One DNA letter can trigger complete sex reversal, Bar-Ilan University study finds

Researchers at Bar-Ilan University have discovered that changing just one letter in DNA can completely alter sex development in mice. In the new study, published in Nature Communications, a single-letter insertion in a non-coding regulatory region caused XX mice, which would normally develop as females, to develop instead as males with testis and male genitalia.

Double Dragon Genomes Helping Explain Sex Determination of Reptiles: A near-complete genome assembly of the bearded dragon Pogona vitticeps provides insights into the origin of Pogona sex chromosomes | A near-telomere to telomere phased genome assembly and annotation for the Australian central bearded dragon Pogona vitticeps | Author Q&A

Two almost complete and gapless genomes of the sex-changing central bearded dragon (Pogona vitticeps) are published back-to-back to help ...

Variation in adult sex ratios in tetrapods is linked to sex chromosomes through mortality differences between males and females

Across tetrapods, ZZ/ZW sex-determination systems are associated with a more male-skewed adult sex ratio than XY/XX systems. Phylogenetic analyses of a large dataset from tetrapod species in the wild reveal an influence of sex-determination system on adult sex ratio via sex-biased adult mortality.

Octopuses have some of the oldest known sex chromosomes

University of Oregon researchers have identified a sex chromosome in the California two-spot octopus. This chromosome has likely been around for 480 million years, since before octopuses split apart from the nautilus on the evolutionary tree. That makes it one of the oldest known animal sex chromosomes. The finding also is evidence that octopuses and other cephalopods, a class of sea animals that includes squid and nautiluses, do use chromosomes to determine their sex, answering a longstanding mystery among biologists.  

Call of the Mole Vole

Genetic mechanism of alternating sexes in walnut trees has some parallels to sex determination in humans

The genetics behind the alternating sexes of walnut trees have been revealed by biologists at the University of California, Davis. The research, published in Science, reveals a mechanism that has been stable in walnuts and their ancestors going back 40 million years—and which has some parallels to sex determination in humans and other animals.

Unraveling the events leading to multiple sex chromosomes using an echidna genome sequence

The short-beaked echidna (Tachyglossus aculeatus)  is one of Australia’s most iconic animals. Belonging to a unique group of mammals called “monotremes” (with the platypus as the other prominent member), echidnas may at first glance be mistaken for a weird-looking hedgehog, but they are in fact egg-laying mammals.  An international team of authors, led by Guojie Zhang and Qi Zhou at Centre for Evolutionary & Organismal Biology at Zhejiang University, Yang Zhou from BGI-research and Frank Grutzner from Adelaide University now present an almost gapless genome sequence of the short-beaked echidna. This work is part of the international Vertebrate Genome Project, and hosted in the VGP Genome Ark Database. The authors used the new data to better understand the evolutionary origin of the highly complex configuration of multiple sex chromosomes which is characteristic for monotremes. The work is published in the open science journal GigaScience.

Genetics of alternating sexes in walnuts

The genetics behind the alternating sexes of walnut trees has been revealed by biologists at  UCDavis. The research reveals a mechanism that has been stable in walnuts and their ancestors going back 40 million years — and which has some parallels to sex determination in humans and other animals. 

Platypus and chicken reveal how chromosomes balance between the sexes

Geneticists uncover new insights into how sex chromosome systems work in the platypus and the chicken—which will lead to better understandings of our own sex chromosome evolution and gene regulation.

Decoding the shared genetic toolkit for male sex determination