A central goal of evolutionary biology is to identify the genes and forces that cause speciation, emergence reproductive isolation between populations. Despite identification several hybrid sterility or inviability-many which have evolved rapidly under positive Darwinian selection-little known about ecological genomic drive evolution postzygotic isolation. Here, we show same gene, Overdrive, causes both male segregation distortion in F1 hybrids Bogota U.S. subspecies Drosophila...

The onset of prezygotic and postzygotic barriers to gene flow between populations is a hallmark speciation. One the earliest isolating arise incipient species sterility heterogametic sex in interspecies' hybrids. Four genes that underlie hybrid have been identified animals: Odysseus, JYalpha, Overdrive Drosophila Prdm9 (Meisetz) mice. Mouse encodes protein with KRAB motif, histone methyltransferase domain several zinc fingers. difference single finger distinguishes alleles cause from those...

Understanding the role of chromosomal inversions in speciation is a fundamental problem evolutionary genetics. Here, we perform comprehensive reconstruction histories Drosophila persimilis and D. pseudoobscura. We provide solution to puzzling origins selfish Sex-Ratio arrangement uncover surprising patterns phylogenetic discordance on this chromosome. These show that, contrary widely held views, all fixed between pseudoobscura were already present their ancestral population long before...

The gene arrangements of Drosophila have played a prominent role in the history evolutionary biology from original quantification genetic diversity to current studies mechanisms for origin and establishment new inversion mutations within populations their subsequent fixation between species supporting reproductive barriers. This review examines causes consequences inversions as recombination suppressors that suppression plays establishing they are involved adaptation heterogeneous...

Essential genes and species incompatibilities Crosses between two fruit fly species, Drosophila melanogaster D. simulans , result in hybrid progeny that are all female. Although some of the responsible for this barrier known, full complement molecular determinants lead to inviable males has remained mysterious. Phadnis et al. used mutagenesis a sequencing-based genomic screen link inviability cell cycle. The from an interaction three genes, one which is essential, precluded its...

The dominance of deleterious mutations has important consequences for phenomena such as inbreeding depression, the evolution diploidy, and levels natural genetic variation. Kacser Burns' metabolic theory provides a paradigmatic explanation why most large-effect are recessive. According to theory, recessivity is consequence diminishing-returns relationship between flux through pathway enzymatic activity at any step in pathway, which turn an inevitable long pathways. A major line support this...

Study of the genetics speciation—and especially intrinsic postzygotic isolation—has enjoyed remarkable progress over last 2 decades. Indeed has been so rapid that one might be tempted to ask if isolation is now wrapped up. Here we argue speciation far from complete. In particular, review topics where recent work revealed major surprises: 1) role meiotic drive in hybrid sterility and 2) gene transposition speciation. These surprises, others like them, suggest evolutionary biologists may...

Understanding the genetic basis of reproductive isolation between recently diverged species is a central problem in evolutionary genetics. Here, I present analyses architecture underlying hybrid male sterility and segregation distortion Bogota USA subspecies Drosophila pseudoobscura. Previously, single gene, Overdrive (Ovd), was shown to be necessary but not sufficient for both F(1) hybrids these subspecies, requiring several interacting partner loci full manifestation phenomena. map...

Endoplasmic reticulum (ER) stress results from an imbalance between the load of proteins entering secretory pathway and ability ER to fold process them. The response is mediated by a collection signaling pathways termed unfolded protein response, which plays important roles in development disease. Here we show that Drosophila melanogaster S2 cells, induces coordinated change expression genes involved carbon metabolism. Genes encoding enzymes carry out glycolysis were up-regulated, whereas...

Abstract Condensins play a crucial role in the organization of genetic material by compacting and disentangling chromosomes. Based on studies few model organisms, condensins I II complexes are considered to have distinct functions, with condensin complex playing meiosis somatic pairing homologous chromosomes Drosophila. Intriguingly, Cap-G2 subunit is absent Drosophila melanogaster, this loss may be related high levels chromosome seen flies. Here, we find that all three non-SMC subunits...

Abstract Despite the fundamental importance of hybrid incompatibilities to process speciation, there are few cases where evolution and genetic architecture understood. One longest studied causes F1 male inviability in crosses between Drosophila melanogaster females males from simulans clade species—Drosophila simulans, mauritiana, sechellia. Here, we discover dramatic differences manifestation this lethal incompatibility among D. species. In particular, sechellia resistant rescue through...

