Sadly, I was wrong. The reality is that the trans community is being relentlessly attacked by this president. The leader of our nation has shown no regard for an already marginalized and struggling community. He has ignored our humanity. He has insulted our dignity. He has made trans people into political pawns as he whips up animus against us in an attempt to energize the most right-wing segment of his party, claiming his anti-transgender policies are meant to “protect the country.” This is politics at its worst. It is unacceptable, it is upsetting, and it has deeply, personally hurt me.

Healthy Mice Born From Same-Sex Parents For the First Time

When scientists made immature human egg cells from donated blood, some speculated that human reproduction was on the verge of a massive disruption.

The future is now.

Last week, a team from China completely overhauled natural reproduction, using genetic engineering to make mice born from same-sex parents for the first time. Babies from two moms were indistinguishable from mouse pups generated through good-old-means: not only were they healthy, they went on to give birth to mouse pups of their own.

Those born with the DNA of two dads—with the help of a surrogate—survived through birth but only lived a few days, underscoring the fact that the new technology is still in its infancy.

A masterful technological tour-de-force aside, the study pinpoints critically important genetic factors that allow an embryo to develop normally. It’s like cracking the biological Enigma code of reproduction—a set of genetic instructions that allow an embryo to survive, regardless of how it’s made.

“This shows us what’s possible,” said senior author Dr. Wei Li at the Chinese Academy of Sciences. The team described their results in Cell Stem Cell.

In this guide, whenever we use the medical term “vagina,” we’ll also include “front hole” as clinically recommended by researchers in the BMC Pregnancy and Childbirth journal.

The sine qua non of human sex designation in humans is chromosomal—all your cells either have two X chromosomes, making you female, or one X and one Y, making you male. End of story. But no: Instead, there’s various chromosomal disorders where individuals can be XYY, XXY, XXX, X, or XXYY. Most result in infertility; some, like Turner syndrome (in which there is solely an X) produce neurological, metabolic, endocrine, and cardiovascular abnormalities.

Much more interesting than these rare disorders is the recent finding that adult men typically have some XX (i.e., female) stem cells scattered throughout the body, which have differentiated into mature cells, including neurons. Meanwhile, women who have given birth to a son have a similar scattering of XY stem cells. Remarkably, during pregnancy, some maternal stem cells become incorporated into the fetus, some fetal stem cells into the mother. Thus, many of us are sex-chromosome mosaics (with, at present, unknown consequences).

Once sex chromosomes are determined, everything else about gender designation follows suit: XX versus XY determines whether you wind up with ovaries or testes. That determines whether it’s predominantly estrogen and progesterone, or testosterone in your bloodstream. The hormones you’re marinated in then determines which type of genitals you form as a fetus, as well as secondary sexual characteristics ranging from the chemical composition of your sweat to the workings of your brain. Chromosomal, gonadal, endocrine, genital, and phenotypic sex go hand in hand.

Except they don’t, as it turns out—there are numerous disorders where someone might be male in some of those ways, but female in others.

To begin with, chromosomal sex and gonadal/anatomical sex can disagree. In a syndrome called 46,XY DSD, people have normal male sex chromosomes, testes—genitals that are usually classified as male—plus a womb and Fallopian tubes. In ovotesticular disorder, the person has the sex chromosomes of one sex, but both ovarian and testicular tissue, producing ambiguous genitals. (...)

Hormones affect target cells by interacting with specific receptors (estrogen receptors bind estrogen, insulin receptors bind insulin). Another type of dissociation at the hormone level is seen with “testicular feminization syndrome,” where there is a mutation that inactivates the androgen receptor, which normally binds testosterone and DHT. Normal XY, normal testes, normal levels of the two hormones, but the hormones have no effects, producing a phenotype that ranges from ambiguous to female. In the latter case, the disorder is usually discovered around puberty, when the girl fails to start menstruating. She fails to start because, as it turns out, there’s no ovaries or uterus, the vagina dead ends, and way up in the stomach are testes pouring out androgens.

Thus there’s numerous ways where chromosomal sex and phenotypic sex differ, accounting for 1 percent of births. This is not rare—pick a human at random and the odds are greater that they were born with ambiguous intersex genitals than they have an IQ greater than 140.

Perhaps the most interesting dissociation occurs one step further down the line. This is where the person has the chromosomes, gonads, hormones, genitals, and secondary sexual characteristics—hair, voice, musculature, facial structure, the works—of one sex. But has always felt like the other. (...)