mRNA Differential Display Technique Research Articles

A putative miR172-targeted CeAPETALA2-like gene is involved in floral patterning regulation of the orchid Cymbidium ensifolium.

APETALA2 plays critical roles in establishing meristem and organ identity during plant floral development. In this study, we obtained a CeAP2-like gene by using the mRNA differential display technique to analyze the wild type and a multitepal mutant of the orchid Cymbidium ensifolium. The full-length cDNA encoding the CeAP2-like transcription factor shows significant similarity to the cDNA of AP2 from Erycina pusilla and contains nucleotides complementary to miR172. Using a transient gene expression system of Arabidopsis protoplasts, we found that the accumulation of CeAP2-like protein and transcripts was negatively regulated by miR172, indicating this gene as a putative target of miR172. Northern blotting revealed that CeAP2-like is dominantly expressed in the sepals and petals of the wild-type flower, and shows low expression in the gynostemium. In contrast, the accumulation of CeAP2-like transcripts decreased significantly, especially in the central part of the mutant flower, corresponding to its abnormal petals and the absence of the gynostemium. Furthermore, we found an antagonistic expression pattern between CeAP2-like and AGAMOUS in the wild type, representing A- and C-class genes that specify floral organ fate. However, this antagonistic distribution was modified in the multitepal mutant, and both genes showed lower expression than that in the wild type. This result suggested that the balance between CeAP2-like and AGAMOUS activity was important for the regulation of floral patterning in C. ensifolium. This study represents the first report on a class A gene and its regulatory role for floral development in the orchid C. ensifolium.

Primarily screening and analyzing ESTs differentially expressed in rats' primary liver cancer.

To screen and analyze key express sequence tags (ESTs) which were differentially displayed in every period of SD rats' primary hepatic carcinoma and reveal the molecular mechanism of carcinogenesis. Using diethylnitrosamine (DENA) as a cancerigenic agent, animal models with different phases of primary hepatic cancer were constructed in SD rats. Rats were respectively sacrificed at d 14, d 28, d 56, d 77, d 105 and d 112 after the rats received DENA by gavage, then the livers were harvested. One part of the livers was classified according to their pathological changes, while the other was reserved for molecular mechanism studies on hepatocarcinogenesis. The differentially expressed genes were isolated from both normal and morbid tissues by mRNA differential display technique (DDRT-PCR). After the fragments were sequenced, bioinformatics were used to analyze the results. Twelve differentially expressed cDNA fragments were obtained. Nine fragments had the homology with known cDNA clones, especially EST-7 was similar to BN/SsNHsdMCW mitochondrion gene and the identity was 100% which suggested EST-7 may be the part of BN/SsNHsdMCW mitochondrion gene. In contrast, other three fragments (EST-1, EST-3 and EST-5) had extremely low identity to any genes registered in GENBANK databases. BN/SsNHsdMCW mitochondrion gene was expressed in different periods of hepatocarcinogenesis. Moreover, EST-1, EST-3 and EST-5 were suggested to contribute to the development of rat hepatocarcinogenesis, and thus may be candidates of new targets of oncogenes or cancer suppressor genes.

Screening and cloning of differentially expressed genes in Dendrobium nobile induced by orchid mycorrhizal fungus promoting the growth

Appropriate mycorrhizal fungi could effectively promote plant growth and development. Our previous research results showed that the growth of Dendrobium nobile was obviously promoted under inoculating one orchid mycorrhizal fungi, Epulorhiza sp. AR-18. To understand the growth-promoting molecular mechanisms, differential displayed real time polymerase chain reaction (DDRT-PCR), reverse Northern blot and Southern blot were used to isolate and identify genes whose transcription were altered in cultured D. nobile plants that were treated with Epulorhiza sp. AR-18. Amplified by 8 primer combinations from one anchor primers and 8 random primers, a total of 14 complementary DNA (cDNA) fragments including 12 differentially expressed cDNA bands were isolated. Reverse northern blot analysis showed that only 2 genes were differentially displayed cDNA bands. One band was an especially expressed fragment, expressed in the treated group but not in the control; while another was a differentially expressed fragment, weak in the treated and strength in the control. Southern blot analysis demonstrated that the two gene fragments were from the plant and not from the fungus. Sequence analysis and database searches revealed no significant homology to any known sequences. The results suggested that the usefulness of messenger RAN (mRNA) differential display technique for the detection of differentially expressed genes in D. nobile whose growth could be promoted by mycorrhizal fungi. Keywords: Dendrobium nobile , differential displayed real time polymerase chain reaction (DDRT-PCR), orchid mycorrhizal fungus, Epulorhiza sp., reverse northern blot

