title: Gonadal development and birth weight in X*X and X*Y females of the wood lemming, Myopus schisticolor.
abstract: A quantitative histological analysis of ovaries from 8- to 10-day-old wood lemmings revealed significant differences between females with X*Y and X*X sex chromosome constitutions. The ovarian volume of X*Y females was on average 57% of X*X, and the number of oocytes was less than half in X*Y compared to X*X. However, the frequency of growing oocytes in relation to the total number was 6.5% for X*Y compared to 3.0% for X*X. Oogenesis in X*Y wood lemmings resembles in many respects that of mice heterozygous for certain translocations and with tertiary trisomy (Ts31H), and those with X0 monosomy. The fertility in X*Y wood lemmings is not reduced. On the contrary, X*Y females have a higher reproductive fitness than X*X and XX. This is discussed in relation to the present findings. The body weight at birth was 8% higher in X*Y than in X*X.
authors.affiliation: Department of Conservation Biology and Genetics, EBC, Uppsala University, Uppsala, Sweden. karl.fredga@ebc.uu.se
authors.forename: K
authors.initials: K
authors.lastname: Fredga
authors.forename: L
authors.initials: L
authors.lastname: Setterfield
authors.forename: U
authors.initials: U
authors.lastname: Mittwoch
mesh_terms: D000782:Aneuploidy; D000818:Animals; D000831:Animals, Newborn; D001724:Birth Weight; D002452:Cell Count; D048429:Cell Size; D002871:Chromosome Banding; D005260:Female; D005298:Fertility / Q000235:genetics; D008040:Genetic Linkage / Q000235:genetics; D007621:Karyotyping; D009115:Muridae / Q000235:genetics*; D009154:Mutation / Q000235:genetics; D009865:Oocytes / Q000378:metabolism / Q000473:pathology; D009866:Oogenesis / Q000235:genetics; D010053:Ovary / Q000002:abnormalities / Q000378:metabolism / Q000473:pathology; D012729:Sex Chromosome Aberrations / Q000235:genetics* / Q000503:physiopathology; D012733:Sex Differentiation / Q000235:genetics*; D014960:X Chromosome / Q000235:genetics*; D014998:Y Chromosome / Q000235:genetics*