Quantitative trait loci analysis for peripheral blood parameters in a (BALB/cW × C57BL/6J-Mpl (hlb219)/J) F(2) mice.

The genetic basis of the peripheral blood cell parameters is not fully elucidated. Thus, it is essential to research the correlation between blood cell counts levels and the genome in laboratory animals and subsequently in humans. In the present study, we examined 288 F(2) mice from a cross between BALB/cW and C57BL/6J-Mpl(hlb219)/J. The C57BL/6J-Mpl (hlb219)/J strain is a mouse model of thrombocytopenia. We found very strong correlations for PLT counts and revealed some highly significant correlations for RBC counts. On the basis of the obtained results, we presume that genetic control of erythrocyte parameters is divided into two pathways: first, the morphological determinants responsible for the red blood cell count (RBC), hematocrit (HCT), and mean corpuscular volume (MCV), and second, the functional pathway determining the hemoglobin content (HGB). The locus on Chromosome 4 is the only detected quantitative trait locus (QTL) influencing the analyzed platelets parameters. We also detected highly significant correlations for erythrocyte parameters on Chromosome 1 (RBC, MCV, MCH), Chr 7 (HGB), Chr 9 (MCHC), Chr 11 (RBC), and Chr 17 (MCH). Finally, with regards to the given correlations, using the Mouse Genome Database resource, we proposed candidate genes with possible meaning for the level of these parameters: cytokine receptor genes (e.g., Mpl), transcription factor genes (e.g., Xbp1, Ikzf1), hemoglobin chain genes (e.g., Hbb-b1, Hbb-ar), and many others localized in the confidence intervals of found QTLs.

Selection for body weight induces differences in exploratory behavior and learning in mice.

Mice that were selected for over 108 generations for body weight at the postnatal (PN) day 21 were examined in the open field (OF) test and in the Lashley maze (LM) for their exploratory behavior and spatial learning. Light (L), heavy (C) and control (K) lines of mice in three age groups: PN-21, PN-56 and PN-90, were tested once in the OF and three times in the LM. During the session in the OF the L mice displayed a steady increase of behavioral activity (sum of locomotion and rearing, climbing, sniffing, and grooming acts), whereas mice C and K habituated in the last stage. During entire session in the OF activity of the L mice was lower than that of the C and K mice. The L mice displayed high defecation/urination scores. In the learning task the L mice performed worse than the C and K mice. In conclusion, behavior of the L line was different from that of the two other lines: they showed higher anxiety and poorer spatial learning.