Maternal corticosterone but not testosterone level is associated with the ratio of second-to-fourth digit length (2D:4D) in field vole offspring (Microtus agrestis).
The steroid environment encountered by a foetus can strongly affect its post-natal physiology and behaviour. It has been proposed that steroid concentrations experienced in utero could be estimated from adults by measuring their second-to-fourth digit length ratio (2D:4D). However, there is still little direct evidence that intra-uterine steroid levels affect individual 2D:4D. We examined whether maternal pre-pregnancy testosterone and corticosterone levels (as estimates of intra-uterine testosterone and corticosterone exposure) affected the 2D:4D of pups in non-domesticated field voles (Microtus agrestis), measured by X-rays at the age of weaning (21 days). Furthermore, for the first time in a non-human species, we studied whether testosterone and corticosterone levels correlated with 2D:4D in adult females. We found that the maternal pre-pregnancy level of testosterone was not associated with offspring 2D:4D in either the left or the right paw. Instead, maternal pre-pregnancy corticosterone level was positively correlated with offspring 2D:4D in the right paw, but unrelated to 2D:4D in the left paw. In addition, the 2D:4D of adult females was not associated with either their circulating testosterone or corticosterone levels. Our results suggest that in field voles maternally administered testosterone is not a major determinant of offspring 2D:4D, whereas maternal stress appears to account for some of the variation in the 2D:4D of their offspring.
Lilley
Thomas
T
Section of Ecology, Department of Biology, University of Turku, FI-20014, Turku, Finland. tmlill@utu.fi
Laaksonen
Toni
T
Huitu
Otso
O
Helle
Samuli
S
D000818:Animals; D000831:Animals, Newborn; D000886:Anthropometry / Q000379:methods; D003411:Arvicolinae / Q000033:anatomy & histology* / Q000378:metabolism*; D001774:Blood Chemical Analysis; D003345:Corticosterone / Q000378:metabolism*; D005243:Feces / Q000737:chemistry; D005260:Female; D008297:Male; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D013739:Testosterone / Q000097:blood*; D034941:Upper Extremity / Q000033:anatomy & histology*; D014965:X-Rays
D013739:Testosterone; D003345:Corticosterone