Biology subjects

Alam, M.

Publications and source records attributed to Alam, M..

At least 19 recordsLinked to original sources

bioRxiv2026

Inflammation is an essential trigger for POLE-driven ultramutated colorectal cancer

Pathogenic variants in the exonuclease (proofreading) domain of DNA polymerase {varepsilon} (POLE) are frequently detected in colorectal cancers (CRC) with high tumor mutational burden (TMB), yet their functional role in intestinal tumorigenesis remains unknown. Here, we investigated the impact of mutation in POLE on intestinal homeostasis using a conditional mouse model expressing the PoleP286R pathogenic driver in intestinal epithelial cells. PoleP286R mutant mice developed invasive adenocarcinomas in the small intestine with incomplete penetrance and extremely long latency but did not spontaneously develop colorectal tumors. However, induction of colitis with dextran sodium sulfate (DSS) resulted in a striking phenotypic shift to colorectal adenocarcinomas at high frequency. Molecular and histological analyses revealed hyperactivation of Wnt/{beta}-catenin, NF-{kappa}B, ERK and STAT3 pathways, accompanied by markedly higher proliferation of intestinal epithelial cells, in DSS-treated PoleP286R mutant mouse colons. Whole genome sequencing of the tumor demonstrated exceptionally high TMB (>100 mutations/megabase) and characteristic trinucleotide signatures, consistent with human POLE tumors. Recurrent mutations in Apc and Ctnnb1 underscored the central role of Wnt signaling in POLE-driven hypermutated CRC. In addition, intestinal organoids derived from PoleP286R mutant mice exhibited accelerated growth and increased expression of pro-proliferative genes. Together, these findings highlight POLE as a gatekeeper of intestinal genomic integrity and identify inflammation as the key driver that unleashes POLE-mutant CRC. Furthermore, this work establishes a mechanistically faithful preclinical platform for studying the molecular pathogenesis of CRC and advancing therapeutic drug discovery.

cancer biology↗

bioRxiv2026

Kappa Prophage Impacts Vibrio cholerae Fitness and is Restricted by BREX Phage Defense System

Vibrio cholerae's pathogenicity largely stems from the acquisition of cholera toxin genes via lysogenic conversion mediated by the CTX prophage. However, the strong association of other prophages with epidemic strains has not been linked to lysogenic conversion. During the first wave of the seventh cholera pandemic, the Kappa prophage was commonly found in clinical isolates and was later shown to confer a competitive fitness advantage in the environment and to accelerate evolution by stimulating horizontal gene transfer; however, its role in virulence remains unknown. Here, we report that the Kappa prophage confers a competitive fitness advantage in vitro and during intestinal tract infection in both Wave 1 and Wave 3 strains. This competitive fitness advantage is due to phage predation on neighboring cells, and not to lysogenic conversion. Furthermore, we show that loss of Kappa coincides with the acquisition of novel phage defense systems from SXT ICEs VchBan9 and VchInd5. Phage defense systems BREX and AbiC inhibited Kappa predation and restricted horizontal gene transfer, thereby reducing Kappas competitive fitness advantage.

microbiology↗

bioRxiv2025

Distinct Virome and Bacteriome Profiles of Term and Preterm Placentas from African, Asian and European Women

While the human placental microbiome has been extensively studied, information regarding the virome remains limited. The association between subclinical placental viral infections and spontaneous preterm birth (PTB) is poorly understood. Hence, we examined fresh placenta samples from women in the UK, Bangladesh, and South Africa to elucidate the virome profiles and association with spontaneous PTB. We employed shotgun metagenomics, real-time PCR, and Gram staining, complemented by bioinformatics, to detect both viruses and bacteria in the decidua and chorionic villous tissues. We did not identify any known pathogenic viruses in 236 placental samples, except for one preterm placenta from the Bangladeshi cohort, where human herpesvirus 6 was detected. The majority of the viruses were bacteriophages present at very low abundance and low frequencies across the three cohorts. Lambdavirus lambda was detected in 14% of UK and 11% of Bangladeshi samples but was absent in South African samples. Papiine betaherpesvirus 3 was identified in 62.5% of South African placentas. Punavirus (29.1%) and Streptococcus phages (16.67%) were also prevalent in South African samples. A variety of bacterial species including Moraxella osloensis, Delftia lacustris, Cutibacterium acnes, Escherichia coli and Staphylococcus epidermidis were detected in samples across the three cohorts in variable frequencies but without any notable tissue immune responses. None of the viruses or bacteria exhibited associations with PTB, except D. lacustris, which was significantly more abundant in preterm compared to term placentas in the Bangladeshi cohort. We conclude that the human placenta harbours a virome predominated by bacteriophages and that subclinical viral infection in spontaneous PTB is rare.

