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Synthetic hormones in wastewater effluents released into the aquatic environments may interfere with the normal endocrine systems of fish in receiving streams. Norgestrel (NGT) is a synthetic progestin widely used in oral contraceptives and frequently detected in wastewater effluents. In this study, adult female mosquitofish (Gambusia affinis) were exposed to three environmentally relevant concentrations of norgestrel (NGT) (i.e., 3.6, 35.8, and 368.0 ng L-1) for 42 d, fin morphology, histology of the ovary, and reproductive behaviors were evaluated. The results showed that NGT at all three concentrations caused an increased frequency of atretic follicular cells in ovaries and impaired mating behaviors exhibited by males toward the NGT-exposed females. In mosquitofish exposed to NGT at 35.8 and 368 ng L-1, the anal fin of females had an increased length ratio of ray4/ray 6, an increased width of ray 3, and increased number of segments in ray 3. The histopathological analysis showed that exposure to NGT increased the incidence of spermatogenesis in ovaries. Mating behavior was impaired 58.4%, 65.7%, and 76.4% (P

Amorphous manganese oxides (a-MnOx) are widely considered promising material systems to fabricate cathodes for aqueous zinc ion batteries (AZIBs). However, the Zn-storage mechanism of a-MnOx is still not understood, and its electrochemical performance is inadequate. Herein, we report porous reduced graphene oxide boosted a-MnOx microspheres (denoted as PrGO–MnOx) as a cathode material for AZIBs. Its electrochemical Zn-storage mechanism was elucidated via a series of ex situ measurements. Particularly, we observe that the a-MnOx phase in PrGO–MnOx is transformed into highly active and stable amorphous Zn-buserite during the initial cycles, effectively promoting Zn-storage. The cathode material can deliver a large capacity (296 mA h g−1 after 100 cycles at 0.1 A g−1), high-rate capability (151 mA h g−1 at 2.5 A g−1), and ultra-long lifespan (5000 cycles at 5.0 A g−1). We attribute this performance to several properties, including (i) the amorphous structure of Zn-buserite with high activity and stability, (ii) fast reaction kinetics, (iii) increased electron conductivity, (iv) improved Zn2+ diffusion rate, and (v) high pseudocapacitance. We also assembled a PrGO–MnOx‖AQ (9,10-anthraquinone) full-battery, which possesses a high discharge plateau (0.8 V) and impressive cycling stability (106 mA h g−1 after 500 cycles at 0.3 A g−1), indicating good potential towards practical applications. [ABSTRACT FROM AUTHOR]

Comparative genomics is a useful tool to investigate gene and genome evolution. Biotin carboxylase (BC), an important subunit of heteromeric acetyl-CoA carboxylase (ACCase) that is a rate-limiting enzyme in fatty acid biosynthesis in dicots, catalyzes ATP, biotin carboxyl carrier protein, and C[O.sub.2] to form carboxybiotin carboxyl carrier protein. In this study, we cloned four genes encoding BC from Brassica napus L. (namely BnaC.BC.a, BnaC.BC.b, BnaA.BC.a, and BnaA.BC.b), and two were cloned from each of the two parental species Brassica rapa L. (BraA.BC.a and BraA.BC.b) and Brassica oleracea L. (BolC.BC.a and BolC.BC.b). Sequence analyses revealed that in B. napus the genes BnaC.BC.a and BnaC.BC.b were from the C genome of B. oleracea, whereas BnaA.BC.a and BnaA.BC.b were from the A genome of B. rapa. Comparative and cluster analysis indicated that these genes were divided into two major groups, BnaC.BC.a, BnaA.BC.a, BraA.BC.a, and BolC.BC.a in group-1 and BnaC.BC.b, BnaA.BC.b, BraA.BC.b, and BolC.BC.b in group-2. The divergence of group-1 and group-2 genes occurred in their common ancestor 13-17 million years ago (MYA), soon after the divergence of Arabidopsis and Brassica (15-20 MYA). This time of divergence is identical to the previously reported triplicated time of paralogous subgenomes of diploid Brassica species and the divergence date of group-1 and group-2 genes of a-carboxyltransferase, another