Conservation genomics provides insights into genetic resilience and adaptation of the endangered Chinese hazelnut, Corylus chinensis

Global climate change has increased concerns regarding biodiversity loss.However,many key conservation issues still required further research,including demographic history,deleterious mutation load,adaptive evolution,and putative introgression.Here we generated the first chromosome-level genome of the endangered Chinese hazelnut,Corylus chinensis,and compared the genomic signatures with its sympatric widespread C.kwechowensis-C yunnanensis complex.We found large genome rearrangements across all Corylus species and identified species-specific expanded gene families that may be involved in adaptation.Population genomics revealed that both C.chinensis and the C.kwechowensis-C.yunnanensis complex had diverged into two genetic lineages,forming a consistent pattern of southwestern-northern differentiation.Population size of the narrow southwestern lineages of both species have decreased continuously since the late Miocene,whereas the widespread northern lineages have remained stable(C.chinensis) or have even recovered from population bottlenecks(C.kwechowensis-C.yunnanensis complex) during the Quaternary.Compared with C.kwechowensis-C. yunnanensis complex,C.chinensis showed significantly lower genomic diversity and higher inbreeding level.However,C.chinensis carried significantly fewer deleterious mutations than C.kwechowensis-C. yunnanensis complex,as more effective purging selection reduced the accumulation of homozygous variants.We also detected signals of positive selection and adaptive introgression in different lineages,which facilitated the accumulation of favorable variants and formation of local adaptation.Hence,both types of selection and exogenous introgression could have mitigated inbreeding and facilitated survival and persistence of C.chinensis.Overall,our study provides critical insights into lineage differentiation,local adaptation,and the potential for future recovery of endangered trees.

Population genomics reveals demographic history and selection signatures of hazelnut (Corylus)

Hazelnut(Corylus spp.)is known as one of the four famous tree nuts in the world due to its pleasant taste and nutritional benefits.However,hazelnut promotion worldwide is increasingly challenged by global climate change,limiting its production to a few regions.Focusing on the eurytopic Section Phyllochlamys,we conducted whole-genome resequencing of 125 diverse accessions from five geo-ecological zones in Eurasia to elucidate the genomic basis of adaptation and improvement.Population structure inference outlined five distinct genetic lineages corresponding to climate conditions and breeding background,and highlighted the differentiation between European and Asian lineages.Demographic dynamics and ecological niche modeling revealed that Pleistocene climatic oscillations dominantly shaped the extant genetic patterns,and multiple environmental factors have contributed to the lineage divergence.Whole-genome scans identified 279,111,and 164 selective sweeps that underlie local adaptation in Corylus heterophylla,Corylus kweichowensis,and Corylus yunnanensis,respectively.Relevant positively selected genes were mainly involved in regulating signaling pathways,growth and development,and stress resistance.The improvement signatures of hybrid hazelnut were concentrated in 312 and 316 selected genes,when compared to C.heterophylla and Corylus avellana,respectively,including those that regulate protein polymerization,photosynthesis,and response to water deprivation.Among these loci,22 candidate genes were highly associated with the regulation of biological quality.Our study provides insights into evolutionary processes and the molecular basis of how sibling species adapt to contrasting environments,and offers valuable resources for future climate-resilient breeding.

Comprehensive Analysis of 9-year Running Data of A^2/O-MBR in Xi an Siyuan University

Since September 2011,A 2/O-MBR wastewater treatment plant in Xi'an Siyuan University has been successfully running without replacing any of membrane modules.A total of 6.661 million m^3 of campus wastewater has been treated,and 4.405 million m^3 of water reaching the national urban miscellaneous water standard has been reclaimed and reused.A total of 25 km pipeline,5 pits,scenery fountains,lakes,and 12 pump stations have been constructed for flushing toilets,irrigating green grass lawn and afforest,and cleaning hardened pavement.The design and construction of 5 pits,scenery fountains,and lakes are important to meet the national urban miscellaneous water standard under occasional phosphorus and/or nitrogen exceed concentration.The unit water cost is 4.19 yuan/m^3,including membrane modules depreciation and amortization.After the A 2/O-MBR system passes the membrane modules depreciation and amortization period,the unit water cost is 2.82 yuan/m^3.The water productivity of the membrane stack rises first at the beginning of operation,reaches the maximum value,and then decreases.The average annual transmembrane pressure difference increases by 1.12 kPa.The average VMD of industrial permeability decreases annually by 0.45 m^3.

