Low genetic diversity and limited genetic structure across the range of the critically endangered Mexican howler monkey (Alouatta palliata mexicana)

Genetic diversity provides populations with the possibility to persist in ever-changing environments, where selective regimes change over time. Therefore, the long-term survival of a population may be affected by its level of genetic diversity. The Mexican howler monkey (Alouatta palliata mexicana) is a critically endangered primate restricted to southeast Mexico. Here, we evaluate the genetic diversity and population structure of this subspecies based on 83 individuals from 31 groups sampled across the distribution range of the subspecies, using 29 microsatellite loci. Our results revealed extremely low genetic diversity (H_O = 0.21, H_E = 0.29) compared to studies of other A. palliata populations and to other Alouatta species. Principal component analysis, a Bayesian clustering method, and analyses of molecular variance did not detect strong signatures of genetic differentiation among geographic populations of this subspecies. Although we detect small but significant F_ST values between populations, they can be explained by a pattern of isolation by distance. These results and the presence of unique alleles in different populations highlight the importance of implementing conservation efforts in multiple populations across the distribution range of A. p. mexicana to preserve its already low genetic diversity. This is especially important given current levels of population isolation due to the extreme habitat fragmentation across the distribution range of this primate.     

Complementary strand analysis: a new approach for allelic separation in complex polyallelic genetic systems.

We describe a method, complementary strand analysis (CSA), for separating alleles potentially from any heterozygous genetic locus. Locus specific PCR is performed generating two allelic products. The antisense strands are isolated and hybridised with a sense reference strand to form a chimeric DNA duplex for each allele which is then separated by non-denaturing PAGE. We demonstrate the application of CSA for separation of highly polymorphic HLA-A, -B and -Cw alleles and characterisation of HLA identity in related bone marrow donors and patients. CSA is capable of resolving one nucleotide differences in a DNA fragment nearly as large as a kilobase in length.     

Profiling SARS-CoV-2 HLA-I peptidome reveals T cell epitopes from out-of-frame ORFs

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Label-Free Enrichment of Adrenal Cortical Progenitor Cells Using Inertial Microfluidics

Passive and label-free isolation of viable target cells based on intrinsic biophysical cellular properties would allow for cost savings in applications where molecular biomarkers are known as well as potentially enable the separation of cells with little-to-no known molecular biomarkers. We have demonstrated the purification of adrenal cortical progenitor cells from digestions of murine adrenal glands utilizing hydrodynamic inertial lift forces that single cells and multicellular clusters differentially experience as they flow through a microchannel. Fluorescence staining, along with gene expression measurements, confirmed that populations of cells collected in different outlets were distinct from one another. Furthermore, primary murine cells processed through the device remained highly viable and could be cultured for 10 days in vitro. The proposed target cell isolation technique can provide a practical means to collect significant quantities of viable intact cells required to translate stem cell biology to regenerative medicine in a simple label-free manner.