Akaike's information criterion for a measure of linkage disequilibrium.

The extent and distribution of linkage disequilibrium ( LD) in humans is a current topic especially for gene mapping of complex diseases. Akaike's information criterion ( AIC) was applied to estimate LD and compared with other standard LD measures, D' and r(2). By comparison of an independent model (IM; linkage equilibrium) and a dependent model (DM; linkage disequilibrium), the parsimonious model is the one with the smaller AIC score.

Sortilin is upregulated during osteoblastic differentiation of mesenchymal stem cells and promotes extracellular matrix mineralization.

Osteoblasts and adipocytes are derived from a common precursor in bone marrow, the mesenchymal stem cell (MSC). Factors driving human MSCs (hMSCs) to differentiate down the two lineages play important roles in determining bone density because it has been shown that bone volume loss associated with osteoporosis and aging is accompanied by reduced osteoblastic bone formation and increased marrow adipose tissue. The genes upregulated in hMSCs during osteogenic differentiation were screened using cDNA microarrays and were semi-quantitated by real-time RT-PCR.

Large-scale screening for candidate genes of ossification of the posterior longitudinal ligament of the spine.

Ossification of the posterior longitudinal ligament of the spine (OPLL) is the predominant myelopathy among Japanese, and is usually diagnosed by ectopic bone formation in the paravertebral ligament in Japanese and other Asians. To detect genetic determinants associated with OPLL, we performed an extensive nonparametric linkage study with 126 affected sib-pairs using markers for various candidate genes by distinct analyses, SIBPAL and GENEHUNTER. Eighty-eight candidate genes were selected by comparing the genes identified by complementary DNA (cDNA) microarray analysis of systematic gene expression profiles during osteoblastic differentiation of human mesenchymal stem cells with the genes known to be involved in bone metabolism.