Evolution of X-Degenerate Y Chromosome Genes in Greater Apes: Conservation of Gene Content in Human and Gorilla, But Not Chimpanzee

  title={Evolution of X-Degenerate Y Chromosome Genes in Greater Apes: Conservation of Gene Content in Human and Gorilla, But Not Chimpanzee},
  author={Hiroki Goto and Lei Peng and Kateryna D. Makova},
  journal={Journal of Molecular Evolution},
Compared with the X chromosome, the mammalian Y chromosome is considerably diminished in size and has lost most of its ancestral genes during evolution. Interestingly, for the X-degenerate region on the Y chromosome, human has retained all 16 genes, while chimpanzee has lost 4 of the 16 genes since the divergence of the two species. To uncover the evolutionary forces governing ape Y chromosome degeneration, we determined the complete sequences of the coding exons and splice sites for 16 gorilla… 

The Y chromosomes of the great apes

Understanding great-ape Y chromosome structure, gene content and diversity would provide a valuable evolutionary context for the human Y, and would also illuminate sex-biased behaviours, and the effects of the evolutionary pressures exerted by different mating strategies on this male-specific part of the genome.

A Gene Catalogue of the Euchromatic Male-Specific Region of the Horse Y Chromosome: Comparison with Human and Other Mammals

It is demonstrated that the horse MSY harbors 20 X-degenerate genes with known orthologs in other eutherian species, and the functions of MSY genes are predominantly related to testis and spermatogenesis.

Multicopy gene family evolution on primate Y chromosomes

Rapid evolution of ampliconic genes cannot be attributed solely to residence on the Y chromosome, nor to variation between primate lineages in the rate of gene family evolution, but other factors, such as natural selection and gene conversion, appear to play a role in driving temporal and genomic evolutionary heterogeneity in primate gene families.

Y Chromosomal Variation Tracks the Evolution of Mating Systems in Chimpanzee and Bonobo

FISH of testis-specific expressed ampliconic fertility genes to metaphase Y chromosomes of 17 chimpanzees derived from 11 wild-born males and 16 bonobos representing seven wild- born males showed contrasting patterns of variation, which might be explained in the context of the species' markedly different social and mating behaviour.

Origins and functional evolution of Y chromosomes across mammals

Although some genes evolved novel functions through spatial/temporal expression shifts, most Y genes probably endured, at least initially, because of dosage constraints, and show notable conservation of proto-sex chromosome expression patterns.

Sex Chromosomes Evolution in Mammals

The latest findings have revealed that mam‑ malian sex chromosomes evolved from a pair of autosome 166 million years ago and in two groups of rodents the mole vole and the Japanese spiny rat the Y chromosome has been removed completely and a new sex determination system has evolved.

The sex-specific region of sex chromosomes in animals and plants

The chicken Z and the human X chromosomes appeared to have acquired testis-expressed genes and expanded in intergenic regions, defying the notion that the pace of evolution in the SDR was fast at early stages but slowed down overtime.

Expression Evolution of Ancestral XY Gametologs across All Major Groups of Placental Mammals

The work uses RNA-seq data from 17 placental mammals to unveil the expression evolution of XY gametologs and describes several features of the Y chromosome in the last common mammalian ancestor.

Evaluating the Relationship between Spermatogenic Silencing of the X Chromosome and Evolution of the Y Chromosome in Chimpanzee and Human

Information is obtained indicating that meiotic and postmeiotic X chromosome silencing might be more effective in chimpanzee than in human spermatogenesis, and it is suggested that the remarkable reorganization of the chimpanzee Y chromosome might have an impact on its meiotic interactions with the X chromosome and thereby on X chromosomesilencing in sperMatogenesis.

Male-specific region of the bovine Y chromosome is gene rich with a high transcriptomic activity in testis development

The results, along with the highly transcriptional activities observed from these Y-chromosome genes and 375 additional noncoding RNAs, challenge the widely accepted hypothesis that the MSY is gene poor and transcriptionally inert.



Conservation of Y-linked genes during human evolution revealed by comparative sequencing in chimpanzee

DNA sequences of unique, Y-linked genes in chimpanzee and human, which diverged about six million years ago, are compared to find evidence that in the human lineage, all such genes were conserved through purifying selection.

The evolutionary history of human and chimpanzee Y-chromosome gene loss.

Y-chromosome sequences in gorilla, bonobo, and several chimpanzee subspecies are characterized for 7 chimpanzee gene-disruptive mutations that predate chimpanzee-bonobo divergence at approximately 1.8 MYA, which indicates significant Y- chromosome change in the chimpanzee lineage relatively early in the evolutionary divergence of humans and chimpanzees.

Divergence of the genes on human chromosome 21 between human and other hominoids and variation of substitution rates among transcription units

A phylogenetic analysis unambiguously confirms the conclusion that chimpanzees were the authors' closest relatives to the exclusion of other primates and the relative divergence of the Homo–Pan and that of (Homo–Pan)–Gorilla are 4.93 million years and 7.26 million years, respectively.

Comparative analysis of chimpanzee and human Y chromosomes unveils complex evolutionary pathway

Reconstruction of the common ancestral Y chromosome reflects the dynamic changes in genomes in the 5–6 million years since speciation and confirmed the accelerated evolutionary rate of the Y chromosome.

Novel Gene Acquisition on Carnivore Y Chromosomes

The discovery of four novel Y chromosome genes that do not have functional copies in the finished human male-specific region of the Y or on other mammalian Y chromosomes explored thus far demonstrates the gene novelty on this chromosome between mammalian orders.

More genes underwent positive selection in chimpanzee evolution than in human evolution

The analysis of the identified positively selected genes lends support to the association between human Mendelian diseases and past adaptations but provides no evidence for either the chromosomal speciation hypothesis or the widespread brain-gene acceleration hypothesis of human origins.

Abundant gene conversion between arms of palindromes in human and ape Y chromosomes

It is concluded that during recent evolution, an average of approximately 600 nucleotides per newborn male have undergone Y–Y gene conversion, which has had an important role in the evolution of multi-copy testis gene families in the MSY.

Genomic divergences between humans and other hominoids and the effective population size of the common ancestor of humans and chimpanzees.

The human lineage apparently had experienced a large reduction in effective population size after its separation from the chimpanzee lineage, suggesting that the gorilla lineage branched off 1.6 to 2.2 million years earlier than did the human-chimpanzee divergence.

High levels of Y-chromosome nucleotide diversity in the genus Pan

Comparisons with mtDNA ND2 sequences from some of the same individuals revealed a larger female versus male effective population size for chimpanzees, and the NRY-based divergence time between chimpanzees and bonobos was estimated at ≈1.8 million years ago.

The DNA sequence of the human X chromosome

This analysis illustrates the autosomal origin of the mammalian sex chromosomes, the stepwise process that led to the progressive loss of recombination between X and Y, and the extent of subsequent degradation of the Y chromosome.