Polymorphic Sites Research Articles

Impact of neutrophil‐activating protein conservation on diagnostic tests and vaccine design

AbstractBACKGROUNDThe neutrophil activating protein (NAP) is a highly immunogenic and virulence factor of Helicobacter pylori, presenting inflammatory and immunomodulatory activity. Consequently, NAP has been explored as a diagnostic and therapeutic target. However, when evaluating a target protein to design diagnostic methods or vaccines, it is critical to determine the protein conservation among the bacterial population, as well the impact of alterations of amino acid residues on the protein antigenic profile.RESULTSIn the present work, NAP conservation and theoretical antigenicity were determined among 51 sequences from H. pylori isolated from patients worldwide. A high NAP conservation (83%) was observed, where 17 amino acid residues, among the 144 residues of the protein, were polymorphic. Alterations at these polymorphic sites had a theoretically low impact on predicted antigenicity, where only 5 NAPs out of 51 NAPs presented a slightly different antigenic profile in relation to the consensus sequence. According to that, it was possible to recognize in western blotting 93% of NAP from different bacteria (n = 15) using polyclonal antibodies developed against a specific NAP.CONCLUSIONSIt was predicted that when working with polyclonal antibodies or large NAP fragments for diagnostic and vaccine design, slight variation in protein sequence will have a minimal impact on NAP recognition. However, if a NAP monoclonal antibody or small NAP epitopes are considered, it is critical to select the most conserved and antigenic NAP regions, to maximize the coverage of NAP variants. © 2024 Society of Chemical Industry (SCI).

Employing genome-wide association studies to investigate acid adaptation mechanisms in Listeria monocytogenes

Listeria monocytogenes is a critical foodborne pathogen known to develop adaptation traits in mildly acidic food processing environments. This study analyzed the genomic data of 49 strains derived from clinical and food sources, utilizing genome-wide association studies (GWAS) to explore the correlation between the genotypic and phenotypic traits of L. monocytogenes, thereby identifying the genetic determinants of its acid adaptation capability. The findings revealed no significant association between the collected acid adaptation genes and the bacterial growth parameters. The GWAS results indicated that numerous single nucleotide polymorphism (SNP) sites were significantly correlated with the growth parameters of L. monocytogenes in a pH = 5.0 acidic environment, whereas the associations diminished as the pH approached neutrality at pH = 6.7. Analysis and annotation of synonymous mutation loci revealed that non-synonymous mutations primarily impact function. The phenotypes pH = 5.0, ΔpH (5.0–5.5), SNPλ, and SNPμmax show the strongest associations with non-synonymous mutation loci. The genes lmo0017, lmo1173, lmo0794, and lmo2783 are significant non-synonymous mutation loci influencing acid adaptation. These genes play critical roles in intracellular pH regulation, cell wall synthesis and environmental response control, directly or indirectly affecting bacterial acid tolerance. Future research could leverage existing data combined with machine learning and causal inference methods to further dissect the genotype-phenotype causal relationships, identifying causative genetic factors that govern the acid adaptation in L. monocytogenes, providing insights for risk assessment and management strategies in food safety.

Genome-Wide Association Study Reveals Loci and New Candidate Gene Controlling Seed Germination in Rice

Improving seed germination and seedling development can potentially increase crop yield and improve quality in direct-seeded rice. This study aimed to detect loci or genes associated with rice seed germination. We reported the phenotypic analysis of seed germination in 103 rice accessions across two years, and a genome-wide association study (GWAS) was conducted to identify loci underlying the genetic regulation of seed germination. A total of seven genetic loci were found to be associated with seed germination, including five loci that overlapped with the previously reported loci/genes, and two novel loci. Of these, two loci (qGP2 and qGP4.1) were stable across different environments. GP4 (Germination percentage 4), encoding a 9-cis-epoxycarotenoid dioxygenase, was identified as the candidate gene of the major locus qGP4.1. A sequence analysis of GP4 revealed that four functional polymorphic sites in the coding region were significantly associated with germination percentage. The disruption of GP4 by gene editing resulted in faster seed germination and seedling establishment. Taken together, we have identified GP4 as a novel gene involved in rice seed germination, and we provide a potential target gene for improving rice seed vigor via gene editing or molecular breeding.

