This paper is a comparative synthesis of the gene diversity and gain based on published results of two Eucalyptus camaldulensis breeding programmes (BP 1&2) in India. The dynamics and genetic gain of four first generation (F1) seedling seed orchards (SPA) of BP1 were compared with three second generation (F2) SPAs and two clonal seed orchards (CSO) of BP2. Three F1 orchards (F1 SPAs 1,3&4) of BP1 had low flowering (30%) and high fertility variation (sibling coefficient, Ψ = 5-11) whereas F1 SPA2 had 73% fertile trees (Ψ = 2.27). No significant gain was obtained in BP1 when the four F1SPA seed crops were evaluated at two locations in genetic gain trials - to estimate the gain obtained in comparison to native provenance and commercial clone checks. For infusing improved seed from BP1 to BP2, three F2SPAs were developed, of which two (F2 SPA 1-2) were thinned genetic gain trials that incorporated bulked seed lots from four F1 SPAs of BP1, and the third (F2 SPA 3) originated from bulked seed of only one F1SPA. Two clone trials of F1 progeny selections were converted to clonal seed orchards (F2 CSO 1&2). Flowering was low (26%) in the F2 SPAs also with high fertility variation (Ψ, 9-14). The CSOs had high flowering (81%) but fertility was highly skewed in CSO2 (Ns = 2) compared to CSO1 (Ns = 11). The F2 SPAs 1&2, which originated from four F1 SPAs in genetic gain trials, had higher effective population size (Ns, 95 and 74) than the F2 SPA3 (Ns = 39) and CSOs, and better progeny performance than the native provenance at 3 years. CSO2 had the lowest gene diversity and survival than the other taxa. Genetic composition and fertility status of the orchards affected the performance and genetic diversity of progeny.

Outbreaks of hemorrhagic septicemia (HS) caused by Pasteurella multocida serogroup B are endemic in Kazakhstan. These outbreaks have repeatedly led to mass mortality events among wild saigas and economic losses to farms. The aim of this study was to conduct the first whole-genome sequencing (WGS) and analysis of P. multocida genomes associated with HS cases in saigas and livestock in Kazakhstan. In this study, WGS was performed on 22 P. multocida isolates obtained from saigas and livestock. A comparative genomic analysis of P. multocida isolates from Kazakhstan and publicly available genomes was performed. All isolates belonged to the B:2:ST122 genotype and formed distinct phylogenetic clusters based on outbreaks in saiga populations and livestock. Clustering also corresponded to identified mutations in virulence genes. Isolates recovered from the 2015 mass mortality of saigas in the Betpak-Dala population were found to have a deletion of the flp1 gene. This observation emphasizes the study of the role of Flp pili in HS pathogenesis. Comparison of the P. multocida B:L2:ST122 genomes revealed low virulence gene diversity and an open pangenome. Prophage annotation did not identify virulence or pathogenicity genes. The obtained results will be useful for future studies of HS pathogenesis.

The rising incidence of human–crocodile conflict involving the endangered Sunda gharial, Tomistoma schlegelii, has led to a growing number of wild-caught individuals being placed in conservation centres and zoos. But the genetic diversity and coancestry of the captive individuals is unknown which could result in an increased inbreeding or outbreeding, defeating the purpose of ex situ conservation efforts. Therefore, this study analysed the genetic diversity, population structure and identification of important clusters for future breeding programs. Blood samples from 38 individuals were analysed using 14 species-specific microsatellite loci and the partial mitochondrial DNA sequences of ND6–tRNAGlu–cyt b region and control region. The STRUCTURE results revealed six clusters displaying low nuclear gene diversity, with mtDNA diversity noted in only one cluster. Two important clusters were identified to facilitate future breeding programs of this species.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-17481-5.

