Differential expression of genes related to glucose metabolism in domesticated pigs and wild boar

Glucose metabolism is a basic biological process that shows substantial variation within and between species. Using pig as a model organism, we investigated differences in glucose metabolic genes in seven tissues from domesticated pigs (Rongchang pig and Tibetan pig, meanwhile, the Tibetan pig just as a special case of the domesticated pig under plateau condition) and wild boar. We found large differences in the expression of genes involved in multiple aspects of glucose metabolism, including genes associated with glucose transport, gluconeogenesis, and glycolysis. In addition, we identified microRNAs (miRNAs) that may be involved in the divergence of glucose metabolism in pig. A combined analysis of mRNA and miRNA expression indicated that some miRNA:mRNA pairs showed ab facto function in it. Our results provide a valuable resource for further determination of miRNA regulatory roles in pig glucose metabolism and reveal the divergence of glucose metabolism in pigs under domestication.     

Molecular characterization and phylogenetic analysis of Wx genes from three Taeniatherum diploid species

In wheat seeds, starch synthase I or the Waxy protein is an enzyme involved in amylose synthesis. The gene encoding this enzyme is Wx and in this study, eight novel Wx alleles were identified in three diploid Taeniatherum species. The variability of these alleles was evaluated, and their nucleotide sequences were compared with those of homologous alleles from wheat. Two types of Taeniatherum Wx alleles were detected in three diploid species Ta. caput-medusae, Ta. asperum, and Ta. crinitum. A phylogenetic analysis indicates that the Taeniatherum Wx alleles were more closely related to Wx alleles from Aegilops species with C, D, M, and U genomes than to Wx alleles of other species. These alleles represent a potential genetic resource that may be useful in wheat breeding programs.     

Trichoderma harzianum及其近缘种的分子系统学研究

Thichoderma harzianum是木霉属内最常见的一个“集合种”。本研究对来源不同的T.harzianum及其相似种的46个菌株进行了ITS序列测定,将其ITSl—5．8S—ITS2序列与来自EMBL的参考菌株的序列进行比较,并进行系统发育分析,此外对其中的18个菌株进行了RAPD多态性分析,试图明确T.harzianum的多样性以及与其相似种之间的关系。ITS结果表明,T.harzianum及其相似种可分成2个群(A、B)：A群由T.hamatum、T.asperellum、T.at-roviride、T.koningii和T.viride组成,并形成2个分支,表明T.viride和T.koningii、T.atroviride的亲缘关系较近,而与T.hamatum、T.asperellum较远;B群由T.spirale、T.hamatum、T.inhamatum、T.harzianum和T.anam。Hypocrea vinosa组成,并形成6个分支。T.inhamatum可分成2个群(Ti1、Ti2)、T.harzianum至少可分成5个群(Thl、Th2、Th4、Th5、Th6)。结果还表明T.hamatum的遗传差异较大,T.hamatum的模式菌株归属于A群,而其他的T.hamatum的菌株归属于B群。RAPD结果与ITS的结果基本一致。     

Somatic embryogenesis and plant regeneration from different wild diploid cotton (Gossypium) species

Calli were successfully induced from hypocotyls of eight wild diploid cotton species (Gossypium) on MSB (MS salts and B₅ vitamins) medium supplemented with 0.09 μM 2,4-D (2,4-dichlorophenoxyacetic acid) and 2.32 μM KT (kinetin). Plant growth regulator (PGR) combinations, adding GA₃ (Gibberellic acid), high inorganic salt stress, and PGR-free media were used to induce embryogenic calli from nonembryogenic calli. Embryogenic cultures were induced from G. aridum S. (D₄ genome), G. davidsonii K. (D₃-d genome), G. klotzschianum A. (D₃-k genome), G. raimondii U. (D₅ genome), and G. stocksii M. (E₁ genome). We then observed somatic embryogenesis in the five species while calli of G. africanum V. (A₁-2 genome), G. anomalum W. (B₁ genome), and G. bickii P. (G genome) remained nonembryogenic. Somatic embryogenesis was adjusted by changing sugar sources, regulating combinations of PGRs, and using cell suspension culture. Embryos at various developmental stages produced mature and germinating embryos when cultured on filter paper placed on the media containing different sugar sources. The utility of different sugar sources promoted globular embryos developing into cotyledonary stage and increased the frequency of cotyledonary embryos developing into normal plants. Normal plantlets were regenerated from G. davidsonii, G. klotzschianum, G. raimondii, and G. stocksii. Only abnormal plantlets were obtained in G. aridum. This work will contribute to broadening the number of regenerable cotton species and provide foundations for somatic hybridization in cotton to create new germplasm.     

