PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Cheirogaleidae”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 19 recordsLinked to original sources
PubMed1994

Relative position of the Cheirogaleidae in strepsirhine phylogeny: a comparison of morphological and molecular methods and results.

An examination of previous morphological and molecular studies of strepsirhine systematics suggests a conflict between the two types of data. Cladistic analyses of morphological data have indicated that the Malagasy primate family Cheirogaleidae is the sister taxon of the Afro-Asian lorisiforms and that together, cheirogaleids and lorisiforms comprise a monophyletic clade that excludes the Malagasy lemuriforms. Molecular studies, on the other hand, have consistently found that cheirogaleids and lemuriforms together are monophyletic to the exclusion of lorisiforms. Both types of studies, however, have suffered from methodological weaknesses: the morphological studies looked at too few characters and the molecular studies looked at too few taxa. This study examines a large and diverse morphological data set as well as molecular data from a comprehensive sample of strepsirhine taxa. The data sets are considered independently and jointly. When they are analyzed independently, the morphological data give weak support, and the molecular data strong support, to the hypothesis of Malagasy primate monophyly. When the two data sets are combined in a single analysis, the results are decisive. The "total evidence" approach yields compelling support to the hypothesis that cheirogaleids and remaining Malagasy lemuriforms comprise a monophyletic assemblage that excludes lorisiforms.

Animals↗
PubMed1983

Chromosomal evolution in Malagasy lemurs. VII. Phylogenic relationships between Propithecus, Avahi (Indridae), Microcebus (Cheirogaleidae), and Lemur (Lemuridae).

A chromosomal banding study was carried out on Propithecus verreauxi verreauxi, P. verreauxi deckeni, and Avahi laniger laniger. Comparison of their karyotypes with those of Microcebus murinus and Lemur fulvus led to reconstruction of the ancestral Lemuriform karyotype and a determination that the branch leading to the Indridae was isolated very early, before the separation of the Lemuridae from the Cheirogaleidae. The karyotype of Avahi remained highly ancestral, whereas that of P. verreauxi was considerably modified, chiefly by Robersonian translocations.

Animals↗
PubMed1989

Lightmicroscopical investigations of the sublingua of Microcebus murinus (Cheirogaleidae, Lemuriformes) with remarks on the phylogenetic relations of the tree shrews (Scandentia) to primates.

The sublingua of Microcebus murinus was studied gross anatomically and light microscopically. The apex of the sublingua ends in two lobe-like projections separated by a distinct median cleft. The lobes exhibit at their oral, free margin tiny processes, but no "comb"-like specializations of intensely keratinized mucosa. At the ventral surface of the sublingua three longitudinally oriented keels or ridges are found; the mucosa of the keels is strongly keratinized, so that these structures maximize the rigidity of the undertongue. In none of the specimens examined was any trace of sublingual cartilage found; in the sublingua of Cheirogaleus (only one individual examined), the nearest relative of Microcebus, cartilage was also absent. The absence of sublingual cartilage and the incidental, irregular occurrence of cartilaginous elements in the sublingua of Tarsius and Tupaia indicate that the sublingual cartilaginous skeleton is not a derivative of the hyoid arch. It is a newly developed supporting structure which does not regularly occur. A sublingua occurs only in prosimians and Tarsius; whether the fimbria linguae of the Hominoidea is the homologue of a sublingua is still disputable. The exclusive occurrence of a sublingua in prosimians and Tarsius indicates a phylogenetic relationship between these two groups and Tupaia. The "Tupaia-problem" concerns the origin of primates and from this point it derives its general importance. At present we are far from a final solution; a definite answer cannot be expected before sufficient fossil records are available which document conclusively the historical paths of the origin of primates.

Animals↗
PubMed1976

Immunodiffusion systematics of the primates. III. The strepsirhini.

Immunodiffusion comparisons have been run using 26 antisera including seven made to strepsirhine species. Spur size data resulting from these comparisons have been analyzed by computer and depict Strepsirhini as a monophyletic group within Primates including Lemuriformes and Lorisiformes. Cheirogaleidae is retained with Lemuriformes. Indriidae rather than Cheirogaleidae is depicted as closer to Lemur. Evidence is presented indicating that Lorisiformes is composed of three groups rather than two as in traditional classifications. The three groups, which are considered here to diverage at a family level, are Galagidae, Lorisidae, and Perodicticidae.

Animals↗
PubMed1989

Cranial morphology of Aegyptopithecus and Tarsius and the question of the tarsier-anthropoidean clade.

