PubMed · 13815920
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
H DENIS. 1960-07-02. Electrophoretic pattern during amphibian development.. https://doi.org/10.1038/187062a0
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
Flavor aversion learning occurs when digestive illness follows ingestion of a novel food. Such learning has been shown to exist in mammals and birds. In this experiment, we looked for flavor aversion learning in amphibians (Bufo paracnemis, Pachytriton breviceps) and reptiles (Basiliscus vitattus, B. basiliscus, Eumeces schneideri, Mabuya multifasciata). After intake of the novel food, the animals received i.p. injection of either lithium chloride (LiCl), an effective illness inducer, or a saline solution. A week later, the LiCl injection had not affected the food intake of the amphibians whereas in the lizards it had produced a strong aversion to the flavor of the novel food. These results are consistent with the hypothesis that specific mental capacities emerged with reptiles.
The germinal vesicle (GV) of Xenopus laevis is an enormous nucleus that contains 18 giant lampbrush chromosomes and thousands of inclusions. The inclusions are primarily of three types: approximately 1500 extrachromosomal nucleoli, 50-100 Cajal bodies, and several thousand B-snurposomes, which correspond to speckles or interchromatin granule clusters in other nuclei. The large size and abundance of the GV organelles, as well as the ease with which they can be studied both in vivo and in vitro, make the GV an ideal object for analysis of nuclear structure and function.
In animals that do not regulate their body temperature by the production of heat, the proportion of the total developmental time spent in a particular developmental stage does not change with temperature. In the quasi-linear region of the relationship between developmental rate and temperature, all of the developmental stages appear to have the same species-specific lower developmental threshold. This trait, which is called developmental isomorphy, constrains developmental adaptations of ectotherms to their environments and facilitates the precise timing of life-history events.