基于线粒体ND2基因的直翅目部分种类分子系统学发育研究

本文的研究目的是通过对直翅目部分种类的线粒体ND2基因进行分析,重建直翅目内部昆虫的系统发育关系,并探讨分子系统发育关系和传统分类结果的异同。基于80个物种ND2基因的研究结果显示直翅目ND2基因存在碱基偏向性A T含量平均为73%,第三位点A T含量79.9%最高,推测这与氨基酸变异有关。直翅目具有单系性,而蝗亚目内部的剑角蝗科、网翅蝗科、槌角蝗科和斑腿蝗科均不是单系群,锥头蝗科和瘤锥蝗科亲缘关系较近,这与Otte分类系统相一致,建议将锥头蝗科和瘤锥蝗科合并为一个科。癞蝗科的分类地位存在争议有待进一步深入的研究。     

Independent evolution of functional Pm3 resistance genes in wild tetraploid wheat and domesticated bread wheat

The Pm3 alleles of cultivated bread wheat confer gene for gene resistance to the powdery mildew fungus. They represent a particular case of plant disease resistance gene evolution, because of their recent origin and possible evolution after the formation of hexaploid wheat. The Pm3 locus is conserved in tetraploid wheat, thereby allowing the comparative evolutionary study of the same resistance locus in a domesticated species and in one of its wild ancestors. We have identified 61 Pm3 allelic sequences from wild and domesticated tetraploid wheat subspecies. The Pm3 sequences corresponded to 24 different haplotypes. They showed low sequence diversity, differing by only a few polymorphic sequence blocks that were further reshuffled between alleles by gene conversion and recombination. Polymorphic sequence blocks are different from the blocks found in functional Pm3 alleles of hexaploid wheat, indicating an independent evolution of the Pm3 loci in the two species. A new functional gene was identified in a wild wheat accession from Syria. This gene, Pm3k , conferred intermediate race-specific resistance to powdery mildew, and consists of a mosaic of gene segments derived from non-functional alleles. This demonstrates that Pm3 -based resistance is not very frequent in wild tetraploid wheat, and that the evolution of functional resistance genes occurred independently in wild tetraploid and bread wheat. The Pm3 sequence variability and geographic distribution indicated that diversity was higher in wild emmer wheat from the Levant area, compared with the accessions from Turkey. Further screens for Pm3 functional genes in wild wheat should therefore focus on accessions from the Levant region.     

Comparative transcriptome analysis to identify putative genes related to trichome development in Ocimum species

Molecular Biology Reports - Genus Ocimum is known to have species possessing important therapeutic essential oil. The major phytoconstituents of essential oil in Ocimum species are...     

DNA content and expression of genes related to cell cycling in developing Gossypium hirsutum (Malvaceae) fibers

The cell cycle in cotton (Gossypium hirsutum) fibers is poorly understood. The objective of this study was to evaluate the cell cycle status and DNA content in developing cotton fibers. The DNA content and cell cycle distribution in fiber and hypocotyl cells were determined by flow cytometry. Expression levels of minichrosomal maintenance protein (mcm), cyclin B, and a retinoblastoma-like protein (rb) genes were determined with real-time PCR in fibers and dividing and nondividing tissues. No endoreduplication occurred, nor did genome size or percentage of G1-phase nuclei differ between hypocotyls and fibers. Approximately 13 and 17% of fiber nuclei were in the S phase in 14 days after anthesis (d) fibers and 25 d fibers, respectively. The mcm and cyclin B were expressed at higher levels in fibers than in mature leaves, but expression levels in fibers were less than 15% of meristematic tissues. Rb was expressed in fibers at levels less than 50% of mature leaves or meristematic tissues. Based on an apparent increase in S-phase cells as fibers mature and the low level of expression of genes associated with cell cycle progression, we conclude that S-phase arrest occurs in developing cotton fiber.     

