Diverse Gene Family Research Articles

Identification of Genomic Regions Conferring Enhanced Zn and Fe Concentration in Wheat Varieties and Introgression Lines Derived from Wild Relatives.

Wild and cultivated relatives of wheat are an important source of genetic factors for improving the mineral composition of wheat. In this work, a wheat panel consisting of modern bread wheat varieties, landraces, and introgression lines with genetic material of the wheat species Triticum timopheevii, T. durum, T. dicoccum, and T. dicoccoides and the synthetic line T. kiharae was used to identify loci associated with the grain zinc (GZnC) and iron (GFeC) content. Using a BLINK model, we identified 31 and 73 marker-trait associations (MTAs) for GZnC and GFeC, respectively, of which 19 were novel. Twelve MTAs distributed on chromosomes 1B, 2A, 2B, 5A, and 5B were significantly associated with GZnC, five MTAs on 2A, 2B, and 5D chromosomes were significantly associated with GFeC, and two SNPs located on 2A and 2B were related to the grain concentration of both trace elements. Meanwhile, most of these MTAs were inherited from At and G genomes of T. timopheevii and T. kiharae and positively affected GZnC and GFeC. Eight genes related to iron or zinc transporters, representing diverse gene families, were proposed as the best candidates. Our findings provide an understanding of the genetic basis of grain Zn and Fe accumulation in species of the Timopheevi group and could help in selecting new genotypes containing valuable loci.

Taxonomic variation, plastic degradation, and antibiotic resistance traits of plastisphere communities in the maturation pond of a wastewater treatment plant.

Wastewater treatment facilities can filter out some plastics before they reach the open environment, yet microplastics often persist throughout these systems. As they age, microplastics in wastewater may both leach and sorb pollutants and fragment to provide an increased surface area for bacterial attachment and conjugation, possibly impacting antimicrobial resistance (AMR) traits. Despite this, little is known about the effects of persistent plastic pollution on microbial functioning. To address this knowledge gap, we deployed five different artificially weathered plastic types and a glass control into the final maturation pond of a municipal wastewater treatment plant in Ōtautahi-Christchurch, Aotearoa/New Zealand. We sampled the plastic-associated biofilms (plastisphere) at 2, 6, 26, and 52 weeks, along with the ambient pond water, at three different depths (20, 40, and 60 cm from the pond water surface). We investigated the changes in plastisphere microbial diversity and functional potential through metagenomic sequencing. Bacterial 16S ribosomal RNA genes composition did not vary among plastic types and glass controls (P = 0.997) but varied among sampling times [permutational multivariate analysis of variance (PERMANOVA), P = 0.001] and depths (PERMANOVA, P = 0.011). Overall, there was no polymer-substrate specificity evident in the total composition of genes (PERMANOVA, P = 0.67), but sampling time (PERMANOVA, P = 0.002) and depth were significant factors (PERMANOVA, P = 0.001). The plastisphere housed diverse AMR gene families, potentially influenced by biofilm-meditated conjugation. The plastisphere also harbored an increased abundance of genes associated with the biodegradation of nylon, or nylon-associated substances, including nylon oligomer-degrading enzymes and hydrolases.IMPORTANCEPlastic pollution is pervasive and ubiquitous. Occurrences of plastics causing entanglement or ingestion, the leaching of toxic additives and persistent organic pollutants from environmental plastics, and their consequences for marine macrofauna are widely reported. However, little is known about the effects of persistent plastic pollution on microbial functioning. Shotgun metagenomics sequencing provides us with the necessary tools to examine broad-scale community functioning to further investigate how plastics influence microbial communities. This study provides insight into the functional consequence of continued exposure to waste plastic by comparing the prokaryotic functional potential of biofilms on five types of plastic [linear low-density polyethylene (LLDPE), nylon-6, polyethylene terephthalate, polylactic acid, and oxygen-degradable LLDPE], glass, and ambient pond water over 12 months and at different depths (20, 40, and 60 cm) within a tertiary maturation pond of a municipal wastewater treatment plant.

