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1.
Zhenzhen Zhang Changjiu He Yu Gao Lu Zhang Yukun Song Tianqi Zhu Kuanfeng Zhu Dongying Lv Jing Wang Xiuzhi Tian Teng Ma Pengyun Ji Wei Cui Guoshi Liu 《Aging cell》2021,20(2)
The fecundity reduction with aging is referred as the reproductive aging which comes earlier than that of chronological aging. Since humans have postponed their childbearing age, to prolong the reproductive age becomes urgent agenda for reproductive biologists. In the current study, we examined the potential associations of α‐ketoglutarate (α‐KG) and reproductive aging in mammals including mice, swine, and humans. There is a clear tendency of reduced α‐KG level with aging in the follicle fluids of human. To explore the mechanisms, mice were selected as the convenient animal model. It is observed that a long term of α‐KG administration preserves the ovarian function, the quality and quantity of oocytes as well as the telomere maintaining system in mice. α‐KG suppresses ATP synthase and alterations of the energy metabolism trigger the nutritional sensors to down‐regulate mTOR pathway. These events not only benefit the general aging process but also maintain ovarian function and delay the reproductive decline. Considering the safety of the α‐KG as a naturally occurring molecule in energy metabolism, its utility in reproduction of large mammals including humans deserves further investigation. 相似文献
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Abstract This paper deals with alternative hosts of an egg parasitoid. Trichogramma dendrolimi Matsumura in three habitats: mixed forest, pure stand and sparse wood. The experiment was conducted in Liuyan County which is located in the eastern part of Hunan Province. The results suggested that there are 103 species of alternative Lepidopteran hosts for T. dendrolimi . There were two critical periods throughout the year when there were no eggs of Dendrolimus punctatus Walker and few eggs of alternative hosts available for ovipsition by the parasitoids. 相似文献
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Peng Li Liang Xiao Qingzhang Du Mingyang Quan Yuepeng Song Yuling He Weixiong Huang Jianbo Xie Chenfei Lv Dan Wang Jiaxuan Zhou Lianzheng Li Qing Liu Yousry A. El-Kassaby Deqiang Zhang 《Plant biotechnology journal》2023,21(10):2002-2018
Heterozygous alleles are widespread in outcrossing and clonally propagated woody plants. The variation in heterozygosity that underlies population adaptive evolution and phenotypic variation, however, remains largely unknown. Here, we describe a de novo chromosome-level genome assembly of Populus tomentosa, an economic and ecologically important native tree in northern China. By resequencing 302 natural accessions, we determined that the South subpopulation (Pop_S) encompasses the ancestral strains of P. tomentosa, while the Northwest subpopulation (Pop_NW) and Northeast subpopulation (Pop_NE) experienced different selection pressures during population evolution, resulting in significant population differentiation and a decrease in the extent of heterozygosity. Analysis of heterozygous selective sweep regions (HSSR) suggested that selection for lower heterozygosity contributed to the local adaptation of P. tomentosa by dwindling gene expression and genetic load in the Pop_NW and Pop_NE subpopulations. Genome-wide association studies (GWAS) revealed that 88 single nucleotide polymorphisms (SNPs) within 63 genes are associated with nine wood composition traits. Among them, the selection for the homozygous AA allele in PtoARF8 is associated with reductions in cellulose and hemicellulose contents by attenuating PtoARF8 expression, and the increase in lignin content is attributable to the selection for decreases in exon heterozygosity in PtoLOX3 during adaptive evolution of natural populations. This study provides novel insights into allelic variations in heterozygosity associated with adaptive evolution of P. tomentosa in response to the local environment and identifies a series of key genes for wood component traits, thereby facilitating genomic-based breeding of important traits in perennial woody plants. 相似文献
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铜对大鳞泥鳅幼鱼的毒性 总被引:3,自引:0,他引:3
本文用流水和换水式试验,在水硬度为115mg/L(以CaCO_3计)条件下研究了铜对大鳞泥鳅幼鱼生长和存活的影响。试验从刚孵出的幼鱼开始,流水式试验持续30d,换水式试验历时16d。结果表明,在流水条件下铜对泥鳅幼鱼存活有明显影响的可观察效应浓度最低是41.2μg/L,而无可观察效应浓度则为25.2μg/L。根据对现存量的影响,用换水式试验测得铜的最低可观察效应浓度为38μg/L,无可观察效应浓度是19μg/L。 相似文献
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稀有鮈鲫──一种新的鱼类毒性试验材料 总被引:7,自引:0,他引:7
本文研究了稀有鲫(Gobiocyprisrarus)作为毒性试验材料的可行性。采用换水式试验,在硬度为200mg/L(以CaCO3计)、pH7.8±0.2、温度24-25℃条件下研究了铬、铜、锌和五氯酚(PCP)对稀有鲫的急性毒性。重铬酸钾对2日龄稀有鲫的24h和96h和LC50控制范围分别263.6-334.7和1153-178.5mg/L(n=8)。铬、铜、锌和五氯酚对2日龄稀有鲫的急性毒性值(96hLC50)范围,从铜的52.2μg/L到铬的52000μg/L,毒性大小的顺序是铜>五氯酚>锌>铬。研究结果表明,稀有鲫有可能发展成为一种较为理想的毒性试验材料。 相似文献
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不同来源的肾综合征出血热病毒对Vero细胞的致病变作用 总被引:3,自引:0,他引:3
前文报道,肾综合征出血热病毒76-118株能使Vero细胞产生病变。本文报道76-118株和另11株不同来源的肾综合征出血热病毒(H537、A9、H5、R178、HB55、R22、Z10,沟3、L99、A16和J10)对Vero细胞的致病变作用(CPE )。其中除沟3株外,大部分毒株在感染Vero细胞后的第一代即可见明显的CPE。CPE的特点与76-118株相似,主要是感染细胞粘聚、融合,形成网状结构。CPE能被特异性抗HFRS病毒血清和型特异性单克隆抗体所中和抑制,但不能被特异性抗呼肠孤病毒Ⅲ型免疫血清所中和抑制。HFRS病毒对Vero细胞的致病变作用,对进一步研究HFRS病毒的某些生物学特性及实验方法等均有重要意义。 相似文献