A novel porcine gene, POT1, differentially expressed in the longissimus muscle tissues from Wujin and Large White pigs

The mRNA differential display technique was performed to investigate the differences of gene expression in the longissimus muscle tissues from Wujin and Large White pigs. One novel gene differentially expressed was identified through quantitative real time PCR and the cDNA complete sequence was then obtained using the rapid amplification of cDNA ends (RACE) method. The nucleotide sequence of the gene is not homologous to any of the known porcine genes. The sequence prediction analysis revealed that the open reading frame of this gene encodes a protein of 507 amino acids that shares high homology with the protection of telomeres 1 isoform 4 (POT1) of human (86%)—so that this gene can be defined as swine POT1 gene. This gene is structured in 12 exons and 11 introns as revealed by computer-assisted analysis. The tissue expression analysis indicated that the swine POT1 gene is differentially expressed in tissues including muscle, heart, liver, fat, kidney, lung, pancreas and spleen. Our experiment is the first to establish the primary foundation for further research on the swine POT1 gene.

Cellular transcripts of chicken brain tissues in response to H5N1 and Newcastle disease virus infection

BackgroundHighly-pathogenic avian influenza (HPAI) H5N1 and Newcastle disease (ND) viruses are the two most important poultry viruses in the world, with the ability to cause classic central nervous system dysfunction in poultry and migratory birds. To elucidate the mechanisms of neurovirulence caused by these viruses, a preliminary study was design to analyze host's cellular responses during infections of these viruses.MethodsAn improved mRNA differential display technique (Gene Fishing™) was undertaken to analyze differentially expressed transcripts regulated during HPAI H5N1 and velogenic neurotropic NDV infections of whole brain of chickens. The identification of differentially expressed genes (DEGs) was made possible as this technique uses annealing control primers that generate reproducible, authentic and long PCR products that are detectable on agarose gels.ResultsTwenty-three genes were identified to be significantly regulated during infections with both viruses, where ten of the genes have been selected for validation using a TaqMan® based real time quantitative PCR assay. Some of the identified genes demonstrated to be key factors involving the cytoskeletal system, neural signal transduction and protein folding during stress. Interestingly, Septin 5, one of the genes isolated from HPAI H5N1-infected brain tissues has been reported to participate in the pathogenic process of Parkinson's disease.ConclusionsIn this limited study, the differentially expressed genes of infected brain tissues regulated by the viruses were found not to be identical, thus suggesting that their neurovirulence and neuropathogenesis may not share similar mechanisms and pathways.

Systemic induction of a Capsicum chinense nitrate reductase by the infection with Phytophthora capsici and defence phytohormones

The mRNA differential display technique was used to identify genes from Habanero pepper (Capsicum chinense Jacq.) seedlings whose expression is modified systemically by infection with the oomycete Phytophthora capsici L. Experiments with different oligonucleotide primer combinations revealed that no single gene was synthesised de novo. Instead, the quantitative accumulation of multiple transcripts was found. From these transcripts, levels of a nitrate reductase (Capsicum chinense nitrate reductase, CcNR), which has a high percentage of identity with other Solanaceae NRs, showed a consistent increase a few hours after inoculation (hai) with P.capsici. Reverse northern blotting revealed the existence of basal levels of CcNR transcripts in different adult tissues; however, systemic levels rose dramatically after spraying seedlings with salicylic acid (SA) and ethephon (ET) but not with methyl jasmonate (MeJa). Both P.capsici and defence phytohormones (DP) also modified NR enzymatic activity (nitrite:NAD(+) oxidoreductase; EC 1.7.1.1) with similar kinetics. Because the application of DP induced and activated the CcNR differentially, it is possible that the activity of CcNR is related to a specific host defence response.

