Luana S Maroja

Luana S Maroja
Williams College · Department of Biology

Ph.D. Cornell University

About

150
Publications
10,872
Reads
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2,436
Citations
Citations since 2016
6 Research Items
1359 Citations
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2016201720182019202020212022050100150200
2016201720182019202020212022050100150200
Introduction
I'm interested in the evolution of barriers to gene exchange, speciation, population genetics and phylogeography. My study systems are crickets (Gryllus), artic plants and butterflies (heliconius). I'm currently an assistant professor at Williams College where I teach Genetics (Biol 202) and Evolution (Biol 305).
Additional affiliations
July 2013 - May 2014
Cornell University
Position
  • visting scholar
August 2010 - June 2016
Williams College
Position
  • Professor (Assistant)
June 2008 - August 2010
University of Cambridge
Position
  • Research Associate

Publications

Publications (150)
Article
Full-text available
The genomic architecture of barriers to gene exchange during the speciation process is poorly understood. The genomic islands model suggests that loci associated with barriers to gene exchange prevent introgression of nearby genomic regions via linkage disequilibrium. But few analyses of the actual genomic location of non-introgressing loci in clos...
Data
Exact distances of all mapped X-linked loci. Distance is measured in cM from leftmost locus (seq1412) on the X chromosome. Data can be found in Dryad: doi: 10.5061/dryad.h0g0kf0. (XLSX)
Article
The wing patterns of butterflies and moths (Lepidoptera) are diverse and striking examples of evolutionary diversification by natural selection(1,2). Lepidopteran wing colour patterns are a key innovation, consisting of arrays of coloured scales. We still lack a general understanding of how these patterns are controlled and whether this control sho...
Article
Full-text available
The Heliconius butterflies are a widely studied adaptive radiation of 46 species spread across Central and South America, several of which are known to hybridize in the wild. Here, we present a substantially improved assembly of the Heliconius melpomene genome, developed using novel methods that should be applicable to improving other genome assemb...
Article
Full-text available
The Heliconius butterflies are a widely studied adaptive radiation of 46 species spread across Central and South America, several of which are known to hybridise in the wild. Here, we present a substantially improved assembly of the Heliconius Melpomene genome, developed using novel methods that should be applicable to improving other genome assemb...
Article
Full-text available
Inositol 1,4,5-trisphosphate (IP3) regulates a host of biological processes from egg activation to cell death. When IP3-specific receptors (IP3Rs) bind to IP3, they release calcium from the ER into the cytoplasm, triggering a variety of cell type- and developmental stage-specific responses. Alternatively, inositol polyphosphate kinases can phosphor...
Preprint
Full-text available
The Heliconius butterflies are a widely studied adaptive radiation of 46 species spread across Central and South America, several of which are known to hybridise in the wild. Here, we present a substantially improved assembly of the Heliconius melpomene genome, developed using novel methods that should be applicable to improving other genome assemb...
Article
Full-text available
Characterizing the extent of genomic differentiation between recently diverged lineages provides an important context for understanding the early stages of speciation. When such lineages form discrete hybrid zones, patterns of differential introgression allow direct estimates of which genome regions are likely involved in speciation and local adapt...
Preprint
Full-text available
A major challenge in evolutionary biology is to understand the origins of novel structures. The wing patterns of butterflies and moths are derived phenotypes unique to the Lepidoptera. Here we identify a gene that we name poikilomousa (poik) , which regulates colour pattern switches in the mimetic Heliconius butterflies. Strong associations between...
Article
Full-text available
Pre-zygotic barriers often involve some form of sexual selection, usually interpreted as female choice, as females are typically the choosier sex. However, males typically show some mate preferences, which are increasingly reported. Here we document previously uncharacterized male courtship behavior (effort and song) and cuticular hydrocarbon (CHC)...
Article
Full-text available
• Premise of the study: We developed 10 novel microsatellite loci for Sagina nodosa, a diploid perennial arctic-alpine herb. To our knowledge, these are the first microsatellite loci for a Sagina species. • Methods and Results: We performed a low-coverage 454 next-generation sequencing of enriched genomic fragments derived from one individual to ge...