subunit of heteromeric ACCase, in Brassica. Reverse transcription PCR revealed that the expression level of group-1 and group-2 genes varied in different organs, and the expression patterns of the two groups of genes were similar in different organs, except in flower. However, two paralogs of group-2 BC genes from B. napus could express differently in mature plants tested by generating BnaA.BC.b and BnaC.BC.b promoter- bglucuronidase (GUS) fusions. The amino acid sequences of proteins encoded by these genes were highly conserved, except the sequence encoding predicted plastid transit peptides. The plastid transit peptides on the BC precursors of Brassica (71-72 amino acid residues) were predicted based on AtBC protein, compared, and confirmed by fusion with green fluorescent protein. Our results will be helpful in elucidating the evolution and the regulation of ACCase in the genus Brassica. Key words: Brassica, acetyl-CoA carboxylase (ACCase), biotin carboxylase (BC), evolution. La genomique comparee permet d'etudier revolution des genes et des genomes. La biotine carboxylase (BC) est une sous-unite; importante de l'aceetyl-CoA carboxylase (ACCase) heteromerique. Cette derniere est une enzyme limitante dans la synthese des acides gras chez les dicotyledones et elle catalyse l'ATP, la proteine porteuse de carboxyle- biotine et le C[O.sub.2] pour former la proteine porteuse de carboxybiotine-carboxyle. Dans ce travail, les auteurs ont clone quatre genes codant la BC chez le Brassica napus L. (nommeement BnaC.BC.a, BnaC.BC.b, BnaA.BC.a et BnaA.BC.b) et deux genes chacun des especes parentales, B. rapa L. (BraA.BC.a et BraA.BC.b)et B. oleracea L. (BolC.BC.a et BolC.BC.b). Les analyses de sequences ont revele que chez le B. napus les genes BnaC.BC.a et BnaC.BC.b provenaient du genome C du B. oleracea, tandis que les genes BnaA.BC.a et BnaA.BC.b etaient deriveesdu genome A du B. rapa. Des analyses com parees et de groupement ont revele que ces genes etaient divises en deux groupes majeurs, BnaC.BC.a, BnaA.BC.a, BraA.BC.a et BolC.BC.a appartenant au sein du groupe 1 et BnaC.BC.b, BnaA.BC.b, BraA.BC.b et BolC.BC.b formant le groupe 2. La divergence entre ces deux groupes de genes se serait produite chez leur ancetre commun il y 13 a 17 millions d'anneees, soit toot apres la divergence entre Arabidopsis et Brassica (15-20 millions d'annees). Cet moment est identique a l'estime de divergence rapporte anterieurement pour la triplication des sous-genomes paralogues chez les espeeces diploldes du genre Brassica et pour la divergence entre les groupes 1 et 2 de genes codant pour l'α-CT, une autre sous- unite de l'ACCase heteeromerique chez le genre Brassica. Des analyses RT-PCR ont revele que l'expression des genes des groupes 1 et 2 variait au sein de differents organes, et que l'expression des deux groupes de genes etait semblable dans differents organes a l'exception des fleurs. Cependant, deux paralogues des genes BC du groupe 2 du B. napus s'exprimaient parfois de maniere differentielle chez des plantes matures lorsque l'expression etait mesuree au moyen de fusions entre les promoteurs BnaA.BC.b et BnaC.BC.b et le gene GUS. Les sequences d'acides amines des proteeines codeees par ces genes etaient largement conservees a l'exception des regions codant pour des peptides de transit vers les plastides. Les peptides de transit vers les plastides chez les precurseurs des messagers BC chez le genre Brassica (71 a 72 acides amines) ont ete predits sur la base de la proteine AtBC, compares et finalement confirmes par fusion avec la GFP. Ces resultats aideront a elucider l'e;volution et la re;gulation de l'ACCase chez le colza. Mots-cles : Brassica, acetyl-CoA carboxylase (ACCase), biotine carboxylase (BC), evolution. [Traduit par la Redaction], Introduction Polyploid genomes undergo rapid changes in the expression of the duplicated genes and genome structure. Brassica napus L. (AACC, 2n = 4x = 38) originated through spontaneous interspecific hybridization [...]

