Molecular divergence of the W chromosomes in pyralid moths (Lepidoptera)

Abstract

Most Lepidoptera have a WZ/ZZ sex chromosome system. We compared structure of W chromosomes in four representatives of the family Pyralidae--Ephestia kuehniella, Cadra cautella, Plodia interpunctella, and Galleria mellonella--tracing pachytene bivalents which provide much higher resolution than metaphase chromosomes. In each species, we prepared a W-chromosome painting probe from laser-microdissected W-chromatin of female polyploid nuclei. The Ephestia W-probe was cross-hybridized to chromosomes of the other pyralids to detect common parts of their W chromosomes, while the species-specific W-probes identified the respective W chromosome. This so-called Zoo-FISH revealed a partial homology of W-chromosome regions between E. kuehniella and two other pyralids, C. cautella and P. interpunctella, but almost no homology with G. mellonella. The results were consistent with phylogenetic relationships between the species. We also performed comparative genomic hybridization, which indicated that the W chromosome of C. cautella is composed mainly of repetitive DNA common to both sexes but accumulated in the W chromosome, whereas E. kuehniella, P. interpunctella, and G. mellonella W chromosomes also possess a large amount of female specific DNA sequences, but differently organized. Our results support the hypothesis of the accelerated molecular divergence of the lepidopteran W chromosomes in the absence of meiotic recombination.

Highly conserved Z and molecularly diverged W chromosomes in the fish genus Triportheus (Characiformes, Triportheidae)

“…However, there are few empirical data for W chromosomes. The data presented here suggest that the W chromosomes of Triportheus have evolved during a relative short (~15-25 Myr) divergence time (phylogenetic data from Mariguela et al, 2016), displaying different genomic composition in terms of repetitive DNA sequences, size, and morphology among species, including accumulation of microsatellites, transposable elements and rDNAs on the W chromosomes (Yano et al, 2014), like the situation in the W chromosomes of pyralid moths (Vítková et al, 2007).…”

Sex chromosome evolution in moths and butterflies

“…Even single W-derived bacterial artificial chromosomes (BACs) label the W chromosome along most of its length in Bombyx mori (FISH using BACs, as probes (BAC-FISH); Sahara et al 2003b). FISH using probes from microdissected W chromosomes provide another generally applicable method to paint the W chromosome Vítková et al 2007). The complex sex chromosome multivalents were still a tough problem until Yoshido et al (2005) introduced telomere FISH combined with GISH to delineate chromosomes in pachytene sex chromosome multivalents (Fig.…”

“…But when the E. kuehniella probe was cross hybridised to W chromosomes of the other species ('Zoo-FISH', Fig. 5), the hybridisation signals were rather patchy in C. cautella and P. interpunctella and scarce and dot-like or absent in G. mellonella (Vítková et al 2007). So even in related species of the same family, the composition of the W has changed to an extent that it is no longer recognised by hybridisation.…”

“…The pachytene chromosome preparations were probed with a whole W probe from E. kuehniella (red signals). Subsequent hybridisation with species-specific W chromosome painting probes (green signals) identified the W chromosomes of the respective species (c, e, g) (from Vítková et al 2007, by courtesy of the authors and with kind permission from Springer Science + Business Media). Bar, 10 μm orthologue on the B. anynana Z chromosome.…”

Sex Chromosomes and Sex Determination in Lepidoptera

“…1 c), genomic in situ hybridisation (GISH) or chromosome painting ( fig. 1 d), even when it is not recognizable from the chromomere pattern [Traut and Marec, 1997; 1999; Mediouni et al, 2004;Fuková et al, 2005Fuková et al, , 2007Yoshido et al, 2005aYoshido et al, , 2006Vítková et al, 2007]. Even some single W-derived bacterial artificial chromosomes (BACs), when used as probes in FISH (BAC-FISH), marked the full length of the W chromosome in B. mori ( fig.…”