RESUMO
ß2-Microglobulin (ß2m) is related to major histocompatibility complex class I alpha chains, and forms cell-surface glycoproteins that mediate a variety of functions in immune defense. In general, ß2m has no isoforms and is not polymorphic in higher vertebrates, but polymorphisms between different alleles have been found in some fish species. In this study, full-length ß2m cDNA and genomic sequences were cloned from the miiuy croaker (Miichthys miiuy). The miiuy croaker ß2m gene shares many of the same characteristics as other fish species. Three exons and two introns were identified in the miiuy croaker ß2m gene; these genomic structural features are similar to those present in other fish. The deduced ß2m amino acid sequence exhibited 34.7-90.1% identity with mammal and teleost ß2m amino acid sequences. Sequence polymorphism analysis in six individuals identified three alleles that encoded two proteins, confirming that ß2m polymorphisms exist in this species. Phylogenetic analysis elucidated the evolutionary history of the ß2m protein among warm-blooded vertebrates and bony fish.
Assuntos
Variação Genética , Genoma , Perciformes/genética , Microglobulina beta-2/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Dados de Sequência Molecular , Filogenia , Alinhamento de Sequência , Microglobulina beta-2/químicaRESUMO
The diversity of microbiota in waste waters has not been thoroughly examined, despite the potential impact of microbes on effluent quality. Wastewater microbial communities harbor pathogenic bacteria, viruses, and parasites. To study microbial communities in domestic sewage outfalls, 454 pyrosequencing technology was used to investigate the composition of microbial communities associated with municipal wastewater during different seasons sampled over the course of one year. A total of 195,103 16S rRNA gene sequences were obtained from 20 samples. The R software was used to calculate the number of indices describing the alpha diversity associated with each bacterial assemblage. In this study, the a-diversity index (H', D, J), in which higher numbers represent more diversity, was found to change with seasonal cycle. The diversity of bacterial assemblages was high in all samples, indicating that species diversity was also very high. The taxonomic composition of the assemblages varied considerably among samples, with some dominated by Proteobacteria, while others were dominated by Bacteroidetes or Firmicutes. In 2 samples, the relative prevalence of Proteobacteria exceeded 90%. α-Proteobacteria, b-proteobacteria, and g-proteobacteria represented 90% or more of all Proteobacteria. The present characterization of wastewater from five sewage outfalls indicated the presence of some pathogenic bacteria. The g-Proteobacteria in sewage wastefalls identified in this study included Enterobacteriaceae, Vibrionaceae, Pseudomonadaceae, Salmonella, Yersinia, Vibrio, and Pseudomonas aeruginosa.
Assuntos
Microbiologia Ambiental , Microbiota , Esgotos/microbiologia , Bactérias/classificação , Bactérias/genética , Biodiversidade , China , Análise por Conglomerados , Geografia , Metagenoma , Filogenia , RNA Ribossômico 16SRESUMO
Rapid and efficient growth is a major consideration and challenge for global mariculture. The differential growth rate of the sea cucumber, Apostichopus japonicus, has significantly hampered the total production of the industry. In the present study, forward and reverse suppression subtractive hybridization libraries were constructed and sequenced from a fast-growth group and a slow-growth group of the sea cucumber. A total of 142 differentially expressed sequence tags (ESTs) with insertions longer than 150 bp were identified and further analyzed. Fifty-seven of these ESTs (approximately 40%) were functionally annotated for cell structure, energy metabolism, immunity response, and growth factor categories. Six candidate genes, arginine kinase, cytochrome c oxidase subunit I, HSP70, ß-actin, ferritin, and the ADP-ribosylation factor, were further validated by quantitative PCR. Significant differences were found between the fast- and slow-growth groups (P < 0.05) for the expression levels of arginine kinase, cytochrome c oxidase, HSP70, the ADP-ribosylation factor, and ß-actin. However, no significant difference was observed for ferritin. Our results provide promising candidate gene markers for practical size screening, and also further promote marker-assisted selective breeding of this species.
Assuntos
Etiquetas de Sequências Expressas , Regulação da Expressão Gênica no Desenvolvimento , Stichopus/genética , Fatores de Ribosilação do ADP/biossíntese , Actinas/biossíntese , Animais , Arginina Quinase/biossíntese , Complexo IV da Cadeia de Transporte de Elétrons/biossíntese , Proteínas de Choque Térmico HSP70/biossíntese , Stichopus/crescimento & desenvolvimentoRESUMO
The full-length complementary DNA (cDNA) of heat shock protein 90 was cloned from Phascolosoma esculenta (PeHSP90) using expressed sequence tag and rapid amplification of cDNA end approaches. The cDNA of PeHSP90 was 2521 bp including a 5'-untranslated region of 110 bp, a 3'-untranslated region of 230 bp, and an open reading frame of 2181 bp. All of the characteristic motifs of the HSP90 family were completely conserved in the deduced amino acid of PeHSP90. The expression of PeHSP90 was induced by 3 heavy metals or elevated temperature, under which Zn²âº displayed effects were more toxic than those of Cd²âº and Cu²âº. The polyclonal antibodies generated from the recombinant product of PeHSP90 were specifically identified not only in the recombinant product but also in the native protein from hemocytes. These results strongly suggested that PeHSP90 was involved in heavy metal challenge and thermal stress regulation in P. esculenta.