Elevated Kir2.1/nuclear N2ICD defines a highly malignant subtype of non-WNT/SHH medulloblastomas

Medulloblastoma(MB)is one of the most common childhood malignant brain tumors(WHO grade IV),traditionally divided into WNT,SHH,Group 3,and Group 4 subgroups based on the transcription profiles,somatic DNA alterations,and clinical outcomes.Unlike WNT and SHH subgroup MBs,Group 3 and Group 4 MBs have similar transcriptomes and lack clearly specific drivers and targeted therapeutic options.The recently revised WHO Classification of CNS Tumors has assigned Group 3 and 4 to a provisional non-WNT/SHH entity.In the present study,we demonstrate that Kir2.1,an inwardly-rectifying potassium channel,is highly expressed in non-WNT/SHH MBs,which promotes tumor cell invasion and metastasis by recruiting Adam10 to enhance S2 cleavage of Notch2 thereby activating the Notch2 signaling pathway.Disruption of the Notch2 pathway markedly inhibited the growth and metastasis of Kir2.1-overexpressing MB cell-derived xenograft tumors in mice.Moreover,Kir2.1^(high)/nuclear N2ICD^(high)MBs are associated with the significantly shorter lifespan of the patients.Thus,Kir2.1^(high)/nuclear N2ICD^(high)can be used as a biomarker to define a novel subtype of non-WNT/SHH MBs.Our findings are important for the modification of treatment regimens and the development of novel-targeted therapies for non-WNT/SHH MBs.

Seroprevalence of neutralizing antibodies against adenovirus type 26 and 35 in healthy populations from Guangdong and Shandong provinces,China

Human adenoviruses type 26(HAdV26)and type 35(HAdV35)have increasingly become the choice of adenovirus vectors for vaccine application.However,the population pre-existing immunity to these two adenoviruses in China,which may reduce vaccine efficacy,remains largely unknown.Here,we established micro-neutralizing(MN)assays to investigate the seroprevalence of neutralizing antibodies(nAbs)against HAdV26 and HAdV35 in the general population of Guangdong and Shandong provinces,China.A total of 1184 serum samples were collected,47.0%and 15.8%of which showed HAdV26 and HAdV35 nAb activity,respectively.HAdV26-seropositive individuals tended to have more moderate nAbs titers(201-1000),while HAdV35-seropositive individuals appeared to have more low nAbs titers(72-200).The seropositive rates of HAdV26 and HAdV35 in individuals younger than 20 years old were very low.The seropositive rates of HAdV26 increased with age before 70 years old and decreased thereafter,while HAdV35 seropositive rates did not show similar characteristics.Notably,the seropositive rates and nAb levels of both HAdV26 and HAdV35 were higher in Guangdong Province than in Shandong Province,but did not exert significant differences between males and females.The seroprevalence between HAdV26 and HAdV35 showed little correlation,and no significant cross-neutralizing activity was detected.These results clarified the characteristics of the herd immunity against HAdV26 and HAdV35,and provided information for the rational development and application of HAdV26 and HAdV35 as vaccine vectors in China.

Diversity analysis of space-time-frequency coded broadband MIMO-OFDM system with correlation across space time and frequency

For the frequency selective and time variant multiple-input multiple-output(MIMO)channel model taking into account transmitting and receiving antenna correlation,the diversity of space-time-frequency coded broadband orthogonal frequency division multiplexing(MIMO-OFDM)system is analyzed.Based on the average pairwise error probability(PEP),the design criterion of space-time-frequency code(STFC)is expanded.For a given STFC,it is found that the achievable diversity order is related to the transmitter and the receiver correlation matrix as well as the time correlation and frequency correlation matrix.The maximum available diversity of STFC over the correlation channel is Lrank(P)rank(Q)rank(RT).The space-time code and space-frequency code are special cases in our approach.Simulation results validate the findings.