Chromosome And Non Mammalian ( Use Drosophila As Example ) Essay examples

1644 Words Dec 15th, 2016 7 Pages
Y chromosome is a sex determine chromosome among many species including modern humans. Modern studies in genome suggested that Y chromosome arose from the accumulations of mutations of other chromosomes and have some special genes on it which determine the gender of the carrier; however, some non-mammalian animals carry the Y chromosome even if their genders are not determine by the appearance of the Y chromosome. The Y chromosome works differently on the mammalian and non-mammalian so in this paper when an aspect about Y chromosome is brought up, it well be discussed in both mammalian (use human as example) and non-mammalian (use Drosophila as example) case.
The paper will mainly focus on three point: how Y chromosome originated; the function of Y chromosome and the position of Y chromosome in the study of evolution.
The origin of Y chromosome
Researchers who study the mammalian Y chromosome believe that the Y chromosome arose from the X chromosome. The researchers found that there is a male-specific region on human Y chromosome which consists of several special sequence: X—transposed and X-degenerate (Skalesky et al. 2003): The X-transposed sequence is very similar to the X chromosome and the X-degenerate sequence showed that the X and Y chromosome shared a pair of autosome ancestors (Skalesky et al. 2003). The arise of Y chromosome was likely due to a mutation event that made the recombination between 2 sex chromosomes lethal, which allowed the accumulation of mutations…

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