Comparison of swab types for collection and analysis of microorganisms.

The human microbiome has begun to emerge as a potential forensic tool, with varied applications ranging from unique identification to investigative leads that link individuals and/or locations. The relative abundance of the combined DNA of the microbiome, compared to human nuclear DNA, may expand potential sources of biological evidence, especially in cases with transfer or low-copy number DNA samples. This work sought to determine the optimal swab type for the collection and analysis of microorganisms.

An Nkx2-5/Bmp2/Smad1 negative feedback loop controls heart progenitor specification and proliferation.

During heart development the second heart field (SHF) provides progenitor cells for most cardiomyocytes and expresses the homeodomain factor Nkx2-5. We now show that feedback repression of Bmp2/Smad1 signaling by Nkx2-5 critically regulates SHF proliferation and outflow tract (OFT) morphology. In the cardiac fields of Nkx2-5 mutants, genes controlling cardiac specification (including Bmp2) and maintenance of the progenitor state were upregulated, leading initially to progenitor overspecification, but subsequently to failed SHF proliferation and OFT truncation.

Generation of conditional Cited2 null alleles.

Cited2 is a transcriptional co-factor that is widely expressed in both embryonic and extraembryonic cells during early development. It is essential for embryonic development with Cited2 null embryos showing abnormal development of organs including heart, neural tube, adrenal glands, and placenta (both in trophoblast derivatives and invading fetal vasculature), as well as having defects in the establishment of the left-right body axis. We report the generation of two conditional null alleles allowing Cre-recombinase-mediated somatic cell gene inactivation.

A tyrosine-rich domain within homeodomain transcription factor Nkx2-5 is an essential element in the early cardiac transcriptional regulatory machinery.

Homeodomain factor Nkx2-5 is a central component of the transcription factor network that guides cardiac development; in humans, mutations in NKX2.5 lead to congenital heart disease (CHD). We have genetically defined a novel conserved tyrosine-rich domain (YRD) within Nkx2-5 that has co-evolved with its homeodomain.