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.

With the development of plant genetic engineering, many transformation methods can be used to transfer heterogeneous genes into plants to develop genetic crops. However, a lot of research results have shown that transgene expression remains largely unpredictable and there is great variation of expression level in different transgenic plant lines. Plant genetic engineering research is reviewed in the present paper. We analysed the reasons why low efficiency of heterogeneous gene expression has happened in transgenic plants in terms of DNA modification, localization of proteins and methods of transformation used. Some strategies for improving heterogeneous gene expression in transgenic plants are also discussed.

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.

Fifty-eight actinomycetes were isolated from surface-sterilized tomato (Lycopersicon esculentum) roots and 43 isolates were screened for herbicidal activities. Isolate S5 was found to have potent herbicidal activity against germination of wheat (Triticum aestivum L.), mung bean (Phaseolus radiatus L.) and grass (Paspalum notatum and Cynodon dactylon) seeds. But the metabolites of isolate S5 showed no influence on the growth of wheat seedlings. The S5 strain was identified as Streptomyces lavendulae var. glaucescens based on its morphological characteristics and physiological properties. The highest herbicidal activity was observed when 2% inocula were applied into S medium (containing 1% glucose, 0.3% beef extract and pH 7.0) and incubated at 25°C on a rotary shaker (160 rpm).

The microsatellite, or short sequence repeat (SSR), is a powerful genetic marker, useful in many areas of fish genetics and breeding. Polymorphic microsatellite loci have been frequently applied to the analysis of genetic diversity, population genetic structure, and genomic mapping. These co-dominant markers have also been applied to the classification and systematics, parentage identification, germplasm conservation, and breeding programme of food fish.

Pancreases obtained from 1–9-day-old rabbits were digested with 1 mg/ml ?? collagenase and cultivated with low-glucose Dulbecco's modified Eagle's medium (DMEM). The cells were subcultured almost until confluence. They were identified as pancreatic stem/progenitor cells using two methods: an immunohistochemical staining technique and the response of glucose-stimulated insulin secretion after β-cell induction. Results showed that the cells of rabbits acquired strong proliferation ability, and expressed the markers of pancreatic stem/progenitor cells: PDX-1, CK19 and nestin. After β-cell induction for 2 days, 20% of cells were dithizone (DTZ) positive, rapidly increasing to 80% after 6 days. Insulin secretion was stimulated by a high glucose concentration (26 mmol/l). These powerful tests demonstrated that isolated and cultivated cells in rabbits were pancreatic stem/progenitor cells. This result has not yet been reported elsewhere.

The cloning and sequencing of two specific molecular markers linked to grape (Vitis vinifera) seedless gene indicated that the full lengths of the markers, 39970524-5-564 (GenBank accession number: AY327513) and 39970524-6-1538 (GenBank accession number: AY327514), were 564 bp and 1538 bp, respectively. The restriction sites of sequences 39970524-5-564 and 39970524-6-1538 were analysed with Wingene231 software. The results indicated that there were 29 and 130 restriction sites in 39970524-5-564 and 39970524-6-1538, respectively, digested by restriction enzymes with recognition sites of six or more than six bases. There was no cleavage site in 39970524-5-564 and there was one site at 135 bp of 39970524-6-1538 when these two markers were digested by EcoRI. Both markers can not be digested by HindIII. Therefore, the full length of 39970524-5-564 and of the two bands of 39970524-6-1538 (1400 bp and 135 bp) could be cut out from the pGEMR-T Easy Vector by EcoRI. The labelled DNA of 39970524-5-564, used as a probe for Southern blotting with genomic DNA from Red Globe, Flame Seedless, Thompson Seedless, four seedless hybrids and three seeded hybrids, showed a unique hybrid band present in all seedless individuals, but absent in all seeded individuals. It was further indicated that the specific marker 39970524-5-564 was derived from the genome of seedless grapes.

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.

