Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “MAMMALS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,477 records · Page 82Linked to original sources
PubMed2000

Paired Ig-like receptor homologs in birds and mammals share a common ancestor with mammalian Fc receptors.

Paired Ig-like receptors (PIR) that can reciprocally modulate cellular activation have been described in mammals. In the present study, we searched expressed sequence tag databases for PIR relatives to identify chicken expressed sequence tags predictive of approximately 25% amino acid identity to mouse PIR. Rapid amplification of cDNA ends (RACE)-PCR extension of expressed sequence-tag sequences using chicken splenic cDNA as a template yielded two distinct cDNAs, the sequence analysis of which predicted protein products with related extracellular Ig-like domains. Chicken Ig-like receptor (CHIR)-A was characterized by its transmembrane segment with a positively charged histidine residue and short cytoplasmic tail, thereby identifying CHIR-A as a candidate-activating receptor. Conversely, CHIR-B was characterized by its nonpolar transmembrane segment and cytoplasmic tail with two immunoreceptor tyrosine-based inhibitory motifs, indicating that it may serve as an inhibitory receptor. The use of CHIR amino acid sequences in a search for other PIR relatives led to the recognition of mammalian Fc receptors as distantly related genes. Comparative analyses based on amino acid sequences and three-dimensional protein structures provided molecular evidence for common ancestry of the PIR and Fc receptor gene families.

Amino Acid Sequence↗
PubMed2003

Divergence of Hoxc8 early enhancer parallels diverged axial morphologies between mammals and fishes.

There is considerable interest in understanding how cis-regulatory modifications drive morphological changes across species. Because developmental regulatory genes, including Hox genes, are remarkably conserved, their noncoding regulatory regions are likely sources for variations. Modifications of Hox cis-regulatory elements have potential to alter Hox gene expression and, hence, axial morphologies. In vertebrates, differences in the axial levels of Hox gene expression correlate with differences in the number and relative position of thoracic vertebrae. Variation in cis-regulatory elements of Hox genes can be identified by comparative sequence and reporter gene analyses in transgenic mouse embryos. Using these approaches, we show a remarkable divergence of the Hoxc8 early enhancers between mammals and fishes representing diverse axial morphologies. Extensive restructuring of the Hoxc8 early enhancer including nucleotide substitutions, inversion, and divergence result in distinct patterns of reporter gene expression along the embryonic axis. Our results provide an evolutionary perspective on how the enhancer elements are engineered and support the hypothesis that remodeling of Hox regulatory elements in different species has played a significant role in generating morphological diversity.

Amino Acid Sequence↗
PubMed1980

Brain size and ecology in small mammals and primates.

Comparisons of brain-body size relationships within small mammal and primate families reveal intergeneric differences related to diet and foraging strategy. These same associations between relative brain size and ecology are also evident among interfamily comparisons.

Animals↗
PubMed1993

Superfamily Gondwanatherioidea: a previously unrecognized radiation of multituberculate mammals in South America.

Multituberculates were the longest-lived order of the Class Mammalia and, during the Mesozoic and early Cenozoic, were among the most diverse and abundant representatives of the class. However, until the recent discovery of two Cretaceous teeth, one from South America and one from Africa, they were known only from northern continents. Additional material of the South American form Ferugliotherium has confirmed its multituberculate affinities and indicates that it may be a derived member of the Suborder Plagiaulacoidea. New specimens provide evidence that two other South American forms, Gondwanatherium and Sudamerica, are also multituberculates and that they are closely related to Ferugliotherium. Gondwanatherium and Sudamerica, each possessing highly specialized hypsodont molars, were previously thought to be the earliest known representatives of the Edentata, to be involved in the origin of edentates, or to represent a previously unknown higher taxon of mammals. However, there are detailed similarities in gross dental morphology, enamel microstructure, and inferred direction of jaw movement among Ferugliotherium, Gondwanatherium, and Sudamerica. All three genera are here regarded as representatives of a highly derived, endemic radiation of South American multituberculates and are allocated to the superfamily Gondwanatherioidea. Multituberculates were therefore more common elements of Late Cretaceous and early Paleocene mammalian faunas of South America than previously recognized.