New crania of the Oligocene anthropoidean Aegyptopithecus provide a test of the hypothesized tarsier-anthropoidean clade. Three cranial characters shared by Tarsius and some modern anthropoideans (apical interorbital septum, postorbital septum, "perbullar" carotid pathway) were examined. 1) An apical interorbital septum is absent in Aegyptopithecus. A septum does occur in Galago senegalensis (Lorisidae) and Microcebus murinus (Cheirogaleidae), so the presence of a septum is not strong evidence favoring a tarsiiform-anthropoidean clade. 2) In Aegyptopithecus and other anthropoideans, the postorbital septum is formed mainly by a periorbital flange of the zygomatic that extends medially from the lateral orbital margin onto or near the braincase. The postorbital plate of Tarsius is formed by frontal and alisphenoid flanges that extend laterally from the braincase to the zygomatic's frontal process, which is not broader than the postorbital bars of other prosimians. Periorbital flanges evolved in Tarsius for support or protection of the enormous eyes, as suggested by the occurrence of maxillary and frontal flanges that cup portions of the eye but do not separate it from temporal muscles. 3) The internal carotid artery of Aegyptopithecus enters the bulla posteriorly and crosses the anteroventral part of the promontorium. The tympanic cavity was probably separated from the anteromedial cavity by a septum stretching from the carotid channel to the ventrolateral bullar wall. In Tarsius, the carotid pathway is prepromontorial, and a septum stretches from the carotid channel to the posteromedial bullar wall. Quantitative analyses indicate that anterior carotid position has evolved because of erect head posture. The cranium of Oligocene anthropoideans thus provides no support for the hypothesized tarsier-anthropoidean clade.

Animals↗
PubMed1994

Molecular evidence on primate phylogeny from DNA sequences.

Evidence from DNA sequences on the phylogenetic systematics of primates is congruent with the evidence from morphology in grouping Cercopithecoidea (Old World monkeys) and Hominoidea (apes and humans) into Catarrhini, Catarrhini and Platyrrhini (ceboids or New World monkeys) into Anthropoidea, Lemuriformes and Lorisiformes into Strepsirhini, and Anthropoidea, Tarsioidea, and Strepsirhini into Primates. With regard to the problematic relationships of Tarsioidea, DNA sequences group it with Anthropoidea into Haplorhini. In addition, the DNA evidence favors retaining Cheirogaleidae within Lemuriformes in contrast to some morphological studies that favor placing Cheirogaleids in Lorisiformes. While parsimony analysis of the present DNA sequence data provides only modest support for Haplorhini as a monophyletic taxon, it provides very strong support for Hominoidea, Catarrhini, Anthropoidea, and Strepsirhini as monophyletic taxa. The parsimony DNA evidence also rejects the hypothesis that megabats are the sister group of either Primates or Dermoptera (flying lemur) or a Primate-Dermoptera clade and instead strongly supports the monophyly of Chiroptera, with megabats grouping with microbats at considerable distance from Primates. In contrast to the confused morphological picture of sister group relationships within Hominoidea, orthologous noncoding DNA sequences (spanning alignments involving as many as 20,000 base positions) now provide by the parsimony criterion highly significant evidence for the sister group relationships defined by a cladistic classification that groups the lineages to all extant hominoids into family Hominidae, divides this ape family into subfamilies Hylobatinae (gibbons) and Homininae, divides Homininae into tribes Pongini (orangutans) and Hominini, and divides Hominini into subtribes Gorillina (gorillas) and Hominina (humans and chimpanzees). A likelihood analysis of the largest body of these noncoding orthologues and counts of putative synapomorphies using the full range of sequence data from mitochondrial and nuclear genomes also find that humans and chimpanzees share the longest common ancestry.

Animals↗
PubMed1979

Chromosomal evolution in Malagasy lemurs. IV. Chromosome banding studies in the genuses Phaner, Varecia, Lemur, Microcebus, and Cheirogaleus.

The karotypes of five species of Malagasy lemurs are described and compared with those of 12 previously studied species or subspecies. Based on these studies, phylogenetic relationships among nearly all the species of Cheirogaleidae and Lemuridae are proposed. The karyotype of the common ancestor is identical or very similar to that of Microcebus. Nearly 60 chromosomal changes, including five intrachromosomal rearrangements of the X chromosome, have been detected during the evolution of these two families. The possible evolutionary role of the different chromosomal rearrangements is discussed.

Animals↗
PubMed1982

Reproduction in Cheirogaleus medius.

The reproductive behavior of 20 captive Cheirogaleus medius was studied over two breeding seasons in 1980 and 1981. Seasonality, estrous cycle, sexual behavior, sexual maturity, and postpartum estrus are described. Reproduction of the different species of the family Cheirogaleidae as well as that of the Galaginae and Lemuridae is compared.

Animals↗
PubMed1998

Topographical localization of iron in brains of the aged fat-tailed dwarf lemur (Cheirogaleus medius) and gray lesser mouse lemur (Microcebus murinus).

