4 edition of Evolution of stomach lysozyme found in the catalog.
Evolution of stomach lysozyme
Thesis (M.Sc.) -- University of Toronto, 1994.
|Series||Canadian theses = -- Thèses canadiennes|
|The Physical Object|
|Pagination||2 microfiches : negative. --|
1. Introduction. Lysozyme (EC ) catalyzes the hydrolysis of the 1,4-β-glycosidic linkage between N-acetylmuramic acid and N-acetylglucosamine of the peptidoglycan present in the cell wall of many bacteria, causing cell me is part of the defense mechanism against bacteria and has been described in most animals (Jollès and Jollès, ), including insects (Dunn, The multiple lysozyme genes expressed in the cow stomach are the result of gene duplications that occurred during ruminant evolution. The recruitment of lysozyme as a major enzyme in the stomach may thus have involved an early regulatory event and a later fold increase in expression allowed by gene amplification.
The stomach lysozyme pseudogenes show a pattern of concerted evo- lution similar to that of the functional stomach genes. At least four nonstomach lysozyme genes exist. The non- stomach lysozyme genes are not monophyletic. A gene encoding a tracheal lysozyme . Ruminants have evolved a gastric c type lysozyme as a digestive enzyme, and profit from digestion of foregut bacteria, after most dietary components, including protein, have been fermented in the rumen. In this work we characterized the biological activities of bovine gastric secretions against membranes, purified murein and bacteria.
Recombinant human lysozyme (h-LZ) and other mammalian lysozymes of mouse, dog, cat and bovine milk elicited similar sweetness as determined using a sensory test, whereas bovine stomach lysozyme (bs-LZ) did not. Assays of cell cultures showed that h-LZ activated the human sweet taste receptor hT1R2/hT1R3, whereas bs-LZ did not. Tree C represents the third possible relationship, in which the cow stomach lysozyme 1 gene is more closely related to the sheep stomach lysozyme 1 gene than to the cow stomach lysozyme 2 gene. and the 3 untranslated regions of these genes all strongly support an evolutionary history of divergent evolution.
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The acquisition of an efficient stomach lysozyme is associated with the success of the ruminants. Advanced ruminants, such as cow, sheep, and deer, have approximately 10 lysozyme genes, some of which are expressed and function in the stomach and some which are expressed and function in nonstomach tissues (e.g., trachea or kidney).Cited by: Molecular genetics and evolution of stomach and nonstomach lysozymes in the hoatzin Article (PDF Available) in Journal of Molecular Evolution 42(6) July with Reads.
The ruminant lysozymes illustrate the important role of regulatory evolution in the adaptation of species to new diets (Dobson et al., ; Irwin et al., ). Stomach lysozymes are derived from the conventional antibacterial lysozymes already present in mammals.
Ruminant stomach lysozyme is a long established model of adaptive gene evolution. Evolution of stomach lysozyme function required changes in the site of expression of the lysozyme c gene and changes in the enzymatic properties of the enzyme.
In ruminant mammals, these changes were associated with a change in the size of the lysozyme c gene. This rapid evolution, coupled with functional and sequence convergence upon cow stomach lysozyme, could imply that positive darwinian selection has driven about 50% of the evolution of langur.
Ruminant stomach lysozyme is a long established model of adaptive gene evolution. Evolution of stomach lysozyme function required changes in the site of expression of the lysozyme c gene and.
Most of the duplications of the lysozyme genes occurred 40–50 million years ago, before the divergence of cow and sheep. Despite this, the coding regions of stomach lysozyme genes within a species (e.g., cow, sheep, or deer) are more similar to each other than to lysozyme.
lysozyme c from the stomach mucosa of a typical ruminant, the domestic cow. Furthermore, by conducting a tree analysis of the sequence data and making quantitative immunological comparisons of cow lysozyme c to other lysozymes, it has been possible to find out whether the rate of sequence evolution.
Background. The vertebrate lysozyme gene family has traditionally been considered to be composed of three genes: lysozyme c, lactalbumin, and calcium-binding lysozyme .Lysozyme c, chicken-type (or conventional) lysozyme, is a bacteriolytic enzyme that is secreted into many body fluids of mammals (e.g., blood, tears, and milk) and is found at a high concentration in the eggs of many bird.