Animals↗
PubMed1994

Evolutionary relationships of lactate dehydrogenases (LDHs) from mammals, birds, an amphibian, fish, barley, and bacteria: LDH cDNA sequences from Xenopus, pig, and rat.

The nucleotide sequences of the cDNAs encoding LDH (EC 1.1.1.27) subunits LDH-A (muscle), LDH-B (liver), and LDH-C (oocyte) from Xenopus laevis, LDH-A (muscle) and LDH-B (heart) from pig, and LDH-B (heart) and LDH-C (testis) from rat were determined. These seven newly deduced amino acid sequences and 22 other published LDH sequences, and three unpublished fish LDH-A sequences kindly provided by G. N. Somero and D. A. Powers, were used to construct the most parsimonious phylogenetic tree of these 32 LDH subunits from mammals, birds, an amphibian, fish, barley, and bacteria. There have been at least six LDH gene duplications among the vertebrates. The Xenopus LDH-A, LDH-B, and LDH-C subunits are most closely related to each other and then are more closely related to vertebrate LDH-B than LDH-A. Three fish LDH-As, as well as a single LDH of lamprey, also seem to be more related to vertebrate LDH-B than to land vertebrate LDH-A. The mammalian LDH-C (testis) subunit appears to have diverged very early, prior to the divergence of vertebrate LDH-A and LDH-B subunits, as reported previously.

Amino Acid Sequence↗
PubMed1994

Mammal extinctions, body size, and paleotemperature.

There is a general inverse relationship between the natural logarithm of tooth area (a body size indicator) of some fossil mammals and paleotemperature during approximately 2.9 million years of the early Eocene in the Bighorn Basin of northwest Wyoming. When mean temperatures became warmer, tooth areas tended to become smaller. During colder times, larger species predominated; these generally became larger or remained the same size. Paleotemperature trends also markedly affected patterns of local (and, perhaps, regional) extinction and immigration. New species appeared as immigrants during or near the hottest (smaller forms) and coldest (larger forms) intervals. Paleotemperature trend reversals commonly resulted in the ultimate extinction of both small forms (during cooling intervals) and larger forms (during warming intervals). These immigrations and extinctions mark faunal turnovers that were also modulated by sharp increases in sediment accumulation rate.

Animals↗
PubMed1995

Parasite abundance and diversity in mammals: correlates with host ecology.

Fecally dispersed parasites of 12 wild mammal species in Mudumalai Sanctuary, southern India, were studied. Fecal propagule densities and parasite diversity measures were correlated with host ecological variables. Host species with higher predatory pressure had lower parasite loads and parasite diversity. Host body weight, home range, population density, gregariousness, and diet did not show predicted effects on parasite loads. Measures of alpha diversity were positively correlated with parasite abundance and were negatively correlated with beta diversity. Based on these data, hypotheses regarding determinants of parasite community are discussed.

Animals↗
PubMed1998

Paleoindian large mammal hunters on the plains of North America.

From approximately 11,200 to 8,000 years ago, the Great Plains of North America were populated by small Paleoindian hunting groups with well developed weaponry and the expertise to successfully hunt large mammals, especially mammoths and bison. Mammoths became extinct on the Plains by 11,000 years ago, and, although paleoecological conditions were worsening, their demise may have been hastened by human predation. After this, the main target of the Plains Paleoindian hunters consisted of subspecies of bison, Bison antiquus and Bison occidentalis. As bison populations gradually diminished, apparently because of worsening ecological conditions, by approximately 8,000 years ago, human subsistence was forced into a greater dependence on small animal and plant foods. Human paleoecology studies of the Paleoindian time period rely heavily on multidisciplinary efforts. Geomorphologists, botanists, soil scientists, palynologists, biologists, and other specialists aid archaeologists in data recovery and analysis, although, with few exceptions, their contributions are derived from the fringes rather than the mainstream of their disciplines.

Animals↗
PubMed2001

Protein sequence signatures support the African clade of mammals.

