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Comptes Rendus Biologies

Sara Falvo, Gabriella Chieffi Baccaria, Giuseppe Spaziano, Luigi Rosati, Massimo Venditti, Maria Maddalena Di Flore, Alessandra Santillo
The Harderian gland (HG) of the rat (Rattus norvegicus) secretes copious amounts of lipids, such as cholesterol. Here we report a study of the expressions of the StAR protein and key steroidogenic enzymes in the HG of male and female rats. The objective of the present investigation was to ascertain (a) whether the rat HG is involved in steroid production starting with cholesterol, and (b) whether the pattern of gene and protein expressions together with the enzymatic activities display sexual dimorphism. The results demonstrate, for the first time, the expression of StAR gene and protein, and Cyp11a1, Hsd3b1, Hsd17b3, Srd5a1, Srd5a2 and Cyp19a1 genes in the rat HG...
March 10, 2018: Comptes Rendus Biologies
Yann Hénaut, Bruno Corbara, Frédéric Azémar, Régis Céréghino, Olivier Dézerald, Alain Dejean
Cupiennius salei (Ctenidae) individuals frequently live in association with tank bromeliads, including Aechmea bracteata, in Quintana Roo (Mexico). Whereas C. salei females without egg sacs hunt over their entire host plant, females carrying egg sacs settle above the A. bracteata reservoirs they have partially sealed with silk. There they avoid predators that use sight to detect their prey, as is known for many bird species. Furthermore, if a danger is more acute, these females dive with their egg sacs into the bromeliad reservoir...
March 9, 2018: Comptes Rendus Biologies
Tousheng Huang, Huayong Zhang, Liming Dai, Xuebing Cong, Shengnan Ma
This research investigates the formation of banded vegetation patterns on hillslopes affected by interactions between sediment deposition and vegetation growth. The following two perspectives in the formation of these patterns are taken into consideration: (a) increased sediment deposition from plant interception, and (b) reduced plant biomass caused by sediment accumulation. A spatial model is proposed to describe how the interactions between sediment deposition and vegetation growth promote self-organization of banded vegetation patterns...
March 1, 2018: Comptes Rendus Biologies
Nicolas Bacaër
This study focuses on the extinction rate of a population that follows a continuous-time multi-type branching process in a random environment. Numerical computations in a particular example inspired by an epidemic model suggest an explicit formula for this extinction rate, but only for certain parameter values.
February 26, 2018: Comptes Rendus Biologies
Bruno Corbara, Pablo Servigne, Alain Dejean, James M Carpenter, Jérôme Orivel
In French Guiana, the arboreal nests of the swarm-founding social wasp Protopolybia emortualis (Polistinae) are generally found near those of the arboreal dolichoderine ant Dolichoderus bidens. These wasp nests are typically protected by an envelope, which in turn is covered by an additional carton 'shelter' with structure resembling the D. bidens nests. A few wasps constantly guard their nest to keep D. bidens workers from approaching. When alarmed by a strong disturbance, the ants invade the host tree foliage whereas the wasps retreat into their nest...
February 22, 2018: Comptes Rendus Biologies
Yan Qun Peng, Ling Ling Fan, Fu Ying Mao, Yun Sheng Zhao, Rui Xu, Yu Jie Yin, Xin Chen, De Guang Wan, Xin Hui Zhang
Polygala tenuifolia Willd. is an important protected species used in traditional Chinese medicine. In the present study, amplified fragment length polymorphism (AFLP) markers were employed to characterize the genetic diversity in wild and cultivated P. tenuifolia populations. Twelve primer combinations of AFLP produced 310 unambiguous and repetitious bands. Among these bands, 261 (84.2%) were polymorphic. The genetic diversity was high at the species level: percentage of polymorphic loci (PPL)=84.2%, Nei's gene diversity (h)=0...
February 21, 2018: Comptes Rendus Biologies
Rafael N Carvalho
Paradiscocyrtus neglectus Mello-Leitão, 1927 is here redescribed and for the first time illustrated. A neotype is proposed to clarify the taxonomic status of this species and to differentiate it from the other two species of Paradiscocyrtus and related genera (e.g., Discocyrtus). Two junior synonyms of this species, currently allocated in Discocyrtus Holmberg, 1876 are here detected. This harvestman is endemic from areas above 2000 meters of altitude, occurring in the Campos Rupestres montane savannas terrestrial eco-region in the states of Minas Gerais and Rio de Janeiro, Brazil...
