Good morning all,
In our labs these past two weeks, we have explored the shuffling of chromosomes that occurs during meiosis, and how the alleles of the genes on the chromosomes get sorted into gametes, which then combine to give offspring unique genotypes (sets of chromosomes and alleles) and phenotypes (physical features). Some of our examples this week included our 'sex chromosomes', the X and the Y, which combine to give us female (XX) or male (XY) characteristics.
When we discussed the phenomenon of nondisjunction, we noted that sometimes things don't quite work according to plan, and that unusual chromosome numbers occur. How about when unusual chromosome combinations occur?
You may have seen a news story recently abut an unusual bird (spotted in Erie, PA) that appeared to be male on one side of its body and female on the other. This is likely to be a gynandromorph, an individual that has male chromosomes (genotype) and characteristics (phenotype) on one side, and female genotype and phenotype on the other side.
A few examples of gynandromorphy have been reported in animals over the years. They appear relatively normal (as male and female organs are generally the same), but their ability to mate and breed is likely very low (as male and female mating behaviors and reproductive structures are very different, of course).
This individual was spotted because, in this species (the Northern cardinal), male and female phenotypes are very obviously different in color (dimorphic). In most bird species, you can't tell females and males apart, as they look the same (monomorphic). It makes me wonder: how many gynandromorphs are out there, and we just don't know about them? And, does this occur in humans?
Have a great weekend -