Fine genetic mapping and transcriptomic analysis revealed major gene modulating the clear stripe margin pattern of watermelon peel.

The peel stripe margin pattern is one of the most important quality traits of watermelon. In this study, two contrasted watermelon lines [slb line (P1) with a clear peel stripe margin pattern and GWAS-38 line (P2) with a blurred peel stripe margin pattern] were crossed, and biparental F2 mapping populations were developed. Genetic segregation analysis revealed that a single recessive gene is modulating the main-effect genetic locus (Clcsm) of the clear stripe margin pattern of peel. Bulked segregant analysis-based sequencing (BSA-Seq) and fine genetic mapping exposed the delimited Clcsm locus to a 19.686-kb interval on chromosome 6, and the Cla97C06G126680 gene encoding the MYB transcription factor family was identified. The gene mutation analysis showed that two non-synonymous single-nucleotide polymorphism (nsSNP) sites [Chr6:28438793 (A-T) and Chr6:28438845 (A-C)] contribute to the clear peel stripe margin pattern, and quantitative real-time polymerase chain reaction (qRT-PCR) also showed a higher expression trend in the slb line than in the GWAS-38 line. Further, comparative transcriptomic analysis identified major differentially expressed genes (DEGs) in three developmental periods [4, 12, and 20 days after pollination (DAP)] of both parental lines. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) functional enrichment analyses indicated highly enriched DEGs involved in metabolic processes and catalytic activity. A total of 44 transcription factor families and candidate genes belonging to the ARR-B transcription factor family are believed to regulate the clear stripe margin trait of watermelon peel. The gene structure, sequence polymorphism, and expression trends depicted significant differences in the peel stripe margin pattern of both parental lines. The ClMYB36 gene showed a higher expression trend for regulating the clear peel stripe margin of the slb line, and the ClAPRR5 gene depicted a higher expression for modulating the blurred peel stripe margin in the GWAS-38 line. Overall, our fine genetic mapping and transcriptomic analysis revealed candidate genes differentiating the clear and blurred peel stripe patterns of watermelon fruit.

Identification of P-efficient elite allele of the TaPHT1;6 gene and development of its functional marker in common wheat (Triticum aestivum L.)

In agriculture, a significant challenge revolves around low phosphate (Pi) use efficiency, leading to increased costs and environmental issues while causing a shortage of phosphorus (P) resources. The TaPHT1;6 gene, which encodes a high-affinity Pi transporter (PHT), plays a crucial role in Pi absorption and transport. In this study, the promoter and coding regions of three TaPHT1;6 gene copies on chromosomes 5A, 5B, and 5D were individually amplified and sequenced from 167 common wheat (Triticum aestivum L.) cultivars. Sequence analysis revealed 16 allelic variation sites within the promoters of TaPHT1;6-5B among these cultivars, forming three distinct haplotypes: Hap1, Hap2, and Hap3. Field trials were conducted over two years to compare wheat genotypes with these haplotypes, with a focus on assessing plant dry weight, grain yield, P content, Pi fertilizer absorption efficiency, and Pi fertilizer utilization efficiency. Results indicated that Hap3 represented the favored Pi-efficient haplotype. The dual-luciferase reporter assay demonstrated that the Hap3 promoter, carrying the identified allelic variation sites, exhibited higher gene-driven capability, leading to increased expression levels of the TaPHT1;6-5B gene. Based on these allelic variation sites, a distributed cleaved amplified polymorphic site marker (dCAPS-571) was developed to distinguish Hap3 from the other two haplotypes, presenting an opportunity for breeding Pi-efficient wheat cultivars. This study successfully identified polymorphic sites on TaPHT1;6-5B associated with Pi efficiency and developed a functional molecular marker to facilitate future breeding endeavors.

