Evolutionary conservation of the insulin gene structure in invertebrates: cloning of the gene encoding molluscan insulin-related peptide III from Lymnaea stagnalis

1993 ◽  
Vol 11 (1) ◽  
pp. 103-113 ◽  
Author(s):  
A B Smit ◽  
A van Marle ◽  
R van Elk ◽  
J Bogerd ◽  
H van Heerikhuizen ◽  
...  
Keyword(s):  
Lymnaea Stagnalis ◽  
Structural Characteristics ◽  
Freshwater Snail ◽  
Coding Region ◽  
Gene Encoding ◽  
Related Peptide ◽  
Genes Encoding ◽  
The Common ◽  
Type Gene ◽  
The Brain

ABSTRACT Although insulins and structurally related peptides are found in vertebrates as well as in invertebrates, it is not clear whether the genes encoding these hormones have emerged from a single ancestral (insulin)-type of gene or, alternatively, have arisen independently through convergent evolution from different types of gene. To investigate this issue, we cloned the gene encoding the molluscan insulin-related peptide III (MIP III) from the freshwater snail, Lymnaea stagnalis. The predicted MIP III preprohormone had the overall organization of preproinsulin, with a signal peptide and A and B chains, connected by two putative C peptides. Although MIP III was found to share key features with vertebrate insulins, it also had unique structural characteristics in common with the previously identified MIPs I and II, thus forming a distinct class of MIP peptides within the insulin superfamily. MIP III is synthesized in neurones in the brain. It is encoded by a gene with the overall organization of the vertebrate insulin genes, with three exons and two introns, of which the second intron interrupts the coding region of the C peptides. Our data therefore demonstrate that in the Archaemetazoa, the common ancestor of the vertebrates and invertebrates, a primordial peptide with a two-chain insulin configuration encoded by a primordial insulin-type gene must have been present.

Organization and regulation of the gene encoding FMRFamide related peptides in the brain of Lymnaea stagnalis

1990 ◽  
Vol 30 (1) ◽  
pp. 35
Author(s):  
J.F. Burke ◽  
S.E. Saunders ◽  
E. Kellett ◽  
K. Bright ◽  
N. Santama ◽  
...  
Keyword(s):  
Lymnaea Stagnalis ◽  
Gene Encoding ◽  
The Brain

scholarly journals Loss of the Reissner Fiber and increased URP neuropeptide signaling underlie scoliosis in a zebrafish ciliopathy mutant

2019 ◽  
Author(s):  
Christine Vesque ◽  
Isabelle Anselme ◽  
Guillaume Pezeron ◽  
Yasmine Cantaut-Belarif ◽  
Alexis Eschstruth ◽  
...  
Keyword(s):  
Receptor Gene ◽  
Urotensin Ii ◽  
Gene Encoding ◽  
Peptide Family ◽  
Juvenile Scoliosis ◽  
Genes Encoding ◽  
Juvenile Stages ◽  
Brain And Spinal Cord ◽  
The Brain ◽  
Axis Straightness

SUMMARYCilia-driven movements of the cerebrospinal fluid (CSF) are involved in zebrafish axis straightness, both in embryos and juveniles [1, 2]. In embryos, axis straightness requires cilia-dependent assembly of the Reissner fiber (RF), a SCO-spondin polymer running down the brain and spinal cord CSF-filled cavities [3]. Reduced expression levels of the urp1 and urp2 genes encoding neuropeptides of the Urotensin II family in CSF-contacting neurons (CSF-cNs) also underlie embryonic ventral curvature of several cilia motility mutants [4]. Moreover, mutants for scospondin and uts2r3 (a Urotensin II peptide family receptor gene) develop scoliosis at juvenile stages [3, 4]. However, whether RF maintenance and URP signaling are perturbed in juvenile scoliotic ciliary mutants and how these perturbations are linked to scoliosis is unknown. Here we produced mutants in the zebrafish ortholog of the human RPGRIP1L ciliopathy gene encoding a transition zone protein [5–7]. rpgrip1l-/- zebrafish had normal embryogenesis and developed 3D spine torsions in juveniles. Cilia lining the CNS cavities were normal in rpgrip1l-/- embryos but sparse and malformed in juveniles and adults. Hindbrain ventricle dilations were present at scoliosis onset, suggesting defects in CSF flow. Immunostaining showed a secondary loss of RF correlating with juvenile scoliosis. Surprisingly, transcriptome analysis of rgprip1l mutants at scoliosis onset uncovered increased levels of urp1 and urp2 expression. Overexpressing urp2 in foxj1-expressing cells triggered scoliosis in rpgrip1l heterozygotes. Thus, our results demonstrate that increased URP signaling drives scoliosis onset in a ciliopathy mutant. We propose that imbalanced levels of URP neuropeptides in CSF-cNs may be an initial trigger of scoliosis.