Heteromeric acetyl coenzyme A carboxylase (ACCase), a rate-limiting enzyme in fatty acid biosynthesis in dicots, is a multi-enzyme complex consisting of biotin carboxylase, biotin carboxyl carrier protein, and carboxyltransferase (α-CT and β-CT). In the present study, four genes encoding α-CT were cloned from Brassica napus, and two were cloned from each of the two parental species, B. rapa and B. oleracea. Comparative and cluster analyses indicated that these genes were divided into two major groups. The major divergence between group-1 and group-2 occurred in the second intron. Group-2 α-CT genes represented the ancestral form in the genus Brassica. The divergence of group-1 and group-2 genes occurred in their common ancestor 12.96-17.78 million years ago (MYA), soon after the divergence of Arabidopsis thaliana and Brassica (15-20 MYA). This time of divergence is identical to that reported for the paralogous subgenomes of diploid Brassica species (13-17 MYA). Real-time reverse transcription PCR revealed that the expression patterns of the two groups of genes were similar in different organs, except in leaves. To better understand the regulation and evolution of α-CT genes, promoter regions from two sets of orthologous gene copies from B. napus, B. rapa, and B. oleracea were cloned and compared. The function of the promoter of gene Bnα-CT-1-1 in group-1 and gene Bnα-CT-2-1 in group-2 was examined by assaying β-glucuronidase activity in transgenic A. thaliana. Our results will be helpful in elucidating the evolution and regulation of ACCase in oilseed rape. Key words: Brassica, acetyl-CoA carboxylase (ACCase), α-CT, evolution. L'aceetyle co-enzyme A carboxylase (ACCase) heteromeerique, une enzyme limitante dans la synthase des acides gras chez les dicotyledones, est un complexe multienzymatique comprenant la biotine carboxylase, la proteine carboxylee transporteuse de biotine et la carboxyltransferase (α-CT et β-CT). Dans ce travail, quatre genes codant pour l'α-CT ont ete clones chez le Brassica napus de meme que deux genes de chacune des deux especes parentales, B. rapa et B. oleracea. Des analyses comparees et de groupement ont indiquee que ces genes forment deux groupes principaux. La divergence majeure entre les groupes 1 et 2 se trouvent au sein du second intron. Les genes du groupe 2 de l'α-CT constituent la forme ancestrale chez le genre Brassica. La divergence des genes des groupes 1 et 2 se serait produite au sein de l'ancetre commun il y a 12,96-17,78 millions d'annees (MA), tot apres la divergence entre l'Arabidopsis thaliana et Brassica (15-20 MA). Ce moment de divergence est identique a celui estimee pour la divergence des sous-genomes paralogues au sein des Brassica diploldes (13-17 MA). Une analyse RT-PCR en temps reel a revele que l'expression des deux groupes de genes est semblable au sein de differents tissus a l'exception des feuilles. Afin de mieux connaitre la regulation et revolution des genes codant pour l'α-CT, les regions promotrices de deux jeux d'orthologues ont ete; cloneees et comparees chez le B. napus,le B. rapa et le B. oleracea. La fonction du promoteur du gene Bnα-CT-1-1 (appartenant au groupe 1) et celui du gene Bnα-CT-2-1 (appartenant au groupe 2) a ete examinee en mesurant l'activite β-glucuronidase chez des lignees transgeniques de l'A. thaliana. Ces resultats seront utiles pour elucider revolution et la regulation de l'ACCase chez le colza okeagineux. Mots-cles : Brassica, acetyl-CoA carboxylase (ACCase), α-CT, evolution. [Traduit par la Redaction], Introduction Brassica napus L. (AACC, 2n = 4x = 38), an amphidiploid species originating from a spontaneous hybridization of B. rapa L. (AA, 2n = 2x = 20) and B. [...]

