Maize (Zea mays ssp. mays) diverged from one of its wild relatives, the teosinte Zea mays ssp. parviglumis, in the lowlands of southwest Mexico approximately 9000 years ago. Following this divergence, maize rapidly expanded throughout the Americas, becoming a staple food. This dispersal was accompanied by significant demographic and selective changes, leading to the development of numerous local varieties with a complex evolutionary history that remains incompletely understood. In recent years, genomic advances have challenged traditional models of maize domestication and spread to South America. At least three distinct genetic lineages associated with different migratory waves have been described: ancestral Andean, ancestral Lowland, and Pan-American. Additionally, the significant role of the teosinte Zea mays ssp. mexicana, in the evolution of modern maize has been recently uncovered. Genomic studies have shed light into highland adaptation processes, revealing largely independent adaptation events in Meso- and South America. As new evidence emerges, the regional complexity underlying maize diversity and the need for comprehensive, multi-scale approaches become evident. In the face of climate change and evolving agricultural landscapes, the conservation of native maize in South America is of growing interest, with genomics serving as an invaluable tool for identifying and preserving the genetic variability of locally adapted germplasm.

BACKGROUND: Zoonotic sporotrichosis caused by Sporothrix brasiliensis has become the main subcutaneous mycosis in Brazil. Minas Gerais (MG) is located in southeast Brazil and since 2015 has experienced an epidemic of zoonotic sporotrichosis.
OBJECTIVE: This study aimed to reconstruct the epidemiological scenario of sporotrichosis from S. brasiliensis in recent epizooty in the Metropolitan Region of Belo Horizonte (MRBH), MG.
METHODS: A total of 95 Sporothrix spp. isolates (Sporothirx brasiliensis n = 74, S. schenckii n = 11 and S. globosa n = 10) were subjected to Amplified Fragment Length Polymorphism (AFLP) genotyping and mating-type analysis to determine genetic diversity and population structure. Of these, 46 S. brasiliensis isolates were recovered from animals (cats n = 41 and dogs n = 5) from MRBH.
RESULTS: Our study describes the high interspecific differentiation power of AFLP-based genotyping between the main phylogenetic Sporothrix groups. S. brasiliensis presents high genetic variability and pronounced population structure with geographically focused outbreaks in Brazil. The genetic groups include older genotypes from the prolonged epidemic in Southeast (Rio de Janeiro and São Paulo), South (Rio Grande do Sul), Northeast (Pernambuco) and new genotypes from the MRBH. Furthermore, we provide evidence of heterothallism mating strategy in pathogenic Sporothrix species. Genotypes originating in Rio de Janeiro and Pernambuco carry the predominant MAT1-2 idiomorph as opposed to genotypes from Rio Grande do Sul, which have the MAT1-1 idiomorph. We observed an overwhelming occurrence of MAT1-1 among MRBH isolates.
CONCLUSIONS: Our study provides clear evidence of the predominance of a genetic group profile circulating in animals in Minas Gerais, independent of that disseminated from Rio de Janeiro. Our data can help us understand the genetic population processes that drive the evolution of this fungus in Minas Gerais and contribute to future mitigation actions for this ongoing epidemic.

Directed evolution seeks to evolve target genes at a rate far exceeding the natural mutation rate, thereby endowing cellular and enzymatic properties with desired traits. In vivo continuous directed evolution achieves these purposes by generating libraries within living cells, enabling a continuous cycle of mutant generation and selection, enhancing the exploration of gene variants. Continuous evolution has become powerful tools for unraveling evolution mechanism and improving cellular and enzymatic properties. This review categorizes current continuous evolution into three distinct classes: non-targeted chromosomal, targeted chromosomal, and extra-chromosomal hypermutation approaches. It also compares various continuous evolution strategies based on different principles, providing a reference for selecting suitable methods for specific evolutionary goals. Furthermore, this review discusses the two primary limitations for further widespread application of in vivo continuous evolution, which are lack of general applicability and insufficient mutagenic capability. We envision that developing generally applicable mutagenic components and methods to enhance mutation rates for in vivo continuous evolution are promising future directions for wide range applications of continuous evolution.

Genetic analyses of host-specific parasites can elucidate the evolutionary histories and biological features of their hosts. Here, we used population-genomic analyses of ectoparasitic seal lice (Echinophthirius horridus) to shed light on the postglacial history of seals in the Arctic Ocean and the Baltic Sea region. One key question was the enigmatic origin of relict landlocked ringed seal populations in lakes Saimaa and Ladoga in northern Europe. We found that that lice of four postglacially diverged subspecies of the ringed seal (Pusa hispida) and Baltic gray seal (Halichoerus grypus), like their hosts, form genetically differentiated entities. Using coalescent-based demographic inference, we show that the sequence of divergences of the louse populations is consistent with the geological history of lake formation. In addition, local effective population sizes of the lice are generally proportional to the census sizes of their respective seal host populations. Genome-based reconstructions of long-term effective population sizes revealed clear differences among louse populations associated with gray versus ringed seals, with apparent links to Pleistocene and Holocene climatic variation as well as to the isolation histories of ringed seal subspecies. Interestingly, our analyses also revealed ancient gene flow between the lice of Baltic gray and ringed seals, suggesting that the distributions of Baltic seals overlapped to a greater extent in the past than is the case today. Taken together, our results demonstrate how genomic information from specialized parasites with higher mutation and substitution rates than their hosts can potentially illuminate finer scale population genetic patterns than similar data from their hosts.

