当前位置： SCI文献检索 > DEVELOPMENTAL BIOLOGY期刊下所有文献 > Defective gap-junctional communication associated with imaginal disc overgrowth and degeneration caused by mutations of the dco gene in Drosophila.

Defective gap-junctional communication associated with imaginal disc overgrowth and degeneration caused by mutations of the dco gene in Drosophila.

Abstract：

:The lethal(3)discs overgrown (dco) locus of Drosophila melanogaster, located on the third chromosome at cytogenetic position 100A5,6-100B1,2, is necessary for normal development and growth control in the imaginal discs of the larva. Three recessive lethal alleles (dco2, dco3, and dco18) in heteroallelic combinations and one allele (dco3) when homozygous cause the imaginal discs to continue to grow beyond the normal disc-intrinsic limit during an extended larval period. Some degeneration also occurs in the overgrowing discs. The discs overgrow even when transplanted early in their development into wild-type hosts, whereas normal discs stop growth at about the normal final size under such conditions, indicating that the overgrowth is a disc-autonomous effect of the mutations. During overgrowth the imaginal discs retain their single-layered epithelial structure except near regions of degeneration, and they differentiate into disc-appropriate but abnormal adult structures when transplanted into wild-type larval hosts. When the mutant larvae are reared under certain conditions a small percentage develop to the pharate adult stage, and these animals show a characteristic syndrome of abnormalities including swollen leg segments with many extra bristles, small or missing eyes, duplicated antennae and palpi, and separated vesicles of cuticle. A fourth recessive lethal allele (dcole88), when homozygous or in heteroallelic combination with the overgrowth alleles, causes the imaginal discs to degenerate, producing a "discless" phenotype. Gap junction-mediated communication was assayed by observing the intercellular transfer of injected fluorescein complexon (dye coupling). Dye coupling in the imaginal discs of the dco genotypes that cause overgrowth was dramatically reduced at 4 days after egg laying (AEL) compared with wild-type controls. Coupling was more normal although still significantly reduced at 7-8 and 12-14 days AEL. In c43hs1, another disc overgrowth mutant, the imaginal disc cells also showed very reduced dye coupling at 4 days and incomplete coupling at 9 days. In contrast, discs from wild-type larvae, two other imaginal disc overgrowth mutants, and a cell death mutant showed extensive dye coupling at all stages tested. Electron microscopic morphometry revealed a reduction in gap-junction length per unit lateral plasma membrane length in dco3/dco18 and c43hs1 wing discs, although not in dco2/dco3, compared with wild-type wing discs. The results suggest that gap-junctional cell communication may be involved in the cell interactions that limit cell proliferation in vivo.

journal_name

Dev Biol

journal_title

Developmental biology

authors

Jursnich VA,Fraser SE,Held LI Jr,Ryerse J,Bryant PJ

doi

10.1016/0012-1606(90)90090-6

subject

Has Abstract

pub_date

1990-08-01 00:00:00

pages

413-29

issue

eissn

0012-1606

issn

1095-564X

pii

0012-1606(90)90090-6

journal_volume

140

pub_type

杂志文章

在线工具

Defective gap-junctional communication associated with imaginal disc overgrowth and degeneration caused by mutations of the dco gene in Drosophila.