Cellular transcripts regulated during infections with Highly Pathogenic H5N1 Avian Influenza virus in 3 host systems

BackgroundHighly pathogenic Avian Influenza (HPAI) virus is able to infect many hosts and the virus replicates in high levels in the respiratory tract inducing severe lung lesions. The pathogenesis of the disease is actually the outcome of the infection as determined by complex host-virus interactions involving the functional kinetics of large numbers of participating genes. Understanding the genes and proteins involved in host cellular responses are therefore, critical for the elucidation of the mechanisms of infection.MethodsDifferentially expressed transcripts regulated in a H5N1 infections of whole lung organ of chicken, in-vitro chick embryo lung primary cell culture (CeLu) and a continuous Madin Darby Canine Kidney cell line was undertaken. An improved mRNA differential display technique (Gene Fishing™) using annealing control primers that generates reproducible, authentic and long PCR products that are detectable on agarose gels was used for the identification of differentially expressed genes (DEGs). Seven of the genes have been selected for validation using a TaqMan® based real time quantitative PCR assay.ResultsThirty seven known and unique differentially expressed genes from lungs of chickens, CeLu and MDCK cells were isolated. Among the genes isolated and identified include heat shock proteins, Cyclin D2, Prenyl (decaprenyl) diphosphate synthase, IL-8 and many other unknown genes. The quantitative real time RT-PCR assay data showed that the transcription kinetics of the selected genes were clearly altered during infection by the Highly Pathogenic Avian Influenza virus.ConclusionThe Gene Fishing™ technique has allowed for the first time, the isolation and identification of sequences of host cellular genes regulated during H5N1 virus infection. In this limited study, the differentially expressed genes in the three host systems were not identical, thus suggesting that their responses to the H5N1 infection may not share similar mechanisms and pathways.

A novel porcine gene, LIPC, differentially expressed in the liver tissues from Meishan and Large White pigs

The mRNA differential display technique was performed to investigate the differences in gene expression in the liver tissues from Meishan and Large White pigs. One novel gene that was differentially expressed was identified through semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) and the cDNA complete sequence was then obtained using the rapid amplification of cDNA ends (RACE) method. The nucleotide sequence of the gene is not homologous to any of the known porcine genes. The sequence prediction analysis revealed that the open reading frame of this gene encoding a protein of 501 amino acids has high homology with the lipase, hepatic (LIPC) of seven species--cattle (82%), rhesus monkey (79%), chimpanzee (78%), rabbit (77%), human (78%), mouse (73%) and rat (72%)--so that it can be defined as the swine LIPC gene. Phylogenetic analysis revealed that the swine LIPC gene has a closer genetic relationship with the LIPC of cattle. Tissue expression profile analysis indicated that the swine LIPC gene is also differentially expressed in other detected tissues from Meishan and Large White pigs. Our experiment suggested that the swine LIPC gene might play an important role in the superabundant fat deposition of Chinese pigs.

Differential gene expression in leaves and roots of winter rape in response to phosphorus starvation

Genes induced by phosphorus deficiency in leaves and roots of winter rape (Brassica napus) seedlings were isolated and analyzed. The mRNA differential display technique was used to visualize cDNA fragments derived from the phosphorus-tolerant cv. Zy 821 and the phosphorus-sensitive cv. No. 1182 grown under conditions of phosphorous starvation. Approximately 2000 cDNA bands were visualized by differential display using 78 primer pair combinations. A total of 61 phosphorus-starvation-induced cDNA fragments differentially expressed were isolated. Among these, 40 were derived from roots and only 21 from leaves. Sequence analysis of 16 fragments revealed that they represented distinct cDNAs. A subsample of five cDNAs was analyzed by semi-quantitative RT-PCR, which showed that they were truly different products. Transcripts coding for enzymes involved in photosynthesis (thylakoid membrane phosphoprotein) and root hair initiation (xyloglucan endotransglycosylase), and two regulators (RNA-binding/nucleic acid-binding mRNA and a structural constituent of ribosomal mRNA) were found to be differentially expressed. These results show that the mechanism of cv. Zy 821 adaptation to P starvation is complex. Although its P-tolerance trait is controlled by a major gene, many other genes influencing P acquisition and remobilization, carbon and secondary metabolism, developmental processes, and regulatory pathways are also involved.