Dgfr: an R package to assess sequence diversity of gene families

BackgroundGene families are groups of homologous genes that often have similar biological functions. These families are formed by gene duplication events throughout evolution, resulting in multiple copies of an ancestral gene. Over time, these copies can acquire mutations and structural variations, resulting in members that may vary in size, motif ordering and sequence. Multigene families have been described in a broad range of organisms, from single-celled bacteria to complex multicellular organisms, and have been linked to an array of phenomena, such as host–pathogen interactions, immune evasion and embryonic development. Despite the importance of gene families, few approaches have been developed for estimating and graphically visualizing their diversity patterns and expression profiles in genome-wide studies.ResultsHere, we introduce an R package named dgfr, which estimates and enables the visualization of sequence divergence within gene families, as well as the visualization of secondary data such as gene expression. The package takes as input a multi-fasta file containing the coding sequences (CDS) or amino acid sequences from a multigene family, performs a pairwise alignment among all sequences, and estimates their distance, which is subjected to dimension reduction, optimal cluster determination, and gene assignment to each cluster. The result is a dataset that allows for the visualization of sequence divergence and expression within the gene family, an approximation of the number of clusters present in the family.Conclusionsdgfr provides a way to estimate and study the diversity of gene families, as well as visualize the dispersion and secondary profile of the sequences. The dgfr package is available at https://github.com/lailaviana/dgfr under the GPL-3 license.

Recurrent Duplication and Diversification of a Vital DNA Repair Gene Family Across Drosophila.

Maintaining genome integrity is vital for organismal survival and reproduction. Essential, broadly conserved DNA repair pathways actively preserve genome integrity. However, many DNA repair proteins evolve adaptively. Ecological forces like UV exposure are classically cited drivers of DNA repair evolution. Intrinsic forces like repetitive DNA, which also imperil genome integrity, have received less attention. We recently reported that a Drosophila melanogaster-specific DNA satellite array triggered species-specific, adaptive evolution of a DNA repair protein called Spartan/MH. The Spartan family of proteases cleave hazardous, covalent crosslinks that form between DNA and proteins ("DNA-protein crosslink repair"). Appreciating that DNA satellites are both ubiquitous and universally fast-evolving, we hypothesized that satellite DNA turnover spurs adaptive evolution of DNA-protein crosslink repair beyond a single gene and beyond the D. melanogaster lineage. This hypothesis predicts pervasive Spartan gene family diversification across Drosophila species. To study the evolutionary history of the Drosophila Spartan gene family, we conducted population genetic, molecular evolution, phylogenomic, and tissue-specific expression analyses. We uncovered widespread signals of positive selection across multiple Spartan family genes and across multiple evolutionary timescales. We also detected recurrent Spartan family gene duplication, divergence, and gene loss. Finally, we found that ovary-enriched parent genes consistently birthed functionally diverged, testis-enriched daughter genes. To account for Spartan family diversification, we introduce a novel mechanistic model of antagonistic coevolution that links DNA satellite evolution and adaptive regulation of Spartan protease activity. This framework promises to accelerate our understanding of how DNA repeats drive recurrent evolutionary innovation to preserve genome integrity.

Genome-wide identification of bZIP transcription factors and their expression analysis in Platycodon grandiflorus under abiotic stress.

The Basic Leucine Zipper (bZIP) transcription factors (TFs) family is among of the largest and most diverse gene families found in plant species, and members of the bZIP TFs family perform important functions in plant developmental processes and stress response. To date, bZIP genes in Platycodon grandiflorus have not been characterized. In this work, a number of 47 PgbZIP genes were identified from the genome of P. grandiflorus, divided into 11 subfamilies. The distribution of these PgbZIP genes on the chromosome and gene replication events were analyzed. The motif, gene structure, cis-elements, and collinearity relationships of the PgbZIP genes were simultaneously analyzed. In addition, gene expression pattern analysis identified ten candidate genes involved in the developmental process of different tissue parts of P. grandiflorus. Among them, Four genes (PgbZIP5, PgbZIP21, PgbZIP25 and PgbZIP28) responded to drought and salt stress, which may have potential biological roles in P. grandiflorus development under salt and drought stress. Four hub genes (PgbZIP13, PgbZIP30, PgbZIP32 and PgbZIP45) mined in correlation network analysis, suggesting that these PgbZIP genes may form a regulatory network with other transcription factors to participate in regulating the growth and development of P. grandiflorus. This study provides new insights regarding the understanding of the comprehensive characterization of the PgbZIP TFs for further exploration of the functions of growth and developmental regulation in P. grandiflorus and the mechanisms for coping with abiotic stress response.

