scholarly journals Evolutionary and phylogenetic insights from a nuclear genome sequence of the extinct, giant, “subfossil” koala lemur Megaladapis edwardsi

2021 ◽  
Vol 118 (26) ◽  
pp. e2022117118
Author(s):  
Stephanie Marciniak ◽  
Mehreen R. Mughal ◽  
Laurie R. Godfrey ◽  
Richard J. Bankoff ◽  
Heritiana Randrianatoandro ◽  
...  

No endemic Madagascar animal with body mass >10 kg survived a relatively recent wave of extinction on the island. From morphological and isotopic analyses of skeletal “subfossil” remains we can reconstruct some of the biology and behavioral ecology of giant lemurs (primates; up to ∼160 kg) and other extraordinary Malagasy megafauna that survived into the past millennium. Yet, much about the evolutionary biology of these now-extinct species remains unknown, along with persistent phylogenetic uncertainty in some cases. Thankfully, despite the challenges of DNA preservation in tropical and subtropical environments, technical advances have enabled the recovery of ancient DNA from some Malagasy subfossil specimens. Here, we present a nuclear genome sequence (∼2× coverage) for one of the largest extinct lemurs, the koala lemur Megaladapis edwardsi (∼85 kg). To support the testing of key phylogenetic and evolutionary hypotheses, we also generated high-coverage nuclear genomes for two extant lemurs, Eulemur rufifrons and Lepilemur mustelinus, and we aligned these sequences with previously published genomes for three other extant lemurs and 47 nonlemur vertebrates. Our phylogenetic results confirm that Megaladapis is most closely related to the extant Lemuridae (typified in our analysis by E. rufifrons) to the exclusion of L. mustelinus, which contradicts morphology-based phylogenies. Our evolutionary analyses identified significant convergent evolution between M. edwardsi and an extant folivore (a colobine monkey) and an herbivore (horse) in genes encoding proteins that function in plant toxin biodegradation and nutrient absorption. These results suggest that koala lemurs were highly adapted to a leaf-based diet, which may also explain their convergent craniodental morphology with the small-bodied folivore Lepilemur.

2020 ◽  
Author(s):  
Stephanie Marciniak ◽  
Mehreen R. Mughal ◽  
Laurie R. Godfrey ◽  
Richard J. Bankoff ◽  
Heritiana Randrianatoandro ◽  
...  

AbstractNo endemic Madagascar animal with body mass >10 kg survived a relatively recent wave of extinction on the island. From morphological and isotopic analyses of skeletal ‘subfossil’ remains we can reconstruct some of the biology and behavioral ecology of giant lemurs (primates; up to ~160 kg), elephant birds (up to ~860 kg), and other extraordinary Malagasy megafauna that survived well into the past millennium. Yet much about the evolutionary biology of these now extinct species remains unknown, along with persistent phylogenetic uncertainty in some cases. Thankfully, despite the challenges of DNA preservation in tropical and sub-tropical environments, technical advances have enabled the recovery of ancient DNA from some Malagasy subfossil specimens. Here we present a nuclear genome sequence (~2X coverage) for one of the largest extinct lemurs, the koala lemur Megaladapis edwardsi (~85kg). To support the testing of key phylogenetic and evolutionary hypotheses we also generated new high-coverage complete nuclear genomes for two extant lemur species, Eulemur rufifrons and Lepilemur mustelinus, and we aligned these sequences with previously published genomes for three other extant lemur species and 47 non-lemur vertebrates. Our phylogenetic results confirm that Megaladapis is most closely related to the extant Lemuridae (typified in our analysis by E. rufifrons) to the exclusion of L. mustelinus, which contradicts morphology-based phylogenies. Our evolutionary analyses identified significant convergent evolution between M. edwardsi and extant folivorous primates (colobine monkeys) and ungulate herbivores (horses) in genes encoding protein products that function in the biodegradation of plant toxins and nutrient absorption. These results suggest that koala lemurs were highly adapted to a leaf-based diet, which may also explain their convergent craniodental morphology with the small-bodied folivore Lepilemur.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Catarina Leal ◽  
Florence Fontaine ◽  
Aziz Aziz ◽  
Conceiçao Egas ◽  
Christophe Clément ◽  
...  

Abstract Background Bacillus subtilis strains have been widely studied for their numerous benefits in agriculture, including viticulture. Providing several assets, B. subtilis spp. are described as promising plant-protectors against many pathogens and as influencers to adaptations in a changing environment. This study reports the draft genome sequence of the beneficial Bacillus subtilis PTA-271, isolated from the rhizospheric soil of healthy Vitis vinifera cv. Chardonnay at Champagne Region in France, attempting to draw outlines of its full biocontrol capacity. Results The PTA-271 genome has a size of 4,001,755 bp, with 43.78% of G + C content and 3945 protein coding genes. The draft genome of PTA-271 putatively highlights a functional swarming motility system hypothesizing a colonizing capacity and a strong interacting capacity, strong survival capacities and a set of genes encoding for bioactive substances. Predicted bioactive compounds are known to: stimulate plant growth or defenses such as hormones and elicitors, influence beneficial microbiota, and counteract pathogen aggressiveness such as effectors and many kinds of detoxifying enzymes. Conclusions Plurality of the putatively encoded biomolecules by Bacillus subtilis PTA-271 genome suggests environmentally robust biocontrol potential of PTA-271, protecting plants against a broad spectrum of pathogens.