Iron deposits in the human brain are characteristic of normal aging but have also been implicated in various neurodegenerative diseases. Among nonhuman primates, strepsirhines are of particular interest because hemosiderosis has been consistently observed in captive aged animals. In particular, the cheirogaleids, because of their small size, rapid maturity, fecundity, and relatively short life expectancy, are a useful model system for the study of normal and pathological cerebral aging. This study was therefore undertaken to explore iron localization in the brain of aged cheirogaleids (mouse and dwarf lemurs) with histochemistry and magnetic resonance microscopy. Results obtained with both techniques were comparable. There was no difference between old animals in the two species. The young animals (3 years old) showed no iron deposits. In the old animals (8-15 years old), iron pigments were mainly localized in the globus pallidus, the substantia nigra, the neocortical and cerebellar white matter, and anterior forebrain structures, including the nucleus basalis of Meynert. This distribution agrees with previous findings in monkeys and humans. In addition, we observed iron in the thalamus of these aged non-human primates. Microscopic NMR images clearly reveal many features seen with the histochemical procedure, and magnetic resonance microscopy is a powerful method for visualizing age-related changes in brain iron.

Aging↗
PubMed1998

Sex-specific usage patterns of sleeping sites in grey mouse lemurs (Microcebus murinus) in northwestern Madagascar.

Sleeping sites are a potentially important resource for grey mouse lemurs since they are confronted with high daily temperature fluctuations and a high predation pressure. In order to determine the existence and degree of resource competition, sleeping site characteristics, locations, and usage patterns as well as sleeping group compositions were investigated in a 3 month field study in a dry deciduous forest of northwestern Madagascar. The daily sleeping sites of females were on average better insulated and safer than those of males. Males used more sleeping sites and changed the site more often than females. During the whole study, males slept alone, whereas the females formed stable sleeping groups in on average 83.7% of the days. Sex-specific differences in usage patterns might be explained by intersexual resource competition and female dominance and could possibly be related to differential parental investment of the sexes. The underlying study indicates that sleeping sites may be a restricted and defendable resource for grey mouse lemurs. The investigation gives new insights into the distribution patterns and social organization of this species.

Animals↗
PubMed1996

Molecular cloning, sequencing, and brain expression of the presenilin 1 gene in Microcebus murinus.

The cDNA encoding the Microcebus murinus presenilin 1 protein (PSI) was cloned by RT-PCR from a brain cDNA library using various combinations of oligonucleotide primers designed on the basis of the human nucleotide sequence. Analysis of five clones isolated from two positive combinations revealed that the deduced open reading frame encodes two protein isoforms of 467 and 463 amino acid residues. The shorter isoform lacked the four residues VRSQ in the N-terminal region and like the 467 amino acid isoform presented 22 substitutions with its human homologue. The 12 bp nucleotide deletion evidenced in the cDNA encoding the shorter isoform is consistent with the use of an alternative 5' splice donor site identified at the end of the human exon 3. The immunohistochemistry performed with a specific polyclonal antiserum raised against a synthetic peptide located in the human large hydrophilic loop of PS1 revealed that the protein is widely distributed independently of age or of pathology in the microcebe brain. PS1 is found predominantly in neurons of the different cortical layers and hippocampus but also in subcortical structures. The PS1 labelling appeared as thin granulations scattered throughout the cytoplasm of numerous neurons and sometimes in neurites.

Aging↗
PubMed1996

Cholinergic axonal dystrophy and mitochondrial pathology in prosimian primates.

Progressive cholinergic axonal dystrophy, cholinergic denervation, and generalized gliosis begin in the prosimian primate species Otolemur at 10% of maximum life span. In these same animals, extensive cerebral beta-amyloidosis follows relatively more abruptly at 50% of maximum life span. In contrast, even at maximum life span, the prosimian primate species Galago senegalensis Moholi, Microcebus murinus, and Eulemur fulvus collaris and insectivore species T. belangeri are either spared or much less affected. In this report, we further document this progressive cholinergic denervation in Otolemur which involves first projections of the pedunculopontine nucleus (PPN, CH5-6) and later projections of CH1-4 cholinergic nuclei, as well as other noncholinergic pathways. Affected cholinergic cell bodies and axons contain abnormal mitochondria with increased content of manganese superoxide dismutase (MnSOD). This syndrome correlates with moderate copper deficiency marked by diminished liver copper levels and cuproenzyme activities, carnitine deficiency possibly secondary to renal Fanconi syndrome, and evidence for stress inflammatory response activation. Mitochondrial pathology was observed in pancreatic islet cells, proximal renal tubule epithelial cells, and choroid plexus epithelial cells, and it involved central cholinergic neurons. In Otolemur garnetti, the degree of central cholinergic injury directly correlated to depression of liver copper stores. The Otolemur syndrome involves "sentinel" central cholinergic injury and selective mitochondrial pathology in cell classes defined by high mitochondrial content and/or metabolic activity and high content of nitric oxide synthetase and MnSOD. Environmental factors affecting copper and carnitine metabolism could interact with genetic defects or traits to produce abnormal and aggressive aging of Otolemur. Subclinical, cell-class specific mitochondrial dysfunction in these prosimian primates may be a model for human neurodegenerative diseases.