In vitro development of goat embryos obtained by fertilizing oocytes using intracytoplasmic sperm injection (ICSI) was investigated. The results showed that the blastocyst rate was significantly higher (P<0.05) when the embryos were co-cultured with granular cells (GCs) in media CR1aa supplemented with 10% bovine follicular fluid (BFF) (22.2%) than with 5% (13.1%) and 15% BFF (2.7%). When embryos were co-cultured with GCs in SOFaa media, the highest blastocyst rate was obtained from supplementation with 10% BFF (25.1%), which was significantly different from 5% (12.9%) and 15% BFF (3.0%) groups. When 10% BFF and fetus bovine serum (FBS) were added into CR1aa or SOFaa media, the goat ICSI blastocyst rates were 22.6 and 26.9% or 5.8 and 6.1% respectively. These results suggest that both CR1aa and SOFaa could be used as culture media for goat ICSI embryos, 10% BFF could significantly increase the blastocyst rate and BFF was more efficient than FBS for the early in vitro development of goat ICSI embryos.

The effects of hormone additions at various stages and different basic media, with or without serum, on porcine oocyte maturation in vitro were studied. The results showed that the rate of maturation was not significantly different with three different stages of hormone supplement; the rate of maturation on modified TCM199 medium (54.01%) was higher than that on TCM199 (46.16%) and (47.14%), but these differences were not significant; and the rate of maturation on serum-free medium (67.10%) was significantly higher than that on medium plus serum (52.22%). Therefore, modifed tissue culture medium 199 (mTCM199)+10I U/ml pregnant mare serum gonadotrophin (PMSG)+10I U/ml human chorionic gonadotrophin (hCG)+2.5 IU/ml follicle stimulating hormone (FSH) was a suitable medium for culture of porcine oocytes in vitro, and the rate of maturation was 67.10%.

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.

An amplification fragment length polymorphism (AFLP) molecular linkage map with a relatively high density for location of quantitative trait loci (QTLs) controlling the quantitative traits of silkworm (Bombyx mori) cocoons, was constructed using 91 individuals of the F2 generation. Among the 692 effective loci, 550 were allocated to subgroups a and b, of which 21 linkage groups in subgroup a had 233 molecular markers and 28 linkage groups in subgroup b had 317 markers. The number of markers on each linkage group in subgroups a and b ranged from 4 to 43 and 3 to 35, respectively. The total length of linkage groups for subgroup a was 1868.10 cM, and 2677.50 cM for subgroup b. The length of linkage group varied from 22.3 to 424.3 cM in subgroup a and from 2.4 to 366.5 cM in subgroup b. The average variation in the distance between markers was 3.39–17.43 cM in subgroup a and 0.8–26.96 cM in subgroup b. The average distance between the markers was 8.81 cM in subgroup a and 9.26 cM in subgroup b. There were 14 linkage groups, with an average distance below 10 cM, in subgroup a and 18 linkage groups in subgroup b. There were seven linkage groups with an average distance between 10 and 20 cM in subgroup a and ten linkage groups in subgroup b. Each linkage group in subgroup a had 11.1 loci on average, while there were 11.31 loci on each linkage group on average in subgroup b. The mean length for linkage groups in subgroups a and b was 89 and 95.6 cM, respectively. The total average length for both a and b subgroups was 2272.8, and 9.06 cM for the average marker distance, fulfilling the basic known requirements for locating QTLs.

The genetic variations of the 5′-upstream region and the second intron of the porcine H-FABP gene were investigated by polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) in 256 pigs, including Duroc, Large White, Landrace, Neijiang, Rongchang, Bamei pig, Hanjiang Black, Hanzhong White, and wild pigs. The effect of the H-FABP gene on intramuscular fat (IMF) content was analysed by the least square method. Results showed a HinfI-RFLP in these eight pig breeds and wild pigs, among which Large White, Bamei pig, Hanjiang Black, Hanzhong White and wild pigs presented low polymorphism, while the other breeds had intermediate polymorphism. There were no HaeIII or MspI-RFLPs in the four Chinese local pig breeds tested, but Duroc, Landrace, Large White, Hanzhong White and wild pig displayed polymorphism. Landrace, Large White and wild pigs had low levels of HaeIII- and MspI-RFLP, while the others had intermediate polymorphism. H-FABP genotypes significantly affected IMF content (P<0.05). IMF content according to H-FABP genotypes were HH>Hh>hh, DD<Dd<dd, AA<Aa<aa. The genetic effect values were 3.95 (HH), 3.48 (Hh), 3.23 (hh), 2.33 (DD), 2.55 (Dd), 2.97 (dd), 2.34 (AA), 2.76 (Aa) and 3.01 (aa). Results suggest that porcine meat quality may be improved by increasing the frequency of genotype aa-dd-HH in pig breeds.

