It might look modest , but it ’s got a circle to offer and it ’s here to abide . I am of track talking about the Y chromosome , the chunky partner of X. This comparatively meager looking chromosome has long been think to play few function aside from sex determination in mammals . But a newstudy , issue in the journalNature , has demonstrated that we should n’t judge a chromosome by its size of it , and that the few genes this chromosome does possess are pivotal to the survival of the fittest of males .
Mammals own two sex chromosome ; X and Y. Normal female have two ten chromosome , whereas males have one X and one Y. These chromosomesevolvedfrom non - sex chromosome , call in autosome , over the last 300 million years . During this prison term the Y chromosome experienced a dramatic charge per unit of decomposition , losing 97 % of its ancestral genes , go forth a rather dwarfed remainder containing less than 100 genes .
The X chromosome on the other hand retains98%of its ancestral gene and has today around 2000 cistron . Over the last 25 million long time , however , the charge per unit of Y chromosome decay has well-nigh ceased . Are these few stay genes present purely by chance having escaped decline , or are they there for a reason ?
to gain some answers , researcherscomparedthe genes get hold on Y chromosomes across numerous unlike mammal species to see if there was some commonality between the remain genes . Having already pick out that humans , chimp and rhesus macaques possess almost identical ancestral gene capacity on the Y chromosome , the team used five other mammals for sequence compare . These were the mouse , marmoset , bull , phalanger and rat .
The investigator discovered that factor survival was not random as a diverse position of18 similar geneswere find across all eight mintage , which is highly unlikely to be strictly concurrent . moreover , most of these gene required two written matter to function , meaning that they are dosage - pendent . This is in line to legion other sexual practice chromosome genes that ask only one copy ; the second factor on the X chromosome is commonly switched off in females , whereas it is miss in males .
study that the majority of the remaining Y chromosome gene are not actually involve in sexual activity determination , and the fact that they are active in cells all across the body , it is becoming increasingly discernible that the Y chromosome play a much bigger theatrical role than once believed . “ organic evolution is severalize us these cistron are really important for survival,”said Winston Bellott , head source of the study . “ They ’ve been select and purify over time . ”