The unprecedented habitat fragmentation or loss has threatened the existence of many species. Therefore, it is essential to understand whether and how these species can pace with the environmental changes. Recent advantages in landscape genomics enabled us to identify molecular signatures of adaptation and predict how populations will respond to changing environments, providing new insights into the conservation of species. Here, we investigated the pattern of neutral and putative adaptive genetic variation and its response to changing environments in a tertiary relict tree species, Taxus cuspidata Sieb. et Zucc, which is distributed in northeast China and adjacent regions. We investigated the pattern of genetic diversity and differentiation using restriction site-associated DNA sequencing (RAD-seq) and seven nuclear microsatellites (nSSRs) datasets. We further explored the endangered mechanism, predicted its vulnerability in the future, and provided guidelines for the conservation and management of this species. RAD-seq identified 16,087 single nucleotide polymorphisms (SNPs) in natural populations. Both the SNPs and nSSRs datasets showed high levels of genetic diversity and low genetic differentiation in T. cuspidata. Outlier detection by F ST outlier analysis and genotype-environment associations (GEAs) revealed 598 outlier SNPs as putative adaptive SNPs. Linear redundancy analysis (RDA) and nonlinear gradient forest (GF) showed that the contribution of climate to genetic variation was greater than that of geography, and precipitation played an important role in putative adaptive genetic variation. Furthermore, the genetic offset and risk of non-adaptedness (RONA) suggested that the species at the northeast edge may be more vulnerable in the future. These results suggest that although the species has maintained high current genetic diversity in the face of recent habitat loss and fragmentation, future climate change is likely to threaten the survival of the species. Temperature (Bio03) and precipitation (Prec05) variables can be potentially used as predictors of response of T. cuspidata under future climate. Together, this study provides a theoretical framework for conservation and management strategies for wildlife species in the context of future climate change.

Zanthoxylum is a versatile economic tree species utilized for its spice, seasoning, oil, medicinal, and industrial raw material applications, and it has a lengthy history of cultivation and domestication in China. This has led to the development of numerous cultivars. However, the phenomenon of mixed cultivars and confusing names has significantly obstructed the effective utilization of Zanthoxylum resources and industrial development. Consequently, conducting genetic diversity studies and cultivar identification on Zanthoxylum are crucial. This research analyzed the genetic traits of 80 Zanthoxylum cultivars using simple sequence repeat (SSR) and inter-Primer Binding Site (iPBS) molecular markers, leading to the creation of a DNA fingerprint. This study identified 206 and 127 alleles with 32 SSR markers and 10 iPBS markers, respectively, yielding an average of 6.4 and 12.7 alleles (Na) per marker. The average polymorphism information content (PIC) for the SSR and iPBS markers was 0.710 and 0.281, respectively. The genetic similarity coefficients for the 80 Zanthoxylum accessions ranged from 0.0947 to 0.9868 and from 0.2206 to 1.0000, with mean values of 0.3864 and 0.5215, respectively, indicating substantial genetic diversity. Cluster analysis, corroborated by principal coordinate analysis (PCoA), categorized these accessions into three primary groups. Analysis of the genetic differentiation among the three Zanthoxylum (Z. bungeanum, Z. armatum, and Z. piperitum) populations using SSR markers revealed a mean genetic differentiation coefficient (Fst) of 0.335 and a gene flow (Nm) of 0.629, suggesting significant genetic divergence among the populations. Molecular variance analysis (AMOVA) indicated that 65% of the genetic variation occurred within individuals, while 35% occurred among populations. Bayesian model-based analysis of population genetic structure divided all materials into two groups. The combined PI and PIsibs value of the 32 SSR markers were 4.265 × 10- 27 and 1.282 × 10- 11, respectively, showing strong fingerprinting power. DNA fingerprints of the 80 cultivars were established using eight pairs of SSR primers, each assigned a unique numerical code. In summary, while both markers were effective at assessing the genetic diversity and relationships of Zanthoxylum species, SSR markers demonstrated superior polymorphism and cultivar discrimination compared to iPBS markers. These findings offer a scientific foundation for the conservation and sustainable use of Zanthoxylum species.