Twenty-two rice lines were used to evaluate salt tolerance at seedling stage. Salinity screening was conducted following IRRI standard protocol and salinized (EC14dS/m) with culture solution at vegetative stage. Initial and final scoring for visual salt injury using the IRRI Standard Evaluation System (SES) was done 21 days after salinization (DAS). Based on 1-9 scale scoring, eight rice genotypes (Binadhan 8, Binadhan 10, FL478, RC217, RC221, RC222, RC225) were found as salt tolerant, five genotypes (RC191, RC192, RC193, RC251, RC249) were identified as moderately tolerant, the rest genotypes were susceptible and the Binadhan 7 was highly susceptible at seedling stage. In seedling stage, Binadhan 8, Binadhan 10, FL478, RC217, RC221, RC222 and RC225 were identified as tolerant, while RC227, RC229, Binadhan 12, Joli Aman, Binadhan 11, BRRI dhan29, Pajam and BRRI dhan39 were found as susceptible. Three selected SSR markers viz. RM7075, RM10701 and RM11504 were used to screen the germplasm for salt tolerance. The highest genetic diversity (0.8967) was observed in loci RM7075 and the lowest gene diversity (0.5537) was found in loci RM10701 with a mean diversity of 0.7231. These SSR markers offer a potential, simple, rapid, and reliable method in marker-assisted breeding and a great impact on identifying salt-tolerant rice genotypes. Res. Agric. Livest. Fish. Vol. 12, No. 1, April 2025: 137-147

This study investigates the genetic structure and demographic history of contemporary Thai populations from Tak and Ranong, two border provinces between Thailand and Myanmar with complex immigration histories. We analyzed 20 Y-SNP markers (327 samples) and 24 Y-STR profiles (241 samples), along with published datasets, and observed significant genetic differentiation between these regions. Tak is dominated by O2a2b1a1a (44.53%) and O1b1a1a (21.17%). The presence of NO1 (14.6%) suggests genetic contributions from nearby populations such as the Karen, Lawa, and Khuen. Notably, Tak shows low gene diversity (GD) at the DYS391 (0.2208), contrasting with Ranong (0.5247) and the overall Thailand population (0.4708). Ranong exhibits a more diverse haplogroup distribution, with prominent frequencies of O1b1a1a (20.75%), F (16.98%) and O2a2b1a1a (13.21%). The presence of haplogroups K (11.32%) and R* (7.55%) reflects a genetic connection with the Maniq or other mainland Negrito groups, as well as historical gene flow from South Asia. These findings enhance our understanding of the genetic landscape shaped by migration and localized admixture. We also expanded the Thailand Y-chromosome database with novel Y-STR haplotypes, updated forensic parameters and Y-haplogroup frequencies, providing valuable resources for paternal ancestry inference and kinship verification in both forensic science and population genetics

Wild populations across the globe face an escalating risk of decline and potential extinction due to a variety of threats. Key among these are habitat loss and degradation, which results in smaller, isolated populations that are vulnerable to stochastic effects. The Endangered black lion tamarin (Leontopithecus chrysopygus) survives in 17 fragments of the Atlantic Forest within the Paranapanema River basin, in southeast Brazil, with an estimated 2,255 individuals. Life history and threat data from the 2005 Population Viability Analysis (PVA) for this species were updated and augmented, including new estimates of environmental resistance factors present in, or projected for, their habitat. Notably, improved estimates of carrying capacity for this species were developed using a plant-based energetic model. Climate change and fire risk data were incorporated to project future carrying capacity, and habitat connectivity supported estimates of black lion tamarin dispersal across this fragmented landscape. The resulting population viability projections using Vortex simulation software identify core subpopulations with low extinction risk and high gene diversity, as well as smaller subpopulations with low long-term viability, highlighting the need for targeted conservation strategies across the fragmented metapopulation.

