不同小麦品种茎秆特性及其与抗倒性的关系

以黄淮麦区优良品种矮抗58、周麦18、豫麦49、百农418为研究对象,采用田间试验与实验室分析相结合的方法,对不同小麦品种在不同生育时期的抗倒伏性状进行研究.结果表明: 茎秆机械强度在开花期至花后20 d处于较高水平,在花后30 d明显下降;倒伏指数在开花期最小,花后30 d最大,其余两个时期处于中间水平.相关分析表明,开花期机械强度与重心高度呈显著负相关,与纤维素、木质素含量呈显著正相关,倒伏指数与节长、株高、重心高度呈显著正相关,与纤维素、木质素含量呈显著负相关;花后10 d和花后20 d机械强度与节长、株高、重心高度呈显著负相关,与茎粗、纤维素、半纤维素、木质素含量呈显著正相关,倒伏指数这段时期正好与之相反;花后30 d机械强度与株高、重心高度呈显著负相关,倒伏指数与株高、重心高度呈显著正相关,与木质素含量呈显著负相关.因此,明确各个生育时期与抗倒性相关的茎秆特性,可为黄淮麦区高产抗倒性品种的选育提供依据.     

Macrophage colony-stimulating factor expression in retrovirally transduced cells is dependent upon both the adherence status of the target cells and its 5' flanking untranslated region

Numerous cell types retrovirally transduced with macrophage colony-stimulating factor (M-CSF) using LXSN-based vectors showed a variable expression of the transgene. Expression of M-CSF correlated with the cells' adherent status. Transduced adherent cells produced the M-CSF, whereas the non-adherent cells synthesized little M-CSF. Studies showed that the 5'-UTR of the M-CSF gene regulated transgenic M-CSF gene expression. Ligation of this 5'-UTR to the enhanced green fluorescent protein gene (EGFP) caused the expression of EGFP to show the same dichotomy as previously seen with the M-CSF. Transgenic M-CSF was expressed within non-adherent cells when the 5'-UTR was removed from the LXSN vector. Quantitative real-time polymerase chain reaction analysis confirmed that lesser production of M-CSF mRNA occurred within the non-adherent cells than in the adherent cells. This difference was eliminated when the 5'-UTR was removed from the retroviral vector. Our work suggests that this 5'-UTR of the M-CSF gene could be an important way to get transgenic expression within adherent cells, but not in non-adherent cells.     

A novel mutation at the JK locus causing Jknull phenotype in a Chinese family

Jk (kidd) blood group antigens are carried by the urea transporter UT-B[1,2]. The Jknull phenotype, lack-ing urea permeability in erythrocytes[3,4], has a very low frequency in all populations except Polynesians and Finns[5]. In Japan, only 14 individuals with Jk (a-b-) phenotype were identified from 638460 screened donor’s blood samples using the 2 mol/L urea solution hemolysis test[6]. The frequency of Jknull is 0.27% in Polynesian, about 0.03% in Finland[7], and extremely rare in Fran…     

黔西北铅锌矿区植物群落分布及其对重金属的迁移特征

重金属耐性植物和超富集植物的筛选、鉴定和驯化是植物修复技术研究与发展的关键。以黔西北4个不同恢复年限的铅锌矿为研究对象,通过群落生态调查利用聚类分析方法筛选出研究区域中重金属耐性植物优势种,并分析其对重金属Pb、Zn、Cu、Cd的迁移富集能力。结果表明:4个矿区共发现高等植物22种,分属13科21属,筛选出9种重金属耐性植物优势种,其中转运系数大于1的植物有:黄花蒿(Cu)、珠光香青(Zn)、大叶醉鱼草(Zn/Pb/Cd)、野艾蒿(Cu/Zn/Pb/Cd);没有富集系数大于1的植物。其中大叶醉鱼草具有耐贫瘠、耐旱、生物量大等优势,可将其作为典型的重金属耐性先锋植物,用于矿区废弃地的植物修复。     

Spoiling the Whole Bunch: Quality Control Aimed at Preserving the Integrity of High-Throughput Genotyping

False-positive or false-negative results attributable to undetected genotyping errors and confounding factors present a constant challenge for genome-wide association studies (GWAS) given the low signals associated with complex phenotypes and the noise associated with high-throughput genotyping. In the context of the genetics of kidneys in diabetes (GoKinD) study, we identify a source of error in genotype calling and demonstrate that a standard battery of quality-control (QC) measures is not sufficient to detect and/or correct it. We show that, if genotyping and calling are done by plate (batch), even a few DNA samples of marginally acceptable quality can profoundly alter the allele calls for other samples on the plate. In turn, this leads to significant differential bias in estimates of allele frequency between plates and, potentially, to false-positive associations, particularly when case and control samples are not sufficiently randomized to plates. This problem may become widespread as investigators tap into existing public databases for GWAS control samples. We describe how to detect and correct this bias by utilizing additional sources of information, including raw signal-intensity data.     

Developmental aspects of the tympanic membrane: Shedding light on function and disease

The ear drum, or tympanic membrane (TM), is a key component in the intricate relay that transmits air‐borne sound to our fluid‐filled inner ear. Despite early belief that the mammalian ear drum evolved as a transformation of a reptilian drum, newer fossil data suggests a parallel and independent evolution of this structure in mammals. The term “drum” belies what is in fact a complex three‐dimensional structure formed from multiple embryonic cell lineages. Intriguingly, disease affects the ear drum differently in its different parts, with the superior and posterior parts being much more frequently affected. This suggests a key role for the developmental details of TM formation in its final form and function, both in homeostasis and regeneration. Here we review recent studies in rodent models and humans that are beginning to address large knowledge gaps in TM cell dynamics from a developmental biologist's point of view. We outline the biological and clinical uncertainties that remain, with a view to guiding the indispensable contribution that developmental biology will be able to make to better understanding the TM.     

Androgen and the elaborate courtship behavior of a tropical lekking bird

In most bird species, male courtship behavior is controlled by testosterone (T) and its metabolites. In species breeding in temperate and arctic regions T circulates at high levels during a relatively short courtship period because high levels of T can be costly in terms of immunocompetence and parental care. Few studies have investigated androgen modulation of courtship behavior in tropical birds. Male golden-collared manakins (Manacus vitellinus) aggregate in leks for several months and perform spectacular, acrobatic courtship displays. Here we examined whether T is elevated in golden-collared manakins during the displaying period and if courtship behavior is modulated by androgen action on androgen receptors. We measured T levels in displaying males at the beginning of the breeding season and again, one month later. In addition, both wild and captive males were treated with the anti-androgen, flutamide, and their courtship behavior was recorded for several weeks. T levels were relatively high shortly after leks were established but decreased substantially a month later, even though the amount of courtship did not change. Flutamide reduced male courtship activity for one week, but display behavior then increased after two weeks of flutamide treatment. Our studies show that androgens modulate male manakin courtship, but the amount of courtship is not directly correlated with the concentration of circulating T. These results suggest that the relationships between androgen and courtship might differ between tropical and temperate birds.