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271.
Kathy Feng‐Yi Su Sujatha Narayanan Kutty Rudolf Meier 《Cladistics : the international journal of the Willi Hennig Society》2008,24(6):902-916
The Sepsidae is, with approximately 300 described species, a relatively small family of cyclorrhaphan flies whose behaviour, morphology, and development have been extensively studied. However, currently the only available tree for Sepsidae is more than 10 years old and was based entirely on morphological characters. Here, we present the results of parsimony and Bayesian analyses based on 75 species, ten genes, and morphology. Parsimony and Bayesian analyses produce largely congruent and well‐supported topologies regardless of whether indels are coded as 5th character states, as missing values, or all sites with indels are removed. The tree confirms the monophyly of Sepsidae and identifies the Ropalomeridae as its sister group. With regard to higher‐level relationships, we identify widespread conflict between the morphological and the DNA sequence data. The proposed hypothesis based on both partitions largely reflects the signal in the molecular data. Particularly surprising is the rejection of two relationship hypotheses with strong morphological support, namely the sister group relationship between Orygma and the remaining Sepsidae and the monophyly of the Sepsis species group. Our partitioned Bremer support (PBS) analyses imply that indel coding has a stronger effect on the relative performance of individual gene partitions than the exclusion of alignment‐ambiguous sequences or the location of a gene on the mitochondrial or nuclear genome. However, these analyses also reveal unexpectedly strong fluctuations in PBS values given that indel treatment has only a minor effect on tree topology and jacknife support. These unexpected fluctuations highlight the need for a comparative study across multiple data sets that investigates the influence of conflict and indel treatment on PBS values. © The Willi Hennig Society 2008. 相似文献
272.
Murashige and Skoog’s (MS) basal medium with benzylaminopurine (BA), kinetin (KN), zeatin (Z), and thidiazuron (TDZ) were
tested for induction of multiple shoots from mature-tree-derived axillary meristems of Pongamia pinnata. Sprouting of buds was 64% on medium devoid of plant growth regulators (PGR). Incorporation of BA, KN, or Z was ineffective
in enhancing sprouting frequency or induction of multiple shoots. Sprouting was completely suppressed in the presence of TDZ.
Caulogenic buds appeared in nodal meristems of these explants after withdrawal of TDZ. The number of shoot buds was more on
explants precultured in higher concentrations. At higher concentrations of this PGR, a swelling developed at the axil. Multiple
shoot primordia appeared and differentiated from this swelling after culturing these explants on MS medium for six passages
of 2 wk each. Shoots were harvested and cultured on 0.45 μM TDZ for further proliferation. Primary explants after harvesting
of shoots were identified as ‘stump’. Reculturing of stumps on 0.45 μM TDZ produced more shoots. This step was followed for
six cycles to obtain additional shoots in each cycle. Shoots maintained on 0.45 μM TDZ elongated and rooted (70%) on growth
regulator-free medium. Rooted shoots (65%) survived transfer to a sand/soil mixture. This report describes the protocol for
micropropagation of P. pinnata using mature-tree-derived nodal meristems. Recycling of mature stock to produce a stream of useable shoots for subculturing
and eventual stabilization is of great value and can possibly be generalized as an isolation protocol especially for woody
species. Repeated proliferation of caulogenic buds from the same origin may also find application in rescue of endangered
germplasm. 相似文献
273.
Mahima Sharma Sujatha Narayanan Unni Subalakshmi Balasubramanian Sandhya Sundaram Priya Krishnamurthy Anoosha Hegde 《Journal of biophotonics》2021,14(5):e202000475
Polarimetric imaging and image analysis have gained increased interest in soft tissue analysis at the cellular level. However, polarimetric imaging has widely been tested on thin tissue sections to provide reliable information correlated with histopathological findings. Polarimetric bulk tissue analysis always offered an overall assessment of various tissue optical properties for diagnosis. In this study, the histopathological correlation of bulk tissue polarimetry images for soft tissues is discussed. The first-hand information on the use of bulk tissue Mueller polarimetry and image analysis as an alternative to tissue histopathology is presented for surgically extracted colon and breast tissues. 相似文献
274.
