Biosynthesis of an insulin precursor by islet tissue of cod (Gadus callarias).
Ontology highlight
ABSTRACT:
SUBMITTER: Grant PT
PROVIDER: S-EPMC1187207 | biostudies-other | 1968 Nov
REPOSITORIES: biostudies-other
Similar Datasets
Project description:1. S-Aminoethylcysteinyl derivatives of the A and B chains of cod insulin were prepared from the individual S-sulpho chains. 2. Studies on small peptides derived from the S-aminoethylated peptide chains by treatment with trypsin allowed the amino acid sequences in the region of the cysteinyl residues of the A and B peptide chains to be defined. 3. The six amide groups in cod insulin were located by complete digestion of small peptides from the A and B chains with aminopeptidase followed by amino acid analyses. 4. The results, together with previous studies on the oxidized A and B chains, define the sequences of the 51 amino acids that constitute cod insulin.
| S-EPMC1187208 | biostudies-other
Project description:1. Insulin has been isolated by gel filtration and ion-exchange chromatography from extracts of the discrete islet tissue of cod. The final preparation yielded a single band on electrophoresis at two pH values. The biological potency was 11.5 international units/mg. in mouse-convulsion and other assay procedures. 2. Glycine and methionine were shown to be the N-terminal amino acids of the A and B chains respectively. An estimate of the molecular weight together with amino acid analyses indicated that cod insulin, like the bovine hormone, consists of 51 amino acid residues. In contrast, the amino acid composition differs markedly from bovine insulin. 3. Oxidation of insulin with performic acid yielded the A and B peptide chains, which were separated by ion-exchange chromatography. Sequence studies on smaller peptides isolated from enzymic digests or from dilute acetic acid hydrolysates of the two chains have established the sequential order of 14 of the 21 amino acid residues of the A chain and 25 of the 30 amino acid residues of the B chain.
| S-EPMC1198534 | biostudies-other
Project description:BACKGROUND: Hemoglobin (Hb) polymorphism, assessed by protein gel electrophoresis, has been used almost exclusively to characterize the genetic structure of Atlantic cod (Gadus morhua) populations and to establish correlations with phenotypic traits such as Hb oxygen binding capacity, temperature tolerance and growth characteristics. The genetic system used to explain the results of gel electrophoresis entails the presence of one polymorphic locus with two major alleles (HbI-1; HbI-2). However, vertebrates have more than one gene encoding Hbs and recent studies have reported that more than one Hb gene is present in Atlantic cod. These observations prompted us to re-evaluate the number of Hb genes expressed in Atlantic cod, and to perform an in depth search for polymorphisms that might produce relevant phenotypes for breeding programs. RESULTS: Analysis of Expressed Sequence Tags (ESTs) led to the identification of nine distinct Hb transcripts; four corresponding to the alpha Hb gene family and five to the beta Hb gene family. To gain insights about the Hb genes encoding these transcripts, genomic sequence data was generated from heterozygous (HbI-1/2) parents and fifteen progeny; five of each HbI type, i.e., HbI-1/1, HbI-1/2 and HbI-2/2. beta Hb genes displayed more polymorphism than alpha Hb genes. Two major allele types (beta1A and beta1B) that differ by two linked non-synonymous substitutions (Met55Val and Lys62Ala) were found in the beta1 Hb gene, and the distribution of these beta1A and beta1B alleles among individuals was congruent with that of the HbI-1 and HbI-2 alleles determined by protein gel electrophoresis. RT-PCR and Q-PCR analysis of the nine Hb genes indicates that all genes are expressed in adult fish, but their level of expression varies greatly; higher expression of almost all Hb genes was found in individuals displaying the HbI-2/2 electrophoretic type. CONCLUSION: This study indicates that more Hb genes are present and expressed in adult Atlantic cod than previously documented. Our finding that nine Hb genes are expressed simultaneously in adult fish suggests that Atlantic cod, similarly to fish such as rainbow trout, carp, and goldfish, might be able to respond to environmental challenges such as chronic hypoxia or long-term changes in temperature by altering the level of expression of these genes. In this context, the role of the non-conservative substitution Lys62Ala found in the beta1 Hb gene, which appears to explain the occurrence of the HbI-1 and HbI-2 alleles described by gel electrophoresis, and which was found to be present in other fish such as eel, emerald rockcod, rainbow trout and moray, requires further investigation.
