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Interpretation of inverse acclimation to temperature 总被引:2,自引:0,他引:2
Jeffrey Hazel C. Ladd Prosser 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1970,67(2):217-228
Summary In kidney of goldfish acclimated to 5, 15 and 25° C the peroxisomal enzyme peroxidase and the peroxisomal and cytoplasmic matrix enzyme catalase showed inverse (Precht type 5) acclimation. Peroxisomal D-amino acid oxidase and lysosomal acid phosphatase were unchanged in activity (Precht type 4).A review of literature data on enzyme acclimation patterns shows that generally enzymes concerned with energy liberation — enzymes of glycolysis, hexose monophosphate shunt, TCA cycle and electron transport, also Na, K-ATPase and the synthetic amino acyl transferase — show compensatory acclimation to temperature (Precht type 3). Enzymes for degradation of metabolic intermediates and products such as peroxisomal and lysosomal enzymes, Mg-ATPase, acetylcholine esterase, show no or inverse acclimation to temperature. Changes in digestive enzymes depend on state of nutrition.Support from Research Grant GB 4005 from National Science Foundation is acknowledged. 相似文献
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Summary Somatic embryos produced in vitro may exhibit structural abnormalities that affect their subsequent germination and conversion into plants. To assess the influence of auxin type on embryo initiation and development, a morphological and histological comparison was made of pecan (Carya illinoinensis) somatic embryogenic cultures induced on media with naphthaleneacetic acid or 2,4-dichlorophenoxyacetic acid (2,4-D), using light and scanning electron microscopy. Both auxins promoted enhanced cell division, particularly in subepidermal cell layers. However, notable differences were observed in mitotic activity, location of embryogenic cell proliferation, epidermal continuity, callus growth, and embryo morphology. Cultures induced on naphthaleneacetic acid had embryogenic regions composed of homogeneous, isodiametric, meristematic cells. Embryos derived from these cultures generally had a normal morphology, were single, and had a discrete apical meristem. In contrast, tissues induced on media with 2,4-D had more intense and heterogeneous regions of cell division. Proliferating cell regions were composed of meristematic cells interspersed with callus and involved more extensive regions of the mesophyll. Marked callus proliferation caused epidermal rupture in some areas. Embryos induced on medium with 2,4-D had a higher incidence of abnormalities that included fasciated, fan-shaped, and tubular embryos. Defined apical meristems were often lacking or partially obliterated due to callus proliferation. The heterogeneous, often intensive proliferation of cells in cultures induced with 2,4-D may interfere with normal patterns of embryo development.Abbreviations 2,4-D
2,4-dichlorophenoxyacetic acid
- BAP
6-benzylaminopurine
- NAA
naphthaleneacetic acid
- SEM
scanning electron microscopy 相似文献
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SUMMARY We studied the developmental basis of exaggerated eye span in two species of stalk-eyed flies ( Cyrtodiopsis dalmanni and Sphyracephala beccarri ). These flies have eyes laterally displaced at the end of eyestalks, and males have greatly exaggerated eye span, which they use as a sexual display. To investigate eye span development we have compared eye-antennal disc morphology and the expression of three key regulator genes of Drosophila head development, Distal-less ( Dll ) , engrailed ( en ), and wingless ( wg ), in the stalk-eyed flies and Drosophila . We found great similarity in the basic division of the disc into anterior-antennal and posterior-eye portions and in the general patterning of Dll, en , and wg . Unexpectedly, our results showed that although the eye and antenna are adjacent in adult stalk-eyed flies, their primordia are physically separated by the presence of an intervening region between the anterior and posterior portions of the disc. This region is absent from Drosophila eye-antennal discs. We chose two stalk-eyed fly species that differed in the degree of eyestalk exaggeration but surprisingly we found no corresponding difference in the size of the en-wg expression domains that mark the boundaries of the dorsal head capsule primordia. In summary, our expression data establish the regional identity of the eye-antennal disc and provide a framework from which to address the developmental genetics of hypercephaly. 相似文献
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