BackgroundAs a nexus of routine antibiotic use and zoonotic pathogen presence, the livestock farming environment is a potential hotspot for the emergence of zoonotic diseases and antibiotic resistant bacteria. Livestock can further facilitate disease transmission by serving as intermediary hosts for pathogens before a spillover event. In light of this, we aimed to characterize the microbiomes and resistomes of dairy workers, whose exposure to the livestock farming environment places them at risk for facilitating community transmission of antibiotic resistant genes and emerging zoonotic diseases.ResultsUsing shotgun sequencing, we investigated differences in the taxonomy, diversity and gene presence of 10 dairy farm workers and 6 community controls’ gut metagenomes, contextualizing these samples with additional publicly available gut metagenomes. We found no significant differences in the prevalence of resistance genes, virulence factors, or taxonomic composition between the two groups. The lack of statistical significance may be attributed, in part, to the limited sample size of our study or the potential similarities in exposures between the dairy workers and community controls. We did, however, observe patterns warranting further investigation including greater abundance of tetracycline resistance genes and prevalence of cephamycin resistance genes as well as lower average gene diversity (even after accounting for differential sequencing depth) in dairy workers’ metagenomes. We also found evidence of commensal organism association with tetracycline resistance genes in both groups (including Faecalibacterium prausnitzii, Ligilactobacillus animalis, and Simiaoa sunii).ConclusionsThis study highlights the utility of shotgun metagenomics in examining the microbiomes and resistomes of livestock workers, focusing on a cohort of dairy workers in the United States. While our study revealed no statistically significant differences between groups in taxonomy, diversity and gene presence, we observed patterns in antibiotic resistance gene abundance and prevalence that align with findings from previous studies of livestock workers in China and Europe. Our results lay the groundwork for future research involving larger cohorts of dairy and non-dairy workers to better understand the impact of occupational exposure to livestock farming on the microbiomes and resistomes of workers.

Seventeen microsatellite loci from the non-recombining region of the human Y chromosome were typed using AmpFlSTR® Yfiler® PCR amplification systems in 404 male subjects belonging to the three largest ethnic groups in Bangladesh. A total of 150 haplotypes from the Chakma, 144 from the Tripura, and 110 from the Khasia were detected with a corresponding discrimination capacity of 73.885%, 65.563%, and 81.250%, respectively. The highest allele frequency of 0.828 was detected in DYS391 locus in the Tripuras, while the lowest allele frequency of 0.009 was detected at the same locus for the Chakma population. The highest gene diversity (0.964) was observed at DYS385a/b locus in the Khasias, while the lowest gene diversity (0.301) was detected at DYS391 locus in Tripuras population. The overall haplotype diversity for the studied populations was 0.986141. Both the Neighbour-Joining tree and pairwise genetic distances showed that Chakma lies closer to a clade consisting of Tripuras (Khagrachari, Bangladesh) and Tripuri (Tripura, India). In contrast, the Khasias demonstrated a close affinity with the Oraon (Chhattisgarh, India), followed by the Santals. The Y-STR haplotype matching probabilities within and between populations demonstrated that the Chakma, Tripura, and Khasia were 100% genetically distinct. The studied ethnic populations exhibited higher frequency for haplogroups L and Q as opposed to haplogroups R1a, H, and L found in the mainstream Bengali population. The Median-joining networking showed haplogroups L and R1a have the most compact clustering within populations, followed by haplogroups Q and H. The presence of haplogroup R1a suggests that Bengali may have originated through west-to-east migration, whereas haplogroups L and Q distribution in the studied tribes reveal a very significant affinity with the South-East Asian populations and may have shared a common ancestral origin with the Mongoloid stock populations. Bioresearch Commu. 10(2): 1482-1488, 2024 (July)