| S-EPMC2757024 | biostudies-literature
Project description:The eastern Baltic cod (Gadus morhua) population has been decreasing in the Baltic Sea for at least 30 years. Condition indices of the Baltic cod have decreased, and previous studies have suggested that this might be due to overfishing, predation, lower dissolved oxygen or changes in salinity. However, numerous studies from the Baltic Sea have demonstrated an ongoing thiamine deficiency in several animal classes, both invertebrates and vertebrates. The thiamine status of the eastern Baltic cod was investigated to determine if thiamine deficiency might be a factor in ongoing population declines. Thiamine concentrations were determined by chemical analyses of thiamine, thiamine monophosphate and thiamine diphosphate (combined SumT) in the liver using high performance liquid chromatography. Biochemical analyses measured the activity of the thiamine diphosphate-dependent enzyme transketolase to determine the proportion of apoenzymes in both liver and brain tissue. These biochemical analyses showed that 77% of the cod were thiamine deficient in the liver, of which 13% had a severe thiamine deficiency (i.e. 25% transketolase enzymes lacked thiamine diphosphate). The brain tissue of 77% of the cod showed thiamine deficiency, of which 64% showed severe thiamine deficiency. The thiamine deficiency biomarkers were investigated to find correlations to different biological parameters, such as length, weight, otolith weight, age (annuli counting) and different organ weights. The results suggested that thiamine deficiency increased with age. The SumT concentration ranged between 2.4-24 nmol/g in the liver, where the specimens with heavier otoliths had lower values of SumT (P = 0.0031). Of the cod sampled, only 2% of the specimens had a Fulton's condition factor indicating a healthy specimen, and 49% had a condition factor below 0.8, indicating poor health status. These results, showing a severe thiamine deficiency in eastern Baltic cod from the only known area where spawning presently occurs for this species, are of grave concern.
| S-EPMC6939936 | biostudies-literature
Project description:The mitochondrial DNA (mtDNA) from the Atlantic cod, Gadus morhua, was mapped using 11 different restriction enzymes and cloned into plasmid vectors. Sequence data obtained from more than 10 kilobases of cod mtDNA show that the genome organization, genetic code, and the overall codon usage have been conserved throughout the evolution of vertebrates. Comparison of the derived amino acid sequences of proteins encoded by cod mtDNA to the ones encoded by Xenopus laevis mtDNA revealed that the amino acid identity range from 46% to 93% for the different proteins. ND4L is most divergent while COI is most conserved. GUG was found as the translation initiation codon of the COI gene, indicating a dual coding function for this codon. The sequences of the 997 base pair displacement-loop (D-loop)-containing region and the origin of L-strand replication (oriL), are presented. Only few of the primary and secondary structure features found to be conserved among mammalian mitochondrial D-loops, can be identified in cod. Presence of CSB-2 in the D-loop-containing region and the conserved hairpin structure at oriL, indicates that replication of bony fish mtDNA may follow the same general scheme as described for higher vertebrates.
| S-EPMC333442 | biostudies-other
Project description:Insulin synthesis in pancreatic ?-cells is initiated as preproinsulin. Prevailing glucose concentrations, which oscillate pre- and postprandially, exert major dynamic variation in preproinsulin biosynthesis. Accompanying upregulated translation of the insulin precursor includes elements of the endoplasmic reticulum (ER) translocation apparatus linked to successful orientation of the signal peptide, translocation and signal peptide cleavage of preproinsulin-all of which are necessary to initiate the pathway of proper proinsulin folding. Evolutionary pressures on the primary structure of proinsulin itself have preserved the efficiency of folding ("foldability"), and remarkably, these evolutionary pressures are distinct from those protecting the ultimate biological activity of insulin. Proinsulin foldability is manifest in the ER, in which the local environment is designed to assist in the overall load of proinsulin folding and to favour its disulphide bond formation (while limiting misfolding), all of which is closely tuned to ER stress response pathways that have complex (beneficial, as well as potentially damaging) effects on pancreatic ?-cells. Proinsulin misfolding may occur as a consequence of exuberant proinsulin biosynthetic load in the ER, proinsulin coding sequence mutations, or genetic predispositions that lead to an altered ER folding environment. Proinsulin misfolding is a phenotype that is very much linked to deficient insulin production and diabetes, as is seen in a variety of contexts: rodent models bearing proinsulin-misfolding mutants, human patients with Mutant INS-gene-induced Diabetes of Youth (MIDY), animal models and human patients bearing mutations in critical ER resident proteins, and, quite possibly, in more common variety type 2 diabetes.
