Search results for "Biological Evolution"
showing 10 items of 522 documents
The Physcomitrella genome reveals evolutionary insights into the conquest of land by plants
2008
We report the draft genome sequence of the model moss Physcomitrella patens and compare its features with those of flowering plants, from which it is separated by more than 400 million years, and unicellular aquatic algae. This comparison reveals genomic changes concomitant with the evolutionary movement to land, including a general increase in gene family complexity; loss of genes associated with aquatic environments (e.g., flagellar arms); acquisition of genes for tolerating terrestrial stresses (e.g., variation in temperature and water availability); and the development of the auxin and abscisic acid signaling pathways for coordinating multicellular growth and dehydration response. The …
A novel member of an ancient superfamily: sponge (Geodia cydonium, Porifera) putative protein that features scavenger receptor cysteine-rich repeats
1997
Proteins featuring scavenger receptor cysteine-rich (SRCR) domains are prominent receptors known from vertebrates and from one phylum of invertebrates, the echinoderms. In the present study we report the first putative SRCR protein from the marine sponge Geodia cydonium (Porifera), a member of the lowest phylum of contemporary Metazoans. Two forms of SRCR molecules were characterized, which apparently represent alternative splicing of the same transcript. The long putative SRCR protein, of 1536 aa, features twelve SRCR repeats, a C-terminal transmembrane domain and a cytoplasmic tail. The sequence of the short form is identical with the long form except that it lacks a coding region near th…
Molecular cloning of a tyrosine kinase gene from the marine spongeGeodia cydonium: a new member belonging to the receptor tyrosine kinase class II fa…
1994
We have isolated and characterized a cDNA from the marine sponge Geodia cydonium coding for a new member of the tyrosine protein kinase (TK) family. The cDNA encodes a protein of M(r) = 68,710, termed GCTK, which is homologous to class II receptor tyrosine kinases (RTKs). GCTK contains conserved amino acids (aa) characteristic of all protein kinases, and the sequences DLATRN and PIRWMATE which are highly specific for TKs. Furthermore, the sequence N-L-Y-x(3)-Y-Y-R is highly homologous to the sequence D-[LIV]-Y-x(3)-Y-Y-R found only in class II RTKs. The sponge TK, when compared with mammalian class II RTKs, shows maximum 31% homology in the TK domain indicating that this the oldest member o…
Immunoglobulin-like domain is present in the extracellular part of the receptor tyrosine kinase from the marine sponge Geodia cydonium.
1994
We have isolated and characterized two cDNAs from the marine sponge Geodia cydonium coding for a new member of a receptor tyrosine kinase of class II. The deduced amino acid sequence shows two characteristic domains: (i) the tyrosine kinase domain; and (ii) and immunoglobulin-like domain. The latter part shows high homology to the vertebrate C2 type immunoglobulin domain. This result demonstrates that immunoglobulin domains are not recent achievements of higher animals but exist also in those animals which have diverged from other organisms about 800 million years ago.
Social transmission in the wild can reduce predation pressure on novel prey signals
2021
Funder: Suomen Kulttuurirahasto (Finnish Cultural Foundation); doi: https://doi.org/10.13039/501100003125
Intestinal helminth communities of the long-finned pilot whale (Globicephala melas) off the Faroe Islands.
1993
SUMMARYThe intestines of 170 long-finned pilot whales, Globicephala melas, caught off the Faroe Islands (N.E. Atlantic) were examined for helminth parasites. Eight species were detected but only 4 occurred in at least 10% of the sample. No core or recurrent group of species were identified and no correlations between abundances of species were significant. Diversity values were far below those reported for other endotherms. Colonization by helminths was random, whales not being readily colonized. These features point to largely unpredictable, isolationist infracommunities, there being little potential for inter-specific interactions. Older hosts tended to harbour more diverse infracommuniti…
Sequencing ancient calcified dental plaque shows changes in oral microbiota with dietary shifts of the Neolithic and Industrial revolutions
2013
The importance of commensal microbes for human health is increasingly recognized, yet the impacts of evolutionary changes in human diet and culture on commensal microbiota remain almost unknown. Two of the greatest dietary shifts in human evolution involved the adoption of carbohydrate-rich Neolithic (farming) diets (beginning ∼10,000 years before the present) and the more recent advent of industrially processed flour and sugar (in ∼1850). Here, we show that calcified dental plaque (dental calculus) on ancient teeth preserves a detailed genetic record throughout this period. Data from 34 early European skeletons indicate that the transition from hunter-gatherer to farming shifted the oral m…
High temperature and bacteriophages can indirectly select for bacterial pathogenicity in environmental reservoirs
2010
The coincidental evolution hypothesis predicts that traits connected to bacterial pathogenicity could be indirectly selected outside the host as a correlated response to abiotic environmental conditions or different biotic species interactions. To investigate this, an opportunistic bacterial pathogen, Serratia marcescens, was cultured in the absence and presence of the lytic bacteriophage PPV (Podoviridae) at 25°C and 37°C for four weeks (N = 5). At the end, we measured changes in bacterial phage-resistance and potential virulence traits, and determined the pathogenicity of all bacterial selection lines in the Parasemia plantaginis insect model in vivo. Selection at 37°C increased bacterial…
Bilabiate Flowers: The Ultimate Response to Bees?
2007
† Background and Aims Bilabiate flowers have evolved in many lineages of the angiosperms, thus representing a convincing example of parallel evolution. Similar to keel blossoms, they have obviously evolved in order to protect pollen against pollen-collecting bees. Although many examples are known, a comprehensive survey on floral diversity and functional constraints of bilabiate flowers is lacking. Here, the concept is widened and described as a general pattern. † Methods The present paper is a conceptional review including personal observations of the authors. To form a survey on the diversity of bilabiate blossoms, a search was made for examples across the angiosperms and these were combi…
DEVELOPMENTAL ASPECTS OF DRUG METABOLISM
1977
Publisher Summary This chapter discusses the developmental aspects of drug metabolism and those of other biological phenomena that are twofold. Development is described by examining various species of different levels of biological evolution or by studying the ontogenetic evolvement of the features in question in one animal species or groups of related species. A review on diene-organochlorine insecticides epitomizes the fact that insects, birds, and fish possess the enzymatic mechanisms for epoxidation of these insecticides to only a slightly less degree than do mammals. Thus, the ability to oxidize foreign compounds does not seem to be restricted to animals of higher organization, and con…