Ruminant stomach lysozyme is a long established model of adaptive gene evolution. Evolution of stomach lysozyme function required changes in the site of expression of the lysozyme cgene and changes in the enzymatic properties of the enzyme. In ruminant mammals, these changes were associated with a change in the size of the lysozyme cgene family.
Therefore, the langur stomach lysozyme gene has probably evolved recently (i.e., within the period of monkey evolution) from a conventional primate lysozyme. The sequences of cDNAs for the stomach lysozyme of langur and the conventional lysozymes of three other Old World monkeys were determined.
The process of concerted evolution in stomach lysozymes may have had roles both in adapting lysozyme to the stomach environment in early ruminants as well as in retarding amino acid sequence evolution in the well adapted lysozyme of modern ruminants. PMID: [PubMed - indexed for MEDLINE] Publication Types: Comparative Study.
The vertebrate lysozyme gene family has traditionally been considered to be composed of three genes: lysozyme c, lactalbumin, and calcium-binding lysozyme [1–4].Lysozyme c, chicken-type (or conventional) lysozyme, is a bacteriolytic enzyme that is secreted into many body fluids of mammals (e.g., blood, tears, and milk) and is found at a high concentration in the eggs of many bird species [1.
A major regulatory shift affecting the expression of lysozyme c may have been involved in the origin of two groups of mammals whose nutrition depends on foregut bacteria. A survey of 23 mammalian species reveals that the lysozyme c activity per g of stomach mucosa is many times higher for ruminants and a leaf-eating monkey than for animals.
The multiple lysozyme genes expressed in the cow stomach are the result of gene duplications that occurred during ruminant evolution. The recruitment of lysozyme as a major enzyme in the stomach may thus have involved an early regulatory event and a later fold increase in expression allowed by gene amplification.
Abstract. This report describes a lysozyme expressed at high levels in the stomach of the hoatzin, the only known foregut-fermenting bird.
Evolutionary comparison places it among the calcium-binding lysozymes rather than among the conventional types. titration. Lysozyme appears in the stomach mucosa before birth and reaches adult levels before weaning. Other tissues tested from cattle lack lysozyme c and may instead have low levels of another lysozyme that could belong to the g class, the first indication that lysozyme g.
Expansion of the lysozyme gene family is associated with the evolution of the ruminant lifestyle in ruminant artiodactyls such as the cow. Gene duplications allowed recombination between stomach lysozyme genes that may have assisted in the evolution of an enzyme adapted to survive and function in the stomach environment.
During ruminant evolution, the number of lysozyme genes has risen from 1 per haploid genome to about To study the evolutionary sequence of lysozyme genes, amino acid sequences of lysozyme C from camel and goat stomachs were determined, and compared with those of 18 other species (obtained from published data).
Tree analysis suggested that the rate of amino acid replacement increased as. Contradictory evolutionary histories of ruminant lysozymes have been predicted by analysis of genomic blots (Irwin, D.M., Sidow, A., White, R., and Wilson, A.C. () in The Immune Response to Structurally Defined Proteins: The Lysozyme Model (Smith-Gill, S.J., and Sercarz, E.E., eds) pp.Adenine Press, Guilderland, NY) and sequences of cow stomach lysozyme cDNAs (Irwin, D.M., and.
It also turns out that colubine monkeys such as languars, which are also foregut fermenters, also show high levels of expression of stomach-type lysozyme. Thus, gastric lysozymes are also a good example of convergent evolution of proteins in distantly related species (cows and languars) that happen to share a digestive strategy.Evolution of calcium-binding lysozyme Equine and pigeon lysozymes bind one calcium ion [9,contrary to the other mammalian and avian conventional non-calcium-binding lysozymes [ The above-named lysozymes are strongly suggested to bind a calcium ion with the same binding site as that of a-lactalbumin , because.Abstract.
Cow stomach lysozyme genes have evolved in a mosaic pattern. The majority of the intronic and flanking sequences show an amount of sequence difference consistent with divergent evolution since duplication of the genes 40–50 million years ago.