Julio Rozas

University of Barcelona | UB · Department of Genetics

Hybridisation is a double-edged sword: while it can erode distinct evolutionary lineages, it can also introduce genetic diversity and adaptive potential into dwindling populations. In the Critically Endangered Balearic shearwater (Puffinus mauretanicus), this dilemma is exacerbated by a limited understanding of the extent and consequences of hybrid...

The spider genus Dysdera has undergone a remarkable diversification in the oceanic archipelago of the Canary Islands, with ~60 endemic species having originated during the 20 million years since the origin of the archipelago. This evolutionary radiation has been accompanied by substantial dietary shifts, often characterised by phenotypic modificati...

The Catalan Initiative for the Earth BioGenome Project (CBP) is an EBP-affiliated project network aimed at sequencing the genome of the >40 000 eukaryotic species estimated to live in the Catalan-speaking territories (Catalan Linguistic Area, CLA). These territories represent a biodiversity hotspot. While covering less than 1% of Europe, they are h...

Motivation Gene clusters, defined as a set of genes encoding functionally-related proteins, are abundant in eukaryotic genomes. Despite the increasing availability of chromosome-level genomes, the comprehensive analysis of gene family evolution remains largely unexplored, particularly for large and highly dynamic gene families or those including ve...

The spider genus Dysdera has undergone a remarkable diversification in the oceanic archipelago of the Canary Islands, ~60 endemic species originated during the 20 million years since the origin of the archipelago. This evolutionary radiation has been accompanied by substantial dietary shifts, often characterized by phenotypic modifications encompas...

Motivation Gene clusters, defined as a set of genes encoding functionally-related proteins, are abundant in eukaryotic genomes. Despite the increasing availability of chromosome-level genomes, the comprehensive analysis of gene family evolution remains largely unexplored, particularly for large and highly dynamic gene families or those including ve...

The Balearic shearwater ( Puffinus mauretanicus ) is the most threatened seabird in Europe. The fossil record suggests that human colonisation of the Balearic Islands resulted in a sharp decrease of the population size. Currently, populations continue to be decimated mainly due to predation by introduced mammals and bycatch in longline fisheries, a...

Chemoreception is critical for the survival and reproduction of animals. Except for a reduced group of insects and spiders, the molecular identity of chemosensory proteins is poorly understood in invertebrates. Gastropoda is the extant mollusk class with the greatest species richness, including marine, freshwater, and terrestrial lineages, and like...

Speciation is a continuous and complex process shaped by the interaction of numerous evolutionary forces. Despite the continuous nature of the speciation process, the implementation of conservation policies relies on the delimitation of species and evolutionary significant units (ESUs). Puffinus shearwaters are globally distributed and threatened p...

Estimating gene gain and losses is paramount to understand the molecular mechanisms underlying adaptive evolution. Despite the advent of high-throughput sequencing, such analyses have been so far hampered by the poor contiguity of genome assemblies. The increasing affordability of long-read sequencing technologies will however revolutionize our cap...

Odorant-binding proteins (OBPs) are encoded by a gene family involved in the perception of olfactory signals in insects. This chemosensory gene family has been advocated as a candidate to mediate host preference and host shifts in insects, although it also participates in other physiological processes. Remarkable differences in the OBP gene reperto...

The Balearic shearwater (Puffinus mauretanicus) is the most threatened seabird in Europe and member of the most speciose group of pelagic seabirds, the order Procellariiformes, which exhibit extreme adaptations to a pelagic lifestyle. The fossil record suggests that human colonization of the Balearic Islands resulted in a sharp decrease of the Bale...

The Balearic shearwater (Puffinus mauretanicus) is the most threatened seabird in Europe. The fossil record suggests that human colonisation of the Balearic Islands resulted in a sharp decrease of the population size. Currently, populations continue to be decimated mainly due to predation by introduced mammals and bycatch in longline fisheries, and...