scholarly journals Markerless Mutagenesis in Methanococcus maripaludis Demonstrates Roles for Alanine Dehydrogenase, Alanine Racemase, and Alanine Permease

2005 ◽  
Vol 187 (3) ◽  
pp. 972-979 ◽  
Author(s):  
Brian C. Moore ◽  
John A. Leigh
Keyword(s):  
Negative Selection ◽  
Alanine Racemase ◽  
Selection Strategy ◽  
Methanococcus Maripaludis ◽  
Gene Encoding ◽  
Gram Positive Bacteria ◽  
Alanine Dehydrogenase ◽  
Genes Encoding ◽  
Base Analog ◽  
Type Gene

ABSTRACT Among the archaea, Methanococcus maripaludis has the unusual ability to use l- or d-alanine as a nitrogen source. To understand how this occurs, we tested the roles of three adjacent genes encoding homologs of alanine dehydrogenase, alanine racemase, and alanine permease. To produce mutations in these genes, we devised a method for markerless mutagenesis that builds on previously established genetic tools for M. maripaludis. The technique uses a negative selection strategy that takes advantage of the ability of the M. maripaludis hpt gene encoding hypoxanthine phosphoribosyltransferase to confer sensitivity to the base analog 8-azahypoxanthine. In addition, we developed a negative selection method to stably incorporate constructs into the genome at the site of the upt gene encoding uracil phosphoribosyltransferase. Mutants with in-frame deletion mutations in the genes for alanine dehydrogenase and alanine permease lost the ability to grow on either isomer of alanine, while a mutant with an in-frame deletion mutation in the gene for alanine racemase lost only the ability to grow on d-alanine. The wild-type gene for alanine dehydrogenase, incorporated into the upt site, complemented the alanine dehydrogenase mutation. Hence, the permease is required for the transport of either isomer, the dehydrogenase is specific for the l isomer, and the racemase converts the d isomer to the l isomer. Phylogenetic analysis indicated that all three genes had been acquired by lateral gene transfer from the low-moles-percent G+C gram-positive bacteria.

Transgene expression and agronomic improvement of rice

1993 ◽  
Vol 342 (1301) ◽  
pp. 197-201 ◽  
Keyword(s):  
Transgenic Plants ◽  
Triosephosphate Isomerase ◽  
Viral Infections ◽  
Specific Protein ◽  
Coding Region ◽  
Gene Encoding ◽  
Gus Reporter ◽  
Genes Encoding ◽  
Flanking Region ◽  
Viral Sequences

A reliable system for transformation and regeneration of rice protoplasts yielding fertile transgenic plants has been established. After co-electroporation of DNAs encoding a selectable marker and the gene of interest, protoplasts are regenerated to yield fertile plants. To date more than 70 different genes of interest have been successfully introduced and their patterns of expression are being studied. As in the case of dicot plants transformed by the Ti-plasm id vector approach, integration and expression appear to be stable in the transgenic monocots over several generations. Detailed com parative studies on gene expression in rice are underway using promoters for triosephosphate isomerase, a ubiquitously expressed gene encoding a cytosolic enzyme vital in the glycolytic cycle, two genes encoding members of the cyclophilin family, peptidyl-prolyl cis-trans -isomerases that are abundant in meristematic regions and are thought to participate in the correct folding of nascent proteins, and a gene encoding a tissue (root)- specific protein. Initial analyses suggest that the spatial expression of these genes in transgenic plants, using GUS reporter constructs, appears to be very sensitive to the nature of the 3' flanking region present in the gene construct. Constructs containing a coding region for arcelin, a bean seed protein with putative anti-insecticidal properties, and others containing viral sequences that may provide novel approaches for protection against tungro and other viral infections have been introduced into rice plants.

