We study the biological origins of sex differences, especially in the brain. All sex differences stem from the differential effects of genes on the sex chromosomes. We study the direct efffects of sex chromosome genes on the brain and other cells, differences caused by X- and Y-linked genes. We also study the indirect effects of these genes, for example the powerful sex-specific effects of gonadal hormones. Our studies focus on two model systems in songbirds and mice. We exploit mouse models in which gonadal sex (testes vs. ovaries) is independent of sex chromosome complement(XX vs. XY). In songbirds, we study the neural circuit for song, which is structurally much different in males and females. We also study the basic properites of sex chromosomes in birds, and mechanisms of sex chromosome dosage compensation.
Gatewood JD, Wills A, Shetty S, Xu J, Arnold AP, Burgoyne PS, Rissman EF. 2006. Sex chromosome complement and gonadal sex influence aggressive and parental behaviors in mice Journal of Neuroscience 26: 2335-2342 .
Itoh Y, Kampf K, Arnold AP. 2006. Assignment of human X chromosome-syntenic genes to a zebra finch microchromosome by in situ hybridization of BAC clones Cytogenetic and Genome Research 112: 343-344 .
Xu J, Taya, S, Kaibuchi K, Arnold AP.. 2005. Spatially and temporally specific expression in mouse hippocampus of Usp9x, a ubiquitin-specific protease involved in synaptic development. Journal of Neuroscience Research 80: 47-55 .
Itoh Y, Arnold AP. 2005. Chromosomal polymorphism and comparative painting analysis in the zebra finch Chromosome Research 13: 47-56 .
Palaszynski KM, Smith DL, Burgoyne PS, Arnold AP, Voskuhl RR. 2005. A yin-yang effect between sex chromosomes and sex hormones on the immune response Endocrinology 146: 3280-3285 .
Chen X, Agate RJ, Itoh Y, Arnold AP. 2005. Sexually dimorphic expression of trkB, a Z-linked gene, in early posthatch zebra finch brain Proceedings of the National Academy of Sciences USA 102: 7730-7735 .
Xu J, Taya S, Kaibuchi K, Arnold AP. 2005. Sexually dimorphic expression of Usp9x is related to sex chromosome complement in adult mouse brain European Journal of Neuroscience 21: 3017-3022 .
Kim Y-H, Arnold AP.. 2005. Distribution and onset of aldehyde dehydrogenase (zRalDH) expression in zebra finch brain: lack of sex difference in HVC and RA at early posthatch ages Journal of Neurobiology 65: 260-268 .
Xu J, Watkins R, Arnold AP.. 2005. Sexually dimorphic expression of the X-linked gene Eif2s3x mRNA but not protein in mouse brain Gene Expression Patterns 6: 146-155 .
Luo M., Yu Y, Kim H, Kudrna D, Itoh Y, Agate RJ, Melamed E, Goicoechea JL, Talag J, Mueller C, Wang W, Currie J, Sisneros NB, Wing RA, Arnold AP. 2005. Utilization of a zebra finch BAC library to determine the structure of an avian androgen receptor genomic region Genomics 87: 181-190 .