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Biomedical subjects

J Couturier

Publications and source records attributed to J Couturier.

At least 91 records · Page 5Linked to original sources
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↗
PubMed1983

The karyotype of Galago crassicaudatus is ancestral for lorisiforms.

The karyotype, comprised of 62 chromosomes, of Galago crassicaudatus is described. It is compared to the karyotype of Galago senegalensis and to that of the presumed common ancestor to Lorisiforms, previously reconstructed. Most of the reconstructed chromosomes were found, unmodified, in G. crassicaudatus, strengthening the validity of the reconstruction.

Animals↗
PubMed1982

[Increased activity of adenine phosphoribosyl transferase in a child trisomic for 16q22.2 to 16qter due to malsegregation of a t(16;21) (q22.2;q22;2)pat].

Two cousins with trisomy for the distal third of 16q due to a familial translocation, t(16;21)(q22.2;q22.2), are reported. The APRT gene locus could be assigned to 16q22.2 to 16qter. The phenotypic similarities of the first patient, who had trisomy 16q22.3 to 16qter and monosomy 21q22.3, to six other patients with partial trisomy 16q reported in literature allows the delineation of a syndrome due to trisomy 16qter. In the second patient, with trisomy 16q22.3 to 16qter and trisomy 21pter to 21q22.2, similar features are present, but in association with the classical symptoms of trisomy 21.

Adenine Phosphoribosyltransferase↗
PubMed1982

Cytogenetical and biochemical characterization of a dG + dC-rich satellite DNA in the primate Cebus capucinus.

A very abundant and dG + dC rich DNA satellite from primate Cebus capucinus has been characterized in its cytogenetic and biochemical properties with the purpose of studying the correlation between the staining properties of heterochromatin and the base composition of the corresponding very repetitive DNA. The staining techniques, as well as incorporation of base analogues, show that the heterochromatin segments of C. capucinus chromosomes correspond to a dG + dC-rich satellite. This satellite was detected and isolated by centrifugation in density gradient, radioactively labelled and localized by in situ hybridization on heterochromatin segments.

Animals↗
PubMed1982

Chromosomal evolution in "lemurs". VI. Chromosomal banding studies of Galago senegalensis, Galago alleni, Galago demidovii and Euoticus elegantulus.

The karyotype of four Galagidae (Galago senegalensis, G. demidovii, G. alleni and Euoticus elegantulus) are studied and compared with the aid of various banding techniques. Many common chromosome segments were found, and it was possible to reconstruct a hypothetical ancestral karyotype for the family. It was also possible to show the relation between the chromosomes of Galagidae with those of two Lorisidae. The general scheme of chromosomal evolution of the Lorisiforms can be proposed, resulting from a common populational evolution followed by an accumulation of translocations, mostly of the Robertsonian type. Several pericentric inversions have also occurred in the trunk of the Lorisidae, emerging from this common population. Then, Galagidae have evolved, each species independently, by an accumulation of translocations, mostly Robertsonian, whereas Lorisidae have accumulated pericentric inversions prior diverging.

Animals↗
PubMed1982

[Increased activity of adenine phosphoribosyl transferase in a child trisomic for 16q22.2 to 16qter due to malsegregation of a t(16;21) (q22.2;q22;2)pat (author's transl)].

Two cousins with trisomy for the distal third of 16q due to a familial translocation, t(16;21)(q22.2;q22-2), are reported. The APRT gene locus could be assigned to 16q22.2 to 16qter. The phenotypic similarities of the first patient, who had trisomy 16q22.3 to 16qter and monosomy 21q22.3, to six other patients with partial trisomy 16q reported in literature allows the delineation of a syndrome due to trisomy 16qter. In the second patient, with trisomy 16q22.3 to 16qter and trisomy 21pter to 21q22.2 similar features are present but in association with the classical symptoms of trisomy 21.

Adenine Phosphoribosyltransferase↗
PubMed1982

[Comparative karyotyping of our gibbon species or subspecies (author's transl)].

The karyotypes of several Hylobatidae Hylobates (Hylobates) lar pileatus, H. (Nomascus) concolor leucogenys, H. (N.) concolor ssp, Hybrid H. (N.) concolor leucogenys x H. (N.) concolor gabriellae, H (Symphalangus) syndactylus are compared both each others and also to those of other Primates. Many rearrangements of their chromosomes have occurred during their evolution, and some polymorphism still exists in the living species. This high rate of chromosome rearrangements is in contrast with their phenotypic stability. It is very likely that reciprocal translocations have occurred, these rearrangements being very rare in the evolution of other Primates.

Animals↗
PubMed1982

Chromosomal phylogeny of forty-two species or subspecies of cercopithecoids (Primates Catarrhini).

