What type of mutagen is nitrous acid?

mutagenic agent
Nitrous acid is a mutagenic agent that exhibits two types of chemical reactions with DNA: firstly it converts exocyclic amino groups of DNA heterocycles to carbonyl groups (1,2) and secondly it produces interstrand cross-links in duplex DNA (3,4).

Is nitrous an acid mutagen?

Nitrous acid, a potent chemical mutagen, exerts its effect by the deamination of the aminogroups of the adenine, cytosine and guanine residues of the nucleic acid (causing chemical alterations A—»HX, G—»X, C—>U) as well as cross-links of undefined structures, deletions (Schuster, 1960; Kotaka and Baldwin, 1964; …

How does nitrous acid mutation DNA?

Apparently nitrous acid produces genetic alterations, expressed as antibiotic-resistant markers, directly on heat-denatured transforming DNA of Haemophilus influenzae, rather than producing DNA which acts as a non-specific mutagen.

Is hydroxylamine a mutagen?

Hydroxylamine and nitrous acid belong to this category of mutagens. Planar, hydrophobic compounds like acridine dyes and Benza[a]pyrine intercallate in DNA and increase the frequency of slippage during DNA replication, thus leading to frameshift mutations.

What are the effects of nitrous acid?

A statistically significant decrease in forced vital capacity was seen on days when subjects were exposed to nitrous acid. This effect was most marked at 25 min and 85 min after exposure began. Aggregate respiratory and mucous membrane symptoms were also significantly higher with nitrous acid.

Is acridine orange a mutagen?

Acridine orange (AO) was selected as the model contaminant since it is frequently reported to be present as one of the major recalcitrant organic pollutants in urban wastewaters and is also a highly potent mutagen [17, 18] .

What are chemical mutagens?

Most chemical mutagens are alkylating agents and azides. Physical mutagens include electromagnetic radiation, such as gamma rays, X rays, and UV light, and particle radiation, such as fast and thermal neutrons, beta and alpha particles.

Why are transitions more common than Transversions?

Transitions appear significantly more often in coding regions because they are less likely than transversions to alter the underlying amino acids that the mutated base codes for, especially if they appear in the third nucleotide of a codon.

What type of mutagen is a 5 Bromouracil and how does it bring about mutation?

5-Bromouracil (BrU) is a base analogue of thymine (T) which can be incorporated into DNA. It is a well-known mutagen, causing transition mutations by mispairing with guanine (G) rather than pairing with adenine (A) during replication.

What is the effect of nitrous on asthma?

Aggregate respiratory and mucous membrane symptoms were also significantly higher with nitrous acid. We conclude that this concentration and duration of exposure to nitrous acid alters lung mechanics slightly, does not induce significant airflow obstruction, and produces mild irritant symptoms in asthmatics.

What is acridine orange used for?

Acridine Orange is a cell-permeant nucleic acid binding dye that emits green fluorescence when bound to dsDNA and red fluorescence when bound to ssDNA or RNA. This unique characteristic makes acridine orange useful for cell-cycle studies. Acridine orange has also been used as a lysosomal dye.

How does EMS cause mutations?

Ethyl methanesulfonate (EMS) is a mutagenic, teratogenic, and carcinogenic organic compound with formula C3H8SO3. It produces random mutations in genetic material by nucleotide substitution; particularly through G:C to A:T transitions induced by guanine alkylation. EMS typically produces only point mutations.

How is nitrous acid used as a mutagen?

Deamination: Nitrous Acid as a mutagen. Sodium Nitrate (NaNO 3) is a common food additive that also occurs naturally in meats preserved by smoking.

What are the genetic effects of nitrous acid?

Genetic effects of nitrous acid. Nitrous acid-induced pure and sectored mutant clones Nitrous acid as a deaminating mutagen should lead to a DNA double helix with a mutant and a non-mutant strand. This should produce, during the first post-treatment cell division, one mutant and one non-mutant chromosome or even gene.

How does nitrous acid lead to the deamination of nucleobases?

The remaining aldehyde-phosphodiester forms a crosslink with an amino group in the complementary DNA strand. All in all, it can be concluded that nitrous acid leads to a deamination of nucleobases in RNA and in single- and doublestranded DNA.

Which is a chemical that can be mutagenic when metabolized?

Sodium Nitrate is one of many chemicals which, although not directly mutagenic themselves, become mutagenic when metabolized. Standard mutagenicity tests (such as the Ames Test) [iGen 7.14] simulate metabolism by mixing the chemicals with liver extracts .