Molecular Evolution of Rice Blast Resistance Gene bsr-d1

Rice blast, caused by the fungus Magnaporthe oryzae, reduces rice yields by 10% to 35%. Incorporating plant blast resistance genes into breeding programs is an effective strategy to combat this disease. Understanding the genetic variants that confer resistance is crucial to this strategy. The gene Bsr-d1 encodes a C2H2-like transcription factor, and its recessive allele confers broad-spectrum resistance against infections by various strains of M. oryzae. In this study, we investigated the molecular evolution of the rice blast resistance gene bsr-d1 in a representative population consisting of 827 cultivated and wild rice varieties. Our results revealed that wild rice exhibited significantly higher nucleotide diversity, with polymorphic regions primarily concentrated in the promoter region, in contrast to indica and japonica rice varieties. The Bsr-d1 gene displayed significant differentiation between indica and japonica, with the bsr-d1 resistance allele being unique to indica. Haplotype network and phylogenetic analyses suggested that the bsr-d1 resistance allele most likely originated from Oryza nivara in the region adjacent to the Indian Peninsula and the Indochina Peninsula. Moreover, we explored the utilization of bsr-d1 resistance alleles in China and designed a pair of DNA primers based on the polymorphic sites for the detection of the bsr-d1 resistance gene. In summary, our study uncovering the origin and evolution of bsr-d1 will enhance our comprehension of resistance gene variation and expedite the resistance breeding process.

DNA BARCODING OF HIPPOPHAE RHAMNOIDES L. COLLECTED FROM NATURAL AND INTRODUCED POPULATIONS IN KAZAKHSTAN

In this study, we analyzed eight samples of Hippophae rhamnoides L. collected in Kazakhstan, along with twenty-five samples of Hippophae species and three outgroup species from NCBI GenBank, using ITS sequences. The alignment of the ITS sequences, which was 639 bp in length with outgroup samples and 642 bp without them, revealed polymorphism, with 31 positions (4.85%) being polymorphic among the ingroup samples. The highest number of polymorphic sites was found in ITS1 (13 sites), followed by ITS2 (10 sites) and the 5.8S rRNA region (8 sites). The maximum likelihood (ML) phylogenetic tree delineated four distinct clades within the Hippophae species. The H. rhamnoides samples from northeastern Kazakhstan clustered with H. rhamnoides ssp. mongolica from GenBank suggests a close genetic relationship. Introduced samples formed separate subclades and clustered with various subspecies from GenBank. Notably, hybrid peaks were observed in the ITS sequences of introduced plants, which were not present in samples from natural populations. This study underscores the utility of ITS sequences in identifying plants from natural and introduced populations of H. rhamnoides and highlights the marker's importance in plant genetic research and biodiversity conservation.

Understanding molecular mechanisms of vertebral number of variations on Mongolian sheep using candidate genes analysis.

This study aimed to investigate the genetic link between variations in vertebral number and meat production traits, such as body weight and body measurements (body length, body height, heart girth, and shin width) in Mongolian (Bayantsagaan) sheep. Additionally, we examined the association of single-nucleotide polymorphisms (SNPs) in candidate genes, particularly Vertnin (VRTN), Nuclear receptor subfamily 6, group A, member 1 (NR6A1), and synapse differentiation-inducing 1-like (SYNDIG1L), with vertebral number variations and their potential impact on meat production traits. The study involved 220 Bayantsagaan sheep from Bayantsagaan soum, Tov province, Mongolia, including 104 sheep with extra vertebrae group and 116 individuals with typical vertebral number as the control group. Morphological data, including body weight and body measurements, were collected, and genetic samples were obtained. The impact of vertebral number on morphological traits was estimated using a general linear model. SNPs in the VRTN, NR6A1, and SYNDIG1L genes were sequenced, and their association with vertebral number was analyzed using one-way ANOVA. Bayantsagaan sheep with extra vertebrae were, on average, 4.45 kg heavier and exhibited higher variability in body size traits compared to the control group. Four polymorphic sites were identified at the VRTN gene, with one polymorphic locus (VRTN1716) showing a significant association with vertebrae number and body size. Sheep with C/C genotype at VRTN1716 locus, had more vertebrae and larger body size compared to other genotypes. The findings suggest that variations in vertebral number and VRTN gene polymorphisms are linked to favorable meat production traits in Bayantsagaan sheep. The identified SNP (VRTN1716) associated with vertebral number and body size offers the potential for marker-assisted selection in breeding programs. These results provide valuable insights into the genetic basis of meat production traits in Bayantsagaan sheep and may contribute to the development of more efficient breeding strategies.

