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Jean-Marie Exbrayat

Jean-Marie Exbrayat
Université Catholique de Lyon and Ecole pratique des Hautes Etudes

PhD, D Sci

About

399
Publications
36,612
Reads
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1,780
Citations
Introduction
Emeritus Professor at both UCLy and EPHE, Jean-Marie Exbrayat managed a School of Histology for 25 years. He was Dean of the Faculty of Sciences of UCLy from 1997 until 2005. He taught animal biology, system biology, origin of life, history and philosophy of sciences. His current major interests include the cyclic variations of genital tracts and endocrine organs, embryonic development in vertebrates living in different biotopes, and also include history and philosophy of life sciences.
Additional affiliations
January 2004 - April 2019
Université Catholique de Lyon and Ecole pratique des Hautes Etudes
Position
  • Head of Department
December 1991 - present
Ecole Pratique des Hautes Etudes
Position
  • Professor
Description
  • - Developmental biology - Important embryonic steps for building and analyzing vertebrate models - Apoptosis and et embryonic development - Some aspects of the history of embryology
September 1991 - present
Ecole Pratique des Hautes Etudes
Position
  • Head of Department
Education
September 1979 - January 1986
Sorbonne Université
Field of study
  • Biology
September 1976 - July 1977
Université de Montpellier (USTL)
Field of study
  • Biology
September 1975 - August 1976
Université de Montpellier
Field of study
  • Biology

Publications

Publications (399)
Article
RFamide-related peptide (RFRP-3), the Mammalian ortholog of the Avian gonadotropin-inhibitory hormone (GnIH), is a novel neuropeptide known for its inhibitory regulatory effect on reproduction in various mammalian species. However, a stimulatory action has been reported. This paper aims to: i) study the histology of the epididymis (caput) of Gerbil...
Article
Both androgens and estrogens play key, albeit incompletely described, roles in the functioning of the epididymis. Because this tightly-coiled tubular structure is compartmented, precise mapping of the distribution of sex ste-roid's receptors is important. Such receptors have been located in the first segments (caput, corpus), but the last part (cau...
Article
The aim of this study was to visualize apoptosis throughout the reproductive cycle and after castration, castration then treatment with testosterone, and ligation of efferent ducts. The sand rat, Psammomysobesus, Cretzschmar 1828, is a diurnal rodent belonging to the family Gerbillidae. Its breeding cycle is seasonal with reproduction in autumn, wi...
Article
Full-text available
Reproduction in vertebrates is controlled by the hypothalamo-pituitary-gonadal axis, and both the sex steroid and pituitary hormones play a pivotal role in the regulation of the physiology of the oviduct and events occurring within the oviduct. Their hormonal actions are mediated through interaction with specific receptors. Our aim was to locate α...
Article
Full-text available
Background: The efferent ducts are mainly involved in the reabsorption of the seminiferous tubular fluid. Testosterone and oestrogens regulate efferent ducts functions via their receptors. Materials and methods: This paper presents an experimental investigation on the location of the P450 aromatase, the 17-b oestradiol (E2), the androgen receptor...
Article
To better understand the adaptive mechanisms in Uromastyx acanthinura to the seasonal variations in the arid environment, the present study aimed to explore the kidney functional morphology involved in body water economy. These investigations were carried out by the histological, histochemical and immuno-histochemical methods using conventional lig...
Article
The Sand rat, Psammomys obesus, living northwest of the Algerian Sahara, presents a seasonal reproductive cycle. The purposes of this study were firstly to determine the stages of seminiferous epithelium cycle (SEC) by histological and morphometric analysis and secondly to investigate, for the first time, the testicular expression of RFamide-relate...
Article
Full-text available
L’Hyperhomocystéinémie (Hhcy), facteur de risque associé à différents états pathologiques en particulier vasculaires, impacte négativement sur la biochimie de la matrice extracellulaire (MEC). L’objectif de ce travail est l’étude de l’impact de Hhcy sur l’intégrité testiculaire par l’analyse biochimique de la MEC d’une part et de l’occludine d’autr...