Dinesh Kumar Kannan Palaniyandi Vijay K. Challu Prahlad Kumar Sujatha Narayanan 《Archives of microbiology》2013,195(1):75-80
Serine/threonine protein kinases (STPK) play a major role in the physiology and pathogenesis of Mycobacterium tuberculosis. Here, we have examined the role of pknE, a STPK in the adaptive responses of M. tuberculosis using a deletion mutant ΔpknE. The survival of ΔpknE was assessed in the presence of stress (pH, surfactant and cell wall–damaging agents) and anti-tuberculosis drugs. ΔpknE had a defective growth in pH 7.0 and lysozyme (a cell wall–damaging agent) with better survival in pH 5.5, SDS and kanamycin (a second-line anti-tuberculosis drug). Furthermore, ΔpknE was reduced in cell size during growth in liquid media and exhibited hypervirulence in a guinea pig model of infection. In conclusion, our data suggest that pknE plays a role in adaptive response of M. tuberculosis regulating cellular integrity and survival. 相似文献
275.
The sillaginid fishes of Visakhapatnam Coast, Bay of Bengal, are found to be hosts for 16 species of digeneans of which seven are adult digeneans belonging to families Opecoelidae, Zoogonidae and Hemiuridae and nine are larval digeneans representing families Bucephalidae, Heterophyidae, Cryptogonimidae, Acanthocolpidae, Hemiuridae and Didymozoidae. The digenean fauna of sillaginid fishes from shallow coastal waters (< 10 m depth) and deeper offshore waters (30–50 m depth) are compared and results are discussed in the light of existing information on the migratory movements of different species of sillaginids and their occurrence in coastal or offshore waters. The usefulness of metacercariae of these fishes as 'biological tags' is considered. 相似文献
276.
M. Sujatha M. Lakshminarayana M. Tarakeswari P. K. Singh Rakesh Tuli 《Plant cell reports》2009,28(6):935-946
Castor (cv. DCS-9) has been transformed through Agrobacterium-mediated and particle gun bombardment methods using appropriate vectors containing the Bt chimeric gene cry1EC driven by enhanced 35S promoter. About 81 and 12 putative transformants were regenerated following selection on hygromycin
and kanamycin, respectively. Southern analysis of DNA extracted from T0 plants confirmed integration of the introduced gene in castor genome. The integration and inheritance of the introduced genes
was demonstrated up to T4 generation by PCR and Southern analysis. Southern analysis of two events having single and two copies showed the same pattern
of integration in the subsequent generations. Insect feeding experiments conducted in the laboratory by releasing neonate
larvae of castor semilooper and S. litura on leaf tissues excised from transgenic and control plants showed varying degrees of larval mortality and slow growth in
larvae fed on transgenic leaf tissue. Field bioassays against Spodoptera litura and castor semilooper conducted for eight events in T1–T4 generations under net confinement were more informative and events conferring resistance to the two major defoliators were
identified. 相似文献
277.
Natural hazards like landslides, earthquakes, and floods are a major deterrent to the development of mountain regions of the world. Recently, there has been a rise in the number of landslides in Western Ghats, India. Several factors cause landslides and they depend on the local geo-environmental set-up of the region. This study attempts to map the spatial distribution of landslide hazard and analyze the risk for a typical hill town, Kodaikkanal in the Western Ghats, India, facing rapid urbanization and infra-structure growth, using a weighted linear combination model in a geographic information system platform. Landslides in the region are triggered by rainfall and it is fairly uniform throughout the area. Hence, the susceptibility map is used as the hazard map. Validation of the weighted linear combination model using landslide hazard index shows that landslide density increases with the hazard class. The risk assessment matrix (RAM) is used to evaluate risk based on the land use and landslide hazard category. The land use map is reclassified by assigning damage potential for each land use feature. The risk map is classified into low, moderate, and high risk categories. Suitable control measures are suggested for various risk categories. 相似文献