Study of the association between oxytocin receptor gene polymorphism, childhood adversity and negative symptoms of schizophrenia

Is known that the neurohormone oxytocin plays an important role in the pathogenesis of mental illness, and also models the relationship between stress factors, especially those acting in the early stages of development, and the development of mental disorders. Based on these data, we investigated the effects of the interaction of the environmental factor, which was considered the adversity of childhood (ND) and the oxytocin receptor (OXTR) genotypes in the polymorphic sites rs4686302 and rs7632287, on the severity of negative symptoms of schizophrenia. The study involved 592 patients with schizophrenia (headings F20. according to ICD-10). Information about the presence of ND was obtained from case histories and patient interviews. Analysis of covariance (GML) was used for statistical data processing; in post-hoc pairwise comparison, Tukey’s test was used. A significant effect of the interaction between ND and OXTR gene polymorphism rs7632287(G/A) on the severity of negative symptoms in patients with schizophrenia was revealed. In patients without ND, polymorphisms did not have a significant effect on the studied phenotype. Thus, our study showed for the first time that the rs7632287(G/A) polymorphism and ND have a mutual effect on the severity of negative symptoms of schizophrenia.

Construction and Evaluation of Pepper Core Collection Based on Phenotypic Traits and SSR Markers

To streamline germplasm preservation, enhance resource utilization, and improve breeding efficiency, a core germplasm bank was established using 24 phenotypic traits and DNP markers from 155 pepper resources across various regions. Selection of the optimal core germplasm was based on intra-group retention ratio, overall retention scale, and intra-group stepwise clustering retention. Evaluation of phenotypic trait data for the core germplasm utilized mean, variance, range, and coefficient of variation, with principal component analysis confirming the selection. For molecular evaluation, the core germplasm pre-selection plan was based on SSR clustering, allele retention ratio, and Shannon-Weaver diversity index. This approach resulted in a core germplasm of 41 resources, including 6 var. fasciculatum, 7 var. grossum, 3 var. cerasiorme, 6 var. conoides, and 19 var. longum, representing the maximum phenotypic retention and genetic diversity of the 155 pepper resources. Additionally, a core germplasm of 32 resources was generated based on SSR markers, retaining all 54 polymorphic loci. By integrating phenotypic and molecular core collections, a combined core collection of 57 varieties was developed. This collection achieved a 92.55% phenotype retention ratio and a 100% polymorphism site retention ratio. With a 90% compression ratio, it encapsulates the broad genetic diversity of the original germplasm, serving as a comprehensive resource for further research and breeding applications.

A comparative analysis of chloroplast genomes revealed the chloroplast heteroplasmy of Artemisia annua.

