Summary: Although chloral hydrate has been used as an anesthetic since 1872, its effect on cell structures and its mechanism of action are not clearly known. Early investigators (Nemec, 1904; van Regemorter, 1916; Strasburger, 1907; Sakamura, 1916) have shown that chloralhydrate produces uncoordinated chromosome movements and c-mitosis i.e. colchicine mitosis(Levan, 1938). Ris (1949) reported that chloral hydrate causes the disappearance of the mitotic spindle in grasshopper spermatocytes. Using eggs of Pleurodeles waltlii, Sentein (1974) demonstrated that chloral hydrate alters the ultrastructure of chromosomes and arrests mitosis by destroying spindle fibres. Mole-Bajer (1969) found that immediately afterchloral hydrate treatment in Haemanthus katherinae, the kinetochore and continuous microtubules were absent, but microtubules soon began to re-form anew. Since most of these studies were not quantitative, the chloral hydrate effect has mainly been described qualitatively.

The simple eukaryote Aspergillus nidulans has certain advantages for the study of mitosis, the most important of which is that the genetics of the organism are well known. The cytology of mitosis in A. nidulans is similar to that of the higher eukaryotes in most respects (Robinow & Caten, 1969). During mitosis, the chromosomes condense, a mitotic spindle is formed, the chromosomes undergo anaphase separation, the spindle then disappears, the chromosomes relax and two daughter nuclei are formed (Robinow & Caten, 1969). As with many other fungi, the nuclear membrane remains intact during all phases of mitosis. A set of temperature-sensitive, conditionally lethal, mitotic mutants of A. nidulans has been isolated (Morris, unpublished observations). One of these mutants has been used as a tool to analyse quantitatively the effect of chloral hydrate on mitosis.


Article metrics loading...

Loading full text...

Full text loading...


Most cited this month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error