Molecular characterization and functional analysis of elite genes in wheat and its related species

The tribe Triticeae includes major cereal crops (bread wheat, durum wheat, triticale, barley and rye), as well as abundant forage and lawn grasses. Wheat and its wild related species possess numerous favourable genes for yield improvement, grain quality enhancement, biotic and abiotic stress resistance, and constitute a giant gene pool for wheat improvement. In recent years, significant progress on molecular characterization and functional analysis of elite genes in wheat and its related species have been achieved. In this paper, we review the cloned functional genes correlated with grain quality, biotic and abiotic stress resistance, photosystem and nutrition utilization in wheat and its related species.     

Molecular characterization and phylogenetic analysis of ascarid nematodes from twenty-one species of captive wild mammals based on mitochondrial and nuclear sequences

SUMMARY Although ascarid nematodes are important parasites of wild animals of public health concern, few species of ascarids from wild animals have been studied at the molecular level so far. Here, the classification and phylogenetic relationships of roundworms from 21 species of captive wild animals have been studied by sequencing and analysis of parts of the ribosomal 18S and 28S genes and the mitochondrial (mt) 12S gene. Phylogenetic relationships were inferred by 3 methods (NJ/MP/ML) based on the data of single gene sequences and concatenated sequences. Homology analysis indicated that the 18S sequences were conserved among roundworms from all 21 species and that 28S showed interspecies variability. Divergence levels displayed in 12S suggested that 12S appears to be either intra- or interspecifically variable. Evolutionary trees indicated that the ascarids split into 2 families, 4 genera and 7 species, with high bootstrap support for each clade. Combined trees suggested that Baylisascaris ailuri is more closely related to B. transfuga than to B. schroederi. This study provides useful molecular markers for the classification, phylogenetic analysis and epidemiological investigation of roundworms from wild animals.     

Molecular cloning and expression analysis of RrNHX1 and RrVHA-c genes related to salt tolerance in wild Rosa rugosa

Salt stress is one important factor influencing the growth and development of plants, and salt tolerance of plants is a result of combined action of multiple genes and mechanisms. Rosa rugosa is not only an important ornamental plant, but also the natural aromatic plant of high value. Wild R. rugosa which is naturally distributed on the coast and islands of China has a good salt tolerance due to the special living environment. Here, the vacuolar Na⁺/H⁺ reverse transporter gene (NHX1) and the vacuolar H⁺-ATPase subunit C gene (VHA-c) closely related to plant salt tolerance were isolated from wild R. rugosa, and the expression patterns in R. rugosa leaves of the two genes under NaCl stress were determined by real-time quantitative fluorescence PCR. The results showed that the RrNHX1 protein is a constitutive Na⁺/H⁺ reverse transporter, the expression of the RrNHX1 gene first increased and then decreased with the increasing salt concentration, and had a time-controlled effect. The RrVHA-c gene is suggestive of the housekeeping feature, its expression pattern showed a similar variation trend with the RrNHX1 gene under the stress of different concentrations of NaCl, and its temporal expression level under 200 mM NaCl stress presented bimodal change. These findings indicated that RrNHX1 and RrVHA-c genes are closely associated with the salt tolerance trait of wild R. rugosa.     

Molecular phylogenetic analysis of New Zealand mosquito species

ABSTRACT

Taxonomic information for New Zealand mosquito species is predominantly morphological with very few molecular data available to date. In this study, the mitochondrial COI gene and nuclear ITS1 were amplified and sequenced from DNA templates representing 17 species; 15 previously known New Zealand species, a newly discovered undescribed Aedes species from the Chatham Islands and a recently eradicated invader, Ae. camptorhynchus. This paper provides DNA barcoding sequences for the entire known New Zealand mosquito fauna, the first for the majority of these species. Phylogenetic analysis of COI and ITS1 indicated that the endemic species are all genetically distinct from the exotic species examined including vector species of pathogens of human diseases. The genus Opifex is distant from the genus Aedes based on analysis of ITS1 sequences, and Ae. chathamicus is more closely related to species within Aedes than to the genus Opifex. Results show Culex asteliae to be a valid species but Cx. rotoruae is not necessarily so. The Aedes species appears to be closely related to Ae. subalbirostris. The introduced Cx. quinquefasciatus was clearly shown to be related to Cx. pipiens; however, the endemic Cx. pervigilans was not. No evidence of population variation based on geographic location was detected.     