Preprint
The aim of this study was to visualize apoptosis throughout the reproductive cycle and after castration, castration then treatment with testosterone, and ligation of efferent ducts. The sand rat, Psammomys obesus, Cretzschmar 1828, is a diurnal rodent belonging to the family Gerbillidae. Its breeding cycle is seasonal with reproduction in autumn, w...
Article
Full-text available
The efferent ducts are mainly involved in the reabsorption of the seminiferous tubular fluid. Testosterone as well as estrogens regulate efferent ducts functions via their receptors. This paper presents an experimental investigation on the location of the P450 aromatase, the 17-beta-estradiol (E2), the androgen receptor (AR), the estrogen receptor...
Article
Abstract: The aim of this study was to assess the relationships between the evolution of the corpus luteum size determined by ultrasonography and plasma progesterone concentration in Cheurfa cows during the estrous cycle. Luteal activity was evaluated daily by plasma progesterone concentrations determined by radioimmunassay at each ultrasound exami...
Poster
The poster explains the difference of kidney sensitivity to testes androgens evaluated during the breeding and the non breeding season, in a free-living Saharan rodent, the Libyan jird Meriones libycus
Article
Full-text available
Le laboratoire de biologie générale de l’UCLy, autrement dit le LBG, est connu pour plusieurs aspects : ses travaux en sciences du vivant, avec ses deux équipes de « Biologie animale, reproduction et développement comparé » et « Épidémiologie moléculaire des maladies hépatiques et infections au virus de l’hépatite B en Afrique de l’Ouest ». Il exce...
Article
Objective: Numerous studies have shown that a methionine-rich diet induces hyperhomocysteinemia (Hhcy), a risk factor for cardiovascular diseases. The objective of the present study was to determine the involvement of Hhcy in cardiac remodeling in the sand rat Psammomys obesus. Materials and methods: An experimental Hhcy was induced, in the sand...
Article
Full-text available
Amphibians are anamniotic vertebrates having conquered the terrestrial environment. Their reproduction anddevelopment occur in water. After metamorphosis, the animal leaves the water to live on the ground. Yet, somespecies remain in the water and certain of them are viviparous. Since a long time, amphibians are used such asanimal models to understa...
Article
Full-text available
In animals, the sound vibrations are captured by the auditory cells, then transformed into electrical signals and conveyed to the nervous centers where they can be interpreted such as music. A lot of studies concern the effect of sound on the auditory cells and on the brain. Nevertheless, musical vibrations also affect other cells types in several...
Book
Dans le cadre de ce travail, une hyperhomocystéinémie expérimentale est engendrée chez le rat Wistar mâle, par une administration chronique per os de méthionine à raison de 200 mg/Kg de poids corporel/jour pendant 6 mois. Nous nous sommes intéressés aux répercussions de celle-ci sur certains paramètres plasmatiques et la matrice extracellulaire du...
Article
Full-text available
Unraveling morphological and chemical features of the eggs' jelly layers and other clutch elements, formed by the oviduct of a female, is necessary for the understanding of reproductive adaptation in amphibians. Our study is the first microstructural and histochemical descriptions about the complexity of oviduct, ovisac, jelly layer of the ovum, an...
Article
Full-text available
In this work, we present the first data on the reproductive cycle of the wall lizard females Podarcis vaucheri (Boulenger, 1905) in Djurdjura mountains. The macroscopic and histological study of the ovaries showed the existence of a discontinuous reproductive cycle, characterized by a sexual activity period (from April to June), followed by a long...
Article
We studied the composition and seasonal changes in diet and prey selection in the wall lizard Podarcis vaucheri of the Djurdjura Mountains throughout its activity period, from April to October 2014. The analysis of 238 faecal pellets revealed 1 206 prey items distributed in 19 prey categories. The most important prey categories were: Formicidae, Co...