Somatic genome architecture and molecular evolution are decoupled in "young" linage-specific gene families in ciliates.

The evolution of lineage-specific gene families remains poorly studied across the eukaryotic tree of life, with most analyses focusing on the recent evolution of de novo genes in model species. Here we explore the origins of lineage-specific genes in ciliates, a ~1 billion year old clade of microeukaryotes that are defined by their division of somatic and germline functions into distinct nuclei. Previous analyses on conserved gene families have shown the effect of ciliates' unusual genome architecture on gene family evolution: extensive genome processing-the generation of thousands of gene-sized somatic chromosomes from canonical germline chromosomes-is associated with larger and more diverse gene families. To further study the relationship between ciliate genome architecture and gene family evolution, we analyzed lineage specific gene families from a set of 46 transcriptomes and 12 genomes representing x species from eight ciliate classes. We assess how the evolution lineage-specific gene families occurs among four groups of ciliates: extensive fragmenters with gene-size somatic chromosomes, non-extensive fragmenters with "large'' multi-gene somatic chromosomes, Heterotrichea with highly polyploid somatic genomes and Karyorelictea with 'paradiploid' somatic genomes. Our analyses demonstrate that: 1) most lineage-specific gene families are found at shallow taxonomic scales; 2) extensive genome processing (i.e., gene unscrambling) during development likely influences the size and number of young lineage-specific gene families; and 3) the influence of somatic genome architecture on molecular evolution is increasingly apparent in older gene families. Altogether, these data highlight the influences of genome architecture on the evolution of lineage-specific gene families in eukaryotes.

Evolutionary history of the cytochrome P450s from Colletotrichum species and prediction of their putative functional roles during host-pathogen interactions

The genomes of species belonging to the genus Colletotrichum harbor a substantial number of cytochrome P450 monooxygenases (CYPs) encoded by a broad diversity of gene families. However, the biological role of their CYP complement (CYPome) has not been elucidated. Here, we investigated the putative evolutionary scenarios that occurred during the evolution of the CYPome belonging to the Colletotrichum Graminicola species complex (s.c.) and their biological implications. The study revealed that most of the CYPome gene families belonging to the Graminicola s.c. experienced gene contractions. The reductive evolution resulted in species restricted CYPs are predominant in each CYPome of members from the Graminicola s.c., whereas only 18 families are absolutely conserved among these species. However, members of CYP families displayed a notably different phylogenetic relationship at the tertiary structure level, suggesting a putative convergent evolution scenario. Most of the CYP enzymes of the Graminicola s.c. share redundant functions in secondary metabolite biosynthesis and xenobiotic metabolism. Hence, this current work suggests that the presence of a broad CYPome in the genus Colletotrichum plays a critical role in the optimization of the colonization capability and virulence.

Phylogenomics of Plant NLR Immune Receptors to Identify Functionally Conserved Sequence Motifs.

In recent years, the increase in genome sequencing across diverse plant species has provided a significant advantage for phylogenomics studies, allowing the analysis of one of the most diverse gene families in plants: nucleotide-binding leucine-rich repeat receptors (NLRs). However, due to the sequence diversity of the NLR gene family, identifying key molecular features and functionally conserved sequence patterns is challenging through multiple sequence alignment. Here, we present a step-by-step protocol for a computational pipeline designed to identify evolutionarily conserved motifs in plant NLR proteins. In this protocol, we use a large-scale NLR dataset, including 1,862 NLR genes annotated from monocot and dicot species, to predict conserved sequence motifs, such as the MADA and EDVID motifs, within the coiled-coil (CC)-NLR subfamily. Our pipeline can be applied to identify molecular signatures that have remained conserved in the gene family over evolutionary time across plant species. Key features • Phylogenomics analysis of plant NLR immune receptor family. • Identification of functionally conserved sequence patterns among plant NLRs.

