Molecular diversity of the 5S nuclear ribosomal DNA in Campeiostachys with StHY haplome constitution

To detect the genomic constitutions and investigate the evolutionary relationships between Campeiostachys Drobov and Elymus L. species, we have cloned and analyzed 271 5S nuclear ribosomal DNA sequences from 27 accessions of these species, mostly of Chinese origin. We identified Long H1, Short S1, and Long Y1 unit classes in nine Campeiostachys or Elymus species. The identification of the three orthologous unit classes was confirmed by the neighbor‐joining tree of each unit class from PAUP and the phylogeny tree of three unit classes from MrBayes. The results suggested that these Elymus species comprise StYH haplomes and should be included in Campeiostachys. The phylogeny tree showed a clear separation between the S1 unit class and Y1 unit class. However, Y1 unit class sequences formed a sister clade to the S1 unit class, implying that although the St and Y haplomes might have some affinity, they are distinct from one another. The phylogeny tree also indicated that the five species in sect. Turczaninovia (C. dahurica var. cylindrica, C. dahurica var. dahurica, C. dahurica var. tangutorum, E. purpuraristatus, and E. dahuricus Turcz. ex Griseb. var. violeus C. P. Wang & H. L. Yang) might share a more recent common ancestor, whereas the four species in sect. Elymus (C. nutans, E. breviaristatus (Keng) Keng ex Keng f., E. sinosubmuticus (Keng) Keng f., and E. atratus (Nevski) Hand.‐Mazz.) share a close relationship. By identifying only one type of unit class for each haplome, we propose that the 5S nuclear ribosomal DNA sequences of species within Campeiostachys might have undergone haplome‐specific concerted evolution.     

Base excision repair but not DNA double‐strand break repair is impaired in aged human adipose‐derived stem cells

The decline in DNA repair capacity contributes to the age‐associated decrease in genome integrity in somatic cells of different species. However, due to the lack of clinical samples and appropriate tools for studying DNA repair, whether and how age‐associated changes in DNA repair result in a loss of genome integrity of human adult stem cells remains incompletely characterized. Here, we isolated 20 eyelid adipose‐derived stem cell (ADSC) lines from healthy individuals (young: 10 donors with ages ranging 17–25 years; old: 10 donors with ages ranging 50–59 years). Using these cell lines, we systematically compared the efficiency of base excision repair (BER) and two DNA double‐strand break (DSB) repair pathways—nonhomologous end joining (NHEJ) and homologous recombination (HR)—between the young and old groups. Surprisingly, we found that the efficiency of BER but not NHEJ or HR is impaired in aged human ADSCs, which is in contrast to previous findings that DSB repair declines with age in human fibroblasts. We also demonstrated that BER efficiency is negatively associated with tail moment, which reflects a loss of genome integrity in human ADSCs. Mechanistic studies indicated that at the protein level XRCC1, but not other BER factors, exhibited age‐associated decline. Overexpression of XRCC1 reversed the decline of BER efficiency and genome integrity, indicating that XRCC1 is a potential therapeutic target for stabilizing genomes in aged ADSCs.     

Induced pluripotent stem cell‐derived myeloid cells expressing OX40 ligand amplify antigen‐specific T cells in advanced melanoma

Immune checkpoint inhibitors improved the survival rate of patients with unresectable melanoma. However, some patients do not respond, and variable immune‐related adverse events have been reported. Therefore, more effective and antigen‐specific immune therapies are urgently needed. We previously reported the efficacy of an immune cell therapy with immortalized myeloid cells derived from induced pluripotent stem cells (iPS‐ML). In this study, we generated OX40L‐overexpressing iPS‐ML (iPS‐ML‐Zsgreen‐OX40L) and investigated their characteristics and in vivo efficacy against mouse melanoma. We found that iPS‐ML‐Zsgreen‐OX40L suppressed the progression of B16‐BL6 melanoma, and prolonged survival of mice with ovalbumin (OVA)‐expressing B16 melanoma (MO4). The number of antigen‐specific CD8⁺ T cells was higher in spleen cells treated with OVA peptide‐pulsed iPS‐ML‐Zsgreen‐OX40L than in those without OX40L. The OVA peptide‐pulsed iPS‐ML‐Zsgreen‐OX40L significantly increased the number of tumor‐infiltrating T lymphocytes (TILs) in MO4 tumor. Flow cytometry showed decreased regulatory T cells but increased effector and effector memory T cells among the TILs. Although we plan to use allogeneic iPS‐ML in the clinical applications, iPS‐ML showed the tumorgenicity in the syngeneic mice model. Incorporating the suicide gene is necessary to ensure the safety in the future study. Collectively, these results indicate that iPS‐ML‐Zsgreen‐OX40L therapy might be a new method for antigen‐specific cancer immunotherapy.     

Effect of woody plant expansion on decomposition of fine root mixtures in a grass-dominated temperate wetland

Wetlands Ecology and Management - Little is known about the effect of woody plant expansion on decomposition of root mixtures in grass-dominant temperate wetlands. Here, we collected fine roots...     