Chapter
Though histochemical techniques have been used for decades, they are still very important in basic research. They make it possible to work on fixed tissues and provide a large amount of information in a relatively short time and at a low cost. Here we describe methods for indirect immunohistochemistry and immunofluorescence on sections of tadpoles...
Article
Objective: Numerous studies have shown that a methionine-rich diet induces hyperhomocysteinemia (Hhcy), a risk factor for cardiovascular diseases. The objective of the present study was to determine the involvement of Hhcy in cardiac remodeling in the sand rat Psammomys obesus. Materials and methods: Anexperimental Hhcy was induced, inthe sand rat...
Chapter
Résumé. La biologie n’utilise pas le mot « personne » mais « individu », qui qualifie une unité vivante caractéristique d’une espèce. Cet individu est doué d’une « autonomie » et non d’une « liberté » qui lui est propre. Chaque individu est limité dans l’espace et dans le temps, soumis à sa propre structure et aux facteurs environnementaux qui « ca...
Article
The aim of this study was to assess the relationships between the evolution of the corpus luteum size determined by ultrasonography and plasma progesterone concentration in Cheurfa cows during the estrous cycle. Luteal activity was evaluated daily by plasma progesterone concentrations determined by radioimmunassay at each ultrasound examination. Th...
Article
Full-text available
t a time when the decline of biodiversity is serious, many organisms currently live in different biotopes, even the most unexpected. For this, organisms have adapted to all environments, often developing very specialized anatomical and physiological characteristics. Looking at nature when traveling around the world, it is obvious that the adaptatio...
Article
Gerbillus tarabuli est un rongeur saharien qui se reproduit selon un mode saisonnier caractérisé par une période de pleine activité testiculaire au printemps et une période de régression et repos gonadique aux autres saisons. L’objectif de ce travail est la détection par immunohistochime indirecte l’expression des récepteurs aux estrogènes (ERα and...
Article
Le RFamide-related peptides 3 (RFRP-3), l’orthologue mammalien de la gonadotropin inhibitory hormone aviaire (GnIH) et son récepteur GPR147 ont été étudiés au niveau testiculaire chez un rongeur déserticole Gerbillus tarabuli par une approche immunohistochimique. L’étude a été menée sur des adultes en période d’activité sexuelle. Les résultats indi...
Article
Dans leur environnement aride, la grande Gerbille et le Mérion de Libye présentent des variations saisonnières inverses des axes corticotrope et gonadotrope, suggérant l’existence d’interrelations négatives entre ces deux fonctions. L’objectif de ce travail est de mettre en évidence l’influence des androgènes testiculaires sur l’axe corticotrope en...
Article
Introduction Dans un précédent travail, nous avons montré que l’hyperhomocystéinémie (Hhcy), facteur indépendant de risque cardiométabolique est associée à des altérations structurales (matricielles, cellulaires et vasculaires) des vésicules séminales du rat des sables ou Psammomys obesus (Po). Objectif Notre travail a pour objectif d’analyser la...
Article
Gerbillus tarabuli is a nocturnal seasonal breeder desert rodent with a main breeding season in spring and summer, and sexual quiescence in winter. This species is an interesting model for studying testis function in rodents. Therefore, the present study was performed firstly to investigate the stages of seminiferous epithelium cycle of Gerbillus t...
Book
La science se manifeste par ses répercussions techniques, allant des moyens de transport à la médecine, des médias aux biotechnologies. L’Homme n’a jamais acquis autant de connaissances, il est devenu capable d’intervenir sur l’inerte et le vivant, sur lui-même. La science lui amène de multiples possibilités lui simplifiant la vie mais elle est aus...