Article
Full-text available
• Premise of the study: Twelve microsatellite markers were developed for Primula mistassinica, a distylous, diploid arctic-alpine plant. The markers will be used to investigate the landscape genetics of a disjunct population on Isle Royale, Michigan, and the phylogeographic patterns of the species. • Methods and Results: We used Roche/454 high-thro...
Article
Full-text available
Heliconius butterflies are an excellent system for understanding the genetic basis of phenotypic change. Here we document surprising diversity in the genetic control of a common phenotype. Two disjunct H. erato populations have each recruited the Cr and/or Sd loci that control similar yellow hindwing patterns, but the alleles involved partially com...
Article
Full-text available
Phylogenetic reconstruction, divergence times, and population genetics are critical concepts for a complete understanding of evolution. Unfortunately, students generally lack “tree-thinking” skills and are often unmotivated to explore these concepts using typical classroom exercises that feature taxa unknown to students or simulated datasets. To ge...
Article
Full-text available
The evolutionary importance of hybridization and introgression has long been debated. Hybrids are usually rare and unfit, but even infrequent hybridization can aid adaptation by transferring beneficial traits between species. Here we use genomic tools to investigate introgression in Heliconius, a rapidly radiating genus of neotropical butterflies w...
Article
Full-text available
The evolution of pigmentation in vertebrates and flies has involved repeated divergence at a small number of genes related to melanin synthesis. Here, we study insect melanin synthesis genes in Heliconius butterflies, a group characterised by its diversity of wing patterns consisting of black (melanin), and yellow and red (ommochrome) pigmented sca...
Article
Full-text available
Heliconius butterflies are an excellent system for studies of adaptive convergent and divergent phenotypic traits. Wing colour patterns are used as signals to both predators and potential mates and are inherited in a Mendelian manner. The underlying genetic mechanisms of pattern formation have been studied for many years and shed light on broad iss...
Data
Heliconius miRNAs identified by deep sequencing of two colour pattern races. miRNAs identified in H. m. melpomene and H. m. rosina. Two or more miRNAs are listed when a sequence matches to two different, but related miRNAs in miRBase (the sequences and read counts of all miRNA variants detected are given in Additional files 2 and 3). Normalised abu...
Data
miRNA sequences and read counts detected in H. m. rosina. FASTA file of all identified miRNA sequence variants detected in H. m. rosina. x refers to the number of reads obtained for each sequence.
Data
Expression of miRNAs in pupal tissue. Northern blots for miRNAs in Heliconius pupal tissue collected at 24, 48 and 72 hours post-pupation (± 30 mins). H.m.m = H. melpomene melpomene, H.m.r = H. m. rosina. FW = forewing, HW = hindwing, T = thorax, U6 = U6 loading control. Gels were run for two biological replicates (A and B) for each race and stage...
Data
Full-text available
Identification of hme-miR-193 and hme-miR-2788 in Heliconius. Alignments of different sequences of hme-miR-193 and hme-miR-2788, their star sequences and sequence read counts to Heliconius melpomene BAC sequence.
Data
Probe sequences used for Northern blots. Probe sequences for ten miRNAs analysed by Northern blot.
Data
miRNA sequences and read counts detected in H. m. melpomene. FASTA file of all identified miRNA sequence variants detected in H. m. melpomene. x refers to the number of reads obtained for each sequence.
Data
Decay of linkage disequilibrium with distance within gene markers. Data are shown for combined H. m. amaryllis and H. m. aglaope populations, both for coding and non-coding markers in regions linked and unlinked to colour pattern. (0.22 MB PDF)
Data
Annotation of genes in the HmB region. (0.12 MB DOC)
Data
Estimates of Tajima's D and nucleotide diversity estimates for each locus by population. (0.28 MB DOC)
Data
Full-text available
Phenotypes of two hybrid individuals sampled in the Peruvian hybrid zone. Both individuals are phenotypically most similar to H. m. amaryllis, but with expression of the dominant HmD allele from the Amazonian race controlling the red hindwing rays and basal red patch on the forewing. (1.62 MB PDF)
Data
Gene sequencing and quantitative PCR primers. (0.40 MB DOC)
Data
HmB and unlinked gene SNP data. All variable SNPs used in the analysis for the aglaope/amaryllis comparison at the HmB locus and at unlinked loci. (0.05 MB XLS)
