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851.
852.
Penny A. Spiering Micaela Szykman Gunther David E. Wildt Michael J. Somers Jesús E. Maldonado 《Conservation Genetics》2009,10(6):2005-2007
Modern non-invasive genetic technologies are useful in studies of rare and difficult-to-observe species. An examination of
endangered African wild dog (Lycaon pictus) faecal DNA revealed that 11.4% of samples were assigned incorrectly to an individual. Sampling mistakes in the field are
not normally considered in non-invasive genetic assessments, but can be a significant source of error. To ensure meticulous
data interpretation, non-invasive genetic studies should track and report sampling inaccuracies. 相似文献
853.
854.
d-Glucose, turanose, maltose, melibiose, isomaltose, and inulin were each degraded in aqueous barium tritioxide under nitrogen. The saccharinic acids subsequently isolated contained carbon-bound tritium. Maltose, similarly degraded in the presence of air, gave, in addition, O-d-glucosylaldonic acids which were not tritium-labelled. The application of these observations to the structural analysis of oligosaccharides is discussed. 相似文献
855.
856.
S. G. SUGUNA K. GOPALA RATHINAM A. R. RAJAVEL V. D HAN DA 《Medical and veterinary entomology》1994,8(1):88-94
Abstract. Anopheles subpictus Grassi is shown to comprise four reproductively distinct species, designated A, B, C and D, occurring sympatrically in villages of Pondicherry, southeast India.
Adult females were reared individually from wild larvae and examined for their morphological and chromosomal characters. Paracentric fixed inversions on the X-chromosome serve to distinguish the species cytogenetically, with no inversion heterozygotes (i.e. no interspecific hybrids) among totals of 717 species A (X+a ,+b ), 1863 species B (Xa, b), 869 species C (Xa,+b ) and 1365 species D (X +a ,b) identified.
Morphologically, diagnostic characters for each of the four species are seen in the egg float ridge number, larval mesothoracic seta 4, pupal seta 7-1 and the palpi of female adults. Species A. C and D immatures inhabit freshwater, whereas the malaria vector species B breeds in saltwater and was found only in coastal villages. 相似文献
Adult females were reared individually from wild larvae and examined for their morphological and chromosomal characters. Paracentric fixed inversions on the X-chromosome serve to distinguish the species cytogenetically, with no inversion heterozygotes (i.e. no interspecific hybrids) among totals of 717 species A (X+
Morphologically, diagnostic characters for each of the four species are seen in the egg float ridge number, larval mesothoracic seta 4, pupal seta 7-1 and the palpi of female adults. Species A. C and D immatures inhabit freshwater, whereas the malaria vector species B breeds in saltwater and was found only in coastal villages. 相似文献
857.
Characterization of botulinum type A neurotoxin gene: delineation of the N-terminal encoding region 总被引:3,自引:0,他引:3
M J Betley E Somers B R DasGupta 《Biochemical and biophysical research communications》1989,162(3):1388-1395
A 456 basepair HindIII fragment that encoded a portion of the type A botulinum neurotoxin gene was cloned into Escherichia coli using a plasmid vector. DNA sequence analysis revealed that this botulinum DNA insert encoded an open reading frame of 35 amino acid residues of which 34 corresponded to the N-terminal residues of botulinum neurotoxin type A. 相似文献
858.
Sea urchin fertilization envelope assembly provides an ideal model system for investigating the production and modification of an extracellular matrix. The contents of secretory vesicles and the egg glycocalyx mix to initiate assembly. Limited proteolysis and covalent crosslinking by a transglutaminase act as early events to modify the nascent envelope. A subset of secreted proteins binds to this matrix through ionic interactions that require divalent cations. For example, one secreted protein, proteoliaisin, is responsible for attaching ovoperoxidase to the envelope. Ovoperoxidase hardens the envelope by using hydrogen peroxide, produced by the egg during the respiratory burst, to form dityrosine crosslinks between a subset of fertilization envelope proteins. Numerous spatial and temporal regulatory mechanisms exist to ensure that proper assembly occurs in an environment isolated from the normal cytosolic regulatory machinery. 相似文献
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