, assuming that all BBHs in the universe have the same masses and spins as this event, imposing a search FAR threshold of 1 per 100 years, and assuming that the BBH merger rate is constant in the comoving frame, we infer a 90% credible range of merger rates between – -- 2 53 Gpc yr 31 ( comoving frame ) . Incorporating all search triggers that pass a much lower threshold while accounting for the uncerta inty in the astrophysical origin of each trigger, we estimate a higher rate, ranging from – -- 13 600 Gpc yr 31 depending on assumptions about the BBH mass distribution. All together, our various rate estimat es fall in the conservative range – -- 2 600 Gpc yr 31

Combining video and GPS-tracking to study the spatial foraging distribution of a single-prey loading seabird

Seabirds are valuable indicators of marine ecosystem processes and studying seabird diets can shed light on natural or human-induced variability in food-web composition. Specifically single-prey loading seabird species such as terns have the potential to act as visual sentinels of prey availability offshore. However, obtaining diet information from remote bird colonies is often challenging and time consuming. In this pilot study we present a novel approach to combine two established methods to study seabird foraging ecology, providing a powerful and cost-effective tool to study the distribution of prey items available to seabirds. We combined GPS tracking data of Sandwich Terns (Thalasseus sandvicensis) with prey-observations from a hide in 2012 and 2013, and from semi-continuously recorded camera footage in 2017. By doing so, we identified 115 approximate catch locations of prey (86 herring/sprat Clupeidae, 29 sandeel Ammodytidae). Combining GPS-data and prey observations yielded detailed knowledge on the movements and chick diets of tracked birds as well as the spatial origin and lengths of captured prey items. Further catch distances of both Clupeidae and Ammodytidae resulted in deliveries of larger prey items and thus higher energy yield per trip, but also a higher energy expenditure per trip. We discuss the limitations and potential of our methodological approach to study foraging energetics during chick-provisioning of seabirds that carry prey items visible in their beaks

The Drosophila Mre11/Rad50 complex is required to prevent both telomeric fusion and chromosome breakage.

The MRN complex consists of the two evolutionarily conserved components Mre11 and Rad50 and the third less-conserved component Nbs1/Xrs2. This complex mediates telomere maintenance in addition to a variety of functions in response to DNA double-strand breaks, including homologous recombination, nonhomologous end joining (NHEJ), and activation of DNA damage checkpoints. Mutations in the Mre11 gene cause the human ataxia-telangiectasia-like disorder (ATDL). Here, we show that null mutations in the Drosophila mre11 and rad50 genes cause both telomeric fusion and chromosome breakage. Moreover, we demonstrate that these mutations are in the same epistasis group required for telomere capping and mitotic chromosome integrity. Using an antibody against Rad50, we show that this protein is uniformly distributed along mitotic chromosomes, and that Rad50 is unstable in the absence of its binding partner Mre11. To define the roles of rad50 and mre11 in telomere protection, mutant chromosome preparations were immunostained for both HP1 and HOAP, two proteins that protect Drosophila telomeres from fusion. Cytological analysis revealed that mutations in rad50 and mre11 drastically reduce accumulation of HOAP and HP1 at telomeres. This suggests that the MRN complex protects Drosophila telomeres by facilitating recruitment of HOAP and HP1 at chromosome ends

On the persistence of P element in cultured lineages of Drosophila melanogaster

P transposon is known to have invaded the Drosophila melanogaster genome in the 1950s as a result of horizontal transmission from D. willistoni. Part of the evidence supporting the timing of its invasion comes from analyses of cultured drosophila lineages originating from wild flies cultivated long time in laboratory before analysis. Such analyses have shown that P element was absent from the genomes of cultured lineages established from wild flies caught from the wild before the 1950s. Although the hypothesis of P element transmission has obtained multiple lines of evidence and is beyond doubt today, we decided to test whether analysis of cultured lineages can provide some temporal information on the P element population dynamics. In the present work we demonstrate that P element present the in wild­caught flies may be lost in the cultured fly lineages after some generations. This result is in accordance with the results of at least one published work and suggests that analysis of the cultured fly lineages may sometimes be unreliable in establishing historical trends in P element population dynamics, as the transposon may be occasionally lost, perhaps in the highly inbred lineages in which not all founding females carry it.Известно, что Р транспозон попал в геном Drosophila melanogaster в 50-х годах прошлого столетия результате горизонтального переноса от D. willistoni. Частично время инвазии было рассчитано на основании анализа культивируемых линий дрозофилы, которые происходят от диких особей, культивируемых как изосамковые линии задолго до анализа. Такой анализ показал, что Р элемент отсутствовал в геномах культивируе-мых линий, которые основаны из особей, собранных в природе до 1950 г. Хотя гипотеза переноса Р элемента подтверждена различными доказательствами и ее достоверность не вызывает сомнений, мы решили проверить, дает ли анализ культивируемых линий информацию о временных факторах популяционной динамики Р элемента. В настоящей работе мы показываем, что Р элемент, присутствующий в диких особях, может быть утрачен в культивируемых линиях через некоторое количество поколений. Такие результаты согласуются с данными как минимум одной опубликованной работы и свидетельствуют о том, что анализ культивируемых линий дрозофилы не всегда надежен при воссоздании исторических трендов популяционной динамики Р элемента, поскольку этот транспозон может быть случайным образом утерян, очевидно, вследствие высокой инбредности линий, у которых геномы не всех самок-основателей содержали его.Відомо, що Р транспозон потрапив до геному Drosophila melanogaster у 50-х роках минулого століття в результаті горизонтального переносу від D. willistoni. Частково час інвазії був розрахований на основі аналізу культивованих ліній дрозофіли, що походять від диких особин, котрі культивувались у лабораторії як ізосамкові лінії задовго до аналізу. Такий аналіз показав, що Р елемент був відсутній у геномах культивованих ліній, заснованих з особин, що зібрані у природі до 1950 р. Хоча гіпотеза переносу Р елемента підтверджується різноманітними доказами та її достовірність не викликає сумніву, ми вирішили перевірити, чи дає аналіз культивованих ліній інформацію щодо часового фактора популяційної динаміки Р елемента. В даній роботі ми показуємо, що Р елемент, присутній у диких особин, може втрачатись в культивованих лініях через певну кількість поколінь. Такі результати узгоджуються з даними щонайменше однієї опублікованої роботи та свідчать про те, що аналіз культивованих ліній дрозофіли може інколи бути ненадійним для відтворення історичних трендів популяційної динаміки Р елемента, оскільки цей транспозон може випадковим чином втрачатись, очевидно, через високу інбредність ліній, в яких геноми не всіх самиць-засновників містили його