Diversity of sex determination mechanisms Flashcards
What are some triggers for sex determination
Temperature e.g. American alligator (33 degrees produces males)
Relative/body size
Food/ nest availability
Social status
Who discovered sex chromosomes
Nettie Stevens in the early 1900s
What are the most recent sex chromosomes to be discovered
ZW sex chromosomes, example in fish and geckos
What do sex chromosomes play an important role in
Sexual dimorphism
Reproductive isolation
How do we acquire sex chromosomes
Recombination is supressed between chromosome pairs via inversions, overtime you get more recombination and more strata forms
How many strata in humans
4
What causes recombination supression
Inversions
What happens without recombination
Deleterious mutations start to accumulate
Where is W present
Only in females
What does gene conversion involve
The transfer of genes from the donor sequence to the acceptor sequence facilitated by the ampliconic regions
What are palindrome regions
Mirror image repeat structures
How many palindromes do humans have
9