Simple SummaryThis study investigated the developmental differences between in vivo-developed (IVV) and in vitro embryos (in vitro fertilization (IVF) and parthenogenetic activation (PA)) in pigs using single-cell RNA sequencing data from the oocyte to the 8-cell stages. Findings show that in vitro embryos have more similar developmental trajectories and lower gene diversity, especially PA, compared to IVV. Significant variations were observed in maternal mRNA, influencing mRNA splicing, energy metabolism, and chromatin remodeling, where key genes like SMARCB1 and HDAC1 (in vivo) and SIRT1 and EZH2 (in vitro) might be playing crucial roles. Despite similar ZGA timings across embryo types, IVV embryos exhibited more upregulated genes, particularly during major ZGA, and global epigenetic modification differences were evident from the oocyte stage and continued to expand during minor ZGA. They also uniquely upregulated genes linked to mitochondrial function, ATP synthesis, and oxidative phosphorylation. A notable difference in mRNA degradation between in vivo and in vitro embryos was observed during major ZGA, and the timely decay of maternal mRna in IVV except in in vitro embryos was related to phosphatase activity and cell junctions. The study also highlighted the higher expression of mitochondrially encoded genes in in vitro embryos, though nucleosome occupancy and ATP8 expression were higher in IVV.In vitro-fertilized (IVF) and parthenogenetically activated (PA) embryos, key to genetic engineering, face more developmental challenges than in vivo-developed embryos (IVV). We analyzed single-cell RNA-seq data from the oocyte to eight-cell stages in IVV, IVF, and PA porcine embryos, focusing on developmental differences during early zygotic genome activation (ZGA), a vital stage for embryonic development. (1) Our findings reveal that in vitro embryos (IVF and PA) exhibit more similar developmental trajectories compared to IVV embryos, with PA embryos showing the least gene diversity at each stage. (2) Significant differences in maternal mRNA, particularly affecting mRNA splicing, energy metabolism, and chromatin remodeling, were observed. Key genes like SMARCB1 (in vivo) and SIRT1 (in vitro) played major roles, with HDAC1 (in vivo) and EZH2 (in vitro) likely central in their complexes. (3) Across different types of embryos, there was minimal overlap in gene upregulation during ZGA, with IVV embryos demonstrating more pronounced upregulation. During minor ZGA, global epigenetic modification patterns diverged and expanded further. Specifically, in IVV, genes, especially those linked to H4 acetylation and H2 ubiquitination, were more actively regulated compared to PA embryos, which showed an increase in H3 methylation. Additionally, both types displayed a distinction in DNA methylation. During major ZGA, IVV distinctively upregulated genes related to mitochondrial regulation, ATP synthesis, and oxidative phosphorylation. (4) Furthermore, disparities in mRNA degradation-related genes between in vivo and in vitro embryos were more pronounced during major ZGA. In IVV, there was significant maternal mRNA degradation. Maternal genes regulating phosphatase activity and cell junctions, highly expressed in both in vivo and in vitro embryos, were degraded in IVV in a timely manner but not in in vitro embryos. (5) Our analysis also highlighted a higher expression of many mitochondrially encoded genes in in vitro embryos, yet their nucleosome occupancy and the ATP8 expression were notably higher in IVV.

Genetic analyses of ancient tea trees provide insights into the breeding history and dissemination of Chinese Assam tea (Camellia sinensis var. assamica)

Information regarding genetic diversity and genetic relationships among different genotypes is invaluable in crop improvement of which its success is largely dependent on genetic variability. As molecular markers continue to be an effective tool for localization of a gene to improvement of plant varieties, the need to establish phylogenetic relationships becomes extremely important for the process of breeding new cultivars. This study reports genetic diversity for Tomato accessions across Nigeria (Six geo-Political Zones) as revealed by chloroplast DNA (cpDNA) and Random Amplified Polymorphic DNA (RAPD) markers. cpDNA data showed a Nucleotide diversity for all accessions of Tomato at 0.302 while the number of segregated sites as well as parsimony informative sites to be 4.0. Data from five Random Amplified Polymorphic DNA (RAPD) primers showed a low Gene diversity (h) which ranged from 0.10 to 0.28, Percentage polymorphism (Pp) ranged from 20 % to 84%. The Unweighted Pair Group Method with Arithmetic Mean (UPGMA) dendrogram grouped the accessions into two groups at similarity coefficient of 72%, with a value of r = 0.98, showing an excellent correlation between the accessions and the values of the initial distances (similarity matrix). Similar results were seen with the dendrogram constructed for genetic relationships of Tomato accessions using RAPD or cpDNA (you have mentioned RAPD up) markers. Split tree analysis equally revealed a 2 structured gene pool for Tomato gene pool in Nigeria. The high homogeneity of species observed in the study signifies a low genetic diversity and limited variability in tomato species in Nigeria. Amongst the consequences of low genetic diversity is the absence of unique variants that can possibly combat disease conditions or adapt to unfavourable environmental changes. The use of both cpDNA and RAPD markers in this study has efficiently shown that continuous cycling/shuffling of species within the narrow gene pool is expected to lead to a continuous reduction in genetic variability. No addition of new variant into the gene pool and in turn leads to inbreeding depression, thus suggesting the need to breed with known wild cultivars to increase genetic variability. Key words: CpDNA, Gene pool, Genetic Diversity, Inbreeding depression, RAPD marker, Tomatoes breeding