ELUCIDATING THE FUNCTIONAL ANNOTATION AND EVOLUTIONARY RELATIONSHIPS OF CYTOCHROME P450 GENES IN XYLARIA SP. FL1777 USING IN-SILICO APPROACHES

The higher level of human activities has resulted in several forms of anthropogenic activities with diverse adverse effects on human and environmental sustainability. The traditional means of handling xenobiotics pollutants are no longer sustainable due to the high cost involved, complex procedures and demanding regulatory requirements. Bioremediation using fungi (mycoremediation) is now recognized as an efficient and workable biotechnological tool that effectively employ fungal enzymes via the process of absorption and mineralization to get rid of contaminants. Cytochrome P450s (CYPs) are diverse and unique gene families with varying degree of complexities in the eukaryotes. CYPs mainly utilize molecular oxygen to modify substrate conformation, thereby establishing a mechanism of action for achieving their important physiological and ecological processes. Xylariaceae belongs to the main and highly diversified families of filamentous Ascomycota; it plays an important role as saprotrophs of wood, soil, litter and dung. Genome-wide annotation analysis was carried out to explore the possibility of utilizing the CYPs of Xylaria sp. for achieving mycoremediation. The evolutionary analysis has divided the 214 Xylaria CYPs into fifteen (15) clades. The CYPs were categorized into forty-seven (47 clans) and eighty-six (86) families. MEME suite identified ten (10) conserved motifs. The gene structural investigation reveals high dynamic intron-exon organization. Most of the CYPs have been predicted to be localized in the endoplasmic reticulum. This study therefore calls for deeper exploration of the Xylaria sp and its high potential for application in bioremediation for the degradation of environmental contaminants.

Transcriptomics of ivermectin response in Caenorhabditis elegans: Integrating abamectin quantitative trait loci and comparison to the Ivermectin-exposed DA1316 strain.

Parasitic nematodes pose a significant threat to human and animal health, as well as cause economic losses in the agricultural sector. The use of anthelmintic drugs, such as Ivermectin (IVM), to control these parasites has led to widespread drug resistance. Identifying genetic markers of resistance in parasitic nematodes can be challenging, but the free-living nematode Caenorhabditis elegans provides a suitable model. In this study, we aimed to analyze the transcriptomes of adult C. elegans worms of the N2 strain exposed to the anthelmintic drug Ivermectin (IVM), and compare them to those of the resistant strain DA1316 and the recently identified Abamectin Quantitative Trait Loci (QTL) on chromosome V. We exposed pools of 300 adult N2 worms to IVM (10-7 and 10-8 M) for 4 hours at 20°C, extracted total RNA and sequenced it on the Illumina NovaSeq6000 platform. Differentially expressed genes (DEGs) were determined using an in-house pipeline. The DEGs were compared to genes from a previous microarray study on IVM-resistant C. elegans and Abamectin-QTL. Our results revealed 615 DEGs (183 up-regulated and 432 down-regulated genes) from diverse gene families in the N2 C. elegans strain. Of these DEGs, 31 overlapped with genes from IVM-exposed adult worms of the DA1316 strain. We identified 19 genes, including the folate transporter (folt-2) and the transmembrane transporter (T22F3.11), which exhibited an opposite expression in N2 and the DA1316 strain and were deemed potential candidates. Additionally, we compiled a list of potential candidates for further research including T-type calcium channel (cca-1), potassium chloride cotransporter (kcc-2), as well as other genes such as glutamate-gated channel (glc-1) that mapped to the Abamectin-QTL.

The terpene synthase genes of Melaleuca alternifolia (tea tree) and comparative gene family analysis among Myrtaceae essential oil crops