February 16, 2018: Comptes Rendus Biologies
Jie Jiao, Xiangrong Jia, Pei Liu, Qiaomei Zhang, Feng Liu, Cunde Ma, Pengzhou Xi, Zongsuo Liang
Morphological markers as well as two types of molecular markers, inter-sample sequence repeat (ISSR) and start codon targeted (SCoT) are suitable for species identification of the polygonati rhizoma germplasms. In this paper, we adopted these methods for the identification of rhizomes collected from 47 areas in China. Based on their morphological characters, the collected germplasms were classified into two populations, one with alternate leaf arrangement and the other with verticillate leaf arrangement, and they were comprised of five species and fourteen subgroups...
February 7, 2018: Comptes Rendus Biologies
Annam Pavan-Kumar, Rajan Kumar, Pranali Pitale, Kang-Ning Shen, Philippe Borsa
The blue-spotted maskray, previously N. kuhlii, consists of up to eleven lineages representing separate species. Nine of these species (N. australiae, N. bobwardi, N. caeruleopunctata, N. malaccensis, N. moluccensis, N. orientale, N. vali, N. varidens, N. westpapuensis) have already been formally described and two (Indian Ocean maskray and Ryukyu maskray) remain undescribed. Here, the Indian Ocean maskray is described as a new species, Neotrygon indica sp. nov. Specimens of the new species were generally characterized on their dorsal side by a moderately large number of small ocellated blue spots, a low number of medium-sized ocellated blue spots, the absence of large ocellated blue spots, a high number of dark speckles, a few dark spots, and a conspicuous occipital mark...
February 4, 2018: Comptes Rendus Biologies
Jean-François Agnèse, Halima Louizi, André Gilles, Ouafae Berrada Rkhami, Abdelaziz Benhoussa, Abdeljebbar Qninba, Antoine Pariselle
Euryhaline Cichlid fish of the species Coptodon guineensis are present in different water holes situated in a dried depression in the desert in the extreme South of Morocco, the Sebkha of Imlili. A genetic survey of this population, using complete sequences of the ND2 gene (mtDNA) and sixteen microsatellite loci, revealed that the fish in the sebkha did not form a single population, but rather a metapopulation. This metapopulational structure may be regarded as good news from the point of view of the conservation of fish in the sebkha...
February 2, 2018: Comptes Rendus Biologies
Ronald Fricke, Daniel Golani, Brenda Appelbaum-Golani, Uwe Zajonz
The cutthroat eel Dysomma alticorpus n. sp. is described based on a single specimen collected in a trammel net at a depth of 350m off Eilat, Israel, Gulf of Aqaba, Red Sea. The new species belongs to the Dysomma anguillare species complex, which comprises species possessing a well-developed pectoral fin, intermaxillary teeth, a uniserial row of 7-15 large compound teeth in the lower jaw (which may be followed by a few smaller teeth), and an anteriorly situated anus with the trunk shorter than the head length...
February 2, 2018: Comptes Rendus Biologies
Wazifa Afrin, Mahmudul Hassan Nafis, Muhammed Ali Hossain, Mirza Mofazzal Islam, Md Amir Hossain
The study aims at identifying some submergence-tolerant rice genotypes through morphological and molecular characterization and their genetic variability analysis. Ten rice genotypes including two submergence-tolerant checks, two susceptible varieties and six advanced lines were evaluated for submergence tolerance in the laboratory and in the field during January-December 2015. The experiment was conducted in the field following randomized complete block design in a two-factor arrangement using five replications...
February 1, 2018: Comptes Rendus Biologies
Faiza Ammad, Oussama Moumen, Abdelbaset Gasem, Salam Othmane, Kato-Noguchi Hisashi, Bachar Zebib, Othmane Merah
This study aimed to evaluate the in vitro antifungal activity (AA) of the essential oil (EO) of lemon (Citrus limon L.) against three pathogenic fungi attacking grapevine wood. The composition of the EO was also studied. Ten volatile components were identified by gas chromatography-mass spectrometry. The results showed that the EO consists of volatile components where monoterpene hydrocarbons are the most abundant ones. Four major components were identified, which represent 99.9% of the total EO (limonene, neral, β-pinene, and γ-terpinene)...
February 1, 2018: Comptes Rendus Biologies
Wilson R Lourenço, Lucienne Wilmé, Patrick O Waeber
New comments are proposed on the geographic distribution of genus Opisthacanthus, and the Gondwanian model is further supported. The diversity of the genus is extraordinary in Madagascar, with the same number of species as in continental Africa, but sub-Saharan Africa is home to six out of the nine groups currently recognized of Opisthacanthus. Given the affinities of the Opisthacanthus groups and their current distribution, a center of origin in Africa could be favored for these ancient scorpions. The proposed Gondwana model suggests that the Madagascar Opisthacanthus are closer to those of the New World, which is consistent with the affinities observed in morphological characters...