To map important ESTs to specific chromosomes and (or) chromosomal regions is difficult in hexaploid wheat because of its large genome size and serious interference of homoeologous sequences. Large-scale EST sequencing and subsequent chromosome localization are both laborious and time-consuming. The wheat alien addition line TAi-27 contains a pair of chromosomes of Thinopyrum intermedium (Host) Barkworth & D.R. Dewey that carry the resistance gene against barley yellow dwarf virus. In this research, we developed a modified technique based on chromosome microdissection and hybridization-specific amplification to isolate expressed sequences from the alien chromosome of TAi-27 by hybridization between the DNA of the microdissected alien chromosome and cDNA of Th. intermedium infected by barley yellow dwarf virus. Twelve clones were selected, sequenced, and analyzed. Three of them were unknown genes without any hit in the GenBank database and the other nine were highly homologous with ESTs of wheat, barley, and (or) other plants in Gramineae induced by abiotic or biotic stress. The method used in this research to isolate expressed sequences from a specific chromosome has the following advantages: (i) the obtained expressed sequences are larger in size and have 3' end information and (ii) the operation is less complicated. It would be an efficient improved method for genomics and functional genomics research of polyploid plants, especially for EST development and mapping. The obtained expressed sequence data are also informative in understanding the resistance genes on the alien chromosome of TAi-27. Key words: TAi-27, Thinopyrum intermedium, chromosome microdissection, hybridization-specific amplification (HSA), expressed sequences, barley yellow dwarf virus (BYDV). Il est difficile de situer des EST importants sur des chromosomes ou regions chromosomiques specifiques chez le ble hexaploide en raison de la grande taille de son genome et de serieuses interferences causees par des sequences homeologues. Le sequencage d'EST a grande echelle et leur localisation chromosomique sont laborieux et prennent beaucoup de temps. La lignee d'addition chromosomique exotique TAi-27 contient une paire de chromosomes du Thinopyrum intermedium (Host) Barkworth & D.R. Dewey qui porte le gene de resistance contre le virus de la jaunisse nanisante de l'orge. Dans ce travail, les auteurs ont developpe une technique modifiee basee sur la microdissection chromosomique et l'amplification specifique des sequences hybridees (<< hybridization specific amplification >>) pour isoler des sequences exprimees a partir du chromosome exotique dans TAi-27. Un tel isolement est realise par hybridation entre l'ADN du chromosome exotique, obtenu par microdissection, et l'ADNc du T. intermedium infecte par le virus de la jaunisse nanisante de l'orge. Douze clones ont ete selectionnes, sequences et analyses. Trois de ceux-ci correspondaient a des genes inconnus (sans homologue dans GenBank) et les neuf autres presentaient une forte homologie avec des EST induits par des stress abiotiques ou biotiques chez le ble, l'orge ou d'autres especes de graminees. La methode employee dans ce travail pour isoler des sequences exprimees a partir d'un chromosome specifique presente les avantages suivants : (i) les sequences exprimees obtenues sont de grande taille et fournissent de l'information sur l'extremite 3' et (ii) l'operation est moins compliquee. Il s'agirait d'une methode amelioree efficace pour des travaux en genomique ou en genomique fonctionnelle chez les plantes polyploides, particulierement pour le developpement d'EST et la cartographie. Les donnees obtenues sur les sequences ex primees sont egalement utiles pour la comprehension des genes de resistance situes sur le chromosome exotique present chez TAi-27. Mots-cles : TAi-27, Thinopyrum intermedium, microdissection chromosomique, amplification specifique de sequences hybridees (HSA), sequences exprimees, virus de la jaunisse nanisante de l'orge (BYDV)., Introduction Expressed sequence tag (EST) analysis is one of the ways to clone genes controlling desirable traits in plant (Rounsley and Linx 1998; Sasaki 1998). At present, most ESTs registered [...]

Abstract: Δ6-fatty acid desaturase is an important enzyme in the catalytic synthesis of polyunsaturated fatty acids. Using domain swapping and a site-directed mutagenesis strategy, we found that the region of the C-terminal 67 amino acid residues of Δ6-fatty acid desaturase RnD6C from blackcurrant was essential for its catalytic activity and that seven different residues between RnD6C and RnD8A in that region were involved in the desaturase activity. Compared with RnD6C, the activity of the following mutations, V394A, K395I, F411L, S436P, VK3945AI and IS4356VP, was significantly decreased, whereas the activity of I417T was significantly increased. The amino acids N, T and Y in the last four residues also play a certain role in the desaturase activity. [Copyright &y& Elsevier]