title: Status of dosage compensation of X chromosome in bovine genome.
abstract: Dosage compensation system with X chromosome upregulation and inactivation have evolved to overcome the genetic imbalance between sex chromosomes in both male and female of mammals. Although recent development of chromosome-wide technologies has allowed us to test X upregulation, discrete data processing and analysis methods draw disparate conclusions. A series of expression studies revealed status of dosage compensation in some species belonging to monotremes, marsupials, rodents and primates. However, X upregulation in the Artiodactyla order including cattle have not been studied yet. In this study, we surveyed the genome-wide transcriptional upregulation in X chromosome in cattle RNA-seq data using different gene filtration methods. Overall examination of RNA-seq data revealed that X chromosome in the pituitary gland expressed more genes than in other peripheral tissues, which was consistent with the previous results observed in human and mouse. When analyzed with globally expressed genes, a median X:A expression ratio was 0.94. The ratio of 1-to-1 ortholog genes between chicken and mammals, however, showed considerable reduction to 0.68. These results indicate that status of dosage compensation for cattle is not deviated from those found in rodents and primate, and this is consistent with the evolutionary history of cattle.
authors.affiliation: Department of Agricultural Biotechnology, College of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Republic of Korea.
authors.forename: Sojeong
authors.initials: S
authors.lastname: Ka
authors.affiliation: Department of Agricultural Biotechnology, College of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Republic of Korea.
authors.forename: Hyeonju
authors.initials: H
authors.lastname: Ahn
authors.affiliation: Interdisciplinary Program in Bioinformatics, Seoul National University, Seoul, 08826, Republic of Korea.|C&K Genomics Inc., Seoul National University Research Park, Seoul, 08826, Republic of Korea.
authors.forename: Minseok
authors.initials: M
authors.lastname: Seo
authors.affiliation: Department of Agricultural Biotechnology, College of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Republic of Korea.|Interdisciplinary Program in Bioinformatics, Seoul National University, Seoul, 08826, Republic of Korea.
authors.forename: Heebal
authors.initials: H
authors.lastname: Kim
authors.affiliation: C&K Genomics Inc., Seoul National University Research Park, Seoul, 08826, Republic of Korea. trueman@cnkgenomics.com.
authors.forename: Jin Nam
authors.initials: JN
authors.lastname: Kim
authors.affiliation: Animal Nutritional Physiology Team, National Institute of Animal Science, Jeonju, Jeollabuk-Do, 55365, Republic of Korea. hyunj68@korea.kr.
authors.forename: Hyun-Jeong
authors.initials: HJ
authors.lastname: Lee
mesh_terms: D000818:Animals; D002417:Cattle; D019143:Evolution, Molecular; D005260:Female; D018628:Gene Dosage; D005786:Gene Expression Regulation; D016678:Genome; D059014:High-Throughput Nucleotide Sequencing; D008297:Male; D010802:Phylogeny; D012727:Sex Characteristics; D012737:Sex Factors; D014158:Transcription, Genetic; D014960:X Chromosome
keywords: Cattle; Dosage compensation; Evolution; X chromosome; X upregulation