BackgroundAs a nexus of routine antibiotic use and zoonotic pathogen presence, the livestock farming environment is a potential hotspot for the emergence of zoonotic diseases and antibiotic resistant bacteria. Livestock can further facilitate disease transmission by serving as intermediary hosts for pathogens as they undergo evolution prior to a spillover event. In light of this, we are interested in characterizing the microbiome and resistome of dairy workers, whose exposure to the livestock farming environment places them at risk for facilitating community transmission of antibiotic resistant genes and emerging zoonotic diseases.ResultsUsing shotgun sequencing, we investigated differences in the taxonomy, diversity and gene presence of the human gut microbiome of 10 dairy farm workers and 6 community controls, supplementing these samples with additional publicly available gut metagenomes. We observed greater abundance of tetracycline resistance genes and prevalence of cephamycin resistance genes in dairy workers’ metagenomes, and lower average gene diversity. We also found evidence of commensal organism association with plasmid-mediated tetracycline resistance genes in both dairy workers and community controls (including Faecalibacterium prausnitzii, Ligilactobacillus animalis, and Simiaoa sunii). However, we did not find significant differences in the prevalence of resistance genes or virulence factors overall, nor differences in the taxonomic composition of dairy worker and community control metagenomes.ConclusionsThis study presents the first metagenomics analysis of United States dairy workers, providing insights into potential risks of exposure to antibiotics and pathogens in animal farming environments. Previous metagenomic studies of livestock workers in China and Europe have reported increased abundance and carriage of antibiotic resistance genes in livestock workers. While our investigation found no strong evidence for differences in the abundance or carriage of antibiotic resistance genes and virulence factors between dairy worker and community control gut metagenomes, we did observe patterns in the abundance of tetracycline resistance genes and the prevalence of cephamycin resistance genes that is consistent with previous work.

The use of new high-resolution and forensic identification capabilities for population studies offered by new multiplex methods (such as Yfiler Plus) is crucial in forensic genetics cases. The development of haplotype frequency databases is essential to take full advantage of the new Y chromosome determination capabilities. Development of the haplotype database of the Yfiler Plus kit for a population-based sample of 534 males from northeastern Poland and calculation of suitability parameters for forensic genetics studies. The study was conducted on a population sample of 534 unrelated males from the area of northeastern Poland using the Yfiler Plus panel of 27 markers located on the Y chromosome. Four haplotypes appeared twice. The Discrimination Capacity (DC) of the entire set was 0.9925. The highest Gene Diversity (GD) value was calculated for DYS518 (0.86) belonging to the fast-mutation markers, while the lowest GD was calculated for DYS392 (0.42). The results indicate the need for further research and observation of changes, both in different regions of Poland and across Europe.

