(Below N is a link to NCBI taxonomic web page and E link to ESTHER at designed phylum.) > cellular organisms: NE > Eukaryota: NE > Opisthokonta: NE > Metazoa: NE > Eumetazoa: NE > Bilateria: NE > Deuterostomia: NE > Chordata: NE > Craniata: NE > Vertebrata: NE > Gnathostomata: NE > Teleostomi: NE > Euteleostomi: NE > Sarcopterygii: NE > Dipnotetrapodomorpha: NE > Tetrapoda: NE > Amniota: NE > Mammalia: NE > Theria: NE > Eutheria: NE > Boreoeutheria: NE > Euarchontoglires: NE > Primates: NE > Haplorrhini: NE > Simiiformes: NE > Catarrhini: NE > Hominoidea: NE > Hominidae: NE > Homininae: NE > Gorilla: NE > Gorilla gorilla: NE > Gorilla gorilla gorilla: NE
LegendThis sequence has been compared to family alignement (MSA) red => minority aminoacid blue => majority aminoacid color intensity => conservation rate title => sequence position(MSA position)aminoacid rate Catalytic site Catalytic site in the MSA MSHPQGLLWLPLLFASVCVMLNSNVLLWITALAVKFTVTDSQAQYPVVNT NYGKIQGLRTPLPSEILGPVEQYLGVPYASPPTGERRFQPPESPSSWTGI RNATQFAAVCPQHLDERFLLHDMLPIWFTTSLDTLMTYVQDQNEDCLYLN IYVPTEDDIHEQNSKKPVMVYIHGGSYMEGTGNMIDGSILASYGNVIVIT INYRLGILGFLSTGDQAAKGNYGLLDQIQALRWIEENVGAFGGDPKRVTI FGSGAGASCVSLLTLSHYSEGLFQKAIIQSGTALSSWAVNYQPAKYTRIL ADKVGCNMLDTTDMVECLRNKNYKELIQQTITPATYHIAFGPVIDGDVIP DDPQILMEQGEFLNYDIMLGVNQGEGLKFVDGIVDNEDGVTPSDFDFSVS NFVDNLYGYPEGKDTLRETIKFMYTDWADKENPETRRKTLVALFTDHQWV APAVATADLHAQYGSPTYFYAFYHHCQSEMKPSWADSAHGDEVPYVFGIP MIGPTELFSCNFSKNDVMLSAVVMTYWTNFAKTGDPNQPVPQDTKFIHTK PNRFEEVAWSKYNPKDQLYLHIGLKPRVRDHYRATKVAFWLELVPHLHNL NEILQYVSTTTKVPPPDMTSFPYGTRRSPTKIWPTTKRPAITPANNPKHS KDPHKTGPEDTTVLIETKRDYSTELSVTIAVGASLLFLNILAFAALYYKK DKRRHETHRRPSPQRNTTNDITHIQNEEIMSLQMKQLEHDHECESLQAHD TLRLTGPPDYTLTLRRSPDDIPLMTPNTITMIPNTLMGMQPLHTFNTFSG GQNSTNLPHGHSTTRV
Y chromosomes underlie sex determination in mammals, but their repeat-rich nature has hampered sequencing and associated evolutionary studies. Here we trace Y evolution across 15 representative mammals on the basis of high-throughput genome and transcriptome sequencing. We uncover three independent sex chromosome originations in mammals and birds (the outgroup). The original placental and marsupial (therian) Y, containing the sex-determining gene SRY, emerged in the therian ancestor approximately 180 million years ago, in parallel with the first of five monotreme Y chromosomes, carrying the probable sex-determining gene AMH. The avian W chromosome arose approximately 140 million years ago in the bird ancestor. The small Y/W gene repertoires, enriched in regulatory functions, were rapidly defined following stratification (recombination arrest) and erosion events and have remained considerably stable. Despite expression decreases in therians, Y/W genes show notable conservation of proto-sex chromosome expression patterns, although various Y genes evolved testis-specificities through differential regulatory decay. Thus, although some genes evolved novel functions through spatial/temporal expression shifts, most Y genes probably endured, at least initially, because of dosage constraints.
Title: Evolution of X-degenerate Y chromosome genes in greater apes: conservation of gene content in human and gorilla, but not chimpanzee Goto H, Peng L, Makova KD Ref: Journal of Molecular Evolution, 68:134, 2009 : PubMed
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 Y chromosome genes of the X-degenerate region. We discovered that all studied reading frames and splice sites were intact, and thus, this genomic region experienced no gene loss in the gorilla lineage. Higher nucleotide divergence was observed in the chimpanzee than the human lineage, particularly for genes with disruptive mutations, suggesting a lack of functional constraints for these genes in chimpanzee. Surprisingly, our results indicate that the human and gorilla orthologues of the genes disrupted in chimpanzee evolve under relaxed functional constraints and might not be essential. Taking mating patterns and effective population sizes of ape species into account, we conclude that genetic hitchhiking associated with positive selection due to sperm competition might explain the rapid decline in the Y chromosome gene number in chimpanzee. As we found no evidence of positive selection acting on the X-degenerate genes, such selection likely targets other genes on the chimpanzee Y chromosome.
