Changes in nuclear phenotype frequencies following sequential cold shocks in Triatoma infestans (Hemiptera, Reduviidae)

Abstract

The nuclear phenotypes of Malpighian tubule cells in fifth instar nymphs of

Effect of sequential heat and cold shocks on nuclear phenotypes of the blood-sucking insect, Panstrongylus megistus (Burmeister) (Hemiptera, Reduviidae)

“…These phenotypes had been previously reported not only after single heat and cold shocks in P. megistus (Garcia et al 2000a, b), but also after single heat and cold shocks and sequential cold shocks in Triatoma infestans (Dantas & Mello 1992, Mello et al 2001, Campos et al 2002.…”

Rapid cold-hardening protects Drosophila melanogaster from cold-induced apoptosis

“…To our knowledge these molecular data are the first such reported for cold-induced apoptosis in insects. Cold shock-induced apoptosis was reported in two species of reduviid bugs as evidenced by changes in nuclear phenotypes (nuclear fusion and heterochromatin unraveling) in the Malpighian tubules [35,36]. However, no molecular evidence for apoptosis was provided in these studies.…”

Spatial distribution of AT- and GC-rich DNA within interphase cell nuclei of Triatoma infestans Klug

“…Because heterochromatin decondensation in Triatomini is usually a response to stress (starvation, heavy metals and heat-shock) (Mello, 1989;Mello et al, 1995Mello et al, , 2001Campos et al, 2002), the effect of the 5-AZA demethylation was determined by quantifying the number of nuclei that displayed this phenotype above the baseline levels measured in the controls. Even for the nuclei that contained no visual change in the chromocenter packing state after a 48-h 5-AZA treatment, a slight chromocenter unpackaging was detected with scanning microspectrophotometry and agrees with the presence of methylcytidine in the euchromatin bordering the chromocenters or other non-heterochromatin nuclear areas.…”

“…In addition, the T. infestans chromocenters are able to unpack under stressful conditions such as prolonged starvation, heat or cold shock, and the presence of heavy metals (Mello, 1989;Mello et al, 1990Mello et al, , 1995Mello et al, , 2001Campos et al, 2002). This finding may indicate activation of genes usually silent and contained in the chromocenter body (Mello et al, 1990).…”