I’m talking about Puberty, an embarrassing but important developmental stage where we become capable of reproducing.  People start puberty at different ages as the timing is influenced by both genetic and environmental factors.

Studies have suggested that 50–80% of the variation in puberty timing is due to genetic factors.  These are likely due to multiple gene influences and interactions between the genes and environmental factors.

To figure out the genetics behind puberty rare disorders of puberty have been investigated.  These studies identified the hypothalamic-pituitary-gonadal (HPG) axis as being super important.  This axis controls development, reproduction, and aging in animals by producing important hormones such as gonadotropin-releasing hormone (GnRH), luteinizing hormone (LH), and follicle-stimulating hormone (FSH).  Interestingly the HPG axis has important roles during the prenatal, infant, and prepubertal stages of life too.

Other approaches to finding genes underlying complex traits in humans include:

(1) Sequencing of candidate genes by selecting these genes and determining if sequence variants can explain the phenotypic variation.

(2) Genome-wide linkage analyses which uses an unbiased genome-wide scan to identify genes that regulate a specific trait.

(3) Association studies which assess the frequency of a genetic variant in an affected population versus a control population.

Other interesting things I found out;

- Synthetic and naturally occurring substances can alter normal reproductive development by disrupting hormone signaling.

- It’s the gonads (testes and ovaries) that produce the commonly known estrogen and testosterone hormones.

Sources: Cartoon , Picture.