Terpene synthases (TPS) are responsible for the terminal biosynthetic step of terpenoid production. They are encoded by a highly diverse gene family believed to evolve by tandem duplication in response to adaptive pressures. Taxa in the Myrtaceae family are renowned for their diversity of terpenoid-rich essential oils, and among them, the tribe Eucalypteae has the largest TPS gene family found in any plant (> 100 TPS). In this study, comparative analysis of Melaleuca alternifolia (tea tree), from the related tribe Melaleuceae, revealed some Myrtaceae have smaller TPS families, as a total of 58 putatively functional full-length TPS genes, and 21 pseudogenes were identified by manual annotation of a newly released long-read assembly of the genome. The TPS-a and TPS-b2 subfamilies that synthesise secondary compounds often mediating plant-environment interactions were more diminutive than those in eucalypts, probably reflecting key differences in the evolutionary histories of the two lineages. Of the putatively functional TPS-b1, 13 clustered into a region of around 400 kb on one scaffold. The organisation of these TPS suggested that tandem duplication was instrumental in the evolution and diversity of terpene chemistry in Melaleuca. Four TPS-b1 likely to catalyse the synthesis of the three monoterpenoid components that are used to classify tea tree chemotypes were encoded within a single small region of 87 kb in the larger cluster of TPS-b1, raising the possibility that coregulation and linkage may lead to their behaviour as a single locus, providing an explanation for the categorical inheritance of complex multiple-component chemotypes in the taxon.

Insight into the genomes of dominant yeast symbionts of European spruce bark beetle, Ips typographus.

Spruce bark beetle Ips typographus can trigger outbreaks on spruce that results in significant losses in the forest industry. It has been suggested that symbiotic microorganisms inhabiting the gut of bark beetles facilitate the colonization of plant tissues as they play a role in the detoxification of plant secondary metabolites, degrade plant cell wall and ameliorate beetle's nutrition. In this study, we sequenced and functionally annotated the genomes of five yeasts Kuraishia molischiana, Cryptococcus sp., Nakazawaea ambrosiae, Ogataea ramenticola, and Wickerhamomyces bisporus isolated from the gut of Ips typographus. Genome analysis identified 5314, 7050, 5722, 5502, and 5784 protein coding genes from K. molischiana, Cryptococcus sp., N. ambrosiae, O. ramenticola, and W. bisporus, respectively. Protein-coding sequences were classified into biological processes, cellular and molecular function based on gene ontology terms enrichment. Kyoto Encyclopedia of Genes and Genomes (KEGG) annotation was used to predict gene functions. All analyzed yeast genomes contain full pathways for the synthesis of essential amino acids and vitamin B6, which have nutritional importance to beetle. Furthermore, their genomes contain diverse gene families related to the detoxification processes. The prevalent superfamilies are aldo-keto reductase, ATP-binding cassette and the major facilitator transporters. The phylogenetic relationships of detoxification-related enzymes aldo-keto reductase, and cytochrome P450 monooxygenase, and ATP-binding cassette are presented. Genome annotations also revealed presence of genes active in lignocellulose degradation. In vitro analyses did not confirm enzymatic endolytic degradation of lignocellulose; however, all species can utilize and pectin and produce a large spectrum of exolytic enzymes attacking cellulose, chitin, and lipids.

Genome-Wide Characterization of the SAMS Gene Family in Cotton Unveils the Putative Role of GhSAMS2 in Enhancing Abiotic Stress Tolerance

The most devastating abiotic factors worldwide are drought and salinity, causing severe bottlenecks in the agricultural sector. To acclimatize to these harsh ecological conditions, plants have developed complex molecular mechanisms involving diverse gene families. Among them, S-adenosyl-L-methionine synthetase (SAMS) genes initiate the physiological, morphological, and molecular changes to enable plants to adapt appropriately. We identified and characterized 16 upland cotton SAMS genes (GhSAMSs). Phylogenetic analysis classified the GhSAMSs into three major groups closely related to their homologs in soybean. Gene expression analysis under drought and salt stress conditions revealed that GhSAMS2, which has shown the highest interaction with GhCBL10 (a key salt responsive gene), was the one that was most induced. GhSAMS2 expression knockdown via virus-induced gene silencing (VGIS) enhanced transgenic plants’ susceptibility to drought and salt stress. The TRV2:GhSAMS2 plants showed defects in terms of growth and physiological performances, including antioxidative processes, chlorophyll synthesis, and membrane permeability. Our findings provide insights into SAMS genes’ structure, classification, and role in abiotic stress response in upland cotton. Moreover, they show the potential of GhSAMS2 for the targeted improvement of cotton plants’ tolerance to multiple abiotic stresses.