microbiology↗

bioRxiv2025

Diverse haplotypes at a complex Solanum americanum locus confer resistance to Phytophthora infestans and P. capsici

Plants encounter diverse pathogens and have evolved a two-layered innate immune system to detect pathogen molecules and activate defense mechanisms that restrict infection. Most cloned plant Resistance (R) genes encode NLR immune receptors. NLR genes are often found in clusters of paralogs with sequence and copy number variation; whether these NLR clusters evolve in response to single or multiple pathogens has been unclear. We report here the isolation of a Phytophthora capsici resistance gene, Rpc2, along with a novel P. infestans resistance gene, Rpi-amr5, from two Solanum americanum accessions. These orthologous genes reside in the Rpi-amr1 cluster, which has previously been associated with resistance to P. infestans. By screening RXLR effector libraries of P. infestans and P. capsici, we identified multiple effectors recognized by both NLRs. Our findings highlight the complexity of NLR clusters and evolution driven by interactions with multiple pathogens. This work will underpin efforts to elevate resistance against Phytophthora pathogens and enhances our understanding of NLR evolution.

plant biology↗

bioRxiv2025

Genetic diversity and variation in heterozygosity in Macadamia

BackgroundMacadamia is a diploid (2n =28) rainforest tree of the Proteaceae family, native to Australia. Single-nucleotide polymorphisms (SNPs) have proven to be effective tools for evaluating genetic diversity and heterozygosity. SNPs from the whole genome were used to determine allelic diversity within different species and breeding populations, and to investigate the heterozygosity of genotypes ResultsA total of 349 samples, including wild and domesticated genotypes, were whole genome sequenced, generating 4,180,786 - 7,661,269, 2,446,762 - 7,356,187, 2,829,944 - 4,391,600, 1601519 - 3,182,089 and 3,123,715 to 9,620,640 single nucleotide polymorphism (SNP) positions at the whole genome level for M. integrifolia, M. tetraphylla, M. ternifolia, M. jansenii and the domesticated cultivars and breeding selections respectively. The overall SNP diversity for wild M. integrifolia, M. tetraphylla, M. ternifolia and M. jansenii was 4.43%, 4.33%, 1.80% and 1.1%, respectively. Domesticated M. integrifolia showed an overall SNP diversity of 3.4%, 1.03% lower than wild M. integrifolia, providing evidence of a genetic bottleneck during domestication. Genetic diversity at the individual level for the domesticated gene pool varied from 0.4% to 1.24%, with an overall diversity of 6.10%. Results across different breeding groups revealed that the Australian breeding selections (NMBPA) had the highest diversity, and HAES cultivars had the lowest diversity. Wild M. integrifolia and M. tetraphylla exhibited heterozygosity ranging from 0.36% to 0.71% and 0.30% to 0.71% respectively. The two non-edible species, M. ternifolia and M. jansenii, displayed relatively low heterozygosity (From 0.29% to 0.42% and 0.19% to 0.34% respectively). Domesticated macadamia exhibited a wide range of heterozygosity (0.33% to 1.15%). Additionally, heterozygosity correlated with yield efficiency (kernel yield/tree volume), cumulative kernel yield at age 8 and cumulative nut in shell (NIS) yield at age 8 and showed that performance increased with heterozygosity to an optimal level and declined thereafter. ConclusionThese findings confirmed that there is substantial genetic variation among the different macadamia genotypes. The results also revealed that the greatest diversity is present in wild germplasm. The data will greatly support future genome-wide studies and breeding programs.

plant biology↗

bioRxiv2025

Defense-Suppressive Fragments of RIN4 generated by AvrRpt2 Participate in NDR1-dependent Activation of RPS2