DNA sequence evidence supports a superordinal clade of mammals that comprises elephants, sea cows, hyraxes, aardvarks, elephant shrews, golden moles, and tenrecs, which all have their origins in Africa, and therefore are dubbed Afrotheria. Morphologically, this appears an unlikely assemblage, which challenges-by including golden moles and tenrecs-the monophyly of the order Lipotyphla (Insectivora). We here identify in three proteins unique combinations of apomorphous amino acid replacements that support this clade. The statistical support for such "sequence signatures" as unambiguous synapomorphic evidence for the naturalness of the Afrotherian clade is reported. Using likelihood, combinatorial, and Bayesian methods we show that the posterior probability of the mammalian tree containing the Afrotherian clade is effectively 1.0, based on conservative assumptions. Presenting sequence data for another African insectivore, the otter shrew Micropotamogale lamottei, we demonstrate that such signatures are diagnostic for including newly investigated species in the Afrotheria. Sequence signatures provide "protein-morphological" synapomorphies that may aid in visualizing monophyletic groupings.

Africa↗
PubMed1995

Mouse Zp1 encodes a zona pellucida protein homologous to egg envelope proteins in mammals and fish.

Zp1 encodes one of the three major glycoproteins of the zona pellucida, an extracellular matrix that surrounds growing oocytes, ovulated eggs, and preimplantation embryos. The mouse gene is composed of 12 exons ranging in size from 82 to 364 base pairs and spans 6.5 kilobase pairs on chromosome 19 (2.13 +/- 1.5 centimorgans distal to D19Bir1). The Zp1 exon map is similar to ZPB, a human orthologue, and an E-box (CANNTG), implicated in oocyte-specific gene expression of mouse Zp2 and Zp3, is similarly located upstream of the transcription start site. The single copy Zp1 gene encodes a 623-amino acid protein, the carboxyl-terminal half of which is significantly similar to a corresponding region of mouse ZP2. The conservation of this same region in a fish egg envelope protein suggests that not only has this protein domain been duplicated in mammals but that it has been conserved and used as an egg envelope protein in species that diverged 650 million years ago.

Amino Acid Sequence↗
PubMed1998

Newly identified Chinese hamster ovary cell mutants are defective in biogenesis of peroxisomal membrane vesicles (Peroxisomal ghosts), representing a novel complementation group in mammals.

We isolated peroxisome biogenesis-defective mutants from Chinese hamster ovary cells by the 9-(1'-pyrene)nonanol/ultraviolet (P9OH/UV) method. Seven cell mutants, ZP116, ZP119, ZP160, ZP161, ZP162, ZP164, and ZP165, of 11 P9OH/UV-resistant cell clones showed cytosolic localization of catalase, a peroxisomal matrix enzyme, apparently indicating a defect of peroxisome biogenesis. By transfection of PEX cDNAs and cell fusion analysis, mutants ZP119 and ZP165 were found to belong to a novel complementation group (CG), distinct from earlier mutants. CG analysis by cell fusion with fibroblasts from patients with peroxisome biogenesis disorders such as Zellweger syndrome indicated that ZP119 and ZP165 were in the same CG as the most recently identified human CG-J. The peroxisomal matrix proteins examined, including PTS1 proteins as well as a PTS2 protein, 3-ketoacyl-CoA thiolase, were also found in the cytosol in ZP119 and ZP165. Furthermore, these mutants showed typical peroxisome assembly-defective phenotype such as severe loss of resistance to 12-(1'-pyrene)dodecanoic acid/UV treatment. Most strikingly, peroxisomal reminiscent vesicular structures, so-called peroxisomal ghosts noted in all CGs of earlier Chinese hamster ovary cell mutants as well as in eight CGs of patients' fibroblasts, were not discernible in ZP119 and ZP165, despite normal synthesis of peroxisomal membrane proteins. Accordingly, ZP119 and ZP165 are the first cell mutants defective in import of both soluble and membrane proteins, representing the 14th peroxisome-deficient CG in mammals, including humans.