Author(s):  
Christine Hirschberger ◽  
Victoria A Sleight ◽  
Katharine E Criswell ◽  
Stephen J Clark ◽  
J Andrew Gillis

Abstract The origin of the jaw is a long-standing problem in vertebrate evolutionary biology. Classical hypotheses of serial homology propose that the upper and lower jaw evolved through modifications of dorsal and ventral gill arch skeletal elements, respectively. If the jaw and gill arches are derived members of a primitive branchial series, we predict that they would share common developmental patterning mechanisms. Using candidate and RNAseq/differential gene expression analyses, we find broad conservation of dorsoventral patterning mechanisms within the developing mandibular, hyoid and gill arches of a cartilaginous fish, the skate (Leucoraja erinacea). Shared features include expression of genes encoding members of the ventralising BMP and endothelin signalling pathways and their effectors, the joint markers nkx3.2 and gdf5 and pro-chondrogenic transcription factor barx1, and the dorsal territory marker pou3f3. Additionally, we find that mesenchymal expression of eya1/six1 is an ancestral feature of the mandibular arch of jawed vertebrates, while differences in notch signalling distinguish the mandibular and gill arches in skate. Comparative transcriptomic analyses of mandibular and gill arch tissues reveal additional genes differentially expressed along the dorsoventral axis of the pharyngeal arches, including scamp5 as a novel marker of the dorsal mandibular arch, as well as distinct transcriptional features of mandibular and gill arch muscle progenitors and developing gill buds. Taken together, our findings reveal conserved patterning mechanisms in the pharyngeal arches of jawed vertebrates, consistent with serial homology of their skeletal derivatives, as well as unique transcriptional features that may underpin distinct jaw and gill arch morphologies.


2010 ◽  
Vol 192 (24) ◽  
pp. 6492-6493 ◽  
Author(s):  
Angel Angelov ◽  
Susanne Liebl ◽  
Meike Ballschmiter ◽  
Mechthild Bömeke ◽  
Rüdiger Lehmann ◽  
...  

ABSTRACT Spirochaeta thermophila is a thermophilic, free-living anaerobe that is able to degrade various α- and β-linked sugar polymers, including cellulose. We report here the complete genome sequence of S. thermophila DSM 6192, which is the first genome sequence of a thermophilic, free-living member of the Spirochaetes phylum. The genome data reveal a high density of genes encoding enzymes from more than 30 glycoside hydrolase families, a noncellulosomal enzyme system for (hemi)cellulose degradation, and indicate the presence of a novel carbohydrate-binding module.


2020 ◽  
Author(s):  
Nikola Palevich ◽  
Paul H. Maclean ◽  
William J. Kelly ◽  
Sinead C. Leahy ◽  
Jasna Rakonjac ◽  
...  

AbstractRuminants are essential for maintaining the global population and managing greenhouse gas emissions. In the rumen, bacterial species belonging to the genera rumen Butyrivibrio and Pseudobutyrivibrio constitute the core bacterial rumen microbiome and are important degraders of plant-derived complex polysaccharides. Pseudobutyrivibrio xylanivorans MA3014 was selected for genome sequencing in order to examine its ability to breakdown and utilize plant polysaccharides. The complete genome sequence of MA3014 is 3.58 Mb, consists of three replicons (a chromosome, chromid and plasmid), has an overall G+C content of 39.6% and encodes 3,265 putative protein-coding genes (PCGs). Comparative pan-genomics of all cultivated and currently available P. xylanivorans genomes has revealed highly open genomes and a strong correlation of orthologous genes within this species of rumen bacteria. MA3014 is metabolically versatile and capable of utilizing a range of simple mono-or oligosaccharides to complex plant polysaccharides such as pectins, mannans, starch and hemicelluloses for growth, with lactate, butyrate and formate as the principal fermentation end-products. The genes encoding these metabolic pathways have been identified and MA3014 is predicted to encode an extensive repertoire of Carbohydrate-Active enZYmes (CAZymes) with 80 Glycoside Hydrolases (GHs), 28 Carbohydrate Esterases (CEs) and 51 Glycosyl Transferases (GTs), that suggest its role as an initiator of primary solubilization of plant matter in the rumen.