Aim Palaeoceanographic changes can act as drivers of diversification and speciation, even in highly mobile marine organisms. Shearwaters are a group of globally distributed and highly mobile pelagic seabirds. Despite a recent well-resolved phylogeny, shearwaters have controversial species limits, and show periods of both slow and rapid diversificat...

Spiders (Araneae) have a diverse spectrum of morphologies, behaviours and physiologies. Attempts to understand the genomic-basis of this diversity are often hindered by their large, heterozygous and AT-rich genomes with high repeat content resulting in highly fragmented, poor-quality assemblies. As a result, the key attributes of spider genomes, in...

We present the chromosome-level genome assembly of Dysdera silvatica Schmidt, 1981, a nocturnal ground-dwelling spider endemic from the Canary Islands. The genus Dysdera has undergone a remarkable diversification in this archipelago mostly associated with shifts in the level of trophic specialization, becoming an excellent model to study the genomi...

We present the chromosome-level genome assembly of Dysdera silvatica Schmidt, 1981, a nocturnal ground-dwelling spider endemic from the Canary Islands. The genus Dysdera has undergone a remarkable diversification in this archipelago mostly associated with shifts in the level of trophic specialization, becoming an excellent model to study the genomi...

A Correction to this paper has been published: https://doi.org/10.1038/s41586-021-03473-8.

The chemosensory system has experienced relevant changes in subterranean animals, facilitating the perception of specific chemical signals critical to survive in their particular environment. However, the genomic basis of chemoreception in cave‐dwelling fauna is largely unexplored. We generated de novo transcriptomes for antennae and body samples o...

The common chaffinch, Fringilla coelebs, is one of the most common, widespread and well-studied passerines in Europe, with a broad distribution encompassing Western Europe and parts of Asia, North Africa and the Macaronesian archipelagos. We present a high-quality genome assembly of the common chaffinch generated using Illumina shotgun sequencing i...

The diversification of modern birds has been shaped by a number of radiations. Rapid diversification events make reconstructing the evolutionary relationships among taxa challenging due to the convoluted effects of incomplete lineage sorting (ILS) and introgression. Phylogenomic datasets have the potential to detect patterns of phylogenetic incongr...

The common chaffinch, Fringilla coelebs, is one of the most common, widespread and well-studied passerines in Europe, with a broad distribution encompassing Western Europe and parts of Asia, North Africa and the Macaronesian archipelagos. We present a high-quality genome assembly of the common chaffinch generated using Illumina shotgun sequencing i...

Whole-genome sequencing projects are increasingly populating the tree of life and characterizing biodiversity1,2,3,4. Sparse taxon sampling has previously been proposed to confound phylogenetic inference5, and captures only a fraction of the genomic diversity. Here we report a substantial step towards the dense representation of avian phylogenetic...

The chemosensory system has experienced relevant changes in subterranean animals, facilitating the orientation into darkness via the perception of specific chemical signals critical to survive in this particular environment. However, the genomic basis of chemoreception in cave-dwelling fauna is largely unexplored. We generated de novo transcriptome...

The advent of high-throughput sequencing technologies (HTS) has generated an unprecedented amount of genomic and transcriptomic information. A vast amount of these data is not even used in targeted projects but is made available in public repositories. Previous studies have demonstrated that HTS data constitute a valuable resource to recover mitoge...

An amendment to this paper has been published and can be accessed via the original article.

Chemosensory perception is a fundamental biological process of particular relevance in basic and applied arthropod research. However, apart from insects, there is little knowledge of specific molecules involved in this system, which is restricted to a few taxa with uneven phylogenetic sampling across lineages. From an evolutionary perspective, onyc...

Background: Although native to North America, the invasion of the aphid-like grape phylloxera Daktulosphaira vitifoliae across the globe altered the course of grape cultivation. For the past 150 years, viticulture relied on grafting-resistant North American Vitis species as rootstocks, thereby limiting genetic stocks tolerant to other stressors suc...

