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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular evolution 28 (1989), S. 212-219 
    ISSN: 1432-1432
    Keywords: Primate evolution ; Tandem repeats ; Restriction fragment length polymorphisms
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The clone designated hMF #1 represents a clustered DNA family, located on chromosome 1, consisting of tandem arrays displaying a monomeric length of 40 bp and a repetition frequency of approximately 7×103 copies per haploid genome. The sequence hMF #1 reveals multiple restriction fragment length polymorphisms (RFLPs) when human genomic DNA is digested with a variety of 4–6-bp recognition sequence restriction enzymes (i.e., Taq I, Eco RI, Pst I, etc.). When hamster and mouse genomic DNA was digested and analyzed, no cross-species homology could be observed. Further investigation revealed considerable hybridization in the higher primates (chimpanzee, gorilla, and orangutan) as well as some monkey species. The evolutionary relationship of this repetitive DNA sequence, found in humans, to that of other primates was explored using two hybridization methods: DNA dot blot to establish copy number and Southern DNA analysis to examine the complexity of the RFLPs. Homology to the hMF #1 sequence was found throughout the suborder Anthropoidea in 14 ape and New and Old World monkey species. However the sequence was absent in one species of the suborder Prosimii. Several discrepancies between “established” evolutionary relationships and those predicted by hMF #1 exist, which suggests that repetitive elements of this type are not reliable indicators of phylogenetic branching patterns. The phenomenon of marked diversity between sequence homologies and copy numbers of dispersed repetitive DNA of closely related species has been observed inDrosophila mice,Galago, and higher primates. We report here a similar phenomenon for a clustered repeat that may have originated at an early stage of primate evolution.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Trees 2 (1988), S. 32-38 
    ISSN: 1432-2285
    Keywords: Auxin ; Cytokinin ; Gymnosperm ; Micropropagation ; Tissue culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Adventitious bud formation was induced on detached cotyledons and on cotyledons attached to excised embryos of Pinus caribaea and Pseudotsuga menziesii. The embryonic tissue was exposed to the cytokinin 6-benzyl amino purine contained within an agar medium. This exposure resulted in the formation of a meristematic zone, involving both epidermal and sub-epidermal cells, and then nodules on the tissue surface. Some of these nodules were induced to differentiate into bud primordia, and thence shoots, following exposure to a combination of auxin (IAA) and cytokinin. Shoots were produced over the entire surface of detached cotyledons of Ps. menziesii but predominantly on the adaxial surfaces of detached cotyledons of Pi. caribaea and the tips and adaxial surfaces of the cotyledons on the entire embryos of both species. Thus, inter-specific differences in the distribution of competent areas for adventitious bud production were detected in embryos.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Trees 2 (1988), S. 32-38 
    ISSN: 1432-2285
    Keywords: Auxin ; Cytokinin ; Gymnosperm ; Micropropagation ; Tissue culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Adventitious bud formation was induced on detached cotyledons and on cotyledons attached to excised embryos ofPinus caribaea andPseudotsuga menziesii. The embryonic tissue was exposed to the cytokinin 6-benzyl amino purine contained within an agar medium. This exposure resulted in the formation of a meristematic zone, involving both epidermal and sub-epidermal cells, and then nodules on the tissue surface. Some of these nodules were induced to differentiate into bud primordia, and thence shoots, following exposure to a combination of auxin (IAA) and cytokinin. Shoots were produced over the entire surface of detached cotyledons ofPs. menziesii but predominantly on the adaxial surfaces of detached cotyledons ofPi. caribaea and the tips and adaxial surfaces of the cotyledons on the entire embryos of both species. Thus, inter-specific differences in the distribution of competent areas for adventitious bud production were detected in embryos.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
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