Plant nucleotide-binding, leucine-rich-repeat (NLR) immune receptors recognize pathogen effectors and activate immunity. The NLR RPS2 recognizes AvrRpt2, a Pseudomonas effector that promotes virulence by proteolytically cleaving a membrane-tethered host protein, RIN4. RIN4 cleavage by AvrRpt2 generates fragments that activate RPS2. A model for RPS2 activation by RIN4 destruction is consistent with the ectopic activity of RPS2 in plants lacking RIN4 but does not explain the link between AvrRpt2s virulence activity and RPS2 activation. We found that non-membrane-tethered RIN4 derivatives are potent cytosolic activators of RPS2. Activation of RPS2 by these RIN4 derivatives, like AvrRpt2-induced activation, and unlike ectopic activation in the absence of RIN4, requires the defense signaling protein NDR1. Cleavage products of RIN4 produced by AvrRpt2 play contrasting roles in the activation of RPS2, with the membrane-tethered C-terminal fragment suppressing RPS2 and the non-membrane-tethered internal fragment, dependent on compatibility with the C-terminal fragment, overcoming its suppression of RPS2. HighlightsO_LINon-membrane tethered derivatives of RIN4 activate RPS2-induced cell death C_LIO_LIActivation of RPS2 by non-membrane-tethered derivatives of RIN4 requires NDR1 C_LIO_LIAvrRpt2-induced cleavage fragments of RIN4 play contrasting roles in RPS2 activation C_LI

plant biology↗

bioRxiv2025

Aeromonas: Genomic Insights into an Environmental Pathogen and Reservoir of Antimicrobial Resistance

Aeromonads are an ecologically versatile group of bacteria that cause infection in aquatic animals and are recognised as an emerging human pathogen. Despite this, our understanding of Aeromonas diversity, especially the relationship between clinical and environmental strains, remains limited. Here, we present a complete view of the Aeromonas genus, comprising 1,853 genomes, and a detailed comparison of clinical and environmental strains from South Asia, including 996 newly sequenced genomes from Bangladesh and India. Phylogenetic analyses revealed that Aeromonas is a highly diverse genus, with no distinct clade separating clinical and environmental isolates. We identified 28 Aeromonas species and 905 novel sequence types, comprising 72.5% of the genomes. Notably, we show a high incidence of AMR genes across all isolates, including against front and last-line antibiotics. Finally, we highlight frequent misidentification of Aeromonas as Vibrio cholerae, key to cholera-endemic regions where both genera co-exist and are associated with diarrhoeal disease. Our study underscores Aeromonas as an important environmental AMR reservoir and emerging multi-species pathogen capable of spilling over into human populations.

genomics↗

bioRxiv2025

Associations between floor material and E. coli contamination in rural Bangladeshi households

Soil floors are common in low-income countries and can harbor contamination from unsafely managed human and animal fecal waste. Soil/dust ingestion directly from floors or indirectly via hands, drinking water and food can significantly contribute to childrens ingestion of fecal organisms. We assessed if finished (e.g., concrete) floors are associated with lower E. coli contamination in the domestic environment in rural Bangladesh. We collected samples from 1864 households over 3.5 years, including stored drinking water, child and caregiver hand rinses, courtyard soil, food, and flies (n=24,118 samples), and enumerated E. coli using IDEXX Quanti-Tray/2000. Controlling for potential confounders (socio-demographics, water/sanitation status, animal ownership), households with finished floors had slightly lower log10-transformed E. coli counts ({Delta}log10= -0.10 (-0.20, 0.00)) and prevalence (prevalence ratio=0.90 (0.83, 0.98)) on child hands than households with soil floors; floor material was not associated with contamination levels in other sample types. Finished floors were associated with lower E. coli contamination of child hands, food and stored drinking water following periods of higher rainfall and temperature, and lower E. coli contamination of child hands in households with more domestic animals. Measures to control enteric infections in low-income countries should test flooring improvements to reduce exposure to fecal contamination.