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.

Sox9 is one of the important genes related to sex differentiation and determination. Two partial cDNAs encoding sox9 were derived from brain, testis and ovary of yellow catfish Pelteobagrus fulvidraco using reverse transcriptase-polymerase chain reaction (RT-PCR). Sequence analysis revealed that the ovarian sox9a2 was different from sox9a1 derived from brain and testis. The identity rate of cDNA was 77%, that of amino acids was 84%, and the different nucleotides were distributed in different sites all over the cDNA. This finding confirmed that there were transcripts from two genes. Based on the homology of the amino-acid sequences for sox9 of other animals, the similarity for sox9a1 from yellow catfish and sox9 of other animals averaged 86%. The similarity for sox9a2 reached a mean of 83%. The phylogenetic analysis revealed yellow catfish sox9a1 and sox9a2 were clustered into the fish branch. And yellow catfish sox9a2 was different from the other fish sox9. There was no significant branch including all sox9 derived from testis and brain or including all ovarian sox9. The genetic distance was the same with the results of the traditional taxonomy. RT-PCR analysis indicated that sox9a1 was expressed in male and female yellow catfish forebrain as well as in gonads, whereas sox9a2 was only expressed in ovaries. The function of sox9a2 in female sex formation and ovary development needs to be studied in depth.

Using four oilseed rape (Brassica napus L.) F1 hybrids (7039, 7040, 282 and 5102) as donor plants for microspore culture, the experiment was conducted to select glyphosate- and haloxyfop-resistant embryos through application of these substances to the cultural media with microspore-derived embryos in vitro. Genotypes 7039 and 7040 were used to select glyphosate-resistant regenerated plants, and genotypes 282 and 5102 to select haloxyfop-resistant plants. The embryos at cotyledonary stage were grown on glyphosate- and haloxyfop-containing MS-2 medium for 2 weeks. The non-resistant embryos collapsed after a short time, while the resistant ones turned green and survived for 2 weeks. Transferred into the normal MS-2 medium for further plant regeneration, the regenerated plants from green embryos showed tolerance to 0.25% sprayed glyphosate, indicating the effectiveness and reliability of this in vitro selection method. When the regenerated plants selected from 0.02% haloxyfop were sprayed with 0.05% haloxyfop, most of them grew well; however, the survival rate of the regenerated plants from 0.01% haloxyfop-containing medium was lower. The present experiment indicates that the use of 0.02% haloxyfop in the selection of haloxyfop-resistant plants was more promising than that of 0.01%. The chromosome doubling efficiency of regenerated plants reached 34% and 52% after being treated with 170 mg/l colchicine for 20 and 30 h, respectively.

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.

Bovine mastitis caused by Streptococcus agalactiae is mainly subclinical and therefore can be diagnosed only in the laboratory. A nested polymerase chain reaction (PCR)-based method for specific, sensitive and rapid detection of S. agalactiae in raw milk was developed. The general streptococci primers, which anneal to conserved areas within the 16S rRNA subunit gene, were used as positive controls. The specificity of S. agalactiae primers is based on various areas within conserved areas of the 16S rRNA genes of S. agalactiae. Results have indicated that the method enables the detection of 1 CFU/ml of S. agalactiae in raw milk after enrichment, followed by DNA extraction using a rapid and simple procedure developed for this purpose, and specific PCR reaction. The method developed can be used efficiently in the early infectious status investigation of S. agalactiae in the dairy herd and in prevention and control of S. agalactiae spread in a herd.

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.