A novel tool for individual haplotype inference using mixed data

Background

In many studies, researchers may recruit samples consisting of independent trios and unrelated individuals. However, most of the currently available haplotype inference methods do not cope well with these kinds of mixed data sets.

Methods

We propose a general and simple methodology using a mixture of weighted multinomial (MIXMUL) approach that combines separate haplotype information from unrelated individuals and independent trios for haplotype inference to the individual level.

Results

The new MIXMUL procedure improves over existing methods in that it can accurately estimate haplotype frequencies from mixed data sets and output probable haplotype pairs in optimized reconstruction outcomes for all subjects that have contributed to estimation. Simulation results showed that this new MIXMUL procedure competes well with the EM-based method, i.e. FAMHAP, under a few assumed scenarios.

Conclusion

The results showed that MIXMUL can provide accurate estimates similar to those haplotype frequencies obtained from FAMHAP and output the probable haplotype pairs in the most optimal reconstruction outcome for all subjects that have contributed to estimation. If available data consist of combinations of unrelated individuals and independent trios, the MIXMUL procedure can be used to estimate the haplotype frequencies accurately and output the most likely reconstructed haplotype pairs of each subject in the estimation.     

Selective inhibition of prostaglandin biosynthesis by gold salts and phenylbutazone

Gold salts and phenylbutazone selectively inhibit the synthesis of PGF_2α and PGE₂ respectively. Lowered production of one prostaglandin species is accompanied by an increased production of the other. Selective inhibition by these drugs was observed in the presence of adrenaline, reduced glutathione and copper sulphate under conditions when most anti-inflammatory compounds inhibited PGE₂ and PGF_2α syntheses equally. It is postulated that selective inhibitors may have a different mode of action in vivo and beneficial effects may be related to the endogenous ratio of PGE to PGF required for normal function.     

Proteins of Friend leukemia cells. Comparison of hemoglobin-synthesizing and noninduced populations.

Proteins of Friend leukemia cells induced to form large amounts of hemoglobin by dimethylsulfoxide treatment were compared with proteins from noninduced cells by high resolution two-dimensional polyacrylamide gel electrophoresis. Approximately 98% of more than 500 proteins separated by this technique were qualitatively and quantitatively the same in both cell populations. Changes representing more than 50% of the control cell amount were detected in six non-histone chromosomal proteins, two nucleoplasmic proteins, and three cytoplasmic proteins. It is concluded that dimethylsulfoxide induces an extremely specific pattern of erythroid differentiation in these cells, which should be susceptible to detailed analysis. Comparison of protein patterns from Friend leukemia cells and HeLa cells revealed electrophoretic identity of approximately 20% of cytoplasmic proteins and 50% of non-histone chromosomal proteins.     

Formation of temporary flagellar structures during insect organogenesis

Cilia and flagella are rare in nongerminal tissues of anthropods, and are generally thought to be restricted to sperm and sensory cells in insects (2). Whitten (5) has reported the presence of kinetosomes at the base of mitotrichia in the dipteran fly Sarcophaga bullata, but reports no evidence of the organization of fibrous elements characteristic of cilia and or flagella. During an ultrastructural analysis of morphogenesis of the colleterial gland of the silk moth Hyalophora cecropia, we found the first example of paired flagella associated with an insect secretory cell. These structures are also unusual in that they serve a temporary role in morphogenesis and subsequently disappear at the terminal stages of differentiation.     

The cytoplasmic ribosomal RNAs of Plasmodium spp

Plasmodium spp maintain several structurally distinct sets of ribosomal RNA genes whose expression is developmentally regulated. This feature sets them apart from all other eukaryotes studied to date. In this review, Thomas McCutchan, Jun Li, Glenn McConkey, John Rogers and Andy Waters give an account of the progress in our understanding of this unusual phenomenon as it relates to the biology of the parasite. They also outline an interesting turnabout in scientific direction involving the use of the parasite as an important new model for the study of the eukaryotic ribosome.