microbiology↗

bioRxiv2025

Capturing dynamic phage-pathogen coevolution by clinical surveillance

Bacteria harness diverse defense systems that protect against phage predation1, many of which are encoded on horizontally transmitted mobile genetic elements (MGEs)2. In turn, phages evolve counter-defenses3, driving a dynamic arms race that remains underexplored in human disease contexts. For the diarrheal pathogen Vibrio cholerae, a higher burden of its lytic phage, ICP1, in patient stool correlates with reduced disease severity4. However, direct molecular evidence of phage-driven selection of epidemic V. cholerae has not been demonstrated. Here, through clinical surveillance in cholera-endemic Bangladesh, we capture the acquisition of a parasitic anti-phage MGE, PLE11, that initiated a selective sweep coinciding with the largest cholera outbreak in recent records. PLE11 exhibited potent anti-phage activity against co-circulating ICP1, explaining its rapid and dominating emergence. We identify PLE11-encoded Rta as the novel defense responsible and provide evidence that Rta restricts phage tail assembly. Using experimental evolution, we predict phage counteradaptations against PLE11 and document the eventual emergence and selection of ICP1 that achieves a convergent evolutionary outcome. By probing how PLEs hijack phage structural proteins to drive their horizontal transmission while simultaneously restricting phage tail assembly, we discover that PLEs manipulate tail assembly to construct chimeric tails comprised of MGE and phage-encoded proteins. Collectively, our findings reveal the molecular basis of the natural selection of a globally significant pathogen and its virus in a clinically relevant context.

microbiology↗

bioRxiv2025

Draft genome sequences of four lactic acid bacteria from fermented chicken meat unveil biosynthetic gene clusters for antimicrobial compounds

Lactic acid bacteria play a crucial role in fermented food production and serve as important sources of antimicrobial peptides. This study reports four lactic acid bacteria strains, isolated from fermented chicken meat, which harbor biosynthetic gene clusters encoding antimicrobial compounds. These strains are classified within the genera Pediococcus and Lactiplantibacillus.

genomics↗

bioRxiv2024

Sugarcane carries relatively larger family of CAMTA transcription factors, active against drought stress

As the highly demanding complex genome of the hybrid sugarcane cultivar became publicly available last year (2023), it opened avenues to further study this important crop at molecular level. We are interested in digging the multiple stress responsive transcription factors family, the Calmodulin-Binding Transcription Activator (CAMTA) of sugarcane. This manuscript presents a comprehensive study of ScCAMTA family based on the latest sugarcane genome sequence information. Within the 10 gb genome, through HMM model prepared from sorghum CAMTA common domains, we found 48 genes, 46 out of which carry all the CAMTA-associated domains including CG-1, TIG, IQ and Ank. The phylogenetic analysis clustered then into seven classes. Keeping sorghum as reference, we named them as ScCAMTA1 - ScCAMTA7, while each one representing a class having 5-7 copies such as ScCAMTA1A - ScCAMTA1E, present in each sub-genome (chromosome) within the hybrid sugarcane. In parallel to determining their physico-chemical attributes, gene structure, promoter sequences, protein domains, miRNA targets, protein interaction network, GO, genome collinearity, their expression pattern against drought was determined using the RNAseq data which flaunted that ScCAMTA7 is highly active under drought. This study furthers the insights into complex sugarcane genome and will assist in developing its drought-tolerant varieties.

bioinformatics↗

bioRxiv2024

Interfamily co-transfer of sensor and helper NLRs extends immune receptor functionality between angiosperms

Plant nucleotide-binding, leucine-rich repeat (NLR) immune receptors recognize pathogen effectors and activate defense. NLR genes can be non-functional in distantly related plants (restricted taxonomic functionality, RTF). Here, we enable Solanaceae NLR gene function in rice, soybean and Arabidopsis by co-delivering sensor NLR genes with their cognate NRC-type helper NLRs. In soybean protoplasts and in Arabidopsis plants, Solanum americanum Rpi-amr1, Rpi-amr3 and pepper Bs2 sensor NLRs confer cognate effector responsiveness if co-expressed with NRC helper NLRs. Rice carrying pepper Bs2 and NRCs recognizes the conserved effector, AvrBs2, and resists an important pathogen, Xanthomonas oryzae pv. oryzicola for which no resistance gene is available in rice. Rice lines carrying sensor and helper NLR genes otherwise resemble wild-type, with unaltered basal resistance or field fitness. Thus, interfamily co-transfer of sensor and helper NLRs can broaden utility of sensor NLRs, extending the tools available to control diseases of rice, soybean, Brassicas and other crops.