| S-EPMC6463291 | biostudies-literature
Project description:BackgroundRegulation of gene expression plays a central role in embryonic development. Early stages are controlled by gametic transcripts, which are subsequently substituted with transcripts from the genome of the zygote. Transcriptomic analyses provide an efficient approach to explore the temporal gene expression profiles in embryos and to search for the developmental regulators. We report a study of early Atlantic cod development that used a genome-wide oligonucleotide microarray to examine the composition and putative roles of polyadenylated transcripts.ResultsThe analyses were carried out in unfertilized oocytes, newly fertilized oocytes and embryos at the stages of mid-blastula transition and segmentation. Numerous genes transcribed in oocytes are involved in multiple aspects of cell maintenance and protection, including metabolism, signal perception and transduction, RNA processing, cell cycle, defense against pathogens and DNA damage. Transcripts found in unfertilized oocytes also encoded a large number of proteins implicated in cell adherence, tight junction and focal adhesion, suggesting high complexity in terms of structure and cellular interactions in embryos prior to midblastula transition (MBT). Prezygotic transcripts included multiple regulators that are most likely involved in developmental processes that take place long after fertilization, such as components of ErbB, hedgehog, notch, retinoid, TGFb, VEGF and Wnt signaling pathways, as well as transcripts involved in the development of nervous system. The major event of MBT was the activation of a large group of histones and other genes that modify chromatin structure preceding massive gene expression changes. A hallmark of events observed during segmentation was the induction of multiple transcription factors, including a large group of homeobox proteins in pace with decay of a large fraction of maternal transcripts. Microarray analyses detected a suite of master developmental regulators that control differentiation and maintenance of diverse cell lineages.ConclusionsTranscriptome profiling of the early stages in Atlantic cod revealed the presence of transcripts involved in patterning and development of tissues and organs long before activation of the zygotic genome. The switch from maternal to zygotic developmental programs is associated with large-scale modification of chromosomes.
| S-EPMC4124161 | biostudies-literature
Project description:Atlantic Cod (Gadus morhua) has lost the major histocompatibility complex class II presentation pathway. We recently identified CD8-positive T cells, B cells, and plasma cells in cod, but further characterisation of lymphocyte subsets is needed to elucidate immune adaptations triggered by the absence of CD4-positive T lymphocytes. Here, we use single-cell RNA sequencing to examine the lymphocyte heterogeneity in Atlantic cod spleen. We describe five T cell subsets and eight B cell subsets and propose a B cell trajectory of differentiation. Notably, we identify a subpopulation of T cells that are CD8-negative. Most of the CD8-negative T lymphocytes highly express the homologue of monocyte chemotactic protein 1b, and another subset of CD8-negative T lymphocytes express the homologue of the scavenger receptor m130. Uncovering the multiple lymphocyte cell sub-clusters reveals the different immune states present within the B and T cell populations, building a foundation for further work.
| S-EPMC9276791 | biostudies-literature
Project description:The growth and development of marine fish larvae fed copepods is superior to those fed rotifers, but the underlying molecular reasons for this are unclear. In the following study we compared the effects of such diets on redox regulation pathways during development of Atlantic cod (Gadus morhua) larvae. Cod larvae were fed a control diet of copepods or the typical rotifer/Artemia diet commonly used in commercial marine fish hatcheries, from first feeding until after metamorphosis. The oxidised and reduced glutathione levels, the redox potential, and the mRNA expression of 100 genes in redox system pathways were then compared between treatments during larval development. We found that rotifer/Artemia-fed cod larvae had lower levels of oxidised glutathione, a more reduced redox potential, and altered expression of approximately half of the redox system genes when compared to copepod-fed larvae. This rotifer/Artemia diet-induced differential regulation of the redox system was greatest during periods of suboptimal growth. Upregulation of the oxidative stress response transcription factor, nrf2, and NRF2 target genes in rotifer/Artemia fed larvae suggest this diet induced an NRF2-mediated oxidative stress response. Overall, the data demonstrate that nutritional intake plays a role in regulating the redox system in developing fish larvae. This may be a factor in dietary-induced differences observed in larval growth.
| S-EPMC4488531 | biostudies-literature
Project description:BackgroundThe Atlantic cod is an ecologically and economically important North Atlantic fish species and also an emerging aquaculture species. To study gene expression in Atlantic cod embryonic stem (ES) cells, our goal was to generate and analyze expressed sequence tags (ESTs) from an ES cell cDNA library of mRNA consisting of approximately 3,900 ESTs.ResultsWe sequenced 3,935 EST clones using a directional cDNA library made from pooled ES cells harvested at the blastula stage. Quality filtering of these ESTs allowed identification of 2,719 high-quality sequences with an average length of 442 bp containing 368 contigs and 1,276 singletons (1,644 unique sequences). BLASTX searches produced 889 significant (E-value < 10-3) hits, of which 698 (42.5%) were annotated with Gene Ontology terms (E-value < 10-6). The number of unknown unique sequences was 946 (57.5%). All the high-quality EST sequences have been deposited in GenBank (GenBank: 2,719 sequences in UniGene library dbEST id: 22,021). Gene discovery and annotations are presented and discussed.ConclusionThis set of ESTs represents one of the first attempts to describe mRNA in ES cells from a marine cold-water fish species, and provides a basis for gene expression studies of Atlantic cod ES cells.
| S-EPMC2686721 | biostudies-literature