Sex chromosome complement affects social interactions in mice

Abstract

Sex differences in behavior can be attributed to differences in steroid hormones. Sex chromosome complement can also influence behavior, independent of gonadal differentiation. The mice used for this work combined a spontaneous mutation of the Sry gene with a transgene for Sry that is incorporated into an autosome thus disassociating gonad differentiation from sex chromosome complement. The resulting genotypes are XX and XY − females (ovary-bearing) along with XXSry and XY − Sry males (testes-bearing). Here we report results of basic behavioral phenotyping conducted with these mice. Motor coordination, use of olfactory cues to find a food item, general activity, foot shock threshold, and behavior in an elevated plus maze were not affected by gonadal sex or sex chromosome complement. In a one-way active avoidance learning task females were faster to escape an electric shock than males. In addition, sex chromosome complement differences were noted during social interactions with submissive intruders. Female XY − mice were faster to follow an intruder than XX female mice. All XY − mice spent more time sniffing and grooming the intruder than the XX mice, with XY − females spending the most amount of time in this activity. Finally, XX females were faster to display an asocial behavior, digging, and engaged in more digging than XXSry male mice. All of these behaviors were tested in gonadectomized adults, thus, differences in circulating levels of gonadal steroids cannot account for these effects. Taken together, these data show that sex chromosome complement affects social interaction style in mice.

Biological factors underlying sex differences in neurological disorders

“…XYM and XYF) and the XX mice (i.e. XXM and XXF) -such as DA cell numbers (Carruth et al, 2002), nociception (Gioiosa et al, 2008), habit formation (Quinn et al, 2007), social behaviour (McPhie-Lalmansingh et al, 2008) and susceptibility to autoimmune disease (Smith-Bouvier et al, 2008) -which were independent of the gonadal phenotype. However the "four core genotype" model still has its limitations, as it does not account for the influence of prenatal hormones, fluctuations in hormonal levels and/or the influence of adult circulating hormones secreted from the gonads or other tissues (Ngun et al, 2011).…”

Parent‐of‐origin and trans‐generational germline influences on behavioral development: The interacting roles of mothers, fathers, and grandparents

“…Hence there exists four possibilities: XX gonadal females (XXF), XY gonadal females (XYF), XY gonadal males (XYM), and XX gonadal males (XXM), and comparisons can be made between groups to examine effects of sex hormones (XXF vs. XXM and XYF vs. XYM) or the effects of sex chromosomes independent of the organizational and activational effects of gonadal hormones (XXF vs. XYF and XXM vs. XYM) on behavioral development. Investigations of these mice (who are typically gonadectomized prior to testing) have revealed that genes on the sex chromosomes other than Sry are responsible for variation in the response to thermal and chemical nociceptive stimuli (Gioiosa et al, 2008), learning of addictive habits (Quinn, Hitchcott, Umeda, Arnold, & Taylor, 2007), social interactions (McPhie-Lalmansingh, Tejada, Weaver, & Rissman, 2008), aggression and parental behavior (Gatewood et al, 2006). Interestingly, these effects appear to be highly specific as no effects of sex chromosome complement on other behaviors including olfactory and anxiety-like behavior have been found (Arnold, 2009).…”

Sex differences in the brain–an interplay of sex steroid hormones and sex chromosomes

“…In the same study, social interaction was influenced by the presence of different sex chromosome complements. Mice with the XX genotype, irrespective of gonadal sex, spent less time and engaged in fewer bouts of sniffing and grooming the male intruder mice than XY mice did, and XY females were also faster to follow the intruder than XX females were [144]. …”

“…In the extensive behavioural study by McPhie-Lalmansingh et al [144], gonadectomized FCG mice were subjected to several behavioural tests measuring exploratory activity, anxiety-like behaviours, and motor and olfactory functions. In most of the tests, neither a gonadal nor sex chromosome effect was found, except in the active avoidance test where females, regardless of their sex chromosomal complement, escaped faster than males after receiving mild electric foot shocks.…”