Size-dependent functional response of Xenopus laevis feeding on mosquito larvae

Functional conflicts between feeding and gas exchange in suspension-feeding tadpoles, Xenopus laevis.

Air-breathing tadpoles of Xenopus laevis (Amphibia: Anura) use buccopharyngeal surfaces for both gas exchange and capture of food particles in the water. In dense food suspensions, tadpoles decrease ventilation of the buccopharynx and increase air breathing. The lung ventilatory frequency is elevated even though the rate of oxygen consumption is at or below resting levels, suggesting that the l...

Ultrastructure of diploid and haploid cells of Xenopus laevis larvae.

A study was made of tissues of diploid and haploid Xenopus laevis larvae by electron microscopy. The comparison of the two types of larvae was both quantitative and qualitative. Haploid cells contain fewer similarly sized mitochondria and/or cilia (compared with the diploid), commensurate with their smaller cell size. Cellular differentiation is retarded in haploids and the degree of retardatio...

Biochemical changes in developmentally retarded Xenopus laevis larvae

Premetamorphic tadpoles of Xenopus laevis reared in water containing 001 % propylthiouracil are developmentally retarded and metamorphosis is prevented. When uncrowded, they continue to grow to a giant size. Moderate crowding leads to a slower rate of growth. Thus morphologically premetamorphic tadpoles were produced with lens diameters appropriate to either normal premetamorphic, climactic or ...

ترتیب اعصای جانبی در دم لارو of Xenopus laevis

High-quality frozen extracts of Xenopus laevis eggs reveal size-dependent control of metaphase spindle micromechanics

Cell-free extracts from unfertilized Xenopus laevis eggs offer the opportunity for a variety of biochemical and biophysical assays for analyzing essential cell cycle events such as metaphase spindle assembly. However, the extracts often exhibit substantial variation in quality and have low storage stability, factors that hamper their experimental utility. Here we report a simple two-step method...