Napier (Pennisetum purpureum) fodder is an important fodder supporting livestock systems in Bangladesh. Using gamma irradiation we developed 48 Napier fodder mutants which were analyzed through morpho-molecular characterization. Among 48 Napier fodder mutants, 41 mutants were originated by applying radiation (20Gy, 30Gy, 40Gy and 50 Gy) on them. The Napier mutants showed variations in survival rate and fresh weight. The survival rate (0-75%) was observed, 20Gy treated plants produced higher fresh weight in Napier-2, Napier-3, Rokona, Markiron grasses; whereas, 30Gy treated plants produced higher fresh weight in Napier-1, Napier-4 and Pakchong. The total of the alleles found in molecular characterization were 17 and the mean number of allele per locus was 3.4. The PIC value ranged from 0.3047 to 0.6587 having an average of 0.4704 per locus. The highest gene diversity (0.7101) was observed in primer Xipes0093 and the lowest gene diversity (0.3750) was observed in primer PSMP2255, having an average diversity of 0.5286. Pair wise genetic distance values ranged (0.0-1.0) with highest between Napier-2 40 Gy vs (Napier-1control, Napier-2 20Gy Napier-2 30Gy), Napier -3 control, vs (Napier-1control, Napier-2 20Gy Napier-2 30Gy), Napier- 3 20Gy vs (Napier-1control, Napier-2 20Gy Napier-2 30Gy) ,(Napier-3 20Gy, Napier-3 30Gy Napier-1 20Gy, Napier-3 50Gy) vs (Napier -2 20Gy, Napier-3 control, Napier-3 20Gy) etc. The UPGMA displayed five major clusters including sub-clusters. Cluster 5 included the highest number of genotypes (21) and cluster 3 included the lowest number of genotypes (2). The results may be useful for future breeding program for Napier fodder development. SAARC J. Agric., 20(2): 105-119 (2022)

While foraging for nectar and pollen, bees are exposed to a myriad of xenobiotics, including plant metabolites, which may exert a wide range of effects on their health. Although the bee genome encodes enzymes that help in the metabolism of xenobiotics, it has lower detoxification gene diversity than the genomes of other insects. Therefore, bees may rely on other components that shape their physiology, such as the microbiota, to degrade potentially toxic molecules. In this study, we show that amygdalin, a cyanogenic glycoside found in honey bee-pollinated almond trees, can be metabolized by both bees and members of the gut microbiota. In microbiota-deprived bees, amygdalin is degraded into prunasin, leading to prunasin accumulation in the midgut and hindgut. In microbiota-colonized bees, on the other hand, amygdalin is degraded even further, and prunasin does not accumulate in the gut, suggesting that the microbiota contribute to the full degradation of amygdalin into hydrogen cyanide. In vitro experiments demonstrated that amygdalin degradation by bee gut bacteria is strain-specific and not characteristic of a particular genus or species. We found strains of Bifidobacterium, Bombilactobacillus, and Gilliamella that can degrade amygdalin. The degradation mechanism appears to vary since only some strains produce prunasin as an intermediate. Finally, we investigated the basis of degradation in Bifidobacterium wkB204, a strain that fully degrades amygdalin. We found overexpression and secretion of several carbohydrate-degrading enzymes, including one in glycoside hydrolase family 3 (GH3). We expressed this GH3 in Escherichia coli and detected prunasin as a byproduct when cell lysates were cultured with amygdalin, supporting its contribution to amygdalin degradation. These findings demonstrate that both host and microbiota can act together to metabolize dietary plant metabolites.

The standard fingerprint construction and genetic diversity analysis of maize varieties approved in Jilin province can provide data support for variety approval, protection, and market monitoring. It is also of great significance for variety breeding and germplasm innovation. In this study, 40 pairs of SSR markers were used to construct the standard SSR-DNA fingerprints of 290 maize varieties approved in Jilin province from 2010 to 2017, and the genetic diversity was analyzed. The results showed that the average number of alleles detected by 40 SSRs was 11.85 and the average PIC was 0.64. The average frequency of heterozygous genotypes of varieties was 0.66. The different loci number among varieties was ≥ 2. The genetic diversity analysis of six maturity groups revealed that there were more varieties with middle and late maturity, accounting for 71.72%, and fewer varieties with extremely early maturity, early maturity, and late maturity. The early maturity group had the highest gene diversity parameter of 0.69, and the mid-late maturity group with the largest number of varieties had a relatively low gene diversity value. Clustering results indicated that the varieties approved and popularized in Jilin province were divided into three categories: sweet waxy and popcorn, extremely early and early middle, medium or late maturity. The middle or late maturing varieties had two major trends, representing the differences in the selection of heterozygous groups, the different breeding units, the differences in variety types and so on. This study provides an important theoretical and data basis for maize variety management, variety breeding, and germplasm innovation in Jilin province.