The Withdrawal Response of a Freshwater Snail (Lymnaea Stagnalis L.)

1975 ◽  
Vol 62 (3) ◽  
pp. 783-796
Author(s):  
ANTHONY COOK
Keyword(s):  
Electrical Stimulation ◽  
Response Latency ◽  
Lymnaea Stagnalis ◽  
Intact Animal ◽  
Freshwater Snail ◽  
Response Decrement ◽  
Withdrawal Response ◽  
The Brain ◽  
Incremental Process ◽  
Stimulation Of

1. Electrical stimulation of a variety of nerves towards the brain results in movements of the neck of the snail similar to those associated with the withdrawal response of the intact animal. 2. The columellar and cervical nerves mediate most of the movements being measured. 3. Repetition of the stimuli results in a decline in response amplitude which is complicated by a superimposed incremental process which is itself subject to a decremental process as stimuli are repeated. 4. As stimuli are repeated the response latency increases. 5. Consecutive stimulation of pairs of nerves indicates that the response decrement is specific to the nerve being stimulated. 6. The involvement of the pleuro-pedal connectives in the response has been demonstrated both in a semi-intact preparation stimulated electrically and in a free-roaming animal treated surgically and stimulated visually. 7. Visual stimuli associated with the withdrawal response are detected by photoreceptors on the head and in the mantle.

Advantages of Complementary Stereo Images as Viewed with the Low-Temperature Field-Emission SEM

1992 ◽  
Vol 50 (2) ◽  
pp. 1314-1315
Author(s):  
William P. Wergin ◽  
Eric F. Erbe
Keyword(s):  
Fold Increase ◽  
Horizontal Displacement ◽  
Three Dimensions ◽  
Stereo Image ◽  
Stereo Pair ◽  
Sem Micrograph ◽  
Left And Right ◽  
The Common ◽  
The Brain ◽  
Pair Analysis

The eye-brain complex allows those of us with normal vision to perceive and evaluate our surroundings in three-dimensions (3-D). The principle factor that makes this possible is parallax - the horizontal displacement of objects that results from the independent views that the left and right eyes detect and simultaneously transmit to the brain for superimposition. The common SEM micrograph is a 2-D representation of a 3-D specimen. Depriving the brain of the 3-D view can lead to erroneous conclusions about the relative sizes, positions and convergence of structures within a specimen. In addition, Walter has suggested that the stereo image contains information equivalent to a two-fold increase in magnification over that found in a 2-D image. Because of these factors, stereo pair analysis should be routinely employed when studying specimens.Imaging complementary faces of a fractured specimen is a second method by which the topography of a specimen can be more accurately evaluated.

Measuring the World

2018 ◽  
Author(s):  
Ann-Sophie Barwich
Keyword(s):  
Sensory Information ◽  
Network Models ◽  
Model System ◽  
Stimulus Input ◽  
Expectancy Effects ◽  
Neural Network Models ◽  
Perceptual Object ◽  
External Objects ◽  
The Common ◽  
The Brain

How much does stimulus input shape perception? The common-sense view is that our perceptions are representations of objects and their features and that the stimulus structures the perceptual object. The problem for this view concerns perceptual biases as responsible for distortions and the subjectivity of perceptual experience. These biases are increasingly studied as constitutive factors of brain processes in recent neuroscience. In neural network models the brain is said to cope with the plethora of sensory information by predicting stimulus regularities on the basis of previous experiences. Drawing on this development, this chapter analyses perceptions as processes. Looking at olfaction as a model system, it argues for the need to abandon a stimulus-centred perspective, where smells are thought of as stable percepts, computationally linked to external objects such as odorous molecules. Perception here is presented as a measure of changing signal ratios in an environment informed by expectancy effects from top-down processes.