Artemisia annua L. is the main source of artemisinin, an antimalarial drug. High diversity of morphological characteristics and artemisinin contents of A. annua has affected the stable production of artemisinin while efficient discrimination method of A. annua strains is not available. The complete chloroplast (cp) genomes of 38 A. annua strains were assembled and analyzed in this study. Phylogenetic analysis of Artemisia species showed that distinct intraspecific divergence occurred in A. annua strains. A total of 38 A. annua strains were divided into two distinct lineages, one lineage containing widely-distributed strains and the other lineage only containing strains from northern China. The A. annua cp genomes ranged from 150, 953 to 150, 974bp and contained 131 genes, and no presence or absence variation of genes was observed. The IRs and SC junctions were located in rps19 and ycf1, respectively, without IR contraction observed. Rich sequence polymorphisms were observed among A. annua strains, and a total of 60 polymorphic sites representing 14 haplotypes were identified which unfolding the cpDNA heteroplasmy of A. annua. In conclusion, this study provided valuable resource for A. annua strains identification and provided new insights into the evolutionary characteristics of A. annua.

Genetic evidence for predisposition to acute leukemias due to a missense mutation (p.Ser518Arg) in ZAP70 kinase: a case-control study

BackgroundThe apparent lack of additional missense mutations data on mixed-phenotype leukemia is noteworthy. Single amino acid substitution by these non-synonymous single nucleotide variations can be related to many pathological conditions and may influence susceptibility to disease. This case-control study aimed to unravel whether the ZAP70 missense variant (rs104893674 (C > A)) underpinning mixed-phenotype leukemia.MethodsThe rs104893674 was genotyped in clients who were mixed-phenotype acute leukemia-, acute lymphoblastic leukemia- and acute myeloid leukemia-positive and matched healthy controls, which have been referred to all major urban hospitals from multiple provinces of country- wide, IRAN, from February 11’ 2019 to June 10’ 2023, by amplification refractory mutation system-polymerase chain reaction method. Direct sequencing for rs104893674 of the ZAP70 gene was performed in a 3130 Genetic Analyzer.ResultsWe found that the AC genotype of individuals with A allele at this polymorphic site (heterozygous variant-type) contribute to the genetic susceptibility to acute leukemia of both forms, acute myeloid leukemia and acute lymphoblastic leukemia as well as with a mixed phenotype. In other words, the ZAP70 missense variant (rs104893674 (C > A)) increases susceptibility of distinct cell populations of different (myeloid and lymphoid) lineages to exhibiting cancer phenotype. The results were all consistent with genotype data obtained using a direct DNA sequencing technique.ConclusionOf special interest are pathogenic missense mutations, since they generate variants that cause specific molecular phenotypes through protein destabilization. Overall, we discovered that the rs104893674 (C > A) variant chance in causing mixed-phenotype leukemia is relatively high.

Wild silk insect of Simlipal biosphere and its molecular genetic diversity for conservation.

Designated silkworms (Antheraea mylitta D.) are found in the Smilipal Biosphere Reserve (SBR) and consist of four ecological groups. This study examined the genetics of eight ethnic groups from four ecological groups (Modal, Nalia, Bogai and Jata) using RAPD and ISSR markers. The RAPD primer produced 127 bands, of which 41 out of 116 polymorphic regions had a PIC value above 0.45. ISSR markers assigned PIC data values to 57 of 127 polymorphic sites. Cluster analysis revealed genetic differences between ecological populations, with markers separating ecological populations into groups. Low testicles and high genetic diversity indicate that these individuals are at different levels. If adequate protection is not provided, the risk of extinction of ecospecies designed in SBR increases. This study shows that the combined use of RAPD + ISSR markers can improve the results of the technology in identifying different diseases in situations where genomic information is limited.

Analysis of the Mitochondrial COI Gene and Genetic Diversity of Endangered Goose Breeds.