ATPases Associated with Diverse Cellular Activitie↗
PubMed2001

Rh type B glycoprotein is a new member of the Rh superfamily and a putative ammonia transporter in mammals.

Ammonium transporters play a key functional role in nitrogen uptake and assimilation in microorganisms and plants; however, little is known about their structural counterpart in mammals. Here, we report the molecular cloning and biochemical characterization of Rh type B glycoproteins, human RhBG and mouse Rhbg, two new members of the Rh family with distinct tissue specificities. The RhBG orthologues possess a conserved 12-transmembrane topology and most resemble bacterial and archaeal ammonium transporters. Human RHBG resides at chromosome 1q21.3, which harbors candidate genes for medullary cystic kidney disease, whereas mouse Rhbg is syntenic on chromosome 3. Northern blot and in situ hybridization revealed that RHBG and Rhbg are predominantly expressed in liver, kidney, and skin, the specialized organs involving ammonia genesis, excretion, or secretion. Confocal microscopy showed that RhBG is located in the plasma membrane and in some intracellular granules. Western blots of membrane proteins from stable HEK293 cells and from mouse kidney and liver confirmed this distribution. N-Glycanase digestion showed that RhBG/Rhbg has a carbohydrate moiety probably attached at the NHS motif on exoloop 1. Phylogenetic clustering, tissue-specific expression, and plasma membrane location suggest that RhBG homologous proteins are the long sought major ammonium transporters in mammalians.

Amino Acid Sequence↗
PubMed2003

PRISM, a generic large scale proteomic investigation strategy for mammals.

We have developed a systematic analytical approach, termed PRISM (Proteomic Investigation Strategy for Mammals), that permits routine, large scale protein expression profiling of mammalian cells and tissues. PRISM combines subcellular fractionation, multidimensional liquid chromatography-tandem mass spectrometry-based protein shotgun sequencing, and two newly developed computer algorithms, STATQUEST and GOClust, as a means to rapidly identify, annotate, and categorize thousands of expressed mammalian proteins. The application of PRISM to adult mouse lung and liver resulted in the high confidence identification of over 2,100 unique proteins including more than 100 integral membrane proteins, 400 nuclear proteins, and 500 uncharacterized proteins, the largest proteome study carried out to date on this important model organism. Automated clustering of the identified proteins into Gene Ontology annotation groups allowed for streamlined analysis of the large data set, revealing interesting and physiologically relevant patterns of tissue and organelle specificity. PRISM therefore offers an effective platform for in-depth investigation of complex mammalian proteomes.

Animals↗
PubMed2001

Trypanosomatidae from wild mammals in the neotropical rainforest of French Guiana.

The initial filling of the reservoir behind the Petit Saut hydro-electric dam, on the Sinnamary River in French Guiana, threatened the terrestrial and arboreal animals living in the neotropical rainforest being flooded. During a rescue programme between 24 October and 12 November in 1994, many of these animals were checked for infection with trypanosomatids. Overall, 45 blood samples and 54 skin biopsies were collected from 53 mammals (of 13 species representing five orders) and blood samples were also taken from each of nine reptiles (six species from four families). When the skin biopsies and the buffy-coats from the blood samples were cultured in NNN medium, 10 of the cultures, each initiated with mammalian blood, were found to be positive for trypanosomatids. Multilocus enzyme electrophoresis (MLEE) on cellulose acetate plates, with 20 enzyme systems, was then used to investigate each of the positive cultures. The results were analysed by clustering from a genetic distance matrix, using the unweighted pair group method with arithmetic averages (UPGMA), and applying a bootstrap procedure to Wagner parsimony trees. A stock obtained from Didelphis marsupialis was identified as a zymodeme of Trypanosoma cruzi (Miles' zymodeme 1) known to cause Chagas disease in French Guiana. Five stocks (one each from Bradypus tridactylus, Tamandua tetradactyla and Alouatta seniculus and two from Saguinus midas) were of a single zymodeme close to Trypanosoma rangeli reference stock RGB. This is the first confirmation of the presence of Tr. rangeli in French Guiana, and the first time that it has been identified, by iso-enzyme analysis, in the neotropical primates A. seniculus and S. midas. Two other stocks, isolated from Choloepus didactylus, were related to Endotrypanum schaudinni reference stock LEM 2790. Although the remaining stocks, one from C. didactylus and the other from A. seniculus, clustered together on UPGMA and in a Wagner tree, they did not appear to be related to any of the reference stocks included in the UPGMA dendrogram.

