Biomedical subjects

J C Gautun

Publications and source records attributed to J C Gautun.

6 recordsLinked to original sources

PubMed2001

Cytochrome b sequences reveal Acomys minous (Rodentia, Muridae) paraphyly and answer the question about the ancestral karyotype of Acomys dimidiatus.

Sequences of the cytochrome b (cyt b) mitochondrial gene show that the spiny mouse Acomys from Crete, known as the endemic species A. minous, is composed of two distinct maternal lineages ("A" and "B"). Group "A" sequences cluster with A. nesiotes (Cyprus) and group "B" sequences cluster with A. cilicicus (Turkey), which is evidence of paraphyly of A. minous in regard to these two species. From cyt b sequences, the three taxa are very closely related to A. cahirinus (Egypt): the maximum divergence found among these sequences is 1.6%, which is equivalent to the intraspecific diversity observed in other Acomys species. Paleozoology evidenced that man unintentionally introduced Acomys into Crete and Cyprus during antiquity. The divergence time between Acomys cyt b sequences found in Crete was estimated at 0.4 Myr, which means that the diversity observed did not appear after the introduction but reflects a much more ancient polymorphism. Cytochrome b phylogeny and cytogenetic data together comprise evidence that, within the species A. dimidiatus (Saudi Arabia, Israel, Egypt), it is the karyotypic form with 36 chromosomes that derives from the form with 38 chromosomes, due to a single acrocentric fusion.

Animals↗

PubMed2000

Robertsonian polymorphism, B chromosomes variation and sex chromosomes heteromorphism in the african water rat Dasymys (Rodentia, Muridae).

Chromosome banding analysis (G- and C-bands) of Dasymys rufulus from Senegal, Mali and the Ivory Coast, and D. cf. incomtus from Eastern and South-western Ethiopia was carried out. The diploid numbers (2N) in the former species range between 36 and 39 due to the presence of 0-3 small biarmed heterochromatic B chromosomes, resulting in a corresponding variation of the number of autosomal arms (NFa) between 44 and 50. The basic autosomal set was, however, constant and identical in these specimens. The karyotypes of D. cf. incomtus from Eastern and Western Ethiopia were found to be different (2N = 40 and 38, respectively). Comparison of G-banding patterns of the species studied revealed that they differ from each others by 1-2 Rb fusions/fissions, one paracentric inversion and heteromorphous sex chromosomes resulting from addition/deletion of heterochromatic blocks (X) and pericentric inversion (Y). In the light of the available chromosome banding data, the significance of intraspecies karyotypic variability within D. cf. incomtus and its relevance to the systematics of the genus are discussed.

Africa↗

PubMed1998

Intrageneric phylogeny of Acomys (rodentia, muridae) using mitochondrial gene cytochrome b.

This paper investigates interspecies relationships within the genus Acomys (spiny mice) by analyzing entire mitochondrial cytochrome b gene (1141 bp). This gene provides strong phylogenetic signal, as shown by high support of the topology obtained (bootstrap value and RNA support number). The phylogeny is congruent with inferences from allozymes for the species considered. Controversial taxonomy of Acomys cahirinus, dimidiatus, airensis, and ignitus is clarified, with their specific ranks confirmed on the basis of tree topology and nucleotide distances. Phylogenetic relationship between the undescribed species Acomys sp. from west Africa and A. airensis argue in favor of two distinct colonization events in this zone.

Africa↗

PubMed1996

The chromosome complement of Acomys spp. (Rodentia, Muridae) from Oursi, Burkina Faso--the ancestral karyotype of the cahirinus-dimidiatus group?

We present here data on chromosome banding analysis (R- and C-bands) of Acomys sp. (Rodentia, Muridae) from Oursi, Burkina Faso, characterized by 2n = FN = 68 and comparison of its banding patterns with those of Acomys dimidiatus from Saudi Arabia (2n = 38, FN = 70), studied previously. The study revealed complete homology between acrocentric chromosomes of Acomys sp. and chromosome arms of 16 pairs of metacentric and two pairs of acrocentric chromosomes of A. dimidiatus. In addition to monobrachial homology, one tandem translocation accompanied by a centromeric shift was identified in the karyotype of the latter species. The data obtained show that karyotypes of all the species of the Acomys cahirinus-dimidiatus group studied previously may be derived from that of Acomys sp. from Oursl by means of numerous non-homologous Rb translocations and 1-2 tandem transiocations, and thus its karyotype may be considered as ancestral for the cahirinus-dimidiatus group.

Animals↗

PubMed1985

[Dengue in Burkina Faso (ex-Upper Volta): seasonal epidemics in the urban area of Ouagadougou].

During the rainy season of 1982 30 patients (29 european and 1 voltaic) presented with an intense dengue-like syndrome in Ouagadougou city. 73.3% of these cases possessed anti-flavivirus fluorescent antibodies while 30%, were positive for specific anti-Dengue IgM antibodies. Vero type E 6 cell cultures were used to isolate six strains of Dengue 2 virus; monoclonal antibodies were used for viral identification. These strains constitute the first isolates of human Dengue virus in Upper Volta. Authors present conditions of virus isolations, describe the observed syndrome and discuss the epidemiological interest of this outbreak.

Adolescent↗

PubMed1977

Human poxvirus disease after smallpox eradication.

A 5-year-old boy living in a small camp in the rural Ivory Coast had a disease resembling smallpox. This occurred 4 years after smallpox had been eradicated from the Ivory Coast and 1.5 years after the last case of smallpox was detected in West and Central Africa. Clinical, serological, and epidemiological evidence indicated this disease was probably monkeypox, a poxvirus of the variola/vaccina subgroup. A serologic survey of poxvirus antibodies in the wild animal population detected neutralizing antibodies in rodents, larger mammals, primates, and birds. The laboratory and ecological characteristics of poxviruses require further elucidation, especially those which have been found in animals near human monkeypox cases.

Adolescent↗