Cold and hungry: combined effects of low temperature and resource scarcity on an edge-of-range temperate primate,the golden snub-nose monkey

Both biotic and abiotic factors play important roles in influencing ecological distributions and niche limits. Where biotic and abiotic stressors co-occur in space and time, homeostatic systems face a scenario in which stressors can compound to impose a challenge that is greater than the sum of the separate factors. We studied the homeostatic strategies of the golden snub-nosed monkey Rhinopithecus roxellana, a species living in temperate deciduous forests at the edge of the global distribution range for folivorous primates, to cope with the co-occurrence of cold temperatures and resource scarcity during winter. We discovered that in winter the monkeys experience a dietary energy deficit of 101 kJ mbm⁻¹ d⁻¹ compared with calculated needs, despite increased feeding. This is partly offset by behavioral changes (reduced locomotion and increased resting) and reducing skin temperature by an average of 3.2°C through a cutaneous vasoconstriction to decrease heat loss. However, their major strategy is ingesting surplus energy and accumulating fat reserves when food was not limiting during summer and autumn. Their 14% of body mass lost over the winter represented an energy yield of 102 kJ mbm⁻¹ d⁻¹, which closely matched the calculated winter energy deficit of 101 kJ mbm⁻¹ d⁻¹. However, the latter value assumes that all the 75.41 kJ mbm⁻¹ d⁻¹ of protein ingested in winter was available for energy metabolism. This is almost certainly an over-estimate, suggesting that the study population was in negative energy balance over the study period. Our study therefore suggests that despite its suit of integrated homeostatic responses, the confluence of low temperatures and resource limitation during winter places this edge-of-range primate close the threshold of what is energetically viable. It also provides a framework for quantitative models predicting the vulnerability of temperate primates to global change.     

Glycine metabolomic changes induced by anticancer agents in A549 cells

Amino Acids - Glycine plays a key role in rapidly proliferating cancer cells such as A549 cells. Targeting glycine metabolism is considered as a potential means for cancer treatment. However, the...     

藏药“榜间”主流品种基原植物的潜在分布研究

“榜间”为常用大宗藏药,但其生境特殊,生态位狭窄,部分品种资源量小,甚至濒危。为了明确“榜间”原植物的生态环境,预测生态适宜区分布,寻找影响适宜性分布的主要生态因子,该文以大花龙胆(Gentiana szechenyii)、高山龙胆(G. algida)、蓝玉簪龙胆(G. veitchiorum)、华丽龙胆(G. sino-ornata)和短柄龙胆(G. stipitata)五个主流品种为研究对象,采用生态学调查方法进行实地调查,以分析各品种的分布特征和生境特点,并应用MaxEnt模型和ArcGIS软件,预测潜在分布区。结果表明:(1)“榜间”五个主流品种的生长均需要较好的土壤肥力条件,大花龙胆和短柄龙胆仅分布于草本层低矮的草甸或草甸灌丛,其余品种因茎有较大的伸长幅度,生态幅较广。(2)海拔是影响“榜间”五个主流品种分布的限制因子,对大花龙胆、高山龙胆、蓝玉簪龙胆、华丽龙胆和短柄龙胆生境适宜性的贡献率分别为56.5%、39.6%、49.4%、48.1%和44.2%,高山龙胆主要分布在海拔1 500 m以上的地区,而另外四个品种主要分布于海拔2 600 m以上的地区。(3)藏药“榜间”五个主流品种生长适宜区主要集中在四川、青海、云南、甘肃和西藏五省(区),但不同基原植物在各省(区)的分布面积和空间格局有差异,大花龙胆和高山龙胆的最适分布区集中在四川、甘肃、青海、西藏四省(区)交界处,后者在新疆地区也有最适分布区; 蓝玉簪龙胆最适生长区位于四川中部、四川北部接壤青海及甘肃处、四川西南部接壤云南处、西藏东部; 华丽龙胆与短柄龙胆最适生长区主要位于四川、青海、甘肃的交界地带,适生区范围较蓝玉簪龙胆狭窄。研究结果与实际调查结果基本相符,可以为“榜间”野生资源的保护及相关植物的人工栽培提供科学依据。     

施硼和赤霉素对‘李广杏’坐果率及果实品质的影响

该研究以8年生盛果期的‘李广杏’植株为试材,于花蕾膨大期喷施0.1%(P1)、0.3%(P2)和0.5%(P3)硼砂和盛花初期喷施50(C1)、100(C2)和150 mg/L(C3)赤霉素,测定不同处理下李广杏的坐果率、果实品质及营养生长指标的变化,并用主成分分析不同处理的效果进行综合评价,为敦煌寒旱区‘李广杏’的栽培提供理论依据。结果表明:(1)‘李广杏’叶面积增长量在C1浓度处理下显著高于CK,不同浓度的硼处理对其均具有抑制作用,但C1、P2浓度下新稍生长量高于其他处理。(2)适宜浓度的硼和赤霉素处理可一定程度减少‘李广杏’花的败育率,从而有效提高果树的坐果率,其中硼处理以P3浓度下最优,但P3与P2处理下坐果率无显著差异,赤霉素处理以C2浓度下最优。(3)适宜浓度硼和赤霉素能够明显提高‘李广杏’果实品质,C1浓度处理下的果实糖酸比、可溶性固形物含量显著高于CK,P2处理下的果实维生素C、可滴定酸含量显著高于其他处理;适宜浓度赤霉素和硼对果实的单果重、果形指数、侧径有明显的促进作用。(4)主成分分析结果显示,各处理效果的综合得分由高到低依次为P2(1.20)>C2(0.91)>P1(0.13)>C1(-1.01)>CK(-1.68)>P3(-2.13)>C3(-7.76);果实可溶性糖、可溶性蛋白、糖酸比等主成分占比较高,可作为评价‘李广杏’果实品质的重要依据。研究发现,花期喷施适宜浓度的硼和赤霉素可有效提高‘李广杏’果树的生长状况、坐果率及果实品质,且甘肃敦煌地区以花蕾膨大期喷施0.3%硼和盛花初期喷施100 mg/L赤霉素效果最佳。