The human Y chromosome: The biological role of a "functional wasteland"

Abstract

"Functional wasteland," "Nonrecombining desert" and"Gene-poor chromosome" are only some examples of the differentdefinitions given to the Y chromosome in the last decade. Incomparison to the other chromosomes, the Y is poor in genes,being more than 50% of its sequence composed of repeatedelements. Moreover, the Y genes are in continuous decay probablydue to the lack of recombination of this chromosome. But thehuman Y chromosome, at the same time, plays a central role inhuman biology. The presence or absence of this chromosomedetermines gonadal sex. Thus, mammalian embryos with a Ychromosome develop testes, while those without it develop ovaries(Polani [38]). What is responsible for the male phenotype isthe testis-determining SRY gene (Sinclair [52]) whichremains the most distinguishing characteristic of thischromosome. In addition to SRY, the presence of other genes withimportant functions has been reported, including a regionassociated to Turner estigmata, a gene related to the developmentof gonadoblastoma and, most important, genes related to germ celldevelopment and maintenance and then, related with male fertility(Lahn and Page [31]). This paper reviews the structure andthe biological functions of this peculiar chromosome. © 2001 Hindawi Publishing Corporation.