Article
Typhlonectes compressicauda is a caecilian-tropical amphibian found in South America. In this limbless species, the reproduction cycle varies according to the seasonal alternation (dry season and rainy season) allowing youths birth in a favourable time. Furthermore, when animals aremaintained in water, the lack of dry season particularly disturb th...
Article
Boulengerulataitanus is a caecilian amphibian, the oviparous females of which having an annual sexual cycle submitted to the seasonal variations. With the detection of both cell proliferation and apoptosis, this study focused on the evolution of follicular cells and corpus luteum during the ovarian cycle. The results show a cellular dynamics in the...
Article
Full-text available
Amphibians are among the first vertebrates that have conquered the terrestrial environment. Their way of life is characterized by a compulsory aquatic larval phase and an adult terrestrial phase separated by a metamorphosis. Amphibians remain subservient to the aquatic environment throughout their lives. Several adaptive mechanisms regarding reprod...
Article
Full-text available
Amphibians are among the first vertebrates that have conquered the terrestrial environment. Their way of life is characterized by a compulsory aquatic larval phase and an adult terrestrial phase separated by a metamorphosis. Amphibians remain subservient to the aquatic environment throughout their lives. Several adaptive mechanisms regarding reprod...
Article
Pollution by endocrine disruptors was the main precursor for intersex triggering in fish species Barbuscallensis living in Soummamriver (Algeria), a river known to be an open pit dump. The analysis of the histological sections relating to the intersexed individuals, showed various anomalies and malformations, more particularly in the female part. S...
Article
Since the first representations of animals on the rocky walls, zoology progressively evolved, linked to the evolution of both techniques and concepts. The scientific interest of animal biology may be divided into three domains. The first one concerns knowledge of the animal life history, the second is devoted to the use of animal for activities suc...
Presentation
Full-text available
"Immanence and transcendence" is a hard question, and more especially for the biologist who uses a scientific approach. And often, this question is avoided because it does not belong to the field of science. Nevertheless, this biologist can go beyond his/her own scientific vision in expressing his/her astonishment and interrogation caused by the nv...
Article
In the desert gerbil Gerbillus tarabuli (Thomas, 1902), cortisol is the main glucocorticosteroid produced by the adrenal glands. Plasma cortisol concentrations show highest values when testosterone is reduced and lowest values during the breeding season which occurs from early winter to late spring. In order to specify the implication of testicular...
Article
Full-text available
This study aims to highlight the cellular and molecular events of atresia in the Bedouin goat ovarian follicles. Ovaries collected from slaughterhouses during breeding and non-breeding seasons were submitted to morphological studies and immunolocalization of active caspase-3. The results showed that ovaries were heavier (P<0.05) during the breeding...
Conference Paper
Full-text available
Introduction Dans un précédent travail, nous avons montré que l'hyperhomocystéinémie (Hhcy), facteur indépendant de risque cardio-métabolique est associée à des altérations structurales (matricielles, cellulaires et vasculaires) des vésicules séminales du rat des sables ou Psammomys obesus (Po). Objectif Notre travail a pour objectif d'analyser la...
Poster
Full-text available
Introduction Dans un précédent travail, nous avons montré que l'hyperhomocystéinémie (Hhcy), facteur indépendant de risque cardio-métabolique est associée à des altérations structurales (matricielles, cellulaires et vasculaires) des vésicules séminales du rat des sables ou Psammomys obesus (Po). Objectif Notre travail a pour objectif d'analyser la...
Article
Full-text available
Functioning of the amphibian oviduct is the subject of many studies, but detailed understanding of caecilian reproduction exists for very few species. In this study, a description is made of morphological changes of the oviduct of the caecilian Boulengerula taitana throughout the year, using conventional histology and immunohistochemistry. The repr...
Article
Full-text available
The reproductive cycle of male wall lizard Podarcis vaucheri (Boulenger, 1905) living in Djurdjura mountain, was analyzed from April till October 2014. Its seasonal mixed-type cycle was characterized by three phases: sexual activity, quiescence and recrudescence. After the emergence of lizard from hibernation an intense sexual activity was observed...
