The construction of the sorghum (Sorghum bicolor L. Moench) molecular genetic linkage map started in the early 1990s. Molecular genetic maps with a high density of markers covering almost the entire sorghum genome have been completed and integration of a sorghum genetic and physical map is under way. The correlation between genetic linkage groups and relevant chromosomes was established and the locations of the important structures of chromosomes, such as centromeres, long and short arms, nucleolus organizer region (NOR), etc., have been identified on the linkage groups. Molecular cytogenetic mapping of each chromosome has been advanced substantially. With continuing progress in the field, sequencing of the full sorghum genome and study of sorghum functional genomics will be initiated soon.

Segregation distortion, identified as a strong evolutionary force, is common in genetic mapping research. In plants, the percentage, degree, origin and genetic effects of segregation distortion vary significantly with species, population types, crosses and marker types. The exhibition, common features, causes, methods of mapping segregation distortion loci, effects of segregation distortion on map construction and corresponding mapping strategies in plants, mainly in crops, are reviewed in this paper.

A recombinant enhancin from Trichoplusia ni granulovirus, expressed in Escherichia coli and named P96, had been shown in a previous study to increase significantly the efficacy of bio-insecticides applied to insect pests. Here, several biological characteristics were clarified to provide further proof for the activities of P96. The inclusion bodies formed by P96 were quite stable when expressed in E. coli; however, they could be effectively dissolved in sodium carbonate (Na2CO3) solution or in the midgut digestive secretion of the fifth-instar larvae of the cotton bollworm, Helicoverpa armigera, in vitro. According to sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS-PAGE), the peritrophic membrane of the cotton bollworm was clearly decomposed by P96. With the increase of P96 concentration, the mortality of the cotton bollworm caused by nuclear polyhedrosis virus increased up to its saturation concentration, 6.76×105 inclusion bodies/ml. The bioactivity of P96 was strongly inhibited by ethylenediaminetetraacetic acid (EDTA), which formed a complex compound with the metal ion (Zn2+) in the protein.

We have developed and applied an immunoassay method to detect genetically modified (GM) rape containing phosphinothricin acetyltransferase (PAT). The purified PAT was identified by Western blotting and enzymic activity analysis. The polyclonal antibody against purified PAT protein was obtained and purified by both a saturated ammonium sulphate method and protein A-Sepharose 4B. The sensitivity and cross-reactivity of the polyclonal antibody has been demonstrated in an enzyme-linked immunosorbent assay (ELISA). The result of the ELISA for antiserum sensitivity was about 2×10−5 mg/ml and the cross-reactivity determined experimentally showed a high degree of specificity for the antiserum used, because values were all less than 0.1%. Detection of transgenic plants was evaluated using two transgenic rape lines (MS1/RF1 and MS8/RF3) which could be easily distinguished by ELISA.

Primordial germ cells (PGCs) were isolated from the genital ridges of chicken (Gallus domesticus) embryos at the 19th stage and purified by Ficoll density-gradient centrifugation. PGCs were co-cultured with somatic cells in preliminary culture and subcultured. Identification of PGCs was carried out by histochemical methods, including alkaline phosphatase (AKP) and periodic acid–Schiff (PAS). The proliferating activity of PGCs in subculture was demonstrated by immunocytochemistry of proliferating cell nuclear antigen (PCNA). Meanwhile, proliferating PGCs were compared under different culture conditions of 5–20% fetal cattle serum (FCS), insulin–transferrin–selenite (ITS) medium, conditioned medium (CM), 15% FCS+ITS, 15% FCS+40% CM. The results showed that the cultured PGCs were positive for AKP and PAS staining and displayed intensive proliferating activity by PCNA. The PGCs without centrifugation grew better than those with centrifugation. The PGCs formed larger colonies in media with 5% FCS or ITS than other media, indicating that 5% FCS or ITS supplemented media could be an ideal culture system for PGC proliferation in the PGC-somatic cell co-culture, in addition to the embryonic fibroblast feeder layer.

Random amplified polymorphic DNA (RAPD) analyses were performed with random primer H16 for the B biotype and two non-B populations of Bemisia tabaci collected from Zhejiang (China). The specific sequence fragments containing 446, 390 and 1317 nucleotides were amplified for the B biotype, ZHJ-1, ZHJ-2 populations, respectively. The three specific fragments were cloned and sequenced, and three pairs of SCAR primers were designed according to the sequences determined. With improvement of the conditions of the polymerase chain reaction (PCR), the specific fragments of B biotype, ZHJ-1 and ZHJ-2 populations, namely 439, 366 and 1238 nucleotides, respectively, were amplified with the sequence characterized amplified region (SCAR) primer of the corresponding population, while specific fragments of the other populations of B. tabaci or Trialeurodes vaporariorum could not be amplified.