January 11, 2018: Comptes Rendus Biologies
Aurélie Tréfier, Florian Guillou, Pascale Crépieux
With the advent of next-generation sequencing technologies, identifying the translatome, which includes genome-wide ribosome-associated mRNAs, provides new opportunities to define faithfully the protein repertoire of a cell, as opposed to transcriptomic approaches. In addition, the role that extracellular signals such as hormonal modulations could play on the translatome remains to be deciphered. In particular, the regulation of the translatome by G protein-coupled receptors (GPCR) is still poorly described, albeit the trophic role that many receptors of this family play in their target cells...
January 8, 2018: Comptes Rendus Biologies
Patrick D Mathews, Ana C M F Patta, Gabriella S Gama, Omar Mertins
The occurrence of copepods ergasilid was investigated in two species of cichlids of economic importance for aquaculture in the Amazon region: Cichla monoculus and Chaetobranchus semifasciatus. The fish were collected from a semi-intensive fish farm, near the city of Nauta, Loreto State, Peru. Copepods were found in the gill filaments of 44 of 85 specimens (51.7%) of C. monoculus and in eight of 30 (26.6%) specimens of C. semifasciatus. The parasite was identified as Ergasilus coatiarus based on its morphological features...
December 26, 2017: Comptes Rendus Biologies
Yassine Djelaila, Christiane Denys, Emmanuelle Stoetzel, Raphaël Cornette, Aude Lalis, Malika Adamou-Djerbaoui, Mohamed Boukhemza
In North Africa, the rodents of the species complex Meriones shawii-grandis have a considerable ecological, economic and epidemiological importance. Until now, the systematics of these species was subject to discussion due to the presence of populations displaying high morphological variability. By means of an approach of traditional morphometrics based on cranial distances and by using the method of the log shape-ratio, we attempt to characterize morphologically these two taxa. The results show significant differences in size and shape between the specimens of Morocco, on the one hand, and those of Algeria and Tunisia, on the other hand...
January 2018: Comptes Rendus Biologies
Maria Maddalena Di Fiore, Alessandra Santillo, Sara Falvo, Gabriella Chieffi Baccari, Massimo Venditti, Federica Di Giacomo Russo, Monica Lispi, Antimo D'Aniello
d-Aspartate (d-Asp) is an endogenous amino acid present in the central nervous system and endocrine glands of various animal taxa. d-Asp is implicated in neurotransmission, physiology of learning, and memory processes. In gonads, it plays a crucial role in sex hormone synthesis. We have investigated the effects of chronic (30 days d-Asp drinking solution) and acute (i.p. injection of 2μmol/g bw d-Asp) treatments on sex steroid synthesis in rat brain. Furthermore, to verify the direct effect of d-Asp on neurosteroidogenic enzyme activities, brain homogenates were incubated with different substrates (cholesterol, progesterone, or testosterone) with or without the addition of d-Asp...
January 2018: Comptes Rendus Biologies
Alain Dejean, Frédéric Petitclerc, Frédéric Azémar, Laurent Pélozuelo, Stanislas Talaga, Maurice Leponce, Arthur Compin
In Neotropical rainforest canopies, phytotelmata ("plant-held waters") shelter diverse aquatic macroinvertebrate communities, including vectors of animal diseases. Studying these communities is difficult because phytotelmata are widely dispersed, hard to find from the ground and often inaccessible. We propose here a method for placing in tree crowns "artificial phytotelmata" whose size and shape can be tailored to different research targets. The efficacy of this method was shown while comparing the patterns of community diversity of three forest formations...
January 2018: Comptes Rendus Biologies
Thomas Desvignes, Philippe Bourjon, Bruno Chanet
The green birdmouth wrasse Gomphosus caeruleus is present all year round on the coral reefs of Reunion Island (Indian Ocean). A group of individuals was followed on one of these reefs with the objective of studying the reproduction mode of the species, the influence of environmental factors, and social behaviors on the control of reproduction. Our observations revealed that G. caeruleus is, like many Labridae, a protogynous hermaphrodite species, probably diandric, that the reproduction of G. caeruleus is, like in other reef fish species, influenced by the lunar cycle with a peak of reproductive activity during waxing gibbous phase, and that G...
December 21, 2017: Comptes Rendus Biologies
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