plant biology↗

bioRxiv2024

Detection of Potential Phytochemicals against ctxAB Toxin to Combat Cholera

Vibrio cholerae is a gram-negative curved rod-shaped bacterium responsible for cholera, an intestinal infection characterized by severe acute watery diarrhea that can be fatal if untreated. The major virulence factor for Vibrio cholerae is cholera toxin (ctx), a potent toxin which has two subunits, A and B (ctxAB), that are crucial for the progression of the deadly disease. The B subunit is a pentavalent protein that binds to the intestinal mucosa to allow internalization of the A subunit to initiate rice-watery diarrhea. This study explored potential phytochemicals to inhibit the B subunit from binding to the host mucosa by examining their interaction with ctxB. Proteins encoded by the three genotypes of the ctxB gene (ctxB1, ctxB3, and ctxB7) present in the El Tor biotype strains of V. cholerae O1 responsible for the currently ongoing seventh cholera pandemic were targeted. Analysis of 52 phytochemicals obtained from PubChem identified a group of phytochemicals based on their binding affinity scores with the proteins of ctxB genotypes. Assessment of drug-likeliness and toxicity risk highlighted two phytochemicals, Limonin and Emodin, as the best potential candidates for inhibiting the mode of action of cholera toxin. Molecular dynamic (MD) simulation-based MM-PBSA analysis suggested these compounds stably interact with the receptors. Molecular docking and molecular dynamic simulations revealed that these phytochemicals might have potential to inhibit the cholera toxin function and reduce the severity of cholera. Author SummaryCholera toxin (ctx) subunits A and B (ctxAB) play a significant role in the disease, with the B subunit facilitating the binding of the toxin to the intestinal cells, and the A subunit entering the cells, resulting in the cellular changes that lead to watery diarrhea. To inhibit the B subunit of cholera toxin from binding host mucosa, we explored candidate phytochemicals instead of synthetic molecules as drug agents by examining their binding behavior with ctxB using a molecular docking approach. The molecular docking, molecular dynamic simulations, and toxicity analyses identified two phytochemical compounds that have the potential to inhibit the mechanism of cholera toxin.

bioinformatics↗

bioRxiv2024

Small molecule FICD inhibitors suppress endogenous and pathologic FICD-mediated protein AMPylation

The AMP transferase, FICD, is an emerging drug target finetuning stress signaling in the endoplasmic reticulum (ER). FICD is a bi-functional enzyme, catalyzing both AMP addition (AMPylation) and removal (deAMPylation) from the ER resident chaperone BiP/GRP78. Despite increasing evidence linking excessive BiP/GRP78 AMPylation to human diseases, small molecules to inhibit pathogenic FICD variants are lacking. Using an in-vitro high-throughput screen, we identify two small-molecule FICD inhibitors, C22 and C73. Both molecules significantly inhibit FICD-mediated BiP/GRP78 AMPylation in intact cells while only weakly inhibiting BiP/GRP78 deAMPylation. C22 and C73 also efficiently inhibit pathogenic FICD variants and improve proinsulin processing in {beta} cells. Our study identifies and validates FICD inhibitors, highlighting a novel therapeutic avenue against pathologic protein AMPylation.

cell biology↗

bioRxiv2024

Genome-wide identification of MAPK gene family and comparative transcriptional profiling among different organ and stress response in two jute species

Mitogen activated protein kinase (MAPK) cascade is evolutionary conserved universal signal transduction module that plays central role in the growth and development of plants as well as in biotic and abiotic stress response. Although, MAPKs have been investigated in several model plants, no systematic analysis has been conducted in jute species (Corchorus olitorius and C. capsularis) even though, their genome sequencing has been completed. In the present study we identified 11 and 12 putative MAPKs in C. olitorius and C. capsularis using their genomic database, respectively. Here we provide a comprehensive bioinformatics analysis of the MAPK family from both Corchorus species including identification and nomenclature, chromosomal localization, sequence alignment, domain and Motif, gene structure, phylogenetic, functional analysis and investigation of expression analysis in response to abiotic stress and fiber cell development. The phylogenetic analysis of predicted MAPKs were clustered into four different clades and assigned with specific name based on their orthology based evolutionary relationship with Arabidopsis. Structural analysis of the MAPK genes revealed that there was a large variation among the exon number in both Corchorus species ranged from 2 to 11 but genes with the same clade had similar exon-intron structure. The sequence alignment analysis concede the presence of several conserved domain and motif including crucial signature phosphorylation motif TDY or TEY where first one is harbor in group D sequence and rest of the sequence contain TEY motif in their activation loop. Transcriptome analysis against salinity, drought along with fiber cell formation showed that MAPK4-1 genes in both jute genome highly expressed and may play a potential role in jute on adverse condition as well as jute fiber formation. These findings yielded new insights into the transcriptional control of MAPK gene expression, provide an improved understanding of abiotic stress responses and signaling transduction in jute, that lead to potential applications in the genetic improvement of jute cultivars.

