Sexual conflict drive in the rapid evolution of new gametogenesis genes.

The evolutionary forces underlying the rapid evolution in sequences and functions of new genes remain a mystery. Adaptation by natural selection explains the evolution of some new genes. However, many new genes perform sex-biased functions that have rapidly evolved over short evolutionary time scales, suggesting that new gene evolution may often be driven by conflicting selective pressures on males and females.

Supergene evolution via gain of autoregulation.

Development requires the coordinated action of many genes across space and time, yet numerous species have evolved the ability to develop multiple discrete, alternate phenotypes. Such polymorphisms are often controlled by supergenes, sets of tightly-linked loci that function together to control development of a polymorphic phenotype. Although theories of supergene evolution are well-established, the mutations that cause functional differences between supergene alleles have been difficult to identify.

Acute and Long-Term Consequences of Co-opted doublesex on the Development of Mimetic Butterfly Color Patterns.

Novel phenotypes are increasingly recognized to have evolved by co-option of conserved genes into new developmental contexts, yet the process by which co-opted genes modify existing developmental programs remains obscure. Here, we provide insight into this process by characterizing the role of co-opted doublesex in butterfly wing color pattern development. dsx is the master regulator of insect sex differentiation but has been co-opted to control the switch between discrete nonmimetic and mimetic patterns in Papilio alphenor and its relatives through the evolution of novel mimetic alleles.

Divergent expression of aristaless1 and aristaless2 during embryonic appendage and pupal wing development in butterflies.

Background: Gene duplication events are critical for the evolution of new gene functions. Aristaless is a major regulator of distinct developmental processes. It is most known for its role during appendage development across animals.

aristaless1 has a dual role in appendage formation and wing color specification during butterfly development.

Background: Highly diverse butterfly wing patterns have emerged as a powerful system for understanding the genetic basis of phenotypic variation. While the genetic basis of this pattern variation is being clarified, the precise developmental pathways linking genotype to phenotype are not well understood. The gene aristaless, which plays a role in appendage patterning and extension, has been duplicated in Lepidoptera.

Genomic analyses of new genes and their phenotypic effects reveal rapid evolution of essential functions in Drosophila development.

It is a conventionally held dogma that the genetic basis underlying development is conserved in a long evolutionary time scale. Ample experiments based on mutational, biochemical, functional, and complementary knockdown/knockout approaches have revealed the unexpectedly important role of recently evolved new genes in the development of Drosophila. The recent progress in the genome-wide experimental testing of gene effects and improvements in the computational identification of new genes (< 40 million years ago, Mya) open the door to investigate the evolution of gene essentiality with a phylogenetically high resolution.

The evolution and genetics of sexually dimorphic 'dual' mimicry in the butterfly .

Sexual dimorphism is a major component of morphological variation across the tree of life, but the mechanisms underlying phenotypic differences between sexes of a single species are poorly understood. We examined the population genomics and biogeography of the common palmfly , a dual mimic in which female wing colour patterns are either dark brown (melanic) or bright orange, mimicking toxic and species, respectively. As males always have a melanic wing colour pattern, this makes a fascinating model organism in which populations vary in sexual dimorphism.

The roles of hybridization and habitat fragmentation in the evolution of Brazil's enigmatic longwing butterflies, Heliconius nattereri and H. hermathena.

Background: Heliconius butterflies are widely distributed across the Neotropics and have evolved a stunning array of wing color patterns that mediate Müllerian mimicry and mating behavior. Their rapid radiation has been strongly influenced by hybridization, which has created new species and allowed sharing of color patterning alleles between mimetic species pairs. While these processes have frequently been observed in widespread species with contiguous distributions, many Heliconius species inhabit patchy or rare habitats that may strongly influence the origin and spread of species and color patterns.

Disentangling Population History and Character Evolution among Hybridizing Lineages.

Understanding the origin and maintenance of adaptive phenotypic novelty is a central goal of evolutionary biology. However, both hybridization and incomplete lineage sorting can lead to genealogical discordance between the regions of the genome underlying adaptive traits and the remainder of the genome, decoupling inferences about character evolution from population history. Here, to disentangle these effects, we investigated the evolutionary origins and maintenance of Batesian mimicry between North American admiral butterflies (Limenitis arthemis) and their chemically defended model (Battus philenor) using a combination of de novo genome sequencing, whole-genome resequencing, and statistical introgression mapping.

Butterfly Mimicry Polymorphisms Highlight Phylogenetic Limits of Gene Reuse in the Evolution of Diverse Adaptations.

Some genes have repeatedly been found to control diverse adaptations in a wide variety of organisms. Such gene reuse reveals not only the diversity of phenotypes these unique genes control but also the composition of developmental gene networks and the genetic routes available to and taken by organisms during adaptation. However, the causes of gene reuse remain unclear.