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Abstract Hybrid male sterility is one of the fastest evolving intrinsic reproductive barriers between recently isolated populations. A leading explanation for evolution hybrid involves genomic conflicts with meiotic drivers in germline. There are, however, few examples directly linking drive to sterility. In this study, we report that Sex-Ratio chromosome Drosophila pseudoobscura, which causes X-chromosome within USA subspecies, near-complete when it moved into genetic background Bogota...

Nucleocytoplasmic transport is a broadly conserved process across eukaryotes. Despite its essential function and mechanism, components of the nuclear apparatus have been implicated in genetic conflicts Drosophila, especially male germ line. The best understood case represented by truncated RanGAP gene duplication that part segregation distorter system Drosophila melanogaster. Consistent with hypothesis pathway at heart mediating conflicts, both nucleoporins directionality imposing previously...

Sperm hyper-activation is a dramatic change in sperm behavior where mature burst into final sprint the race to egg. The mechanism of many metazoans, including humans, consists jolt Ca2+ flagellum via CatSper ion channels. Surprisingly, all nine genes have been independently lost several animal lineages. In Drosophila, performed through cooption polycystic kidney disease 2 (pkd2) channel. parallels between CatSpers primates and pkd2 Drosophila provide unique opportunity examine molecular...

Understanding the molecular basis of hybrid incompatibilities is a fundamental pursuit in evolutionary genetics. In crosses between Drosophila melanogaster females and simulans males, an interaction at least three genes necessary for male lethality: Hmr mel, Lhr sim, gfzf sim. Although HMR LHR physically bind each other function together single complex, connection either these proteins remains mysterious. Here, we show that GFZF localizes to many regions genome both D. simulans, including...

Uncovering the genetic and molecular basis of barriers to gene flow between populations is key understanding how new species are born. Intrinsic postzygotic reproductive such as hybrid sterility inviability caused by deleterious interactions known incompatibilities. The difficulty in identifying these incompatibility genes remains a rate-limiting step our speciation. We recently described whole genome sequencing can be applied identify genes, even from genetically terminal hybrids. Using...

The chromosomal inversions of D. persimilis and pseudoobscura have deeply influenced our understanding the evolutionary forces that shape natural variation, speciation, selfish chromosome dynamics. Here, we perform a comprehensive reconstruction histories in these species. We provide solution to puzzling origins Sex-Ratio show this directly descends from an ancestrally-arranged chromosome. Our results further all fixed between were segregating ancestral population long before genes...

Abstract Hybrid incompatibilities are the result of deleterious interactions between diverged genes in progeny two species. In Drosophila , crosses female D. melanogaster and males from simulans clade ( mauritiana sechellia ) fail to produce hybrid F1 males. When attempting rescue by depleting incompatible allele a previously identified incompatibility gene, we observed robust or but no . To investigate genetic basis resistance rescue, designed triple-hybrid cross generate recombinant /...

Abstract Understanding hybrid incompatibilities is a fundamental pursuit in evolutionary genetics. In crosses between Drosophila melanogaster females and simulans males, the interaction of at least three genes necessary for male lethality: Hmr mel , Lhr sim gfzf . All incompatibility are chromatin associated factors. While HMR LHR physically bind each other function together single complex, connection either these proteins remains mysterious. Here, we investigate allele specific binding...

Abstract Segregation distorters violate Mendelian Inheritance by over-representing themselves in the progeny of carrier individuals and are commonly associated with chromosomal inversions. When distorting alleles found on sex chromosomes, will exhibit skewed ratios, as exemplified array Sex-Ratio ( SR ) chromosomes Drosophila. Because strong selective pressures such thought to inflict genomes, segregation their inversions expected experience rapid turn-over. However, X-chromosome Drosophila...

Abstract Hybrid male sterility is one of the fastest evolving intrinsic reproductive barriers between recently isolated populations. A leading explanation for evolution hybrid involves genomic conflicts with meiotic drivers in germline. There are, however, few examples directly linking drive to sterility. Here, we report that Sex-Ratio chromosome Drosophila pseudoobscura , which causes X-chromosome within USA subspecies, near complete when moved into genetic background Bogota subspecies. In...

Abstract Genomic approaches have provided detailed insight into chromosome architecture. However, commonly deployed techniques do not preserve connectivity-based information, leaving large-scale genome organization poorly characterized. Here, we developed CheC-PLS: a proximity-labeling technique that indelibly marks, and then decodes, protein-associated sites. CheC-PLS tethers dam methyltransferase to protein of interest, followed by Nanopore sequencing identify methylated bases - indicative...