linkstream2 microblog

Nice piece on #SingleCell Seq w/ implications for #cancer, neurosci, &c. Singled out for #sequencing
http://www.nature.com/nmeth/journal/v11/n1/full/nmeth.2768.html HT @naivelocus

Lots on brain, cancer & prenatal sequencing, viz:

QT:{{”
For example, as part of the Single Cell Analysis Program supported by the US National Institutes of Health Common Fund, Kun Zhang’s team will generate full transcriptomes from 10,000 cells in three areas of the human cortex. They will group the transcripts into cell
types—perhaps redefining those cell types in the process—and map the transcripts back to cortical slices of the brain. Single-cell RNA-seq itself is no longer a barrier. “If you have a good cell, and you want to get a measure of the transcriptome, there is more than one option that can lead you to that goal,” Zhang says. In general, however, extracting the neurons posthumously, minimizing RNA degradation and preserving some of the neuronal spatial information is challenging, and the group is evaluating several approaches, Zhang says.
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Quite relevant to #transcriptome changes over #development: Earliest Transcribed… Genes Are Short, Newly Evolved…
http://www.cell.com/cell-reports/fulltext/S2211-1247(13)00788-2

http://www.cell.com/cell-reports/fulltext/S2211-1247(13)00788-2

http://arxiv.org/abs/1308.5257

The draft #genome of sweet orange: Nearly 30K genes in only ~370 Mb + #RNAseq to find key Vitamin C genes
http://www.nature.com/ng/journal/v45/n1/full/ng.2472.html

The authors present a draft genome of sweet orange (Citrus sinensis) which covers 87.3% of the relatively compact orange genome
(approximately 367 Mb). Self-alignment of the citrus genome sequences identified one ancient triplication event, which was shared with a number of diverse plants including Arabidopsis thaliana, and no recent whole genome duplication events partially explaining the compact size of its genome. A combination of short sequence repeat (SSR) and SNP markers revealed that sweet orange is an interspecific hybrid between pummelo and mandarin (1:3 in genome composition with female of pummelo origin). Characterization of the unique protein coding genes in the citrus genome and the transcriptome analysis (RNA-Seq and RNA-PET) derived from different tissues in the citrus plant were used to identify the specific genes that are involved in the accumulation of Vitamin C in its fruit (the rate limiting GalUR in the galacturonate pathway is present in 12 copies which are developmentally regulated). Overall, the genome has almost 30,000 genes.

The draft genome of sweet orange (Citrus sinensis).
Xu Q, Chen LL, …., Ruan Y.
Nat Genet. 2013 Jan;45(1):59-66.
PMID: 23179022

QT:{{”

…Recurrent mutations in the potassium channel gene KCNJ5 that result in cell depolarization and Ca(2+) influx cause ∼40% of these tumors. We identified 5 somatic mutations (4 altering Gly403 and 1 altering Ile770) in CACNA1D, encoding a voltage-gated calcium channel, among 43 APAs without mutated KCNJ5…. We also identified de novo germline mutations at identical positions in two children with a previously undescribed syndrome featuring primary aldosteronism and neuromuscular abnormalities….
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http://www.ncbi.nlm.nih.gov/pubmed/23913001

Nat Genet. 2013 Sep;45(9):1050-4. doi: 10.1038/ng.2695. Epub 2013 Aug 4.

Somatic and germline CACNA1D calcium channel mutations in
aldosterone-producing adenomas and primary aldosteronism.

Scholl UI, Goh G, Stölting G, de Oliveira RC, Choi M, Overton JD, Fonseca AL, Korah R, Starker LF, Kunstman JW, Prasad ML, Hartung EA, Mauras N, Benson MR, Brady T, Shapiro JR, Loring E, Nelson-Williams C, Libutti SK, Mane S, Hellman P, Westin G, Åkerström G, Björklund P, Carling T, Fahlke C, Hidalgo P,Lifton RP.

QT:{{”
We discovered abundant (12 to 24%) monoallelic expression of autosomal genes and that expression of the two alleles occurs independently. The monoallelic expression appeared random and dynamic because there was considerable variation among closely related embryonic cells. Similar patterns of monoallelic expression were observed in mature cells. Our allelic expression analysis also demonstrates the de novo inactivation of the paternal X chromosome.
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http://www.sciencemag.org/content/343/6167/193.full

http://www.plosone.org/article/info:doi/10.1371/journal.pone.0081643

Neutral genomic regions refine models of recent rapid human population growth

Elodie Gazave, Li Ma, Diana Chang, Alex Coventry, Feng Gao, Donna Muzny, Eric Boerwinkle, Richard A. Gibbs, Charles F. Sing, Andrew G. Clark, and Alon Keinan

QT:{{”
Recent rapid growth of human populations predicts that a large number of genetic variants in populations today are very rare, i.e., appear in a small number of individuals. This effect is similar to that of purifying selection, which drives deleterious alleles to become rarer. “}}

http://www.gigasciencejournal.com/content/2/1/15