The Pathology and Splenic Transcriptome Profiling of Trionyx sinensis Challenged with Bacillus cereus

The pathogenic Bacillus cereus strain XS0724 isolated from China can cause high lethality to Trionyx sinensis, but little information is available on their detailed interactions. In this study, histopathologic profiling indicated that B. cereus caused vacuolization and cell necrosis in the liver, spleen, kidney, and intestine. The identification of the virulence factor genes non-hemolytic enterotoxin (Nhe), hemolysin BL (Hbl), and enterotoxin FM (entFM) confirmed bacterial pathogenicity. Splenic transcriptomic sequencing at 96 h post-infection identified various immune-related genes mapped to diverse gene families, including interleukin, complement, chemokine, and interferon. The differentially expressed genes (DEGs) were enriched in 2174 GO terms: 1694 in biological processes, 138 in cellular components, and 342 in molecular functions. Further KEGG enrichment indicated that DEGs were primarily associated with the phagosome, NF-kappa B signaling pathway, and PI3K-Akt signaling pathway. The DEGs and enriched pathways may be involved in the elimination of invasive B. cereus. These data laid the foundation for elucidating the potential molecular mechanisms in this bacterial infection process, and provided robust genetic evidence for subsequent work on resistance genes of T. sinensis.

Analyses of gene copy number variation in diverse epigenetic regulatory gene families across plants: Increased copy numbers of BRUSHY1/TONSOKU/MGOUN3 (BRU1/TSK/MGO3) and SILENCING DEFECTIVE 3 (SDE3) in long-lived trees

Long-lived trees experience high risk of damage due to the various types of stresses over their lifespans. Epigenetic regulation is involved in gene regulation, genome integrity, and inhibition of exogenous genetic elements, which are functions important for long-term survival. To narrow down the candidate genes related to tree longevity among diverse epigenetic regulatory genes, it is necessary to identify epigenetic regulatory genes with increased copy number in long-lived tree species as compared to in short-lived annual and perennial herb species. In the present study, to find out the epigenetic regulatory genes with increased copy number in tree species as compared to in annual and perennial herb species, we conducted the systematic comparison of copy number variation in 121 gene families involved in various epigenetic regulatory pathways across 85 plant species with different lifespans using a genome database. Among these 121 gene families, the gene family encoding BRUSHY1/TONSOKU/MGOUN3 (BRU1/TSK/MGO3) and that encoding SILENCING DEFECTIVE 3 (SDE3) were found to exhibit significantly higher copy number of genes in tree species than in both perennial and annual herb species. BRU1/TSK/MGO3 is involved in chromatin modifications and plays an important role in the maintenance of meristems, genome integrity, and the inheritance of chromatin states. SDE3 is involved in RNA silencing and has an important role in antiviral defense through posttranscriptional gene silencing. The systematic comparison of copy number variation in diverse epigenetic regulatory gene families among plant species can find out epigenetic regulatory genes with increased copy number in long-lived tree species and enhance subsequent studies for understanding the relationship between epigenetic regulation and tree longevity.

A lineage-specific Exo70 is required for receptor kinase–mediated immunity in barley

In the evolution of land plants, the plant immune system has experienced expansion in immune receptor and signaling pathways. Lineage-specific expansions have been observed in diverse gene families that are potentially involved in immunity but lack causal association. Here, we show that Rps8-mediated resistance in barley to the pathogen Puccinia striiformis f. sp. tritici (wheat stripe rust) is conferred by a genetic module: Pur1 and Exo70FX12, which are together necessary and sufficient. Pur1 encodes a leucine-rich repeat receptor kinase and is the ortholog of rice Xa21, and Exo70FX12 belongs to the Poales-specific Exo70FX clade. The Exo70FX clade emerged after the divergence of the Bromeliaceae and Poaceae and comprises from 2 to 75 members in sequenced grasses. These results demonstrate the requirement of a lineage-specific Exo70FX12 in Pur1-mediated immunity and suggest that the Exo70FX clade may have evolved a specialized role in receptor kinase signaling.

DNA Metabarcoding Across Disciplines: Sequencing Our Way to Greater Understanding Across Scales of Biological Organization.