The widely used processing method for cDNA microarray data involves background correction, log-ratio transformation and data normalization before the statistical testing can be done. Here we propose a method that avoids the log-transformation step in view of its drawbacks, but goes directly to normalization after background correction. This method could better estimate the ‘noise’ effect by utilizing the information more effectively. Simulation studies were carried out to compare the feasibility and efficiency of this approach for eliminating experimental ‘noise’ with the log-ratio approach. Results showed that our approach worked well and the method was more robust and powerful than the log-ratio approach.

Medium-chain-length polyhydroxyalkanoates (mcl-PHAs) belong to the group of microbial polyesters. The key enzyme for mcl-PHA biosynthesis is type II PHA synthase. The gene phaC2 encoding type II PHA synthase was placed under the control of psbA-pro and psbA-ter of rice (Oryza sativa) to construct a phaC2 cassette, which was ligated with the screening marker gene aadA cassette (prrn–aadA–TpsbA-ter). These recombined fragments were cloned between the plastid rbcL and accD genes for targeting to the large single copy region of the chloroplast genome. A chloroplast transformation vector, pTC2, was constructed and introduced into the tobacco (Nicotiana tobacum) chloroplast genome by particle bombardment. PCR and Southern blot analysis confirmed stable integration of phaC2 into the chloroplast genomes of T0 and T1 transgenic plants, and T1 transgenic plants exhibited homoplasmy. The expression of phaC2 at transcription level was detected by reverse transcriptase–polymerase chain reaction (RT-PCR). Recombinant transgenes in the tobacco chloroplast genome were maternally inherited and were not transmitted via pollen when out-crossed with untransformed female plants. To our knowledge, this is the first report on the stable transformation of phaC2 encoding type II PHA synthase in tobacco via chloroplast genetic engineering.

The highly conserved DNAs of Equine herpesvirus-1 (EHV-1), Equine arteritis virus (EAV), Equine influenza virus (EIV), Equine infectious anaemia virus (EIAV) and Eastern equine encephalomyelitis virus (EEEV) were acquired by molecular cloning, and spotted on the diagnostic gene chip. The cDNAs reverse-transcribed from RNAs of samples were labelled with Cy5-dUTP/Cy3-dUTP as fluorescent probes. Following specific hybridization of the deposited gene chip and labelled probes, fluorescence signals were scanned by laser scanner and the resulting image was analysed by QiamtArray software on a digital computer. The results showed that the prepared gene chip could detect and distinguish the five equine viruses. Its sensitivity was about 25 viral genome copies. The hybridization specificity was confirmed by the presence of red fluorescence signals on the corresponding sites with samples from the five relevant viruses in horses and by the absence of positive signals with the specimens from irrelevant viruses from other animals. Peripheral blood leucocytes (PBL) from some seropositive horses in post-arrival quarantine were negative according to virus isolation, but were positive for EHV-1 and EAV according to the gene chip technique. The overall results suggest that gene chips, which are quick, specific, sensitive and reliable, can provide a practical alternative for screening quarantined animals, and will be able to deal with a large number of animal samples within a very short period of time.

Two microsatellite markers OarHH35 and BMS2508, closely associated with high levels of reproduction in sheep, were analysed for polymorphisms in Xiangdong black goat, Nanjiang brown goat, Guizhou black goat and Boer goat. The number of alleles for OarHH35 was 11, 8, 7 and 10, respectively, in the four goat breeds. That for BMS2508 was 9, 5, 6 and 7. The polymorphic information content (PIC) values for OarHH35/BMS2508 in the above-mentioned goats were respectively 0.8294/0.8047, 0.8399/0.6894, 0.7985/0.6910 and 0.8582/0.7688. By analysing the dominant effect of the two microsatellite markers on litter size of Xiangdong black goat, it was shown that microsatellite markers BMS2508 and OarHH35 significantly influenced (P<0.05) litter size of goats. At the OarHH35 locus, the least squares means (LSM) of genotype 135/135 bp was the highest (3.67 number born/litter). Moreover, LSM of genotypes 123/135 bp and 125/125 bp also reached 3.00 kids born/litter, indicating that alleles 135 bp and 125 bp exerted a significant positive effect on the litter size in Xiangdong black goat. At the BMS2508 locus, LSM of genotypes 132/145 bp and 93/132 bp for litter size was 4.00 and 3.25 kids born/litter respectively, but that of genotype 122/122 bp for litter size was only 1.00 kid/litter, so alleles 145 bp and 93 bp had significant positive effects on the litter size of Xiangdong black goat, and the allele 122 bp had a significantly negative effect.