Yeast ◽  
2000 ◽  
Vol 1 (3) ◽  
pp. 170-187 ◽  
Author(s):  
Olof Karlberg ◽  
Björn Canbäck ◽  
Charles G. Kurland ◽  
Siv G. E. Andersson

We propose a scheme for the origin of mitochondria based on phylogenetic reconstructions with more than 400 yeast nuclear genes that encode mitochondrial proteins. Half of the yeast mitochondrial proteins have no discernable bacterial homologues, while one-tenth are unequivocally of α-proteobacterial origin. These data suggest that the majority of genes encoding yeast mitochondrial proteins are descendants of two different genomic lineages that have evolved in different modes. First, the ancestral free-living α-proteobacterium evolved into an endosymbiont of an anaerobic host. Most of the ancestral bacterial genes were lost, but a small fraction of genes supporting bioenergetic and translational processes were retained and eventually transferred to what became the host nuclear genome. In a second, parallel mode, a larger number of novel mitochondrial genes were recruited from the nuclear genome to complement the remaining genes from the bacterial ancestor. These eukaryotic genes, which are primarily involved in transport and regulatory functions, transformed the endosymbiont into an ATP-exporting organelle.


2020 ◽  
Vol 9 (4) ◽  
Author(s):  
Yiping He ◽  
Sue Reed ◽  
Terence P. Strobaugh

The complete genome sequence of Campylobacter jejuni YH003, isolated from retail chicken, was determined using PacBio and Illumina technologies. The assembled genome is 1,743,985 bp (G+C content of 30.3%). Genome annotation revealed several genes encoding virulence and antibiotic resistance factors, including a type VI secretion system, cytolethal distending toxins, and a multidrug efflux system.


2019 ◽  
Vol 35 (21) ◽  
pp. 4430-4432 ◽  
Author(s):  
René L Warren ◽  
Lauren Coombe ◽  
Hamid Mohamadi ◽  
Jessica Zhang ◽  
Barry Jaquish ◽  
...  

Abstract Motivation In the modern genomics era, genome sequence assemblies are routine practice. However, depending on the methodology, resulting drafts may contain considerable base errors. Although utilities exist for genome base polishing, they work best with high read coverage and do not scale well. We developed ntEdit, a Bloom filter-based genome sequence editing utility that scales to large mammalian and conifer genomes. Results We first tested ntEdit and the state-of-the-art assembly improvement tools GATK, Pilon and Racon on controlled Escherichia coli and Caenorhabditis elegans sequence data. Generally, ntEdit performs well at low sequence depths (<20×), fixing the majority (>97%) of base substitutions and indels, and its performance is largely constant with increased coverage. In all experiments conducted using a single CPU, the ntEdit pipeline executed in <14 s and <3 m, on average, on E.coli and C.elegans, respectively. We performed similar benchmarks on a sub-20× coverage human genome sequence dataset, inspecting accuracy and resource usage in editing chromosomes 1 and 21, and whole genome. ntEdit scaled linearly, executing in 30–40 m on those sequences. We show how ntEdit ran in <2 h 20 m to improve upon long and linked read human genome assemblies of NA12878, using high-coverage (54×) Illumina sequence data from the same individual, fixing frame shifts in coding sequences. We also generated 17-fold coverage spruce sequence data from haploid sequence sources (seed megagametophyte), and used it to edit our pseudo haploid assemblies of the 20 Gb interior and white spruce genomes in <4 and <5 h, respectively, making roughly 50M edits at a (substitution+indel) rate of 0.0024. Availability and implementation https://github.com/bcgsc/ntedit Supplementary information Supplementary data are available at Bioinformatics online.


Plants ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 358
Author(s):  
Joan Pedrola-Monfort ◽  
David Lázaro-Gimeno ◽  
Carlos G. Boluda ◽  
Laia Pedrola ◽  
Alfonso Garmendia ◽  
...  

Among the most intriguing mysteries in the evolutionary biology of photosynthetic organisms are the genesis and consequences of the dramatic increase in the mitochondrial and nuclear genome sizes, together with the concomitant evolution of the three genetic compartments, particularly during the transition from water to land. To clarify the evolutionary trends in the mitochondrial genome of Archaeplastida, we analyzed the sequences from 37 complete genomes. Therefore, we utilized mitochondrial, plastidial and nuclear ribosomal DNA molecular markers on 100 species of Streptophyta for each subunit. Hierarchical models of sequence evolution were fitted to test the heterogeneity in the base composition. The best resulting phylogenies were used for reconstructing the ancestral Guanine-Cytosine (GC) content and equilibrium GC frequency (GC*) using non-homogeneous and non-stationary models fitted with a maximum likelihood approach. The mitochondrial genome length was strongly related to repetitive sequences across Archaeplastida evolution; however, the length seemed not to be linked to the other studied variables, as different lineages showed diverse evolutionary patterns. In contrast, Streptophyta exhibited a powerful positive relationship between the GC content, non-coding DNA, and repetitive sequences, while the evolution of Chlorophyta reflected a strong positive linear relationship between the genome length and the number of genes.


2020 ◽  
Vol 36 (4) ◽  
pp. 421-423
Author(s):  
Bertrand Jordan

Sophisticated analyses of current human populations compared to a high-coverage Neandertal genome sequence indicate that, contrary to the previous consensus, African genomes carry a small but significant amount of Neandertal-specific DNA. This indicates back-migration into Africa of modern humans (carrying some Neandertal sequences) and underlines the complexity of ancient human migrations.


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