Evolution of sex chromosomes

My first bioinformatics and fieldwork experiences were with Diego Cortez. In fact, I was his first student ever. One of the projects that I worked on was testing male mutation bias in monotremes (mammals that lay eggs like the platypus). Comparing mutation rates at autosomal versus sex chromosomes we estimated whether there was male mutation bias. The X, Y, and autosomes spend different proportions of time in each germline, and since the male germline (sperm) replicates a lot more, there is more room for generating mutations. We tested whether the bias existed in this particular system (venom-producing, egg-laying mammal, 5 pairs of sex chromosomes).

• Male mutation bias is the main force shaping chromosomal substitution rates in monotreme mammals

Another project I participated was in basilisks from the Yucatan peninsula. We found a new XY sex chromosome system in this family:

• Corytophanids Replaced the Pleurodont XY System with a New Pair of XY Chromosomes