Data
Full-text available
Alignment of HmB region BAC clones between H. melpomene and H. erato. To assess gene order using finished BAC sequences, H. melpomene clone 28L23 was compared to finished H. erato clone 31N19 as well as the homologous region from the recently sequenced genome of the silkmoth, Bombyx mori. Gene order and orientation across the H. melpomene HmB locus...
Data
Full-text available
Decay of linkage disequilibrium with distance across the two regions. Data are shown for HmB (red circles) and HmYb (green triangles) for combined H. m. amaryllis and H. m. aglaope populations, both for all sites (A) and with sites showing a significant association with phenotype removed (B). The only remaining comparisons showing long-range LD aft...
Data
HmYb SNP data. Details of all sites significantly associated with phenotype at the HmYb locus. (0.05 MB XLS)
Data
Supplementary methods. (0.03 MB DOC)
Data
Summary of gene regions sequenced for population genetic analysis. (0.12 MB DOC)
Article
Full-text available
Wing patterning in Heliconius butterflies is a longstanding example of both Müllerian mimicry and phenotypic radiation under strong natural selection. The loci controlling such patterns are "hotspots" for adaptive evolution with great allelic diversity across different species in the genus. We characterise nucleotide variation, genotype-by-phenotyp...
Article
In recently diverged species, ancestral polymorphism and introgression can cause incongruence between gene and species trees. In the face of hybridization, few genomic regions may exhibit reciprocal monophyly, and these regions, usually evolving rapidly under selection, may be important for the maintenance of species boundaries. In animals with int...
Article
Data on patterns of variation within hybrid zones, combined with studies of life history, mate choice, and hybrid performance, allow estimates of the contribution of different pre-zygotic and post-zygotic barriers to reproductive isolation. We examine the role of behavioural barriers to gene exchange in the maintenance of a hybrid zone between Nort...
Article
Full-text available
In many animals, male seminal proteins influence gamete interactions and fertilization ability and are probably involved in barriers to gene flow between diverging lineages. Here we use a proteomic approach to identify seminal proteins that are transferred to females during copulation and that may be involved in fertilization barriers between two h...
Article
Full-text available
Wolbachia are cytoplasmically inherited alpha-proteobacteria that can cause cytoplasmic incompatibility (CI) in insects. This incompatibility between sperm and egg is evident when uninfected females mate with infected males. Wolbachia-driven reproductive incompatibilities are of special interest because they may play a role in speciation. However,...
Article
Tree-feeding insects that are widespread in north temperate regions are excellent models for studying how past glaciations have impacted differentiation and speciation. We used mitochondrial DNA (mtDNA) sequences and allele frequencies at nine microsatellite loci to examine genetic population structure across the current range of the spruce beetle...
Article
Full-text available
This study reports 2 years of the population dynamics and reproduction of a small mammal community using the removal method. The study was conducted in a rural area of the Atlantic Forest, in Sumidouro, Rio de Janeiro State, Brazil. The population sizes, age structure and reproduction were studied for the four most common species in the study area....
Article
Full-text available
Accessory reproductive gland proteins (Acps) in Drosophila evolve quickly and appear to play an important role in ensuring the fertilization success of males. Moreover, Acps are thought to be involved in establishing barriers to fertilization between closely related species. While accessory glands are known to occur in the males of many insect grou...
Article
Full-text available
In sexually reproducing organisms, male ejaculates are complex traits that are potentially subject to many different selection pressures. Recent experimental evidence supports the hypothesis that postmating sexual selection, and particularly sexual conflict, may play a key role in the evolution of the proteinaceous components of ejaculates. However...
Article
Full-text available
Seven microsatellite loci were used to investigate the genetic variability and structure of six mainland and two island populations of the Neotropical water rat Nectomys squamipes, a South American semi-aquatic rodent species with a wide distribution. High levels of variability were found within mainland populations while island populations were le...