The X chromosome still has a lot to reveal – revisiting Hermann Henking's work on firebugs

Abstract

In 1891, the existence of an X chromosome was noted for the first time. Hermann Henking was studying spermatocyte divisions of the firebug Pyrrhocoris apterus and observed that one chromosome behaved differently than all of the rest of the chromosomes. Henking called this chromosome ‘Element x’. Henking's discovery of the X element (later called X chromosome) initiated more than a century of fascinating genetics and cell biology, forming the foundation of several avenues of research in biology. His work led to exploration of a number of questions in a wide range of model systems and very soon to the abandonment of the firebug as a model for studies on the behavior of chromosomes in meiosis. Here, we argue that studies on both bivalent and univalent chromosome behavior in general, and work on how to solve chromosome lagging to prevent aneuploidy in particular, should lead us back to using the firebug as a model for error correction during cell division.

Chromosome-Aware Phylogenomics of Assassin Bugs (Hemiptera: Reduvioidea) Elucidates Ancient Gene Conflict

“…Although the X chromosome was observed for the first time in the true bug Pyrrhocoris apterus in 1891 ( Paliulis et al 2023 ), the genomic study of X chromosomes in invertebrates has lagged behind vertebrates. Relatively few chromosomal-level genome assemblies are available to assess the prevalence of a faster X effect across taxa, and the conservation of chromosomal gene content across deep phylogenetic scales is largely unknown.…”