17 Y-chromosomal STRs which are part of the Yfiler Amplification Kit were investigated in 493 unrelated Pakistani individuals belonging to the Punjabi, Sindhi, Baloch, and Pathan ethnic groups. We have assessed the forensic parameters and population genetic structure for each group. Among the 493 unrelated individuals from four ethnic groups (128 Baloch, 122 Pathan, 108 Punjabi, and 135 Sindhi), 82 haplotypes were observed with haplotype diversity (HD) of 0.9906 in Baloch, 102 haplotypes with HD value of 0.9957 in Pathans, 80 haplotypes with HD value of 0.9924 in Punjabi, and 105 haplotypes with HD value of 0.9945 in the Sindhi population. The overall gene diversity for Baloch, Pathan, Punjabi, and Sindhi populations was 0.6367, 0.6479, 0.6657, and 0.6112, respectively. The results had shown us that Pakistani populations do not have a unique set of genes but share the genetic affinity with regional (Central Asia and Northern India) populations. The observed low gene diversity (heterozygosity) values may be because of endogamy trends and this observation is equally supported by the results of forensic parameters which are mostly static across 4 combinations (minimal STRs, extended 11 Y-STRs, Powerplex 12 Y System, and Yfiler 17 Y-STRs) of STRs in these four populations.

While foraging for nectar and pollen, bees are exposed to a myriad of xenobiotics, including plant metabolites, which may exert a wide range of effects on their health. Although the bee genome encodes enzymes that help in the metabolism of xenobiotics, it has lower detoxification gene diversity than the genomes of other insects. Therefore, bees may rely on other components that shape their physiology, such as the microbiota, to degrade potentially toxic molecules. In this study, we show that amygdalin, a cyanogenic glycoside found in honey bee-pollinated almond trees, can be metabolized by both bees and members of the gut microbiota. In microbiota-deprived bees, amygdalin is degraded into prunasin, leading to prunasin accumulation in the midgut and hindgut. In microbiota-colonized bees, on the other hand, amygdalin is degraded even further, and prunasin does not accumulate in the gut, suggesting that the microbiota contribute to the full degradation of amygdalin into hydrogen cyanide. In vitro experiments demonstrated that amygdalin degradation by bee gut bacteria is strain-specific and not characteristic of a particular genus or species. We found strains of Bifidobacterium, Bombilactobacillus, and Gilliamella that can degrade amygdalin. The degradation mechanism appears to vary since only some strains produce prunasin as an intermediate. Finally, we investigated the basis of degradation in Bifidobacterium wkB204, a strain that fully degrades amygdalin. We found overexpression and secretion of several carbohydrate-degrading enzymes, including one in glycoside hydrolase family 3 (GH3). We expressed this GH3 in Escherichia coli and detected prunasin as a byproduct when cell lysates were cultured with amygdalin, supporting its contribution to amygdalin degradation. These findings demonstrate that both host and microbiota can act together to metabolize dietary plant metabolites.

Pathogenicity and microsatellite characterization of Puccinia hordei in South Africa

Introduction: The natural ecosystems of northern Mato Grosso, Brazil, are in process of fragmentation, mainly due to population growth and the expansion of agriculture. This endangers the palm Euterpe precatoria (locally known as açaí), used for construction, palm hearts, juices and ice cream. Objective: To evaluate the local diversity and genetic structure in native populations of E. precatoria. Methods: We collected leaves from 106 fruiting palms from five populations in Mato Grosso State, for analysis of microsatellite markers with Polymerase Chain Reaction. Results: The five SSR loci revealed a total of 30 alleles, ranging from 5 (EE23 and EE43) to 7 (EE2 and EE15), with an average of 6 alleles per locus. The mean PIC was 0.74 and confirmed low heterozygosity and inbreeding. The UPGMA dendrogram produced two groups and molecular variance revealed greater genetic differentiation within populations. The high levels of homozygous microsatellite loci indicate low genetic diversity. Conclusions: These populations have low gene diversity, high average number of alleles per locus, and rare and exclusive alleles. We recommend the establishment of permanent conservation units with corridors among them.