Generation of selectable marker-free soft transgenic rice with transparent kernels by downregulation of SSSⅡ-2

The amylose content(AC) of rice endosperm starch varies from 0 to 35%,and is associated with rice cooking and eating quality.Soft rice has low AC,generally between 6% and 15%,and its eating quality is high whether it is consumed hot or cold.However,the appearance quality of current soft rice cultivars needs to be improved,especially opaque endosperm.Conventional genetic engineering has improved some agronomic traits of soft rice varieties,but not endosperm appearance.In the present study,a RNAi construct of the soluble starch synthase Ⅱ-2(SSSⅡ-2) and the hygromycin phosphotransferase(HPT) gene were introduced into an elite japonica rice variety,Kangtiaowuyunjing(KWY8) by co-transformation.Several selectable marker-free(SMF) transgenic lines were obtained,and SSSⅡ-2 expression was significantly downregulated in selected transgenic lines,resulting in lower AC of the endosperm.The physicochemical properties of the transgenic rice kernels,including gel consistency(GC) and rapid visco analyzer(RVA) profile,differed significantly from those of wild-type rice and were similar to those of a soft rice variety,Nanjing 46(NJ46).These findings indicate that the cooking,eating,and processing qualities of transgenic rice are comparable to those of NJ46.However,the transgenic rice endosperm retained a transparent appearance under low-moisture conditions.Thus,SMF SSSⅡ-2 RNAi rice provides a resource for breeding soft rice with transparent endosperm.

Advances in prostate cancer research models:From transgenic mice to tumor xenografting models

The identification of the origin and molecular characteristics of prostate cancer(PCa)has crucial implications for personalized treatment.The development of effective treatments for PCa has been limited;however,the recent establishment of several transgenicmouse lines and/or xenografting models is better reflecting the disease in vivo.With appropriate models,valuable tools for elucidating the functions of specific genes have gone deep into prostate development and carcinogenesis.In the present review,we summarize a number of important PCa research models established in our laboratories(PSA-Cre-ERT2/PTEN transgenic mouse models,AP-OX model,tissue recombination-xenografting models and PDX models),which represent advances of translational models from transgenic mouse lines to human tumor xenografting.Better understanding of the developments of these models will offer new insights into tumor progression and may help explain the functional significance of genetic variations in PCa.Additionally,this understanding could lead to new modes for curing PCa based on their particular biological phenotypes.

Selection of Homozygous Cotton Lines Transformed with Two Insect-Resistant Genes

A plant expression vector containing a chimeric Bt29K gene coding for the activated Cry1Ac protein and the arrowhead proteinase inhibitior gene API B were introduced into the cotton cultivar Jihe321 mediated by Agrobactertium tumefaciens. Based on the results of kanamycin resistant testing, PCR detection for both foreign genes and insect bioassay using Heliethis armigera , nine transgenic homozygous cotton lines with insect resistance of more than 90% and better agronomic traits were bred through six generations from the original transgenic plants. Results from insect bioassay and sequence analysis of the PCR products of plants from some homozygous lines indicated that the chimeric Bt29K gene was stably inherited in these transgenic cotton lines. The main agronomic characters of these homozygous cotton lines, such as boll productivity and fibre strength, were better than that of the original cotton cv. Jihe321.

See the color,see the seed:GmW1 as a visual reporter for transgene and genome editing in soybean

A fast and efficient recognition method of transgenic lines will greatly improve detection efficiency and reduce cost.In this study,we successfully identified the transgenic soybean plants by the color.We isolated a GmW1 gene encoding a flavonoid 3'5'-hydroxylase from a soybean cultivar ZH42(purple flower).We found that purple flowers occurred in the overexpression lines in the Jack and Williams 82 backgrounds(white flower).All plants with purple flowers were positive,and this trait seems stably inherited in the offspring.We have also obtained the editing plants,which were classified into three types according to the different flower colors appeared.We analyzed the phenotype and the homozygous types of the T_1mutants.We also found that a correspondence between flower color and stem color.This study provides a visible color reporter on soybean transformation.It can be quickly and early to identify the transgenic soybean plants by stem color of seedlings,which substantially reduces the amount of labor and cost.

Generation of two transgenic amphioxus lines using the Tol2 transposon system

Amphioxus or lancelets are regarded as a promising model animals for studying developmental mechanisms in chordates, and the evolution of vertebrate characters, because of their important phylogenetic position and their genomic and anatomical simplicity （Bertrand and Escriva, 2011; Holland and Yu, 2004）.

Rapeseed Breeding for Quality Character in Hunan Province

Eight single-low or double-low rapeseed cultivars were bred from 1980 to 2000 in Hunan Province. In this paper, characters and breeding method of these cultivars are introduced.

STABLE EXPRESSION OF HUMAN CYTOCHROME CYP2B6 AND CYP1A1 IN CHINESE HAMSTER CHL CELLS:THEIR USE IN MICRONUCLEUS ASSAYS

With specific designed prmers. CYP2B6 and CYP1A1 cDNA were generatecl by reverse transcrlI7tion-Polymerase chain reaction(RT-PCR )technlque Performed on total RNAs isolated frorn hum1ln liver and 3-rnethylch(,lanthrene(3-Mtt)induc human amnion FL, cells. Cell llnes (CHL, 2B6 and CtHL-1A1 ) capableof expressing hunlan cytochome P 15O (CYP ) 2B6 and 1A1 were establishecl after transfection of corre-sponding eukaryotic reconlbinant expression plasmid with human CYP2ll6 and 1A1 cDNA lnserts respectlvely. These cell lines stably expressed the mRNAs and the enzymatic activltles cc)rresI’onding to ttYP2B6and CYP1A1, respectively’ Compared with Chinese hamster lung (CHL) cells, the n1icr()nucleus frecluencyin CHl,-2B6 cells is markedly lncreased when exPosed to nitrosamines,aflatoxln B, (AFB1) and cyclophos-Phamide (CPA). Thls is also in CHL-1A1 cells,when exposed to carcinogenic polycycllc aromatic hydrocar-bons.