Identifying protein-coding genes from genome and transcriptome data is the first and one of the most important steps towards their comprehensive study. This chapter introduces both general procedures for sequence mining, and specific approaches for recognizing characteristic motives and chemical properties in soluble proteins potentially involved i...

Gene annotation is a critical bottleneck in genomic research, especially for the comprehensive study of very large gene families in the genomes of non‐model organisms. Despite the recent progress in automatic methods, state‐of‐the‐art tools used for this task often produce inaccurate annotations, such as fused, chimeric, partial or even completely...

The evolution of winged insects revolutionized terrestrial ecosystems and led to the largest animal radiation on Earth. However, we still have an incomplete picture of the genomic changes that underlay this diversification. Mayflies, as one of the sister groups of all other winged insects, are key to understanding this radiation. Here, we describe...

The genus Mammillaria occupies diverse habitats and exhibits diverse growth patterns and a large range of morphologies. Most of the species of this genus are used as ornamental plants and are subject to mass habitat loss. Due to these factors, they are being submitted to selective pressure that might affect conservational efforts and management pla...

Gene families underlie genetic innovation and phenotypic diversification. However, our understanding of the early genomic and functional evolution of tandemly arranged gene families remains incomplete as paralog sequence similarity hinders their accurate characterization. The D. melanogaster-specific gene family Sdic is tandemly repeated and impact...

The first winged insects underwent profound morphological and functional transformations leading to the most successful animal radiations in the history of earth. Despite this, we still have a very incomplete picture of the changes in their genomes that underlay this radiation. Mayflies (Ephemeroptera) are one of the extant sister groups of all oth...

Gene annotation is a critical bottleneck in genomic research, especially for the comprehensive study of very large gene families in the genomes of non-model organisms. Despite the recent progress in automatic methods, the tools developed for this task often produce inaccurate annotations, such as fused, chimeric, partial or even completely absent g...

Poster presented at the G10K-VGP/EBP 2019. Advancing the missions of the Vertebrate Genomes Project, Earth Biogenome Project, and other genome projects Tuesday - Friday, 27-30 August 2019 The Rockefeller University, Manhattan, NY, USA

The avocado, Persea americana , is a fruit crop of immense importance to Mexican agriculture with an increasing demand worldwide. Avocado lies in the anciently diverged magnoliid clade of angiosperms, which has a controversial phylogenetic position relative to eudicots and monocots. We sequenced the nuclear genomes of the Mexican avocado race, P. a...

Background We present the draft genome sequence of Dysdera silvatica, a nocturnal ground-dwelling spider from a genus that has undergone a remarkable adaptive radiation in the Canary Islands. Results The draft assembly was obtained using short (Illumina) and long (PaciBio and Nanopore) sequencing reads. Our de novo assembly (1.36 Gb), which repres...

The coexistence of multiple eco‐phenotypes in independently assembled communities makes island adaptive radiations the ideal framework to test convergence and parallelism in evolution. In the radiation of the spider genus Dysdera in the Canary Islands, species diversification occurs concomitant with repeated events of trophic specialization. These...

The avocado, Persea americana , is a fruit crop of immense importance to Mexican agriculture with an increasing demand worldwide. Avocado lies in the anciently-diverged magnoliid clade of angiosperms, which has a controversial phylogenetic position relative to eudicots and monocots. We sequenced the nuclear genomes of the Mexican avocado race, P. a...

Background Gene duplication underlies a significant proportion of gene functional diversity and genome complexity in both eukaryotes and prokaryotes. Although several reports in the literature described the duplication of specific genes in E. coli, a detailed analysis of the extent of gene duplications in this microorganism is needed. Results The...

D. subtentaculata is a paradigmatic species for evolutionary studies. It groups four lineages, of which three are exclusively sexuals (2n). The other one has a broad distribution and shows different reproduction modes. Some populations of this lineage reproduce mostly by fission (3n and 4n), others are facultative (3n) and few of them are exclusive...