Recombinant Bac-GV2 DNA was obtained by inserting a fused gfp gene with the Bacillus thuringiensis vip2A(c) gene encoding a possible enzymatic component under the control of the polyhedrin gene promoter of the baculovirus Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV). The Trichoplusia ni cell line TnHi5 was transfected with Bac-GFP and Bac-GV2 DNAs respectively. Fluorescent cells expressing the fusion protein GV2 were much fewer than those expressing green fluorescent protein (GFP) alone, and did not obviously increase in number from 2 to 5 days after transfection. This result showed that the Vip2A fusion protein might have an ADP-ribosylating activity on cell skeleton actin, exerting an influence on the production and diffusion of the budded virus from insect cells.

According to the sequence of Rccn4, which is highly similar to the nucleotide-binding site (NBS) coding region of the cereal cyst nematode resistance gene, Cre3, three 3′ nested primers were designed to amplify its 3′ flanking region through single oligonucleotide nested polymerase chain reaction (SON-PCR). One 1264 bp band, Rccn-L, was amplified from E-10, a wheat–Aegilops variabilis translocation line containing the cereal cyst nematode resistance gene from Ae. variabilis. Sequence analysis showed that Rccn-L possesses the 3′ flanking sequence of Rccn4 and contains a 55 bp-sized consensus sequence with Rccn4. The coding region was 1026 bp, consisting of an incomplete open reading frame, a terminator codon and no initiation codon and intron; it encoded a peptide of 342 amino acid residues and shared 86% nucleotide sequence identity with Cre3. The peptide had a conserved leucine-rich repeat (LRR) domain, containing the imperfect repeats, XXLXXLXXL, comprising 17% leucine residues, and shares, respectively, 89% nucleotide sequence and 78% amino acid sequence identity with the LRR sequence of the Cre3 locus. In the present study, SON-PCR was used successfully, for the first time, in plant genome research and proved to be a valuable method in plant gene cloning. The acquirement of Rccn-L established the foundation for obtaining the complete Rccn gene and further structural and functional investigations.

In order to investigate the molecular mechanism of rehydration after serious drought in broomcorn millet (Panicum miliaceum L.), a forward subtracted cDNA library was constructed between normal watered leaves and rehydrated leaves after serious drought conditions, using the suppressive subtraction hybridization (SSH) technique. A total of 60 positive clones were picked out at random from the subtracted library and sequenced, and redundancy sequences were removed after sequence alignment. Based on the results of sequence homologous comparison and function querying, 32 expressed sequence tags (EST) were highly homologous with known ESTs. Most of those sequences were related to either abiotic or biotic stress in plants. Of those sequences, 11 ESTs were homologous with ESTs in rat (Rattus norvegicus) liver after partial hepatectomy. The Blast result of proteins revealed that 28 ESTs were similar to known proteins. The functions of these proteins mainly involve signal transduction, transcription and protein processing. This experiment demonstrated that a range of specific genes was induced and expressed in broomcorn millet during the rehydration stage after serious drought.

The molecular genetic characteristics were evaluated, and the genetic effects of marker loci on heterosis of three traits (birth weight, BWT; average daily gain, ADG; and feed and meat ratio, FMR) were analysed in the experimental pig populations: Yorkshire (Y, n=34), Landrace (L, n=46) and Meishan (M, n=55); Yorkshire×Landrace (YL, n=32) and its reciprocal (LY, n=36), Yorkshire×Meishan (YM, n=82) and its reciprocal (MY, n=47), by 39 microsatellite markers selected from pig chromosomes SSC4, 6, 7, 8 and 13. The results indicated that observed alleles ranged from 2 to 6, average 4.13, observed heterozygosity varied from 0.39 (Y) to 0.58 (YM+MY) and average polymorphism information content (PIC) varied from 0.33 (Y) to 0.5 (YM). There were two loci (sw2155 and sw1037) at which the alleles were fixed in Y and L, and there were three loci (sw2409, sw2454 and sw1691) at which the alleles were fixed in M. The results from heterozygosity and kinship analysis revealed an intrinsic genetic relationship among the seven populations. Furthermore, the results on genetic effect analysis indicate that several marker loci had a significant effect on heterosis of the three traits in the two different F1 crossbred populations (P⩽0.01), for example s0161, swr1130 and sw1856 for BWT, sw1856 and swr2036 for ADG, and sw1302 and swr2036 for FMR. The significant marker loci implied a deep genetic relationship between molecular marker loci and heterosis.