Aristaless Controls Butterfly Wing Color Variation Used in Mimicry and Mate Choice.

Neotropical Heliconius butterflies display a diversity of warningly colored wing patterns, which serve roles in both Müllerian mimicry and mate choice behavior. Wing pattern diversity in Heliconius is controlled by a small number of unlinked, Mendelian "switch" loci [1]. One of these, termed the K locus, switches between yellow and white color patterns, important mimicry signals as well as mating cues [2-4].

Gene duplicates resolving sexual conflict rapidly evolved essential gametogenesis functions.

Males and females have different fitness optima but share the vast majority of their genomes, causing an inherent genetic conflict between the two sexes that must be resolved to achieve maximal population fitness. We show that two tandem duplicate genes found specifically in Drosophila melanogaster are sexually antagonistic, but rapidly evolved sex-specific functions and expression patterns that mitigate their antagonistic effects. We use copy-specific knockouts and rescue experiments to show that Apollo (Apl) is essential for male fertility but detrimental to female fertility, in addition to its important role in development, while Artemis (Arts) is essential for female fertility but detrimental to male fertility.

Hidden genetic variation shapes the structure of functional elements in Drosophila.

Mutations that add, subtract, rearrange, or otherwise refashion genome structure often affect phenotypes, although the fragmented nature of most contemporary assemblies obscures them. To discover such mutations, we assembled the first new reference-quality genome of Drosophila melanogaster since its initial sequencing. By comparing this new genome to the existing D.

Molecular evolution patterns reveal life history features of mycoplasma-related endobacteria associated with arbuscular mycorrhizal fungi.

The mycoplasma-related endobacteria (MRE), representing a recently discovered lineage of Mollicutes, are widely distributed across arbuscular mycorrhizal fungi (AMF, Glomeromycota). AMF colonize roots of most terrestrial plants and improve plant mineral nutrient uptake in return for plant-assimilated carbon. The role of MRE in the biology of their fungal hosts is unknown.

A novel dataset for identifying sex-biased genes in Drosophila.

Phenotypic differences between males and females of sexually dimorphic species are caused in large part by differences in gene expression between the sexes, most of which occurs in the gonads. To accurately identify genes differentially expressed between males and females in Drosophila, we sequenced the testis and ovary transcriptomes of D. yakuba, D.

A long-term demasculinization of X-linked intergenic noncoding RNAs in Drosophila melanogaster.

Recent studies have revealed key roles of noncoding RNAs in sex-related pathways, but little is known about the evolutionary forces acting on these noncoding RNAs. Profiling the transcriptome of Drosophila melanogaster with whole-genome tiling arrays found that 15% of male-biased transcribed fragments are intergenic noncoding RNAs (incRNAs), suggesting a potentially important role for incRNAs in sex-related biological processes. Statistical analysis revealed a paucity of male-biased incRNAs and coding genes on the X chromosome, suggesting that similar evolutionary forces could be affecting the genomic organization of both coding and noncoding genes.

Ribosomal RNA gene diversity, effective population size, and evolutionary longevity in asexual glomeromycota.

Arbuscular mycorrhizal fungi (phylum Glomeromycota) are among the oldest and most successful symbionts of land plants. With no evidence of sexual reproduction, their evolutionary success is inconsistent with the prediction that asexual taxa are vulnerable to extinction due to accumulation of deleterious mutations. To explore why Glomeromycota defy this prediction, we studied ribosomal RNA (rRNA) gene evolution in the Claroideoglomus lineage and estimated effective population size, N(e) , in C.

Segmental dataset and whole body expression data do not support the hypothesis that non-random movement is an intrinsic property of Drosophila retrogenes.

Background: Several studies in Drosophila have shown excessive movement of retrogenes from the X chromosome to autosomes, and that these genes are frequently expressed in the testis. This phenomenon has led to several hypotheses invoking natural selection as the process driving male-biased genes to the autosomes. Metta and Schlötterer (BMC Evol Biol 2010, 10:114) analyzed a set of retrogenes where the parental gene has been subsequently lost.

Clonality and recombination in the life history of an asexual arbuscular mycorrhizal fungus.

Arbuscular mycorrhizal (AM) fungi in the phylum Glomeromycota colonize roots of the majority of land plants and assist them in the uptake of mineral nutrients in exchange for plant-assimilated carbon. In the absence of sexual reproductive structures and with asexual spore morphology conserved since the Ordovician, Glomeromycota may be one of the oldest eukaryotic lineages that rely predominantly on asexual reproduction for gene transmission. Clonal population structure detected in the majority of AM fungi examined to date supports this hypothesis.