DNA metabarcoding describes the use of targeted DNA (i.e., amplicon) sequencing to identify community constituents from a complex sample containing genetic material from multiple organisms, such as water, soil, gut contents, microbiomes, or biofilms. This molecular approach for characterizing mixed DNA samples relies on the development of "universal primers" that allow for effective amplification of target sequences across a broad range of taxa. Armed with optimized lab protocols and rigorous bioinformatics tools, DNA metabarcoding can produce a wealth of information about the hidden biodiversity of various sample types by probing for organisms' molecular footprints. DNA metabarcoding has received considerable popular press over the last few years because of gut microbiome studies in humans and beyond. However, there are many other applications that are continually integrating molecular biology with other fields of study to address questions that have previously been unanswerable, for both prokaryotic and eukaryotic targets. For example, we can now sample mostly digested gut contents from virtually any organism to learn about ontogeny and foraging ecology. Water samples collected from different locations can be filtered to extract eDNA (i.e., environmental DNA), revealing the biodiversity of fish and other taxa targeted by carefully selected primer sets. This universal primer metabarcoding approach has even been extended to looking at diverse gene families within single species, which is particularly useful for complex immune system genetics. The purpose of this SICB symposium was to bring together researchers using DNA metabarcoding approaches to (a) showcase the diversity of applications of this technique for addressing questions spanning ecology, evolution, and physiology, and (b) to spark connections among investigators from different fields that are utilizing similar approaches to facilitate optimization and standardization of metabarcoding methods and analyses. The resulting manuscripts from this symposium represent a great diversity of metabarcoding applications and taxonomic groups of interest.

A reflection of life - my tale of microdiversity, equity and inclusion in cell biology (and beyond).

A reflection of life - my tale of microdiversity, equity and inclusion in cell biology (and beyond).

Venom Gene Sequence Diversity and Expression Jointly Shape Diet Adaptation in Pitvipers.

Understanding the joint roles of protein sequence variation and differential expression during adaptive evolution is a fundamental, yet largely unrealized goal of evolutionary biology. Here, we use phylogenetic path analysis to analyze a comprehensive venom-gland transcriptome dataset spanning three genera of pitvipers to identify the functional genetic basis of a key adaptation (venom complexity) linked to diet breadth (DB). The analysis of gene-family-specific patterns reveals that, for genes encoding two of the most important venom proteins (snake venom metalloproteases and snake venom serine proteases), there are direct, positive relationships between sequence diversity (SD), expression diversity (ED), and increased DB. Further analysis of gene-family diversification for these proteins showed no constraint on how individual lineages achieved toxin gene SD in terms of the patterns of paralog diversification. In contrast, another major venom protein family (PLA2s) showed no relationship between venom molecular diversity and DB. Additional analyses suggest that other molecular mechanisms—such as higher absolute levels of expression—are responsible for diet adaptation involving these venom proteins. Broadly, our findings argue that functional diversity generated through sequence and expression variations jointly determine adaptation in the key components of pitviper venoms, which mediate complex molecular interactions between the snakes and their prey.

Genome-wide evolution and expression analysis of the MYB-CC gene family in Brassica spp.

The MYB-CC family is a subtype within the MYB superfamily. This family contains an MYB domain and a predicted coiled-coil (CC) domain. Several MYB-CC transcription factors are involved in the plant’s adaptability to low phosphate (Pi) stress. We identified 30, 34, and 55 MYB-CC genes in Brassica rapa, Brassica oleracea, and Brassica napus, respectively. The MYB-CC genes were divided into nine groups based on phylogenetic analysis. The analysis of the chromosome distribution and gene structure revealed that most MYB-CC genes retained the same relative position on the chromosomes and had similar gene structures during allotetraploidy. Evolutionary analysis showed that the ancestral whole-genome triplication (WGT) and the recent allopolyploidy are critical for the expansion of the MYB-CC gene family. The expression patterns of MYB-CC genes were found to be diverse in different tissues of the three Brassica species. Furthermore, the gene expression analysis under low Pi stress revealed that MYB-CC genes may be related to low Pi stress responses. These results may increase our understanding of MYB-CC gene family diversification and provide the basis for further analysis of the specific functions of MYB-CC genes in Brassica species.