The Wimpy Y Chromosome

What is the Y chromosome overcompensating for?

The human Y chromosome is quite literally the foundation of patriarchal domination. Those that have it receive some amount of privilege, those that don’t have it are trivialized, and those that express femininity in spite of it face demonization.

As such, you might think that Y chromosome is something special, all-powerful, and conferring of insurmountable strength. But actually, that is far from the truth. The human Y chromosome contains the fewest protein-coding genes (i.e. the number of genes which get transcribed into mRNA and then translated into protein) of all human chromosomes with only 47. The next fewest is in chromosome 21 with 252 protein-coding genes.

The very structure of the human Y chromosome is unstable. Typically, chromosomes swap regions of DNA during meiosis in a process called “crossing over”. This helps ensure that DNA sequences don’t accumulate detrimental mutations or unruly structures. However, the Y chromosome contains large regions which cannot undergo crossover. Without crossover, the Y chromosome’s sequence has accumulated suboptimal regions which destabilize the whole chromosome. In fact, the Y chromosome can spontaneously disappear from a cell, and this loss is associated with adverse health conditions like cancer and Alzheimer’s disease.

But, perhaps the Y chromosome is so special because it contains unique genes not found on other chromosomes? Yet, 31 out of the 47 genes on the Y chromosome either undergo crossover (17 genes) or have highly similar genes on the X chromosome (14 genes).¹ While these genes may play slightly different roles in the body, their functions largely overlap. As a result, most of the genes on the Y chromosome aren’t even original.

That leaves 16 genes that are largely unique to the Y chromosome. To gauge their function, I ran the gene list² through a classifier system which returns the broad biological functions the input genes participate in. My hypothesis is simple: the functions associated with these genes represent the basis of Y chromosome fetishism. Do these genes confer special biological skills? Only if you consider spermatogenesis (i.e. the process by which sperm is produced) a special skill. For example, the DAZ family of proteins (encoded by genes DAZ1, DAZ2, DAZ3, and DAZ4) are primarily found in cells that will become sperm.

The most notable gene in this group is SRY. In early development, humans are capable of developing any repertoire of reproductive anatomy. Developmental biologists refer to this nascent organ as a “bipotential gonad” (a term deeply rooted in the false notion of binary of sex). If a developing fetus has a Y chromosome and a functioning SRY gene, then the bipotential gonad develops as testes. Without a functioning SRY gene, ovaries develop. 

However, SRY is not sufficient to promote the development of the genitalia and reproductive structures associated with maleness (i.e. a penis, prostrate, vas deferens, etc.) These structures develop in response to hormones produced by the testes, namely testosterone and anti-Müllerian hormone. So, if the proteins³ that synthesize or effect these hormones are non-functional, then alternate anatomies develop. Such anatomical variations are examples of differences in sex development and intersex traits.

Estrogen and Testosterone

Feminists have long positioned patriarchal domination as phallocentric, or revolving around the penis. A genetic point of view on the Y chromosome refines that notion by emphasizing reproductive capacity and virility. In fact, we are almost led to a ;;; testicentric ;;; understanding. Indeed, the testes are the major site of testosterone production, and their testosterone is required in prenatal stages for penis formation.

The Y chromosome as conferring a base level of virility centers a cis man’s reproductive role within a heteronormative family. All of the other traditionally masculine qualities are then layered onto this canonical virility. Muscular strength, facial hair, broad shoulders are all considered indicators of virility despite being entirely  divorced from sperm development or function. Yet, once this false causality is asserted then cis male assertion of physicality and strength become extensions of the work of reproduction. Domination becomes a means to a specific end - the preservation of the nuclear family. And this supreme gaslighting is enabled by the concept of the Y chromosome because in reality, the human Y chromosome is a minuscule and unstable piece of DNA with only one unique contribution to biology.

1. I am defining this latter group as genes which share over 80% similarity in DNA sequence of the mRNA-coding regions. They include ZFY, RPS4Y1, AMELY, TBL1Y, PCDH11Y, TGIF2LY, USP9Y, DDX3Y, UTY, TMSB4Y, RPS4Y2, KDM5D, VCY, and BPY2.

2. SRY, TSPY1, TSPY2, AZF1, EIF1AY, HSFYL, HSFYL2, PRY, PRY2, RBMY1A1, DAZ1, DAZ2, DAZ3, DAZ4, CDY1, and CDY2.

3. To be clear, the genes that encode these proteins are largely found on other chromosomes than the Y chromosome..