Leaving X: How scale insects repeatedly evolved alternatives to chromosomal sex determination

Clicks: 1
ID: 338290
2026
Free PDF
Article Quality & Performance Metrics
Overall Quality
Not rated
Combines reader engagement with the AI quality analysis. This article has not been analysed, so there is no overall score — reader engagement is measured and shown alongside.
AI Quality Assessment
Not analyzed
Readership in this journal

Ranked #278 of 278 articles by views in molecular biology and evolution

Most read Least read

Bar heights use a square-root scale. Only the 120 most-read articles are drawn; the journal has 278 in total.

Mint this article as an NFT
Not yet minted

Create a permanent, verifiable on-chain record of this article on the Scimatic Network. The NFT is held in your Journament account, and you can withdraw it to your own wallet at any time.

5 SUSD one-off · no wallet required
Sign in to mint
Abstract
Abstract Reproduction is a core feature of life, yet it is still unclear why sex determination systems are conserved for hundreds of millions of years in some taxa but repeatedly turn over in others. A prime example is the true bugs; the vast majority of families employ a conserved X sex chromosomal system, but in scale insects (Coccomorpha), sex determination systems are more varied. Scale insects may retain X chromosomes, employ a form of haplodiploidy known as paternal genome elimination (PGE), or reproduce via selfing as simultaneous hermaphrodites. We sequenced 17 new scale insect species to study sex determination transitions. We recovered two independent losses of the X, once in the family Monophlebidae and a second time at the base of the PGE families. In the former, genomic rearrangements begin before the X is lost, leading to a pair of massive autosomes to which the X fuses in hermaphrodites. In the latter, the X chromosome has multiple fates, from being preserved intact, albeit without sex determination function, to being reshuffled as part of a massive whole genome rearrangement in mealybugs. We analyzed ortholog conservation across the transitions and found few genes lost, with only one orthogroup lost in both, and a number of orthogroups gained, suggesting these transitions did not require large changes to gene content. Finally, extreme sexual dimorphism of gene expression predates sex determination turnover and lingers on some formerly X-linked sequences. Together, these results illustrate the multiple routes to sex determination turnover, refine causal hypotheses, and provide a wealth of new resources for genomic study of scale insects.
Reference Key
openalex_W7127272798 Use this key to autocite in the manuscript while using SciMatic Manuscript Manager or Thesis Manager
Authors Andrew J. Mongue, Erin C. Powell, Tracy Liesenfelt, Ethan Grebler, Amanda Markee
Are you one of these authors? Claim your profile
Journal molecular biology and evolution
Year 2026
DOI
10.1093/molbev/msag275
URL
https://doi.org/10.1093/molbev/msag275
Keywords Keywords not found

Citations

No citations found. To add a citation, contact the admin at info@scimatic.org

Comments

No comments yet. Be the first to comment on this article.