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J M Verdier

Publications and source records attributed to J M Verdier.

At least 55 records · Page 3Linked to original sources
PubMedDate not supplied

Cloning of CDC33: a gene essential for growth and sporulation which does not interfere with cAMP production in Saccharomyces cerevisiae.

The CDC33 gene of Saccharomyces cerevisiae belongs to the class II 'START' genes. Its product is required for the initiation of a new cell division cycle (Hartwell, 1974). Many results suggest that the cAMP signalling pathway is one of the major controlling elements of 'START'. Components of this pathway are encoded by class II 'START' genes. The aim of the present study is to determine whether or not the CDC33 gene interferes with the cAMP signalling pathway. We report here the molecular cloning of the CDC33 gene by complementation of the cdc33-1 thermosensitive mutant. The identity of the cloned gene is confirmed by site-specific reintegration and segregation analysis. This gene is transcribed into a 900-nucleotides mRNA and appears to be relatively abundant in the cell. We also show that the CDC33 gene product is essential for sporulation. cdc33-1 mutant cells are able to enter into the resting state. The cAMP intracellular pool is not modified when the cdc33-1 mutant is shifted to the restrictive temperature. The cdc33-1 mutation is not suppressed by other known elements of the cAMP cascade. All these results suggest that the CDC33 'START' gene does not interfere with the cAMP signalling pathway which controls cell division.

Blotting, Southern↗
PubMedDate not supplied

Lithostathine and pancreatitis-associated protein are involved in the very early stages of Alzheimer's disease.

According to one of the theories formulated to explain the etiology of Alzheimer's disease (AD), amylosis may reflect a specific inflammatory response. Two inflammatory proteins, lithostathine and PAP, were evidenced by immunohistochemistry in senile plaques and neurofibrillary tangles of patients with AD. In addition, lithostathine and PAP were significantly increased in the cerebrospinal fluid of patients with AD when compared to patients with multiple sclerosis, another inflammatory disease, and to normal control subjects. However, no correlation was observed with age of occurrence. Furthermore, lithostathine and PAP were increased even at the very early stages of AD, and their level remained elevated during the course of the AD unlike TNFalpha whose level, very high at very early stages, regularly decreased. Finally, if part of lithostathine and PAP are synthesized in the brain, a large part comes from serum by passage over the blood-brain barrier. These results indicate (i) the existence of an acute phase response followed by a chronic inflammation in AD, and (ii) that lithostathine and PAP are involved even at the first pre-clinical biochemical events of AD. In addition, because lithostathine undergoes an autolytic cleavage leading to its precipitation and the formation of fibrils, we believe that it may be involved in amyloidosis and tangles by allowing heterogeneous precipitation of other proteins.

Acute-Phase Proteins↗
PubMedDate not supplied

[Presence in Camargue of two sympatric, sexually isolated forms of Aedes (Ochlerotatus) detritus (Haliday, 1833) [Diptera-Culicidae] (author's transl)].

The study of allozymic variations at four enzymatic loci (Est-2, alpha-Gpd, Got-1 and Got-2) in populations of Aedes detritus (Hal.) from 27 localities in Southern France has shown that this species is composed of two kinds of sympatric populations which do not interbreed in nature. Single specimens of Aedes detritus can be attributed to one or other type of population (sibling species) by the genotype at the alpha-Gpd or Got-2 loci (type A populations are homozygous for Got-2R allele and the frequency of the alpha-GpdC allele is higher than 98%; type B populations are homozygous for Got-2L allele and the frequency of the alpha-GpdB allele is higher than 98%). Moreover, allelic frequencies at the Est-2 and Got-1 loci are different in both types of populations. The fact that both kinds of populations coexist in the same pond shows that the isolating mechanism is not an adaptation to the larval environment, but rather involves mechanisms pecular to adults (precopulatory mechanism or interpopulation sterility).

Aedes↗
PubMedDate not supplied

[Life cycle of Maupasina weissi Seurat, 1913, Subuluroidea Nematode, parasite of the elephant shrew (author's transl)].

The life cycle of Maupasina weissi Seurat, 1913, the parasite of the elephant shrew, has been experimentally obtained from the intermediate host Locusta migratoria. The biology of this Nematoda is considered as being more primitive than the Subuluridae: -- egg maturation in external environment is in fact necessary to the Maupasina larvae to penetrate into the insect, -- The different localizations of the infective larvae, such as mesenteron regeneration crypta, fat body, demonstrate that the parasite is not completely adaptated to its intermediate host, -- the ontogenesis of cephalic structures is characterized by an hypertrophy of the archaic structures mainly from cuticular origin.

Adipose Tissue↗