A Novel Porcine Gene – SLC9A3R2, Differentially Expressed in the Longissimus Muscle Tissues from Meishan and Large White Pigs

The mRNA differential display technique was performed to investigate the differences of gene expression in the longissimus muscle tissues from Meishan and Large White pigs. One novel gene that was differentially expressed was identified through semi-quantitative RT-PCR and the cDNA complete sequence was then obtained using the rapid amplification of cDNA ends (RACE) method. The nucleotide sequence of the gene is not homologous to any of the known porcine genes. The sequence prediction analysis revealed that the open reading frame of this gene encodes a protein of 337 amino acids that has high homology with the solute carrier family 9 isoform 3 regulator 2 isoform a of four species – human (92 %), mouse (91 %), rat (90 %), rabbit (87 %) – so that this gene can be defined as swine SLC9A3R2 gene. The phylogenetic tree analysis revealed that the swine SLC9A3R2 gene has the closest genetic relationship with the SLC9A3R2 gene of human. This gene is structured in seven exons and six introns as revealed by computer-assisted analysis. The tissue expression analysis indicated that the swine SLC9A3R2 gene is differentially expressed in different tissues. Our experiment is the first to establish the primary foundation for further research on the swine SLC9A3R2 gene.

A novel porcine gene, USP7, differentially expressed in the musculus longissimus from Wujin and Large White pigs

The mRNA differential display technique was performed to investigate differences in the gene expression in the <I>musculus longissimus</I> from Wujin and Large White pigs. A fragment of one differentially expressed gene was isolated and sequenced. A complete cDNA sequence was obtained using the rapid amplification of cDNA ends (RACE) method. The sequence prediction analysis revealed that the open reading frame of this gene encodes a protein of 1 103 amino acids, which is homologous with the ubiquitin specific peptidase 7 (<I>USP7</I>) of four species, rat (identity 98%), human (98%), mouse (98%) and chicken (95%), so it can be defined as the porcine <I>USP7</I> gene. The differences in the USP7 gene expression in muscles from Wujin and Large White pigs were confirmed using semi-quantitative RT-PCR. The gene expression analysis in eight tissues of a Wujin × Large White cross showed that <I>USP7</I> was expressed in all the tissues, except for fat.

A novel porcine gene, MAPKAPK3, is differentially expressed in the pituitary gland from mini-type Diannan small-ear pigs and large-type Diannan small-ear pigs

The mRNA differential display technique was performed to investigate the differences of gene expression in the pituitary gland from mini-type Diannan small-ear pigs and large-type Diannan small-ear pigs. One novel gene differentially expressed was identified through semi-quantitative RT-PCR and its cDNA complete sequence was then obtained using the rapid amplification of cDNA ends (RACE) method. Nucleotide sequence of the gene is not homologous to any of the known porcine genes. The sequence analysis revealed that the open reading frame of this gene encodes a protein of 384 amino acids has high homology with the mitogen-activated protein kinase-activated protein kinase 3 (MAPKAPK3) of eight species--cattle (96%), horse (96%), rhesus monkey (93%), rabbit (77%), human (98%), chimpanzee (98%), mouse (94%) and rat (91%)--so that it can be defined as swine MAPKAPK3 gene. This gene was finally assigned GENE ID: 100233192. Computer assisted analysis revealed that the genomic DNA of open reading frame of the swine MAPKAPK3 gene consists of ten exons and nine introns. The phylogenetic tree analysis revealed that the swine MAPKAPK3 gene has a closer genetic relationship with the MAPKAPK3 of cattle. The tissue expression analysis indicated that the MAPKAPK3 mRNA expression levels of large-type Diannan small-ear pigs are ubiquitously increased in various tissues compared to the mini-type Diannan small-ear pigs. Our experiment suggested that the swine MAPKAPK3 gene might play an important role in the growth and development differences between mini-type Diannan small-ear pigs and large-type Diannan small-ear pigs.

Differential display reveals a novel pig gene, PRPF3, which is differentially expressed in Large White versus Wujin skeletal muscle tissues

The mRNA differential display technique was performed to investigate gene expression differences in the longissimus dorsi muscle from Wujin and Large White pigs. A fragment of one differentially expressed gene was isolated and sequenced. A complete cDNA sequence of the gene was obtained using the rapid amplification of cDNA ends method. The open reading frame of this gene encodes a protein of 683 amino acids, which is homologous with the PRP3 pre-mRNA processing factor 3 (PRPF3) of five species: bovine (99%), human (99%), sumatran orangutan (99%), mouse (99%) and chicken (94%). This newly identified gene was respectively defined as the swine PRPF3 gene. This gene is structured in 15 exons and 14 introns as revealed by computer-assisted analysis. The phylogenetic tree analysis revealed that the swine PRPF3 gene has a closer genetic relationship with the PRPF3 gene of sumatran orangutan.

