Gene‐dosage studies in polyploid hybrids of California newts

Brandom, W.

doi:10.1002/jez.1401430306

Cited by 9 publications

(2 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In spite of differences in motoneuron size and number, the total size of the motor column and some aspects of the motoneuron population's development (e.g., the magnitude of the increase in neuron nuclear size that occurs during development and the percentage of the motoneurons lost during cell death) are the same in diploids and triploids and apparently unaffected by the polyploid condition. These observations agree with data describing the general effects of polyploidy in amphibians (Fankhauser, 1945;Brandom, 1960;Pollack and 0 1991 WILEY-LISS, INC. Koves, 1977;Tompkins et al, 1984;Szaro and Tompkins, 1987). One unexpected feature of hindlimb muscles of triploids is that they have the same mean numbers of myofibers as diploids.…”

Section: Introductionsupporting

confidence: 92%

“…Regardless of their specific origin or ploidy, however, the first cells with the striking size differences made substantial, yet not complete, contributions to the left or right sides of the central nervous system. The resulting L-LMCs have, both during and after naturally occurring neuronal cell death, significant side-to-side differences in cell size and total motoneuron number; and these differences are analogous to the average differences between diploids and polyploids (Fankhauser, 1945;Brandom, 1960;Pollack and Koves, 1977;Tompkins et al, 1984;Szaro and Tompkins, 1987;Sperry, 1988a,l). In contrast to the striking side-to-side differences in cell size and number in the central nervous system, there is little evidence of similar side-to-side differences in other tissues, perhaps indicating that most peripheral tissues are a mixture of descendants of both large and small cells.…”

Section: Stage 56mentioning

confidence: 98%

See 1 more Smart Citation

Lumbar lateral motor columns and hindlimbs of two Xenopus laevis chromosome mosaics

Sperry

1991

Am. J. Anat.

View full text Add to dashboard Cite

Two chromosome mosaic Xenopus laevis, one tadpole and one metamorphic animal, both with different sizes of neurons on the left and right sides of their brains and spinal cords, have left and right lumbar lateral motor columns (L-LMCs) of equal lengths but composed of strikingly different numbers of motoneurons (40% fewer motoneurons on the side composed of larger cells). One portion of the lumbar cord in the metamorphic animal is bilaterally symmetrical; the cells on both sides are small and the numbers of motoneurons per section are the same. The mosaics demonstrate that column length and motoneuron density (number per section) are, or can be, regulated bilaterally and that changing cell size affects factors controlling cell density but not column length. Except for the peripheral nerves, there is no evidence of any side-to-side differences in the hindlimb tissues. Whether the side-to-side difference in L-LMC motoneuron number in the stage 66 mosaic corresponds to any feature of the hindlimbs is unknown, but similar side-to-side differences in an early and a late stage mosaic animal support the idea that whatever creates the initial number may also determine the final number of motoneurons.

show abstract

Section: Introductionsupporting

confidence: 92%

Section: Stage 56mentioning

confidence: 98%

Lumbar lateral motor columns and hindlimbs of two Xenopus laevis chromosome mosaics

Sperry

1991

Am. J. Anat.

View full text Add to dashboard Cite

show abstract

Effect of tetraploidy on dendritic branching in neurons and glial cells of the frog, Xenopus laevis

Szaro

Tompkins

1987

J of Comparative Neurology

View full text Add to dashboard Cite

Morphological aspects of four different groups of Golgi impregnated brain cells from a tetraploid strain of Xenopus laevis frogs were compared to analogous cells in comparably sized diploid frogs. The cells examined included neurons from the telencephalon, caudal hypothalamus, and optic tectum, and radial glial cells from the optic tectum. The brains of tetraploid frogs appeared grossly normal and were the same size and contained similar cell types as diploid brains. As observed in previous studies on polyploid amphibia, somal diameters increased significantly in tetraploid cells for each of the four groups of cells examined. Also, the total length of the dendritic arbors in tetraploid brain cells increased significantly by factors ranging from 1.4 to 2.4 times the total length of the analogous processes in diploid cells. Tetraploid neurons in the telencephalon and hypothalamus increased their arbor lengths predominantly by increasing the number of dendritic branches, while maintaining the average distance between branch points in the dendritic segments. In contrast, the tetraploid large pear-shaped neurons in the optic tectum had significantly longer terminal dendritic segments than the analogous diploid neurons, although these tetraploid neurons maintained their average number of dendritic segments per cell. Tetraploid tectal radial glial cells appeared to increase both their number of branches and the lengths of their terminal segments. Thus, the mode by which tetraploid brain cells achieved longer dendritic arbors varied from cell type to cell type. These results suggest a hypothetical basis for possible effects of genomic size on vertebrate brain structure and evolution at the cellular level.

show abstract

A study of hybridization and heteroploidy in two subspecies of Triturus viridescens

Hughes

1962

Journal of Morphology

View full text Add to dashboard Cite

Gene‐dosage studies in polyploid hybrids of California newts

Cited by 9 publications

References 35 publications

Lumbar lateral motor columns and hindlimbs of two Xenopus laevis chromosome mosaics

Lumbar lateral motor columns and hindlimbs of two Xenopus laevis chromosome mosaics

Effect of tetraploidy on dendritic branching in neurons and glial cells of the frog, Xenopus laevis

A study of hybridization and heteroploidy in two subspecies of Triturus viridescens

Contact Info

Product

Resources

About