Article
Full-text available
The aim of this study was to examine the morphometry and the immunolocalization of androgen receptors in the epididymis of D’Man lamb during postnatal development. The epididymis was collected at the slaughtering lamb, aged of 2 to 5 month. The weight of the epididymis increased with a significant difference at 3 months. The tubular diameter of the...
Article
Full-text available
Many wild species exhibit seasonal cycles of testicular and adrenal functions suggesting important interrelationships between the two. However, data on desert rodents are very scarce. We investigated the pituitary adrenal (PA) axis activity of the Libyan jird from the Sahara desert, during the breeding and the non-breeding seasons. We explored, dur...
Article
Estrogen plays a crucial role in regulating epididymal function and development. Estrogen signaling is mediated via two main receptors essentially involved in the genomic regulating pathway: ERα and ERβ. Recent studies revealed the contribution of a novel estrogen receptor involved in the non-genomic pathway: GPER1. This receptor belongs to the fam...
Article
Sclerophrys mauritanica is an anuran amphibian found in the wetlands of Beni-belaid, Jijel, Algeria. The animals are constrained by wet (from September until May) and dry (from June until August) seasons, however, the sexual cycle of males is continuous (all germ cells categories are present throughout the year). The aim of this study was to follow...
Article
Estrogen plays a crucial role in regulating epididymal function and development. Estrogen signaling is mediated via two main receptors essentially involved in the genomic regulating pathway: ERα and ERβ. Recent studies revealed the contribution of a novel estrogen receptor involved in the non-genomic pathway: GPER1. This receptor belongs to the fam...
Working Paper
Introduction: Elevated plasma homocysteine (Hcy) levels have been associated with several tissue injuries including heart and liver fibrosis. In these diseases, hyperhomocysteinemia (Hhcy) plays a major role in modulating the alteration of the balance between matrix metalloproteinases (MMP) and tissue inhibitors of metalloproteinases (TIMPs), lead...
Article
An increasing number of studies revealed the importance of estrogen in male reproduction. However, most research was conducted in laboratory rodents subjected to standardized environmental conditions. Therefore, seasonal regulations of estrogen pathways remain poorly understood under natural conditions. Using immunohistochemistry, the expression of...
Article
Full-text available
Spermatogenic cycles of hynobiid salamanders are interesting for the study of male reproductive adaptations in amphibians living under different environmental conditions. In order to detect the main differences between spermatogenic cycles of hynobiids, we studied the spermatogenic cycle of Salamandrella keyserlingii from the suburbs of Tomsk (sout...
Article
Gerbillus tarabuli is a nocturnal Saharan rodent which has an annual reproductive cycle characterized by the reproductive activity in spring and a long phase of sexual quiescence in other seasons. We describe the morphology and hormonal regulation of the prostatic complex of this rodent in the two periods, based on anatomical, histological, morphom...
Chapter
Full-text available
In Vertebrates, seminiferous tubes are bordered with an epithelium producing gametes included between Sertoli cells. These cells were first described like a syncytium. With electron microscopy, the observations showed Sertoli cells contained a single nucleus and were limited by a classical plasma membrane. Some studies showed the Sertoli cells of a...
Article
Full-text available
Freshwater gastropods are frequently used as model organisms to assess the effects of certain chemical substances. Among them Radix balthica and Lymnaea stagnalis are commonly used in the laboratory, mesocosm and fields tests. In order to determine the effects of pollutants and more particularly endocrine disrupting substances on the reproduction o...
Article
Full-text available
Typhlonectes compressicauda is an aquatic gymnophionan amphibian living in South America. Its breeding cycle is linked to seasons, characterized by a regular alternation of rainy and dry seasons. During a complex biennial cycle, the female genital tract undergoes a series of alternations of increasing and decreasing, governed by equilibrium of prol...