Differential gene expression profiles in embryos of the lizard Podarcis sicula under in ovo exposure to cadmium

Screening for differentially expressed genes is a straightforward approach to study the molecular basis of contaminant toxicity. In this paper, the mRNA differential display technique was applied to analyze transcriptional regulation in response to cadmium exposure in the lizard embryos. Lizard eggs may be particularly susceptible to soil contamination and in ovo exposure may interfere or disrupt normal physiological function in the developing embryo, including regulation of gene expression. Fertilized eggs of the lizard Podarcis sicula were incubated in cadmium-contaminated soil at 25 °C for 20 days. Gene expression profiling showed 5 down- and 9 up-regulated genes. Four cDNAs had no homology to known gene sequences, thus suggesting that may either encode not yet identified proteins, or correspond to untranslated regions of mRNA molecules. Four fragments exhibited significant sequence similarity with genes encoding novel proteins or ESTs derived from other vertebrates. The remaining genes are mainly involved in molecular pathways associated with processes such as membrane trafficking, signal transduction, cytoskeletal organization, cell proliferation and differentiation. Cadmium also affected the expression of factors actively involved in the regulation of the transcription machinery. Down-regulated genes are mainly associated with cellular metabolism and cell-cycle regulation and apoptosis. All of these differentially expressed genes may represent candidates that function in cadmium responses. The present study leads to an increased understanding of genes and/or the biochemical pathways involved in perturbation of embryo development following cadmium exposure.

Molecular cloning, polymorphism and association analyses of a novel differentially expressed porcine mRNA

The mRNA differential display technique was performed to investigate the differences of gene expression in the longissimus muscle tissues from Meishan and Large White pigs. One novel mRNA that was differentially expressed was identified through semi-quantitative RT-PCR and the full-length cDNA sequence was then obtained using the rapid amplification of cDNA ends (RACE) method. The nucleotide sequence of the mRNA is not homologous to any of the known porcine genes. Sequence prediction analysis revealed that this mRNA is no-coding mRNA. Polymorphism analyses revealed that there was a C-T mutation on the position of 505 bp and PCR-HhaI-RFLP analyses revealed that Chinese indigenous pig breeds and exotic pig breeds displayed obvious genotype and allele frequency differences at this locus. Association analyses revealed that this polymorphic locus was significantly associated with the drip loss rate, water holding capacity, dressing percentage, rib numbers, lean meat percentage, estimated lean meat percentage, loin eye width and loin eye area (P < 0.05).

Identification of a differentially expressed gene, ACL, between Meishan × Large White and Large White × Meishan F1 hybrids and their parents

ATP-citrate lyase (ACL), one of the lipogenic enzymes, catalyses the formation of acetyl-coenzyme A (CoA) involved in the synthesis of fatty acid and cholesterol. In pig, very little is known about the ACL gene. In this work, the mRNA differential display technique was used to analyse the differences in gene expression between Meishan and Large White pigs and the F1 hybrids of both direct and reciprocal crosses. Our results show that among the differentially expressed genes ACL is up-regulated in the backfat of the F1 hybrids. After cloning and analysing the fulllength cDNA and the 870 bp 5'-flanking sequence of the porcine ACL gene, a C/T mutation at position -97 bp upstream of the transcription site was detected. Luciferase activity detection showed that this mutation changed the transcriptional activity. In F1 hybrids, the heterozygous genotype CT was more frequent than the homozygous genotypes CC and TT. Real-time PCR analysis showed that in Meishan pigs, ACL mRNA expression was more abundant in individuals with genotype CT than in those with genotype CC or TT or in Large White pigs. These results indicate that the C/T mutation affects ACL mRNA expression, probably via the activator protein 2.

