RFLP mapping of QTLs for yield and related characters in rice (Oryza sativa L.)

Quantitative triat loci (QTLs) for yield and related traits in rice were mapped based on RFLP maps from two indica/indica F₂ populations, Tesanai 2/CB and Waiyin 2/CB. In Tesanai 2/CB, 14 intervals carrying QTLs for eight traits were detected, including 3 for grain weight per plant (GWT), 2 for number of panicles per plant (NP), 2 for number of grains per panicle (NG), 1 for total number of spikelets per panicle (TNS), 1 for spikelet fertility (SF), 3 for 1000-grain weight (TGWT), 1 for spikelet density (SD), and 1 for number of first branches per main panicle. The 3 QTLs for GWT were located on chromosomes 1, 2, and 4, with 1 in each chromosome. The additive effect of the single locus ranged from 2.0 g to 9.1 g. A major gene (np4) for NP was detected on chromosome 4 within the interval of RG143–RG214, about 4cM for RG143, and this locus explained 26.1% of the observed phenotypic variance for NP. The paternal allele of this locus was responsible for reduced panicles per plant (3 panicles per plant). In another population, Waiyin 2/CB, 12 intervals containing QTLs for six of the above-mentioned traits were detected, including 3 for GWT, 2 for each of NP, TNS, TGWT and SD, 1 for SF. Three QTLs for GWT were located on chromosome 1, 4, and 5, respectively. The additive effect of the single locus for GWT ranged from 6.7 g to 8.8 g, while the dominance effect was 1.7–11.5 g. QTL mapping in two populations with a common male parent is compared and discussed.     

Analysis of wild-type and mutant p21WAF-1 gene activities.

The p21WAF-1 gene is positively regulated by the wild-type p53 protein. p21WAF-1 has been shown to interact with several cyclin-dependent kinase complexes and block the activity of G1 cyclin-dependent kinases (cdks). Mutational analysis with the p21WAF-1 gene localized a site, at amino acid residues 21 and 24 in the amino terminus of the protein, for p21WAF-1 binding to cyclins D and E. This region of the protein is conserved (residues 21 to 26) in other p21WAF-1 family members, p27kip-1 and p57kip-2. The same p21WAF-121,24 mutant also fails to bind to cyclin D1-cdk 4 or cyclin E-cdk 2 complexes in vitro, suggesting that amino acid residues 21 and 24 are important for p21WAF-1-cdk-cyclin trimeric complex interactions. The p21WAF-1 wild-type protein will suppress tumor cell growth in culture while p21WAF-1 mutant proteins with defects in residues 21 and 24 fail to suppress tumor cell growth. The overexpression of cyclin D or E in these cells will partially overcome the growth suppression of wild-type p21WAF-1 protein in cells. These results provide evidence that p21WAF-1 acts through cyclin D1-cdk4 and cyclin E-cdk2 complexes in vivo to induce the growth suppression. The p21WAF-1 binding sites for cyclins (residues 21 to 26), cdk2 (residues 49 to 71), and proliferating-cell nuclear antigen (residues 124 to 164) have all been mapped to discrete sites on the protein.     

Identification of molecular markers in soybean comparing RFLP,RAPD and AFLP DNA mapping techniques

Three different DNA mapping techniques—RFLP, RAPD and AFLP—were used on identical soybean germplasm to compare their ability to identify markers in the development of a genetic linkage map. Polymorphisms present in fourteen different soybean cultivars were demonstrated using all three techniques. AFLP, a novel PCR-based technique, was able to identify multiple polymorphic bands in a denaturing gel using 60 of 64 primer pairs tested. AFLP relies on primers designed in part on sequences for endonuclease restriction sites and on three selective nucleotides. The 60 diagnostic primer pairs tested for AFLP analysis each distinguished on average six polymorphic bands. Using specific primers designed for soybean fromEco RI andMse I restriction site sequences and three selective nucleotides, as many as 12 polymorphic bands per primer could be obtained with AFLP techniques. Only 35% of the RAPD reactions identified a polymorphic band using the same soybean cultivars, and in those positive reactions, typically only one or two polymorphic bands per gel were found. Identification of polymorphic bands using RFLP techniques was the most cumbersome, because Southern blotting and probe hybridization were required. Over 50% of the soybean RFLP probes examined failed to distinguish even a single polymorphic band, and the RFLP probes that did distinguish polymorphic bands seldom identified more than one polymorphic band. We conclude that, among the three techniques tested, AFLP is the most useful.     

Chromosomal Assignment of Human Nuclear Envelope Protein Genes LMNA, LMNB1, and LBR by Fluorescencein SituHybridization

We have used fluorescencein situhybridization to establish precise chromosomal localizations for three human genes encoding four different nuclear envelope proteins. Lamin A/C (LMN1, HGMW-approved symbol LMNA) mapped to 1q21.2–q21.3, with a most probable gene assignment to 1q21.3; lamin B receptor (LBR) was localized to 1q42.1; and lamin B1 (LMNB1) was mapped to the interface of bands 5q23.3–q31.1. Assignments were determined by direct placement of signals relative to high-resolution DAPI or G-bands. Comparison of these results of band positions predicted from fractional length measurements to signal placement indicated that more accurate predictions are made using Francke idiograms and that measurement strategy avoids variance due to polymorphic chromosome segments.     

腥黑粉菌属一新种

本文报道了从意大利进口兔尾草(Lagurus ovatus L.)上截获的腥黑粉菌属一新种——兔尾草腥黑粉菌(Tilletia laguri G.M.Zhang,G.X.Lin & J.R.Deng),同时讨论了该种与近似种的区别,文中对其形态特征有拉丁文和汉文描述,并附有图片。主模式标本保存在深圳动植物检疫局真菌标本室,等模式标本分别保存在德国蒂宾根大学范基黑粉菌标本馆(HUV)、中国科学院微生物研究所真菌标本室和华南农业大学植保系真菌标本室。     

中国脊翅叶蝉属种类记述（同翅目：叶蝉科）

本文记述４种中国脊翅叶蝉,其中包括１新种──杨氏脊翅叶蝉Ｐａｒａｂｏｌｏｐｏｎａｙａｎｇｉｓｐ．ｎ．,并报道了其中２个已知种的新分布地。文中还列有分种检索表。新种模式标本存西北农业大学昆虫博物馆。     

流行性出血热患者皮肤组织内病毒抗原及免疫复合物检测与意义

应用常规病理、免疫病理及超微病理技术,对３３例流行性出血热（ＥＨＦ）患者皮肤活检标本的病理变化及病毒抗原、免疫复合物进行观察,同时与血清病毒抗原、抗体及循环免疫复合物检出情况进行比较。在２３例ＥＨＦ患者皮肤微血管内皮细胞中检出病毒抗原,部分组织中可同时检出免疫球蛋白及Ｃ３,少数组织仅能检出病毒抗原或免疫球蛋白。配对血清小也可检出ＥＨＦ病毒抗原、抗体及循环免疫复合物。组织及血清免疫复合物形成与血清补体Ｃ３水平下降有关,组织内肥大细胞脱颗粒与血清ＩｇＥ水平升高相关,提示多种变态反应参与了流行性出血热的发病机制。