小孢子链格孢endoPG基因核苷酸序列分析及系统发育研究

对供试小孢子链格孢菌株的内聚半乳糖醛酸酶(endoPG)基因进行扩增,大部分菌株都可获得PCR产物。核苷酸和氨基酸序列比较表明:不同种小孢子链格孢endoPG基因核苷酸序列存在明显差异,甚至表现在氨基酸水平,这些差异可以作为一些种如梨黑斑链格孢、长柄链格孢区分的分子性状。利用邻近结合法构建系统发育树,所有菌株被分为8个聚类组。在系统发育树上,链格孢的一些不同分离物被聚在不同组中,而细极链格孢、链格孢的部分菌株、苹果链格孢、柑橘链格孢、粗柠檬褐斑链格孢、橘树链格孢被聚为一组,显示根据形态学特征划分的这些种与分子性状的不一致性。endoPG基因核苷酸序列富于变化,为小孢子链格孢系统发育研究提供了一种有用的手段。     

小孢子链格孢endoPG基因核苷酸序列分析及系统发育研究

对供试小孢子链格孢菌株的内聚半乳糖醛酸酶(endoPG)基因进行扩增,大部分菌株都可获得PCR产物。核苷酸和氨基酸序列比较表明:不同种小孢子链格孢endoPG基因核苷酸序列存在明显差异,甚至表现在氨基酸水平,这些差异可以作为一些种如梨黑斑链格孢、长柄链格孢区分的分子性状。利用邻近结合法构建系统发育树,所有菌株被分为8个聚类组。在系统发育树上,链格孢的一些不同分离物被聚在不同组中,而细极链格孢、链格孢的部分菌株、苹果链格孢、柑橘链格孢、粗柠檬褐斑链格孢、橘树链格孢被聚为一组,显示根据形态学特征划分的这些种与分子性状的不一致性。endoPG基因核苷酸序列富于变化,为小孢子链格孢系统发育研究提供了一种有用的手段。     

Resistance to silverleaf whitefly, Bemisia argentifolii (Hem., Aleyrodidae), in Gossypium thurberi, a wild cotton species

Abstract  Gossypium thurberi Todaro is a wild cotton species native to Mexico and parts of the southwestern USA. Four years of field studies in California's Imperial Valley revealed consistent very high levels of resistance in G. thurberi against silverleaf whitefly, Bemisia argentifolii Bellows and Perring, an important pest of cotton in many regions of the world. Naturally developing field infestations in plots of G. thurberi were significantly lower than in plots of the commercial cotton cultivars DP 5415, Siokra L23, and Stoneville 474. Gossypium thurberi has two morphological traits that, in past research, have been associated with lower levels of whitefly susceptibility: smooth- and okra-leaf; however, the levels of resistance observed in G. thurberi were significantly greater than in the cotton cultivar DP 5415, which is a smooth-leaf cotton, and Siokra L23 which, like G. thurberi , has both smooth- and okra-leaf traits. Therefore, the high level of resistance in G. thurberi seems to be due to factors above and beyond smooth- and okra-leaf. Siokra L23, which is among the least whitefly-susceptible cotton cultivars, developed whitefly populations over 30 times those on G. thurberi in all 3 years that Siokra L23 was tested. The difference in whitefly population development between G. thurberi and the other two cotton cultivars was even more striking, up to a 475-fold difference. In contrast to the clear results on naturally developing field infestations, experiments comparing nymphal survival among G. thurberi and commercial cotton cultivars did not detect antibiosis, and both choice and no-choice oviposition experiments did not detect antixenosis. Thus, the mechanisms of resistance in G. thurberi remain unknown.