Chromosome chains and platypus sex: kinky connections

The Strange Case of Platypus Sex

OF PLATYPUS SEX The platypus, Ornithorhynchus anatinus, is clearly one of life’s strangest animals. It possesses a furry coat and, like a mammal, is warm blooded and produces milk to nourish its young, but it lacks teeth, has a bill, and lays eggs like a bird. The feet are webbed like those of a duck, and females have no nipples (offspring suck milk directly from the abdominal skin); males have...

Sex chromosome evolution: platypus gene mapping suggests that part of the human X chromosome was originally autosomal.

To investigate the evolution of the mammalian sex chromosomes, we have compared the gene content of the X chromosomes in the mammalian groups most distantly related to man (marsupials and monotremes). Previous work established that genes on the long arm of the human X chromosome are conserved on the X chromosomes in all mammals, revealing that this region was part of an ancient mammalian X chro...

Karyotype and Sex-Chromosome Polymorphism in Nesokia indica, from Iran

Kinky clients, kinky counselling? The challenges and potentials of BDSM

One of the most demonised forms of consensual sexuality is BDSM (bondage and discipline, domination and submission, and sadomasochism). Many counsellors still consider it appropriate to make negative comments about BDSM in a way that is perceived unacceptable in relation to other aspects of sexuality (Hudson-Allez, 2005). Kolmes, Stock and Moser (2006, p.315) found 118 reports of ‘biased or ina...

Bird-like sex chromosomes of platypus imply recent origin of mammal sex chromosomes.

In therian mammals (placentals and marsupials), sex is determined by an XX female: XY male system, in which a gene (SRY) on the Y affects male determination. There is no equivalent in other amniotes, although some taxa (notably birds and snakes) have differentiated sex chromosomes. Birds have a ZW female: ZZ male system with no homology with mammal sex chromosomes, in which dosage of a Z-borne ...