The mitochondrial cytochrome c oxidase subunit I (COI) genes of six endangered goose breeds (Xupu, Yangjiang, Yan, Wuzong, Baizi, and Lingxian) were sequenced and compared to assess the genetic diversity of endangered goose breeds. By constructing phylogenetic trees and evolutionary maps of genetic relationships, the affinities and degrees of genetic variations among the six different breeds were revealed. A total of 92 polymorphic sites were detected in the 741 bp sequence of the mtDNA COI gene after shear correction, and the GC content of the processed sequence (51.11%) was higher than that of the AT content (48.89%). The polymorphic loci within the populations of five of the six breeds (Xupu, Yangjiang, Yan, Baizi, and Lingxian) were more than 10, the haplotype diversity > 0.5, and the nucleotide diversity (Pi) > 0.005, with the Baizi geese being the exception. A total of 35 haplotypes were detected based on nucleotide variation among sequences, and the goose breed haplotypes showed a central star-shaped dispersion; the FST values were -0.03781 to 0.02645, The greatest genetic differentiation (FST = 0.02645) was observed in Yan and Wuzong breeds. The most frequent genetic exchange (Nm > 15.00) was between the Wuzong and Yangjiang geese. An analysis of molecular variance showed that the population genetic variation mainly came from within the population; the base mismatch differential distribution analysis of the goose breeds and the Tajima's D and Fu's Fs neutral detection of the historical occurrence dynamics of their populations were negative (p > 0.10). The distribution curve of the base mismatches showed a multimodal peak, which indicated that the population tended to be stabilised. These results provide important genetic information for the conservation and management of endangered goose breeds and a scientific basis for the development of effective conservation strategies.

Polycyclic aromatic hydrocarbon and its adducts in peripheral blood: Gene and environment interaction among Chinese population

BackgroundBenzo(a)pyrene (B[a]P) is the most widely concerned polycyclic aromatic hydrocarbons (PAHs), which metabolizes benzo(a)pyrene-7,8-dihydrodiol-9,10-epoxide (BPDE) in vivo to produce carcinogenic effect on the body. Currently, there is limited research on the role of the variation of metabolic enzymes in this process. MethodsWe carried out a study including 752 participants, measured the concentrations of 16 kinds PAHs in both particle and gaseous phases, urinary PAHs metabolites, leukocyte BPDE-DNA adduct and serum BPDE- Albumin (BPDE-Alb) adduct, and calculated daily intake dose (DID) to assess the cumulative exposure of PAHs. We conducted single nucleotide polymorphism sites (SNPs) of metabolic enzymes, explored the exposure–response relationship between the levels of exposure and BPDE adducts using multiple linear regression models. ResultOur results indicated that an interquartile range (IQR) increase in B[a]P, PAHs, BaPeq, 1-hydroxypyrene (1-OHP), 1-hydroxynaphthalene (1-OHNap) and 2-hydroxynaphthalene (2-OHNap) were associated with 26.53 %, 24.24 %, 28.15 %, 39.15 %, 12.85 % and 14.09 % increase in leukocyte BPDE-DNA adduct (all P < 0.05). However, there was no significant correlation between exposure with serum BPDE-Alb adduct (P > 0.05). Besides, we also found the polymorphism of CYP1A1(Gly45Asp), CYP2C9 (Ile359Leu), and UGT1A1(downstream) may affect BPDE adducts level. ConclusionOur results indicated that leukocyte BPDE-DNA adduct could better reflect the exposure to PAHs. Furthermore, the polymorphism of CYP1A1, CYP2C9 and UGT1A1affected the content of BPDE adducts.

Genomic structures of insulin-like growth factor from golden pompano (Trachinotus ovatus) and their expression responses to the feed types.