Animals↗
PubMed1987

Spontaneous primary myopathies in domestic mammals: a review.

By reviewing the literature concerning primary myopathies in man and animals, a classification of spontaneous primary myopathies in domestic mammals is made. This classification is based on aetiological factors. Primary myopathies are divided into metabolic, immunologic, toxic, nutritional, congenital, inherited, and inflammatory myopathies. Muscular dystrophies, in accordance with the definition in human cases, are considered as a separate entity. In the description of the different muscle disorders the emphasis is on the structural changes and the pathogenesis. Clinical signs and diagnostic criteria are considered only briefly.

Animals↗
PubMedDate not supplied

Signal recognition particles in chloroplasts, bacteria, yeast and mammals (review).

The Signal Recognition Particle (SRP) plays a critical role in the sorting of nascent secretory and membrane proteins. Remarkably, this function has been conserved from bacteria, where SRP delivers proteins to the inner membrane, through to eukaryotes, where SRP is required for targeting of proteins to the endoplasmic reticulum. This review focuses on present understanding of SRP structure and function and the relationship between the two. Furthermore, the similarities and differences in the structure, function and cellular role of SRP in bacteria, chloroplasts, fungi and mammals will be stressed.

Animals↗
PubMed1999

Phylogenetic assessment of molecular and morphological data for eutherian mammals.

The interordinal relationships of eutherian (placental) mammals were evaluated by a phylogenetic analysis of four published data sets (three sequences and one morphological). The nature and degree of support and conflict for particular groups were assessed by separate bootstrap and homogeneity tests, which were followed by combined analyses of the sequence and morphological data. Between orders, strong support (i.e., > or = 95% bootstrap scores) was found for a paraphyletic Artiodactyla (relative to Cetacea) and a monophyletic Cetartiodactyla (Artiodactyla and Cetacea) and Paenungulata (Hyracoidea, Proboscidea, and Sirenia). In turn, some reasonable to strong evidence (> or = 85%) was obtained for Hyracoidea with Sirenia, Dermoptera with Scandentia, Glires (Lagomorpha with Rodentia), and Afrotheria (Amblysomus, Macroscelidea, Paenungulata, and Tubulidentata). Otherwise, no other interordinal clades were supported at these reasonable to strong levels. This overall lack of resolution for eutherian interordinal clusters agrees with other studies that suggest further progress will continue to be slow and difficult. Further resolution will require the integration of more recently published data, the continued sampling of taxa and characters, and the use of more powerful methods of data analysis.

Animals↗
PubMed2000

c-myc gene sequences and the phylogeny of bats and other eutherian mammals.

The complete protein-coding sequences of the c-myc proto-oncogene were determined for five species of four new orders of eutherian (placental) mammals. These newly obtained sequences were aligned to each other and to other available orthologs for the phylogenetic estimation of eutherian interordinal relationships. Several measures of sequence difference and base composition were first calculated to assess the major evolutionary properties of the three codon positions and two protein-coding exons of the gene. On the basis of these calculations, different parsimony, distance, and maximum likelihood approaches were adopted, with the most sophisticated involving the separate, then combined, likelihood analyses of the third codon positions of exon 2 versus all other sites. These phylogenetic approaches provided clear support for the grouping of Chiroptera (bats) with Artiodactyla (ruminants, camels, and pigs) and Carnivora (cats, dogs, and their allies), an interordinal arrangement that receives strong corroboration from other lines of evidence including complete mitochondrial DNA sequences. In contrast, these analyses failed to provide strong to reasonable support for any other interordinal group. This study concludes with specific recommendations about sampling and other strategies for maximizing the phylogenetic contributions of the c-myc gene to the continued resolution of the eutherian ordinal tree.

Animals↗