BACKGROUND: Trueperella pyogenes is an opportunistic pathogen that causes suppurative infections in various animal species, including goats. So far, only limited knowledge of phenotypic and genotypic properties of T. pyogenes isolates from goats has been gathered. In our study, we characterized the phenotypic and genotypic properties of caprine T. pyogenes isolates and established their relationship by Random Amplified Polymorphic DNA-Polymerase Chain Reaction (RAPD-PCR).
RESULTS: From 2015 to 2023, 104 T. pyogenes isolates were obtained from 1146 clinical materials. In addition, two T. pyogenes isolates were obtained from 306 swabs collected from healthy goats. A total of 51 T. pyogenes isolates were subjected to detailed phenotypic and genotypic characterization. The virulence genotype plo/nanH/nanP/fimA/fimC/luxS was predominant. All of the tested isolates showed the ability to form a biofilm but with different intensities, whereby most of them were classified as strong biofilm formers (72.5%). The high level of genetic diversity among tested caprine T. pyogenes isolates (19 different RAPD profiles) was observed. The same RAPD profiles were found for isolates obtained from one individual, as well as from other animals in the same herd, but also in various herds.
CONCLUSIONS: This study provided important data on the occurrence of T. pyogenes infections in goats. The assessment of virulence properties and genetic relationships of caprine T. pyogenes isolates contributed to the knowledge of the epidemiology of infections caused by this pathogen in small ruminants. Nevertheless, further investigations are warranted to clarify the routes of transmission and dissemination of the pathogen.

Cryptosporidiosis has previously been reported in animals, humans, and water sources in the United Arab Emirates (UAE). However, most reports were only to the genus level, or generically identified as cryptosporidiosis. We aimed to investigate the genetic diversity of Cryptosporidium species occurring in diarrhetic ungulates which were brought to the Central Veterinary Research Laboratory (CVRL) in Dubai. Using a combination of microscopic and molecular methods, we identified five species of Cryptosporidium occurring among ungulates in the UAE, namely C. parvum, C. hominis, C. xiaoi, C. meleagridis, and C. equi. Cryptosporidium parvum was the most prevalent species in our samples. Furthermore, we identified subtypes of C. parvum and C. hominis, which are involved in both human and animal cryptosporidiosis. This is also the first reported occurrence of Cryptosporidium spp. in the Arabian Tahr, to our knowledge. Since the animals examined were all in contact with humans, the possibility of zoonotic spread is possible. Our study correlates with previous reports in the region, building upon the identification of Cryptosporidium sp. However, there is a need to further investigate the endemic populations of Cryptosporidium, including more hosts, sampling asymptomatic animals, and location data.

BACKGROUND: Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) plays a critical role in the ecology and economy of Western North America. This conifer species comprises two distinct varieties: the coastal variety (var. menziesii) along the Pacific coast, and the interior variety (var. glauca) spanning the Rocky Mountains into Mexico, with instances of inter-varietal hybridization in Washington and British Columbia. Recent investigations have focused on assessing environmental pressures shaping Douglas-fir\'s genomic variation for a better understanding of its evolutionary and adaptive responses. Here, we characterize range-wide population structure, estimate inter-varietal hybridization levels, identify candidate loci for climate adaptation, and forecast shifts in species and variety distribution under future climates.
RESULTS: Using a custom SNP-array, we genotyped 540 trees revealing four distinct clusters with asymmetric admixture patterns in the hybridization zone. Higher genetic diversity observed in coastal and hybrid populations contrasts with lower diversity in inland populations of the southern Rockies and Mexico, exhibiting a significant isolation by distance pattern, with less marked but still significant isolation by environment. For both varieties, we identified candidate loci associated with local adaptation, with hundreds of genes linked to processes such as stimulus response, reactions to chemical compounds, and metabolic functions. Ecological niche modeling revealed contrasting potential distribution shifts among the varieties in the coming decades, with interior populations projected to lose habitat and become more vulnerable, while coastal populations are expected to gain suitable areas.
CONCLUSIONS: Overall, our findings provide crucial insights into the population structure and adaptive potential of Douglas-fir, with the coastal variety being the most likely to preserve its evolutionary path throughout the present century, which carry implications for the conservation and management of this species across their range.

Bergenia ciliata (Haw.) Sternb. is a perennial medicinal herb distributed in Indian Himalayan Region (IHR). A total of eight populations of B. ciliata were collected from diverse locales of IHR, and 17 EST-SSR markers were used in this study. The present study revealed moderate genetic diversity at the locus level with the mean number of alleles (Na = 7.823), mean number effective of alleles (Ne = 3.375), mean expected heterozygosity (He = 0.570), and mean Shannon\'s diversity index (I = 1.264). The MSR (He = 0.543, I = 1.067) and DRJ populations (He = 0.309, I = 0.519) revealed the highest and lowest genetic diversity at the population level, respectively. AMOVA analysis showed that 81.76% of genetic variation was within populations, 10.55% was among populations, and 7.69% was among the regions. In addition, a moderate to high level of differentiation was found among the populations (FST = 0.182), which could be indicative of low to moderate gene flow (Nm = 0.669) in the B. ciliata populations. UPGMA and PCoA analysis revealed that eight populations could be differentiated into two groups, while the structure analysis of the 96 individuals differentiated into three groups. The Mantel test showed a positive relationship between genetic and geographical distance. The findings of this study will provide the development of conservation and germplasm management strategies for this valuable medicinal species.