Golden pompano is an important aquaculture product in the coastal regions of southern China, which is highly dependent on insulin-like growth factor (IGF) for various biological processes. The cDNAs of ToIGF1, ToIGF2, and ToIGF3 are 1718bp, 1658bp, and 2272bp in length, respectively, with corresponding amino acid sequences of 185 aa, 215 aa, and 194 aa. These sequences consist of 5 parts, including the signal peptide, the B domain, the C domain, the A domain, the D domain, and the E domain, which are also found in other species. While ToIGF1 has no SSR polymorphism, ToIGF2 and ToIGF3 have 3 and 1 SSR polymorphism sites, respectively. In terms of tissue expression, ToIGF1 is predominantly expressed in the liver, ToIGF2 shows its highest expression in the gills, and ToIGF3 also shows its highest expression in the gills, but no expression in the liver and spleen. These tissue distribution results suggest that ToIGFs are not only present in growth-related tissues such as the brain, muscle, and liver, but also in reproductive tissues, tissues that regulate osmotic pressure, and tissues related to food intake. This observation is consistent with other bony fish species and highlights the extensive biological functions of ToIGFs that need to be further explored and exploited. In addition, the expression levels of ToIGFs were found to be different in the different dietary groups, including the pelleted food group, the frozen squid group, and the frozen fish group. In the pelleted diet group, ToIGF1 and ToIGF2 were highly expressed in the liver and intestinal tissues, followed by the frozen fish group. These results suggest that the type of diet can affect the body's energy metabolism by influencing tissue expression of growth-related genes, which in turn affects individual growth.

Morphology and COI barcodes reveal local loaches (Nemacheilus spp.) from Pasuruan River, East Java, Indonesia

Abstract. Sulung CAVT, Chair NE, Rahayu DA, Nugroho ED, Rusdianto. 2024. Morphology and COI barcodes reveal local loaches (Nemacheilus spp.) from Pasuruan River, East Java, Indonesia. Biodiversitas 25: 2806-2819. The family Nemacheilidae is one of the most diverse and widespread family of freshwater fishes. The nemacheilid loach in the Pasuruan river is relatively abundant; however, there is limited information available about this species. Therefore, further research is necessary to identify loaches from the Pasuruan area. This research aimed to identify the local loach species from Pasuruan District. The pectoral fins were stored in pure-grade ethanol and subjected to DNA extraction, polymerase chain reaction (PCR), and sequence analysis using bioinformatics tool, BOLD systems, and Automatic Barcode Gap Discovery (ABGD) web. The morphological identification revealed two local loaches, Nemacheilus chrysolaimos Valenciennes 1846 and Nemacheilus fasciatus Valenciennes 1846. The high haplotype diversity (Hd) of 0.9 and nucleotide diversity (?) of 0.1 indicate a wide range of genetic variations. The frequency of parsimony informative sites at 25.6% and 16 polymorphic sites and the overall ts/tv ratio of 2.3. The phylogenetic trees demonstrated a clear and unambiguous branching pattern for N. fasciatus and N. chrysolaimos forming their own monophyletic branches. Kimura's 2-parameter genetic distance of the COI gene sequences between these two species was 0.11. This finding was strengthened by morphological and molecular identification results, which indicated that there are two local loach species in Pasuruan District.

Underground speciation: Unraveling the systematics and evolution of the highly diverse tuco-tucos (genus Ctenomys) with genomic data

Subterranean rodents of the genus Ctenomys (tuco-tucos) are endemic to South America and have experienced relatively recent radiation. There are about 67 recognized species that originated in approximately 1–2 MY. They stand out for their species richness, extraordinary chromosomal diversity, and wide range of habitat they occupy in the continent. Phylogenetic relationships among species of tuco-tucos have been challenging to resolve. Groups of closely-related species have been suggested, but their relationships must be resolved. This study estimates the phylogeny of the genus using massive sequencing, generating thousands of independent molecular markers obtained by RADseq, with a taxonomic sampling that includes 66% of the recognized species. The sequences obtained were mapped against the C. sociabilis genome, recovering up to 1,215 widely shared RAD loci with more than 19,000 polymorphic sites. Our new phylogenetic hypothesis corroborated the species groups previously proposed with cytochrome b gene sequences and provided a much greater resolution of the relationships among species groups. The frater group is sister to all other tuco-tucos, whereas some of the earlierliest proposals placed the sociabilis group as sister to all other tuco-tucos. Ctenomys leucodon, previously proposed as an independent lineage, is associated with the frater group with moderate statistical support. The magellanicus and mendocinus are sister groups in a major clade formed by the boliviensis, talarum, tucumanus, torquatus, and opimus groups. Ctenomys viperinus, included in the phylogeny for the first time, belongs to the tucumanus group. This multi-locus phylogenetic hypothesis provides insights into the historical biogeography of understanding this highly diverse genus.

