The Chromosomes ofRhopalurus(Scorpiones-Buthidae)

Abstract

In a series of papers it has been shown that Tityus chromosomes are provided with one centromere at each end (2, 4, 5 and 6). Proofs of such a view were found in the behaviour of the chromosomes in the course of spermatogenesis in the widely distributed Brasilian species T. bahiensis (Perty). Indeed, the long rod-shaped bivalents of this interesting species orient themselves in such a way that, while their bodies lie flat in the equatorial plane, the partners' corresponding ends are turned towards opposite poles. Metaphase side views show that the paired chromosomes are separated throughout their length. Being entirely unconnected by chiasmata, the chromosomes move toward the poles in perfect parallel, with the ends forward until late anaphase, when they bend strongly. Fragments bearing a single terminal centromere perform anaphase movement parallel to the spindle axis, as do the orthodox acrocentric rod-shaped chromosomes (11).

Comparison of different cytogenetic methods and tissue suitability for the study of chromosomes in Cimex lectularius (Heteroptera, Cimicidae)

“…Historically, classical histology was the first method used for preparing arthropod chromosomes, including insect ones, when the tissue in paraffin wax was cut into sections 7-20 microns in thickness (McClung 1899, Montgomery 1901, Darlington 1939, Slack 1939, Parshad 1957, Piza 1957. This method is no longer used for study of insect chromosomes.…”

“…The next method developed was a squashing technique (Sáez 1950), which began to be widely used in second half of the 20 th century (e.g. Leston 1957, Piza 1957, Warren et al 1960, Ueshima 1963 and it is still considered as a classical method by the majority of insect cytogeneticists including heteropterologists (e.g. Bressa et al 2002a, Poggio et al 2006, Grozeva et al 2010, Yang et al 2012.…”

Comparison of different cytogenetic methods and tissue suitability for the study of chromosomes in Cimex lectularius (Heteroptera, Cimicidae)

“…Historically, classical histology was the first method used for preparing arthropod chromosomes, including insect ones, when the tissue in paraffin wax was cut into sections 7-20 microns in thickness (McClung 1899, Montgomery 1901, Darlington 1939, Slack 1939, Parshad 1957, Piza 1957, and others). This method is no longer used for study of insect chromosomes.…”

“…The next method developed was a squashing technique (Sáez 1950), which began to be widely used in second half of the 20 th century (e.g. Leston 1957, Piza 1957, Warren et al 1960, Ueshima 1963) and it is still considered as a classical method by the majority of insect cytogeneticists including heteropterologists (e.g. Bressa et al 2002a, 2003, Poggio et al 2006, Grozeva et al 2010, Yang et al 2012).…”