Differential expression of wheat transcriptomes in response to varying cadmium concentrations

This study aims to understand the changes in the transcriptome of durum wheat (Tricitum durum cv. Balcali-85) upon exposure to varying Cd concentrations using mRNA differential display (mRNA DD) technique. Sequence analyses of the two heavily induced genes upon exposure to Cd showed high homology to NADH dehydrogenase subunit 1 (EC907725) and PsaC gene encoding a photosystem 1 (PS 1) 9 kDa subunit protein (EC907731). Additionally, three differentially expressed genes (EC907726, EC907729 and EC907730) were identified. Their sequence analyses revealed no significant homologies to known genes. The expressions of NADH dehydrogenase subunit 1 and PsaC genes were confirmed by Northern blot analysis and quantified by real time PCR. This is the first report for the induction of NADH dehydrogenase subunit 1 gene during Cd stress in wheat.

Molecular characterization and expression profile of a novel porcine gene differentially expressed in the muscle and backfat tissues from Chinese Meishan and Russian Large White pigs

The mRNA differential display technique was performed to investigate the differences of gene expression in the longissimus dorsi muscle and backfat tissues from Chinese Meishan and Russian Large White pigs. One novel gene that was differentially expressed was identified through semi-quantitative RT-PCR and the cDNA complete sequence was then obtained using the rapid amplification of cDNA ends (RACE) method. The cDNA sequence of this gene is not homologous to any of the known porcine genes. The sequence prediction analysis revealed that the open reading frame of this gene encodes a protein of 402 amino acids that contains the putative conserved transposase DDE domain and further Blast analysis revealed that this protein has 100% homology with the Tn10 transposase from Oryza sativa, Serratia marcescens, and Salmonella, and therefore, this gene can be defined as the swine Tn10 transposase gene. This novel porcine gene was finally assigned to Gene ID: 100049649. The RT-PCR analysis of the tissue expression profile was carried out using the tissue cDNAs of one Meishan pig as the templates, and the result indicated that this novel swine gene is moderately expressed in fat, and weakly expressed in small intestine, liver, kidney, and spleen but almost not expressed in heart, ovary, muscle, and lung. Our experiment established the primary foundation for further research into the biological significance of swine Tn10 transposase gene.

Molecular cloning, polymorphism and association analyses of a novel porcine mRNA differentially expressed in the Longissimus muscle tissues from Meishan and Large White pigs

The mRNA differential display technique was performed to investigate the differences of gene expression in the longissimus muscle tissues from Meishan and Large White pigs. One novel mRNA that was differentially expressed was identified through semi-quantitative RT-PCR and the cDNA complete sequence was then obtained using the rapid amplification of cDNA ends (RACE) method. The nucleotide sequence of the mRNA is not homologous to any of the known porcine genes. Sequence prediction analysis revealed that the this mRNA is not protein-coding mRNA. Polymorphism analyses revealed that there was a C-T mutation on the position of 669 bp and PCR -Dra I-RFLP analyses revealed that Chinese indigenous pig breeds and exotic pig breeds displayed obvious genotype and allele frequency differences at this locus. Association analyses revealed that this polymorphic locus was significantly associated with the drip loss rate, skin percentage, meat color value (m.Longissimus Dorsi, LD), loin eye width, loin eye area, water holding capacity, carcass length, caul fat weight, intramuscular fat (m.Longissimus Dorsi, LD), lean meat weight, lean meat percentage, backfat thickness at buttock (P < 0.05).

Up-Regulation of JAM-1 in AR42J Cells Treated with Activin A and Betacellulin and the Diabetic Regenerating Islets

Pancreatic AR42J cells demonstrate the pluripotency in precursor cells of the gut endoderm and also provide an excellent model system to study the differentiation of the pancreas. Using the mRNA differential display technique, we identified junctional adhesion molecule-1 (JAM-1), a component of the tight junction, was highly up-regulated during the differentiation of AR42J cells, although junctions were not formed. The expression level of JAM-1 showed an up-regulation in the mRNA level after 3 hours and in the protein level after 24 hours in [activin A + betacellulin]-treated AR42J cells. The expressions of its signaling molecules, PAR-3 and atypical PKC lambda, also increased after the addition of activin A + betacellulin. When JAM-1 was over-expressed in [activin A + betacellulin]-treated AR42J cells, tagged-JAM-1 was observed in cytoplasm as vesicular structures and JAM-1 was colocalized with Rab3B and Rab13, members of the Rab family expressed at tight junctions. In streptozotocin-induced regenerating islets, the expression of JAM-1 was also up-regulated in the mRNA level and the protein level. JAM-1 might therefore play an important role in the differentiation of AR42J cells and the regeneration of pancreatic islets.