Arguably, the hermaphroditic gender is able to self-fertilize and could be evolu

Question

Arguably, the hermaphroditic gender is able to self-fertilize and could be evolutionarily advantageous over the flies because the requirement for the male gender occurs at such a low frequency and isn’t completely necessary for the nematodes to reproduce. Therefore, the nematode may have a selective advantage over the flies in this case. Although, the male does help with genetic diversity, when the DCC impairs the male single X chromosome from interacting with its nuclear pore proteins seen in the hermaphrodite. However, there is evidence that developmental plasticity has been found to be decreased in hermaphrodite only organism so it depends on the level of diversity required in that generation of nematode. What do you think?

Explanation / Answer

In 1980s, the Dosage compensation (DC) theory was firstly hypothesised by Barbara J. Meyer. DC is indispensable in the polyploid species. In C. elegansdosage compensation is operated to maintained by reducing 50% of the expression of X-linked genes in hermaphrodite species which has two X-chromosome (XX). Recently, this adjustment of the expression of X-chromosome linked genes are widely studied. In C. elegans, Interestingly, in males who have single X-chromosome (XO) the X-chromosome interact with the nuclear pore proteins. In contrary, in hermaphrodite, dosage compensation complex (DCC) impairs this interaction and alters X localization. There are some genes like dpy and sdc genes which regulates the organism DC property and hermaphrodite nature, as mutation in these genes severely causes abnormalities. Interestingly, proteins of the sex-specific Dpy and Sdc class genes product interact and form a single complex called as the DC complex (DCC). Notably, structurally DCC is similar to condensing I protein, and binds to the rex site (recruitment element on X) of the X-chromosome and mainly characterized by a 12-base pair (bp) motif enriched on X (MEX) consensus sequence. Approximately, 38 rex sites are known where DCC complex binds and but bioinformatics sequence study suggest there could be upto 300 such sites present on the X-chromosome. So DCC bind to those sites and moves and accumulates at the promoter sites/ upstream region of the genes associated with the X-chromosome, there by reduces the transcription of X-linked genes. Therefore, DCC binding is expected to have effect on the transcriptional level in hermaphrodite species.

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