Formaldehyde‐induced acentric chromosome fragments and chromosome stickiness in Chortophaga neuroblasts

Abstract

Embryos of the grasshopper Chortophaga viridifasciata were exposed in vitro to formaldehyde (FA), as formalin, at concentrations ranging from 10(-8)M (0.0003 ppm) to 10(-3) M (30 ppm) at 38 degrees C. A low frequency of distinct acentric chromosome fragments (0.02-0.04/cell) was observed in the neuroblasts after 1 hr exposure to 7.5 X 10(-4) or 10(-3) M FA plus 3 hr recovery, but not at lower concentrations, even with 4 hr exposure. There was no obvious relation between distinct fragment frequency and concentration of FA. Neuroblasts with sticky chromosomes were observed at 10(-4), 7.5 X 10(-4), and 10(-3) M FA, the percent of cells with slight, moderate, or severe stickiness varying with FA concentrations. Fragments were associated with the sticky chromosomes. The frequency of these sticky fragments at the two higher concentrations (0.15-0.30/cell) was greater than the frequency of distinct fragments. It is concluded that the distinct acentric fragments induced by FA result from breakage at a single sticky point (slight stickiness) between separating sister chromatids. The chromosome effects observed probably result from the action of daughter products that are formed by the interaction of FA with culture medium components, especially the fetal calf serum.

Chromosome stickiness during meiotic behavior analysis of Passiflora serrato-digitata L. (PassifloraCEAE)

“…GAULDEN (1987) hypothesizes that chromosome stickiness may be caused by a failure or a bad functioning in one or two types of non-histonic chromosome proteins. DOWD et al (1986) classifies stickiness from moderate to severe, according to the number of chromosomes involved in the genome. According to his classification, stickiness investigated in the current study is moderate as, during anaphase, the presence of bridges, which broke down at the end of the anaphase with the subsequent fragmentation and formation of micronuclei in telophase, has been verified.…”

Chromosome stickiness impairs meiosis and influences reproductive success in Panicum maximum (Poaceae) hybrid plants

“…Among the chromosome aberrations, Dowd et al (1986) and Gaulden (1987) reported the occurrence of bridges and fragments. In P. maximum, fragments were commonly found in the meiocytes, but bridges were not observed because anaphase failed to occur.…”

Cytogenetic Variation among Populations of <i>Aster thomsonii</i> C. B. Clarke from District Sirmaur, Himachal Pradesh (India)

“…The laggards fail to reach the poles, generally form micronuclei (Utsunomiya et al 2002), or form micro-pollen/uneven gametes. According to Dowd et al (1986), irregularity in mircosporogenesis (formation of micronuclei at telophase) could be due to patchy breakage of chromatin bridge at anaphase-I. Heterogeneous sized pollen grains and reduced pollen viability in tetra-and hexaploid cytotypes (Figs.…”