Development and validation of a 40 K liquid SNP array for the mud crab (Scylla paramamosain)

Genomic selection (GS) and genome-wide association studies (GWAS) have been widely implemented to accelerate the genetic improvement of important economic traits. Developing an efficient and reliable high-throughput genotyping tool is the premise and basis of implementing GS and GWAS on the mud crab (Scylla paramamosain). In this study, leveraging the whole-genome resequencing data of 146 mud crabs from the southeast coast of China, a total of 16,714,943 high-quality SNPs were discovered. Based on polymorphic information content and evenly distribution on 49 chromosomes, a total of 40,352 SNPs was selected to develop a 40 K liquid SNP array (named “Xiexin No. 1”) using the genotyping by target sequencing (GBTS) technology. The genotyping performance test showed that this SNP array had a high site polymorphism (over 92.70%) and individual calling rate (97.02%). Furthermore, the mean of SNP concordance, genotype concordance, non-reference sensitivity, and non-reference discrepancy between “Xiexin No. 1” SNP array and resequencing were identified to be 0.986, 0.954, 0.942, and 0.097, respectively. Using this SNP array data, the genomic heritabilities were evaluated as 0.887 ± 0.065, 0.643 ± 0.108, 0.599 ± 0.111, and 0.624 ± 0.111 for body weight (BW), carapace length (CL), carapace length (CW), and body height (BH) in a cultured population (233 crabs). Furthermore, five significant SNPs associated with growth traits were identified by GWAS. After annotation, one candidate gene (XP_027221997.1) associated with BW and one candidate gene (XP_027210446.1) associated with CW and BH were identified. Most importantly, the prediction accuracy of GBLUP for BW, BH, CL, and CW were 0.535 ± 0.064, 0.544 ± 0.101, 0.574 ± 0.087, and 0.585 ± 0.083, with the unbiasedness values of 0.988 ± 0.22, 1.015 ± 0.274, 1.011 ± 0.196 and 1.037 ± 0.235. In conclusion, the “Xiexin No. 1” SNP array provides an efficient and reliable platform for high-quality genotyping, which would greatly promote the genetic studies and thus accelerate the genetic improvement of mud crabs.

SJPedPanel: A Pan-Cancer Gene Panel for Childhood Malignancies to Enhance Cancer Monitoring and Early Detection.

The purpose of the study was to design a pan-cancer gene panel for childhood malignancies and validate it using clinically characterized patient samples. In addition to 5,275 coding exons, SJPedPanel also covers 297 introns for fusions/structural variations and 7,590 polymorphic sites for copy-number alterations. Capture uniformity and limit of detection are determined by targeted sequencing of cell lines using dilution experiment. We validate its coverage by in silico analysis of an established real-time clinical genomics (RTCG) cohort of 253 patients. We further validate its performance by targeted resequencing of 113 patient samples from the RTCG cohort. We demonstrate its power in analyzing low tumor burden specimens using morphologic remission and monitoring samples. Among the 485 pathogenic variants reported in RTCG cohort, SJPedPanel covered 86% of variants, including 82% of 90 rearrangements responsible for fusion oncoproteins. In our targeted resequencing cohort, 91% of 389 pathogenic variants are detected. The gene panel enabled us to detect ∼95% of variants at allele fraction (AF) 0.5%, whereas the detection rate is ∼80% at AF 0.2%. The panel detected low-frequency driver alterations from morphologic leukemia remission samples and relapse-enriched alterations from monitoring samples, demonstrating its power for cancer monitoring and early detection. SJPedPanel enables the cost-effective detection of clinically relevant genetic alterations including rearrangements responsible for subtype-defining fusions by targeted sequencing of ∼0.15% of human genome for childhood malignancies. It will enhance the analysis of specimens with low tumor burdens for cancer monitoring and early detection.