Aunque la bioinformática y la evolución molecular pueden parecer disciplinas científicas muy heterogéneas, comparten gran parte de sus intereses y fundamentos, concretamente, el mismo interés por el estudio y análisis de secuencias de DNA y proteínas; no sólo eso: estos estudios son el núcleo central de ambas disciplinas.

Chemoreception is a widespread biological function that is essential for the survival, reproduction, and social communication of animals. Though the molecular mechanisms underlying chemoreception are relatively well known in insects, they are poorly studied in the other major arthropod lineages. Current availability of a number of chelicerate genom...

While interplay between BRCA1 and AURKA-RHAMM-TPX2-TUBG1 regulates mammary epithelial polarization, common genetic variation in HMMR (gene product RHAMM) may be associated with risk of breast cancer in BRCA1 mutation carriers. Following on these observations, we further assessed the link between the AURKA-HMMR-TPX2-TUBG1 functional module and risk...

Predicting the phenotypic impact of mutations is a central challenge in population and functional genetics. The analysis of DNA and amino acid sequence variation in an evolutionary context is a robust approach to infer the fitness effects of genetic variants. In this review, we discuss the most popular methods based on this approach, covering both...

We present version 6 of the DnaSP (DNA Sequence Polymorphism) software, a new version of the popular tool for performing exhaustive population genetic analyses on multiple sequence alignments. This major upgrade incorporates novel functionalities to analyse large datasets, such as those generated by high-throughput sequencing (HTS) technologies. Am...

Carnivorous plants exploit animals as a nutritional source and have inspired long-standing questions about the origin and evolution of carnivory-related traits. To investigate the molecular bases of carnivory, we sequenced the genome of the heterophyllous pitcher plant Cephalotus follicularis, in which we succeeded in regulating the developmental s...

Unlike hexapods and vertebrates, in chelicerates, knowledge of the specific molecules involved in chemoreception comes exclusively from the comparative analysis of genome sequences. Indeed, the genomes of mites, ticks and spiders contain several genes encoding homologs of some insect membrane receptors and small soluble chemosensory proteins. Here,...

Gene clusters of recently duplicated genes are hotbeds for evolutionary change. However, our understanding of how mutational mechanisms and evolutionary forces shape the structural and functional evolution of these clusters is hindered by the high sequence identity among the copies, which typically results in their inaccurate representation in geno...

Manduca sexta, known as the tobacco hornworm or Carolina sphinx moth, is a lepidopteran insect that is used extensively as a model system for research in insect biochemistry, physiology, neurobiology, development, and immunity. One important benefit of this species as an experimental model is its extremely large size, reaching more than 10 g in the...

Motivation: The development of molecular markers is one of the most important challenges in phylogenetic and genome wide population genetics studies, especially in studies with non-model organisms. Highly promising approach for obtaining suitable markers are the utilization of genomic partitioning strategies for the simultaneous discovery and geno...

The animal chemosensory system is involved in essential biological processes, most of them mediated by proteins encoded in multigene families. These multigene families have been fundamental for the adaptation to new environments, significantly contributing to phenotypic variation. This adaptive potential contrasts, however, with the lack of studies...

Manduca sexta, known as the tobacco hornworm or Carolina sphinx moth, is a lepidopteran insect that is used extensively as a model system for research in insect biochemistry, physiology, neurobiology, development, and immunity. One important benefit of this species as an experimental model is its extremely large size, reaching more than 10 g in the...

Chemoreception is an essential process for the survival and reproduction of animals. Many of the proteins responsible for recognizing and transmitting chemical stimuli in insects are encoded by genes that are members of moderately sized multigene families. The members of the CheB family are specialized in gustatory-mediated detection of long-chain...

Ticks transmit more pathogens to humans and animals than any other arthropod. We describe the 2.1 Gbp nuclear genome of the tick, Ixodes scapularis (Say), which vectors pathogens that cause Lyme disease, human granulocytic anaplasmosis, babesiosis and other diseases. The large genome reflects accumulation of repetitive DNA, new lineages of retro-tr...