Aging↗
PubMed1995

Identification of a unique apolipoprotein E allele in Microcebus murinus; ApoE brain distribution and co-localization with beta-amyloid and tau proteins.

This report is devoted to the characterization of the apolipoprotein E (ApoE) in Microcebus murinus. Only one allele homologous to the human ApoE4 allele was evidenced. The distribution of the corresponding ApoE protein in the brain was found in association with the pathological proteins characteristic of Alzheimer's disease (AD). Immunocytochemistry revealed brain deposits of ApoE in: (1) the cortical amyloid plaques; (2) the neurones of the various cortical lobes, the hippocampus and the brainstem; (3) the glial cells, astrocytes of the cortical parenchym and oligodendrocytes of the corpus callosum; and (4) the vessel walls. Most ApoE, beta-amyloid protein, abnormally phosphorylated Tau proteins and gliofilament acid proteins were seen in the same cortical areas. These findings for ApoE report the view that Microcebus murinus, in captivity, presents a pathological profile very similar to that observed in AD.

Alleles↗
PubMed1996

beta-Amyloid protein precursor in Microcebus murinus: genotyping and brain localization.

Senile plaques characterized by beta-amyloid protein (A beta) deposits around dystrophic neurites and glial cells are more abundant in the cerebral cortical parenchyma of Alzheimer's disease (AD) patients than in the aged population. Four different mutations in the amyloid precursor protein (APP) gene have been directly involved in a few cases of familial AD with early onset (before 60 years). Previous studies have shown that Microcebus murinus, a nonhuman primate, also develops analogous deposits of A beta in the cortical parenchyma and blood vessel walls in the brain. Sequence analysis of exons 16 and 17 of the APP gene, encoding for A beta, revealed that even if nucleotide divergences occurred, the resulting peptide is completely homologous with the human A beta. The systematic comparison of the A beta nucleotide sequence in microcebus with or without amyloid deposits revealed that neither the presence of mutations involved in some cases of early onset familial AD nor the presence of a mutational founder effect can explain the amyloidosis observed in some old microcebus of our breeding. Localization of the APP was performed by immunocytochemistry in the brains of adult microcebus (1 to 11 years of age) using two antibodies raised against the C-terminus and N-terminus portions of APP. Microscopic examinations revealed that in the microcebus the APP distribution was similar to that observed in the human: (1) A beta and its precursor were simultaneously observed in amyloid plaques (AP) of the cortical parenchyma; (2) APP was localized in cell bodies and proximal dendrites of neurons, in astrocytes and oligodendrocytes, and in blood vessel and capillary walls; (3) labeling of APP in these structures was correlated with the presence of AP; and (4) labeling of APP increased with the age of the animal.

Amino Acid Sequence↗
PubMed1994

Mouse lemur microscopic MRI brain atlas.

We present a three-dimensional (3D) digital atlas of a mouse lemur head at 60-micron cubic voxel isotropic resolution. It was constructed from a 3D proton magnetic resonance image (MRI) acquired at 500 MHz. It shows views of 3D volume-rendering and movies of contiguous 2D plane cuts in three orthogonal directions. This MR data set was acquired using a spin-echo pulse sequence under conditions of strong T2 and significant diffusion weighting. Experimental parameters were optimized to provide strong intrinsic contrast between gray and white matter. Familiar anatomical structures are clearly identifiable. Fine fiber tracts, laminations of cortices, details of the inner ears, and layering in the lateral geniculate nuclei are all visible. Anatomical identifications of structures in representative slices selected from the atlas are presented. We also describe some difficulties and trade-offs encountered in microscopic resolution MRI. We note that this type of atlas does not suffer from the spatial distortions and slice registration problems introduced by standard histological techniques. Future in vivo longitudinal studies will provide atlases describing in detail the development of the primate brain.

Animals↗
PubMed1995

Effects of aging upon recent memory in Microcebus murinus.

Four young (2 to 4-year-old) and four aged (9 to 10-year-old) grey mouse lemurs (Microcebus murinus) were given a simple visual discrimination task, and a delayed response visual discrimination task with variable retention delay. The response to the test is a motor one, that consists of choosing one out of four corridors of an apparatus based upon the degree of illumination. The aged animals did not show any learning deficiency, and were capable of memorizing the task for several months. However, they were more sensitive to the length of the delay in the delayed response task than the young animals. It is, therefore, possible to argue that the memory for recent stimulus events is affected during aging. These results corroborate those obtained in other primates, and demonstrate the usefulness of the grey mouse lemur as a new animal model for analyzing aging.

Aging↗