The Dioptrique

2017 ◽  
Author(s):  
Walter Ott
Keyword(s):  
Sensory Experience ◽  
The Other ◽  
Brain Image ◽  
Brain Motion ◽  
Natural Geometry ◽  
The Common ◽  
The Brain

Descartes’s treatment of perception in the Optics, though published before the Meditations, contains a distinct account of sensory experience. The end of the chapter suggests some reasons for this oddity, but that the two accounts are distinct is difficult to deny. Descartes in the present work topples the brain image from its throne. In its place, we have two mechanisms, one purely causal, the other inferential. Where the proper sensibles are concerned, the ordination of nature suffices to explain why a given sensation is triggered on the occasion of a given brain motion. The same is true with regard to the common sensibles. But on top of this purely causal story, Descartes re-introduces his doctrine of natural geometry.

scholarly journals Aquaporin-1 and aquaporin-9 gene variations in sudden infant death syndrome

2021 ◽  
Author(s):  
Siri Hauge Opdal ◽  
Linda Ferrante ◽  
Torleiv Ole Rognum ◽  
Arne Stray-Pedersen
Keyword(s):  
Sudden Infant Death Syndrome ◽  
Infant Death ◽  
Brain Function ◽  
Sudden Infant Death ◽  
Sudden Infant ◽  
Unexpected Death ◽  
Aquaporin 9 ◽  
Genes Encoding ◽  
External Risk ◽  
The Brain

AbstractSeveral studies have indicated that a vulnerability in the development and regulation of brain function is involved in sudden infant death syndrome (SIDS). The aim of this study was to investigate the genes encoding the brain aquaporins (AQPs) AQP1 and AQP9 in SIDS. The hypothesis was that specific variants of these genes are part of the genetic vulnerability predisposing infants to sudden unexpected death. The study included 168 SIDS cases with a median age of 15.5 (range 2–52) weeks and 372 adolescent/adult deceased controls with a median age of 44 (range 11–91) years. In the AQP1 gene, the rs17159702 CC/CT genotypes were found to be associated with SIDS (p = 0.02). In the AQP9 gene, the combination of a TT genotype of rs8042354, rs2292711 and rs13329178 was more frequent in SIDS cases than in controls (p = 0.03). In the SIDS group, an association was found between genetic variations in the AQP1 gene and maternal smoking and between the 3xTT combination in the AQP9 gene and being found lifeless in a prone position. In conclusion, this study adds further evidence to the involvement of brain aquaporins in SIDS, suggesting that specific variants of AQP genes constitute a genetic predisposition, making the infant vulnerable to sudden death together with external risk factors and probably other genetic factors.

scholarly journals Expression and function of the cdgD gene, encoding a CHASE–PAS-DGC-EAL domain protein, in Azospirillum brasilense

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
José Francisco Cruz-Pérez ◽  
Roxana Lara-Oueilhe ◽  
Cynthia Marcos-Jiménez ◽  
Ricardo Cuatlayotl-Olarte ◽  
María Luisa Xiqui-Vázquez ◽  
...  
Keyword(s):  
Azospirillum Brasilense ◽  
Type Strain ◽  
Wild Type Strain ◽  
Soil Conditions ◽  
Wild Type ◽  
Gene Encoding ◽  
Wheat Roots ◽  
Genes Encoding ◽  
In The Wild ◽  
Plant Growth Promoting

AbstractThe plant growth-promoting bacterium Azospirillum brasilense contains several genes encoding proteins involved in the biosynthesis and degradation of the second messenger cyclic-di-GMP, which may control key bacterial functions, such as biofilm formation and motility. Here, we analysed the function and expression of the cdgD gene, encoding a multidomain protein that includes GGDEF-EAL domains and CHASE and PAS domains. An insertional cdgD gene mutant was constructed, and analysis of biofilm and extracellular polymeric substance production, as well as the motility phenotype indicated that cdgD encoded a functional diguanylate protein. These results were correlated with a reduced overall cellular concentration of cyclic-di-GMP in the mutant over 48 h compared with that observed in the wild-type strain, which was recovered in the complemented strain. In addition, cdgD gene expression was measured in cells growing under planktonic or biofilm conditions, and differential expression was observed when KNO3 or NH4Cl was added to the minimal medium as a nitrogen source. The transcriptional fusion of the cdgD promoter with the gene encoding the autofluorescent mCherry protein indicated that the cdgD gene was expressed both under abiotic conditions and in association with wheat roots. Reduced colonization of wheat roots was observed for the mutant compared with the wild-type strain grown in the same soil conditions. The Azospirillum-plant association begins with the motility of the bacterium towards the plant rhizosphere followed by the adsorption and adherence of these bacteria to plant roots. Therefore, it is important to study the genes that contribute to this initial interaction of the bacterium with its host plant.

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