After comparison of the chromosomes of 42 species or subspecies belonging to Cercopithecinae, Papioninae and Colobidae, a phylogeny based on the sequence of chromosomal rearrangements is proposed for Cercopithecoidea. From their last common ancestor, which possessed 46 chromosomes, a trifurcation gave 3 branches, very unequal as regards chromosomal rearrangements. One, very short, leads to Papioninae. Another, still poorly known, leads to Colobidae. The last branch leads to a further bifurcation, separating 2 groups of Cercopithecinae, with underwent the most active chromosomal evolution. A tentative to reconcile chromosomal, biochemical and morphological data is presented for Papioninae, for which chromosome study alone is not sufficient to construct a cladogram.

Animals↗
PubMed1982

[Non random position of metaphasic chromosomes. II. Effect of condensation on the position of X chromosomes].

A study is reported on the location of X chromosomes in human female lymphocytes and fibroblasts at mitosis. By the use of BrdU, incorporated during either early or late S-phase, the late and the early replicating Xs were identified, so that it could be determined which was more peripheral in the metaphase plate. In lymphocytes, when BrdU is incorporated during late S-phase, the late-replicating X, which is the less condensed, is the more peripheral. On the contrary, when BrdU is incorporated during early S-phase, the early replicating X, which is the less condensed, is the more peripheral. On the other hand, in fibroblasts grown on coverslips, the late-replicating X is always peripheral, regardless of the time of BrdU treatment. These results confirm the peripheral location of the late-replicating X and demonstrate the presence of artifacts, depending on chromosome condensation, occurring during the procedures of slide preparation.

Female↗
PubMed1982

[Attenuated phenotype of trisomy 4p by translocation t(X;4)(p21.2;p13)].

A 9-year-old girl with trisomy 4p and monosomy Xp by malsegregation of a maternal translocation t(X;4)(p21.2;p13) was found to have less severe clinical abnormalities and mental retardation than expected for a 4p trisomy syndrome. Height and weight were within the normal range. X replication was studied by BrdU incorporation: in the mother, the normal X was late replicating except in a few cells in which the translocation X was late. In all cells studied from the proband, the translocation X was late, and this late replication extended into the adjoined 4p segment.

Child↗
PubMed1981

Conservation of replication chronology of homologous chromosome bands between four species of the genus Cebus and man.

Replication patterns after 5-bromodeoxyuridine incorporation are analyzed in chromosomes of four species of the genus Cebus (C. capucinus, C. albifrons, C. appella, and C. nigrivittatus). They are compared with those of man, taking as reference the banding analyses previously described. It was found that the high degree of conservation of chromosome structures between Cebus and man was accompanied by conservation of the DNA-replication sequence of the bands. It is assumed that this conservation during the course of evolution may apply to other mammals. Thus, replication patterns may be useful for ensuring interspecific comparisons. The only detected difference concerns late-replicating X chromosomes from normal female cells: The predominant lymphocyte pattern described in man is rare in Cebus, in which the usual lymphocyte pattern corresponds to that of human fibroblasts or to the minor human lymphocyte pattern.

Animals↗
PubMed1981

[Cytogenetics of Cercopithecus (mona) campbelli. Comparison with other cercopithecus species and man (author's transl)].

The karyotype of C. (mona) campbelli campbelli is described after applying various banding techniques. After comparing this karyotype with those of numerous other Cercopithecus species it becomes possible to situate C. (m.) c. campbelli in the phylogeny of the group. A comparison with the human karyotype, after high resolution banding, shows that both species differ by some forty rearrangements, essentially fissions and inversions. A fission of the chromosome homologous to the human no. 10 occurred in this taxon, thus reproducing a chromosome present in Prosimii and Lagomorpha (rabbit), which can be considered as a reverse mutation.

Animals↗
PubMed1981

[The karyotypes of Colobus vellersus and of C. palliatus: comparison with Cercopithecidae and man].

The karyotypes of two species of African Colobidae, Colobus vellerosus and C. palliatus, as well that of their hybrid, are described and compared. The two species differ by four pericentric inversions, indicating species divergence a relatively long time ago. Chromosome banding analogies with Papioninae, Cercopithecinae, and man are described. A common origin for Papioninae, Cercopithecinae, and Colobidae is indisputable; but, there are no arguments for considering that a close relationship exists between Colobidae and Hylobatidae as suggested by some authors.

Animals↗
PubMed1980

[Partial 11q trisomy due to missegregation of maternal t(11;22) (q23;q11.1) translocation (author's transl)].

In a 4-month-old female infant with multiple congenital abnormalities karyotyping revealed a 47,XX, + der (22), t (11;22) (q23.1;q11.1) mat pattern, resulting from a maternal translocation, which was also found in other members of the mother's family. The phenotype was consistent with the physical abnormalities described in previously reported cases of partial 11 q trisomy. The apparently high incidence of this type of translocation is surprising.

Abnormalities, Multiple↗