molecular biology↗

bioRxiv2024

GENOME-WIDE IDENTIFICATION, CHARACTERIZATION AND EXPRESSION ANALYSIS OF NA+/H+ EXCHANGER GENE FAMILY IN TWO CORCHORUS SPECIES

Na+/H+ exchangers (NHXs) are secondary ion transporter to exchange H+ and transfer Na+ or K+ across membrane plays crucial role in cellular pH and Na+ and K+ homeostasis in plant. In the present study, we have performed genomewide identification, characterization and comparative analysis of NHXs genes in two cultivated jute species and found seven Co and Cc NHXs in each genome. Subsequently phylogenetic analysis demonstrated that Co and Cc NHXs have three sub-group that correlate with other plant species containing 10-12 transmembrane helices (TMH) and a hydrophilic C-terminal domain in the cytoplasmic region, the TMH compose a hollow cylinder to provide the channel for Na+ and H+ transport. Promoter profiling of both species NHXs genes revealed in enrichment of cis element involved in stress responsiveness reflecting their potential involvement against abiotic stress. Transcriptome data and real time PCR of Co and Cc NHXs gene expression analysis under saline and drought condition showed significant differences, which suggest their potential role in abiotic stress conditions. This is the first comprehensive analysis providing baseline information of Co and Cc NHXs genes in abiotic stress condition which can be used for the development of abiotic stress tolerant jute variety.

bioinformatics↗

bioRxiv2024

The Role of Morphological Adaptability in Vibrio cholerae's Motility and Pathogenicity

Vibrio cholerae, the etiological agent of cholera, exhibits remarkable adaptability to different environmental conditions by undergoing morphological changes that significantly contribute to its pathogenicity and impact the epidemiology of the disease globally. This study investigates the morphological adaptability of the clinically isolated V. cholerae O1 strain, specifically focusing on the motility and pathogenicity differences between the filamentous and original comma-shaped forms within diverse viscosity conditions. Utilizing the El Tor strain of V. cholerae O1, we induced the transformation into the filamentous form and performed a comparative analysis with the canonical comma-shaped morphology. Our approach involved assessing motility patterns, swimming speeds, rotation rates, kinematics, and reversal frequencies through dark-field microscopy and high-speed imaging techniques. The findings reveal that filamentous V. cholerae cell retains enhanced motility in viscous environments. This suggests an evolutionary adaptation enabling survival across a range of habitats, notably the human gastrointestinal tract. Filamentous forms demonstrated increased reversal behavior at mucin interfaces, hinting at an advantage in penetrating the mucus layer. Rabbit intestinal loop assays further showed that both morphological forms exhibit similar fluid accumulation ratios, thus indicating comparable pathogenic potentials. These results underscore the significance of V. choleraes morphological flexibility in adapting to environmental viscosity changes, shedding light on the bacteriums intricate survival and infection strategies. Our study provides critical insights into the dynamics of cholera, underlining the importance of considering bacterial morphology in developing effective cholera control strategies.

microbiology↗

bioRxiv2024

Analysis of genetic variation in Macadamia shows evidence of extensive reticulate evolution

The genus Macadamia in the Proteaceae family includes four species. To explore diversity in macadamia genetic resources, a total of 166 wild genotypes, representing all four species, were sequenced. The four species were clearly distinguished as four separate clades in a phylogenetic analysis of nuclear gene CDS. M. integrifolia and M. tetraphylla formed a clade that had diverged from a clade including M. ternifolia and M. jansenii. The greatest diversity in nuclear and chloroplast genomes was found in the more widely distributed M. integrifolia while the rare M. jansenii showed little diversity. The chloroplast phylogeny revealed a much more complex evolutionary history. Multiple chloroplast capture events have resulted in chloroplast genome clades including genotypes from different species. This suggests extensive reticulate evolution in Macadamia despite the emergence of the four distinct species that are supported by the analysis of their nuclear genomes. The chloroplast genomes showed strong associations with geographical distribution reflecting limited maternal gene movement in these species having large seeds. The nuclear genomes showed lesser geographical differences, probably reflecting longer distance movement of pollen. This improved understanding of the distribution of diversity in Macadamia will aid conservation of these rare species now found in highly fragmented rainforest remnants. HighlightsWhole genome sequencing of population of the four species in the Macadamia genus allowed phylogenetic relationships to be determined and revealed significant reticulate evolution.

evolutionary biology↗