Structure and evolution of the squamate major histocompatibility complex as revealed by two Anolis lizard genomes

Frontiers in Genetics, Journal Year: 2022, Volume and Issue: 13

Published: Nov. 8, 2022

The major histocompatibility complex (MHC) is an important genomic region for adaptive immunity and has long been studied in ecological evolutionary contexts, such as disease resistance mate kin selection. MHC investigated extensively mammals birds but far less so squamate reptiles, the third radiation of amniotes. We localized core two species, green anole (Anolis carolinensis) brown (A. sagrei), provide first detailed characterization MHC, including presence ordering known genes these species comparative assessments structure composition regions. find that Anolis located on chromosome 2 both contains homologs many previously-identified mammalian a single region. repetitive element regions was similar to those observed had distinctions, higher proportions DNA transposons. Moreover, longer introns intergenic result much larger (11.7 Mb 24.6 anole, respectively). Evolutionary analyses anoles other representative amniotes uncovered generally monophyletic relationships between species-specific loss peptide-binding domain exon one mhc2β gene each species. Signals diversifying selection evident across codons mhc1, which appear functionally relevant given structures this protein from chicken, human. Altogether, our investigation fills gap understanding amniote diversity evolution provides foundation future squamate-specific or vertebrate-wide investigations MHC.

Language: Английский

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When adaptation is slowed down: Genomic analysis of evolutionary stasis in thermal tolerance during biological invasion in a novel climate

Molecular Ecology, Journal Year: 2023, Volume and Issue: 33(10)

Published: July 25, 2023

Research conducted during the past two decades has demonstrated that biological invasions are excellent models of rapid evolution. Even so, characteristics invasive populations such as a short time for recombination to assemble optimal combinations alleles may occasionally limit adaptation new environments. Here, we investigated genetic constraints in brown anole (Anolis sagrei)-a tropical ectotherm was introduced southeastern United States, region with much colder climate than its native Caribbean range. We examined thermal physiology 30 and tested climatic cline cold tolerance. Also, used genomics identify mechanisms adaptation. found no support cline, indicating tolerance did not shift adaptively. Concomitantly, population genomic results were consistent occurrence spots comprise more half genome maintain long-range associations among populations. These regions overlap both candidate loci identified using standard genome-wide association test. Moreover, do have large contribution differentiation range, contrary observations suggest limited is constraining swaths anoles. Our study provides an example evolutionary stasis invasion highlights possibility reduced slows down

Language: Английский

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Introduction history and hybridization determine the hydric balance of an invasive lizard facing a recent climate niche shift

Evolution, Journal Year: 2022, Volume and Issue: 77(1), P. 123 - 137

Published: Dec. 9, 2022

As anthropogenic activities are increasing the frequency and severity of droughts, understanding whether how fast populations can adapt to sudden changes in their hydric environment is critically important. Here, we capitalize on introduction Cuban brown anole lizard (Anolis sagrei) North America assess contemporary evolution a widespread terrestrial vertebrate an abrupt climatic niche shift. We characterized balance 30 along large gradient. found that while evaporative cutaneous water loss varied widely, there was no cline, as would be expected under adaptation. Furthermore, skin lizards from more arid environments covered with smaller scales, condition thought limit conservation thus maladaptive. In contrast environmental conditions, genome-averaged ancestry significant predictor loss. This reinforced by our genome-wide association analyses, which indicated ancestry-specific effect for at one locus. Thus, study indicates invasive anoles dictated environment-independent hybridization history highlights genetic interactions or correlations factors might forestall Alternative strategies, including behavioral mitigation, may influence invasion success require future examination.

Language: Английский

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Chromosome-Level Genome Assembly of the Blacktail Brush Lizard, Urosaurus nigricaudus, Reveals Dosage Compensation in an Endemic Lizard

Genome Biology and Evolution, Journal Year: 2023, Volume and Issue: 15(12)

Published: Dec. 1, 2023

Abstract Urosaurus nigricaudus is a phrynosomatid lizard endemic to the Baja California Peninsula in Mexico. This work presents chromosome-level genome assembly and annotation from male individual. We used PacBio long reads HiRise scaffolding generate high-quality genomic of 1.87 Gb distributed 327 scaffolds, with an N50 279 Mb L50 3. Approximately 98.4% contained 14 6 large scaffolds (334–127 Mb) representing macrochromosomes 8 small (63–22 microchromosomes. Using standard gene modeling transcriptomic data, we predicted 17,902 protein-coding genes on genome. The repeat content characterized by proportion interspersed nuclear elements that are relatively old. Synteny analysis revealed some microchromosomes high more prone rearrangements but both macro- well conserved across reptiles. identified scaffold as X chromosome. microchromosome perfect dosage compensation where single males has same expression levels two chromosomes females. Finally, estimated effective population size for U. was extremely low, which may reflect reduction polymorphism related it becoming peninsular endemic.

Language: Английский

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A new cell culture resource for investigations of reptilian gene function

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2023, Volume and Issue: unknown

Published: Sept. 27, 2023

Abstract The recent establishment of CRISPR/Cas9 gene editing in A. sagrei lizards makes it a powerful model system for studies reptilian function. To enhance the versatility this model, we developed an immortalized lizard fibroblast cell line (ASEC-1) exploration function cellular processes. We demonstrate use vitro by scrutinizing role primary cilia Hedgehog (Hh) signaling. Through mutagenesis disrupted ift88 gene, which is required ciliogenesis diverse organisms. find that loss itf88 from cells results absence cilia, partial derepression gli1 transcription, and inability to respond Smoothened agonist, SAG. cross-species analysis SAG-induced transcriptional responses cultured limb bud cells, further determined ∼46% genes induced as response Hh pathway activation sagrei, are also SAG-responsive M. musculus cells. Our highlight conserved diverged aspects signaling anoles establish new resource investigations

Language: Английский

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